Magnet assembly with integrated charged particle beam collector

Abstract

Magnet assemblies (e.g., dipole magnet assemblies) with integrated charged particle beam collectors and systems including the magnet assemblies are described. An example of a dipole magnet assembly includes a dipole deflection magnet and a channel assembly configured with a charged particle beam collector. The dipole magnet may be configured to generate a uniform magnetic field within the channel assembly that deflects a trajectory of a charged particle beam. The channel assembly may be configured to support a vacuum for the charged particle beam while absorbing secondary state particles using the charged particle beam collector. The charged particle beam collector may be removably secured to the channel assembly, welded to the channel assembly, or inserted into the channel assembly. Each charged particle beam collector may utilize an active cooling system, such as a cooling tube or embedded cooling channel, to mitigate excess heat generated by secondary state particle absorption. Materials are also described.

Description

Technical Field

[0001] This specification generally relates to a magnet assembly (e.g., a dipole magnet assembly) having an integrated charged particle beam collector and a system comprising such a magnet assembly. Background Technology

[0002] Boron neutron capture therapy (BNCT) is a treatment for many types of cancer, including some of the most difficult to treat. BNCT is a technique that uses boron compounds to selectively target and kill tumor cells while protecting normal cells. Boron compounds can be effectively taken up by various cell types and selectively accumulate at target sites, such as tumor cells. Boron-loaded cells can be irradiated with neutrons, for example, in the form of a neutron beam. The neutrons react with the boron to destroy the tumor cells.

[0003] Neutron beams used in BNCT can be generated using a variety of techniques. One such technique involves irradiating a target with a suitable neutron beam using a beam of charged particles, such as a proton or deuterium beam. The charged particles react with the nuclei in the target to emit a neutron beam within a target energy range (e.g., the hyperthermal spectrum) suitable for BNCT. To generate the maximum number of neutrons within this target energy range, controlled beam optics are used to ensure that the cross-section and phase space of the charged beam are maintained throughout the beamline. This allows the charged beam to scan onto the target with reasonable homogeneity. Furthermore, dipole magnets (e.g., dipole deflecting magnets) are typically applied to the beamline to alter the trajectory of the charged beam, allowing it to be steered in a desired direction, e.g., toward a target closer to the treatment chamber for BNCT.

[0004] However, charged particle beams are not typically composed entirely of particles of the same kind with identical kinetic energies. A non-negligible number of secondary state particles may also be present. These secondary state particles can include those with different atomic numbers, atomic masses, charges, and / or kinetic energies than the primary state particles of the charged beam, each typically resulting in a different momentum-to-charge ratio. Therefore, when interacting with the magnetic field generated by a dipole magnet, these secondary state particles may deflect at different angles and collide with components of the beamline. Such collisions can cause immediate or eventual damage due to excessive heating and / or ion implantation. This can lead to malfunctions in the beam system, for example, due to vacuum disruption or contamination. Summary of the Invention

[0005] This specification describes a magnet assembly (e.g., a dipole magnet assembly) with an integrated charged particle beam collector and a system (e.g., a beam system) incorporating such a magnet assembly. An example dipole magnet assembly (DMA) is described in the illustrative context of a BNCT system, wherein the DMA is positioned in the beamline and configured to deflect the charged particle beam at a specified deflection angle while filtering secondary state particles (SSPs) from the beam using a charged particle beam collector. For example, the DMA may be positioned at a branch point in the beamline to guide the charged beam axially toward a target. Before the charged beam irradiates the target to generate a neutron beam for BNCT, other beam optics implemented in the beamline (e.g., a quadrupole magnet, a scanning magnet, a beam corrector, or a current monitor) can be used to manipulate or measure the charged particle beam.

[0006] A DMA can include various components based on location, function, size, and / or constituent materials. These components can include dipole deflecting magnets and channel assemblies configured with charged particle beam collectors. The dipole magnets can include a pair of electromagnetic coils and a guard surrounding the coils, providing a flux return path for the coils. The channel assembly can be positioned between the coils of the dipole magnets. The dipole magnets can be configured to generate a uniform magnetic field in the channel assembly to deflect the trajectory of the charged beam at a specified deflection angle. The channel assembly can be connected to multiple beam tubes and configured to support a vacuum for the charged particle beam. The channel assembly can employ various types of charged particle beam collectors to absorb SSPs that deviate from the trajectory of the primary state particles (PSPs) of the charged beam. The charged particle beam collectors can include detachable, welded, or insertable beam collectors, each of which can utilize an active cooling system, such as cooling pipes or embedded cooling channels, to provide improved thermal management. Detachable and welded beam collectors can each use a support structure composed of a material with high thermal conductivity and a high melting point to form the walls of the channel assembly. The support member may be further coated with a refractory metal layer comprising one or more refractory metal elements, such as in pure or alloyed forms, to improve heat resistance and abrasion resistance. The insertable beam collector may be implemented as an insert that can be inserted through a port disposed on the outer surface of the channel assembly. Similar to the aforementioned support member, the insert may be composed of a material with high thermal conductivity and a high melting point, and coated with a refractory metal layer to promote high-temperature elasticity. An embedded cooling channel of the insert may be attached to a dual liquid feedthrough to allow coolant to circulate within the insert when it is positioned within the channel assembly. Depending on the specific implementation, the DMA may have a variety of different configurations and deflection angles. Numerous examples of DMAs with integrated charged particle beam collectors are disclosed, performing some or all of these functions. Numerous exemplary materials with the capability to perform one or more of these functions are also disclosed.

[0007] Specific embodiments of the subject matter described in this specification may be implemented in order to achieve one or more of the following advantages.

[0008] Due to various innovative design options, the disclosed charged particle beam collectors can have relatively long lifecycles and / or high modularity. The beam collectors utilize materials with high thermal conductivity, high melting points, and resistance to decomposition. This allows the charged particle beam collectors to uniformly distribute high heat loads while resisting abrasion from charged particle (e.g., SSP) impacts. Furthermore, the charged particle beam collectors employ active cooling systems, such as cooling pipes or embedded cooling channels, which maximize convective heat transfer with the coolant, further extending their lifecycle. Since the beam collectors exhibit high temperatures (e.g., about 500 Kelvin (K) or higher, about 750 K or higher, about 1000 K or higher), radiative heat transfer becomes a significant factor, which can undesirably alter the temperature distribution of the beam collector in most cases, such as towards hot spots. The active cooling systems disclosed herein provide a means to reduce radiative heat transfer to favor convective heat transfer, which typically provides a more uniform temperature distribution within the beam collector, such as hot spots with minimal or lower temperatures.

[0009] Details of one or more embodiments of the subject matter of this specification are set forth in the accompanying drawings and description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, drawings, and claims. Attached Figure Description

[0010] Figure 1A This is a schematic diagram depicting an example of a neutron beam system used for boron neutron capture therapy (BNCT).

[0011] Figure 1B This is a schematic diagram depicting a more detailed example of a neutron beam system configured for BNCT.

[0012] Figure 2A This is a perspective view depicting an example of a neutron-generating target.

[0013] Figure 2B This is a side view depicting an example of the components used to house the neutron-generating target.

[0014] Figure 2C This is a cross-sectional view depicting an example of the components used to house the neutron-generating target.

[0015] Figure 3 This is a perspective view depicting an example of a dipole magnet assembly, including a dipole magnet and a channel assembly.

[0016] Figures 4A to 4C These are various views depicting examples of dipole deflecting magnets.

[0017] Figure 5A This is a cross-sectional view depicting an example of a channel component.

[0018] Figure 5B This is a cross-sectional view depicting another example of a channel component.

[0019] Figures 6A to 6B This is a cross-sectional view depicting an example of a dipole magnet assembly, including a dipole magnet and a channel assembly.

[0020] Figures 7A to 7B These are various views depicting examples of channel components with detachable charged particle beam collectors.

[0021] Figure 7C This is a cross-sectional view depicting an example of a dipole magnet assembly, which includes a dipole magnet and a channel assembly with a detachable charged particle beam collector.

[0022] Figures 8A to 8B These are various views depicting an example of a channel assembly with a welded charged particle beam collector.

[0023] Figure 8C This is a perspective view of a charged particle beam collector that can be soldered onto a channel assembly.

[0024] Figure 8D This is a cross-sectional view depicting an example of a dipole magnet assembly, which includes a dipole magnet and a channel assembly with a welded charged particle beam collector.

[0025] Figures 9A to 9B These are various views depicting an example of a channel assembly with an insertable charged particle beam collector.

[0026] Figure 9C This is a cross-sectional view depicting an example of a dipole magnet assembly, which includes a dipole magnet and a channel assembly with an inserted charged particle beam collector.

[0027] Figures 10A to 10C This is a schematic diagram depicting an example of a neutron beam system comprising a high-energy beamline configured with one or more dipole magnet assemblies.

[0028] Figure 11 This is a flowchart of an example method for deflecting and filtering charged particle beams using a dipole magnet assembly with an integrated charged particle beam collector.

[0029] Similar reference numerals and names in the various figures indicate similar elements. Detailed Implementation

[0030] The term “particle” is used extensively in this document and, unless otherwise limited, may refer to an electron, a proton (or H+ ion), or a neutron, as well as a class having more than one electron, proton, and / or neutron, such as other ions, atoms, and molecules.

[0031] This article uses the term "primary state particle," abbreviated as "PSP," which generally refers to charged particles in a charged particle beam that have the same atomic number, atomic mass, charge, and kinetic energy. In the context of a beam system, PSPs constitute the majority of the desired particles in a charged particle beam. Since the kinetic energy of free particles is continuous, "same kinetic energy" means particles whose kinetic energy deviates from the average kinetic energy of the charged particle beam by at most about 5%.

[0032] This article uses the term "secondary state particle," abbreviated as "SSP," which generally refers to charged particles in a charged particle beam that have a different atomic number, atomic mass, charge, and / or kinetic energy than the PSPs in the charged particle beam. In other words, SSPs are charged particles of a different kind and / or with different kinetic energies than the PSPs. In the context of the beam system, SSPs constitute the undesirable remaining particles in the charged particle beam. Here, "different kinetic energy" refers to particles whose kinetic energy deviates from the average kinetic energy of the charged particle beam by more than about 5%.

[0033] For example, in a beam system, the particle distribution of a charged particle beam can vary similarly to a Maxwell-Boltzmann distribution, such as a multivariate Gaussian distribution in phase space (e.g., velocity and position components). Deviations in the kinetic energy and injection of the SSP in a charged beam can be caused by factors such as variations in the tandem voltage of the accelerator, voltage ripple in the accelerator's power supply, inefficiencies in the accelerator's charge exchange process, scattering events in low vacuum, temperature variations in the plasma of the ion source, Coulomb interactions in the charged beam, thermal nonequilibrium of the charged beam, and other effects.

[0034] As an example, a proton beam produced by a beam system may comprise approximately 90% PSPs and 10% SSPs, where: (i) PSPs are protons with the same kinetic energy, and (ii) SSPs are also protons, but with approximately half the kinetic energy of the PSPs. In this example, although the SSPs and PSPs belong to the same class, they have different kinetic energies and will therefore have trajectories that deviate from the main trajectory of the PSPs when interacting with the magnetic field. Such a situation may occur in a tandem accelerator if a certain proportion of protons lose kinetic energy from the first acceleration phase, such as during the charge exchange phase when protons are converted from negative hydrogen ions (H-).

[0035] As another example, a deuterium beam generated by a beam system may comprise approximately 95% PSPs and 5% SSPs, where: (i) the PSPs are deuterons with the same kinetic energy, and (ii) the SSPs are protons with the same kinetic energy as the PSPs. In this example, although the SSPs have the same atomic number, charge, and kinetic energy as the PSPs, they have different atomic masses and will therefore have trajectories that deviate from the main trajectory of the PSPs when interacting with a magnetic field. This situation may occur when a negative deuterium ion source produces a small proportion of negative hydrogen ions (H-) in addition to negative deuterium ions (D-).

[0036] This paper describes examples of dipole magnet components (DMAs) that can be implemented into the beamline of a beam system, such as a reactor or particle accelerator. The example DMAs described herein can be used with any type of beam system where the deflection of the charged particle beam and absorption of the SSP throughout the beamline are desired. The DMAs described herein can be used for a variety of applications, one example being a neutron beam system for generating a neutron beam for boron neutron capture therapy (BNCT). BNCT utilizes a beam of hyperthermic neutrons (e.g., with an energy spectrum between one electron volt (eV) and thirty kiloelectron volts (keV)) for cancer treatment. In BNCT, neutrons can be produced by nuclear reactions of charged particles (e.g., protons or deuterons) colliding with a beryllium or lithium target. The neutrons are then applied to the patient for treatment. The charged particle beam can be generated, accelerated, focused, and directed to the target using various devices within the beam system. For example, a DMA can deflect the trajectory of the charged particle beam at a specific angle by applying a calibrated magnetic field. SSPs, exhibiting different Lorentz forces than PSPs, typically follow different trajectories and can be absorbed by one or more integrated charged particle beam collectors positioned within one or more SSP impact zones. Therefore, DMA can guide charged particle beams, for example, toward a target near the treatment chamber, while filtering the charged beam of the SSP, thereby mitigating beam system degradation or failure due to frequent SSP impacts. Furthermore, the filtered charged particle beam typically contains approximately 100% PSP, which can be used in BNCT applications. For example, SSPs irradiating a target are more likely to produce neutrons outside the hyperthermal range. In some cases, a filtered charged particle beam containing nearly 100% PSP can increase the proportion of neutrons produced within the hyperthermal range.

[0037] The examples of dipole magnet assemblies (DMAs) described herein are not intended to be viewed in isolation. Unless otherwise explicitly stated, all features, elements, components, and functions described with respect to any example DMA provided herein can be freely combined and substituted with those from any other example DMA.

[0038] Examples of neutron beam systems

[0039] For ease of description, the examples of DMA described herein will be presented in the context of a neutron beam system that converts a charged particle beam into a neutron beam for BNCT, wherein the DMA is positioned in the beamline of the neutron beam system and configured to direct the charged particle beam toward a target to generate a neutron beam. However, DMA is not limited to this. DMA can be used in other beam systems for generating and manipulating charged particle beams, even those outside of BNCT applications utilizing different energy ranges, such as particle colliders, irradiation testing, isotope production, crystallography, etc. For example, DMA can be implemented in beamlines configured for experiments in particle physics, materials science, life sciences, chemistry and molecular biology, and other applications.

[0040] Figure 1A A schematic diagram of an example beam system 100A configured for BNCT is shown. At a high level, beam system 100A is configured to generate a charged particle beam 61 and propagate it to a target 60 to generate a neutron beam 70. The neutron beam 70 is then directed to the patient's body 80 to be irradiated, such as the head of the patient 80. Beam system 100A includes a charged particle source 20, a low-energy beamline (LEBL) 30, an accelerator 40, and a high-energy beamline (HEBL) 50. Source 20 is configured to generate the charged particle beam 61, which is output to LEBL 30. LEBL 30 is configured to transmit the charged beam 61 from source 20 to accelerator 40. Accelerator 40 is configured to accelerate the charged particle beam 61 to a higher energy. HEBL 50 extends from accelerator 40 to the target 60 housed within a target assembly portion of HEBL 50, see, for example... Figures 2A to 2C HEBL 50 transmits a charged particle beam 61 from the output of accelerator 40 to target 60, where the charged particle beam is converted into a neutron beam 70.

[0041] Figure 1B This is a schematic diagram illustrating a more detailed example of a beam system 100B configured for BNCT. Beam system 100B includes a pre-accelerator system 26 forming at least a portion of LEBL 30, wherein the pre-accelerator system 26 acts as a charged particle beam injector. Beam system 100B includes a high-voltage tandem accelerator 40 coupled to LEBL 30 and a HEBL 50 extending from tandem accelerator 40 to a target 60, as referenced. Figure 1A The beam system 100A is described.

[0042] LEBL 30 transmits a negative ion beam (e.g., hydrogen ions (H-)) from ion source 20 through a pre-accelerator 26 to the input (e.g., input aperture) of accelerator 40, which raises the energy level of the ion beam and focuses it. Accelerator 40 is powered by a high-voltage power supply 42 coupled thereto. Accelerator 40 includes a vacuum chamber, charge exchange tubes, accelerating electrodes, and a high-voltage feedthrough. In some embodiments, accelerator 40 can accelerate the hydrogen ion beam to produce a proton beam, the energy of which is typically equal to twice the voltage applied to the accelerating electrodes positioned within accelerator 40. The energy level of the proton beam can be achieved by accelerating the negatively charged hydrogen ion beam from the input of accelerator 40 to the innermost high-potential electrode, stripping two electrons from each hydrogen ion, and then accelerating the resulting protons downstream by encountering the same voltage in reverse order.

[0043] HEBL 50 transmits a proton beam from the output of accelerator 40 to a neutron-generating target 60 located at the end of a branch 71 of a beamline extending into a patient treatment chamber. Beam system 100B is configured to direct the proton beam to one or more targets 60 and associated target regions. In some specific embodiments, HEBL 50 includes multiple (e.g., three) branches 71, 81, and 91 configured to extend into multiple different patient treatment chambers, each branch terminating at a target 60. HEBL 50 includes a pumping chamber 51, quadrupole magnets 52 and 72 for preventing beam defocusing, dipole (or deflecting) magnets 56 and 58 (e.g., configured as DMA 200) for directing the beam to one or more targets 60, a beam corrector 53, diagnostic devices such as current monitors 54 and 76, a fast beam position monitor segment 55, and a scanning magnet 74 for branch 71. Branches 81 and 91 may contain components similar to those in branch 71.

[0044] The design of HEBL 50 depends on the configuration of the treatment facility (e.g., a single-layer treatment facility, a two-layer treatment facility, etc.). A proton beam can be delivered to the target 60 (e.g., positioned near the treatment room with the patient 80) using a dipole magnet 56. A quadrupole magnet 72 can be included to subsequently focus the proton beam to a specific size at the target 60. The proton beam can be laterally moved across the target surface in a desired pattern (e.g., spiral, curved, stepped in rows and columns, combinations thereof) by one or more scanning magnets 74. This lateral movement of the beam allows the proton beam to produce a smooth and uniform time-averaged distribution on the target 60, preventing overheating of the target 60 and ensuring that particles (e.g., neutrons) are properly positioned on the target 60. Figure 2A The neutrons are produced as uniformly as possible within the neutron-producing layer 121.

[0045] Scanning magnet 74 can be configured to direct the proton beam to current monitor 76, which measures the beam current. The beam current value can be used to operate safety interlock devices. Target assembly 65, containing target 60, can be physically separated from the high-energy beamline volume via valve 77. Valve 77 functions to separate the vacuum volume of the beamline from target 60 during the removal of a used target and the loading of a new target. In some embodiments, the beam can be directed directly to one or more quadrupole magnets 52 located in a horizontal beamline, rather than being deflected 90 degrees by dipole magnet 56. Depending on setup requirements (e.g., patient location or room configuration), the beam can be deflected to a preset angle by another deflecting magnet 58. In some embodiments, deflecting magnet 58 can be positioned at a branch point in the beamline and can be configured to direct the beam in one of two directions in two different treatment rooms located on the same floor of a medical facility, see, for example... Figures 10A to 10C .

[0046] Such as about Figures 1A to 1B The described beam system 100 is an example of different configurations that can be used to generate charged particle beams and neutron beams. Different configurations of the beam system 100 can utilize accelerators other than electrostatic tandem accelerators and fixed or rotating targets. The example of the DMA 200 described herein is not limited to use with any type of beam system or neutron beam generation system.

[0047] Figure 2A This is a perspective view of an example neutron-generating target 60. In this example, the target 60 has a neutron-generating layer 121 with a charged particle receiving surface 122. The neutron-generating layer 121 is positioned on or near a substrate 123. In some cases, layer 121 is covered by one or more other protective layers. Layer 121 may also have one or more sublayers between layer 121 and substrate 123, for example, to prevent bubble formation. A charged particle beam (such as a proton beam) incident on surface 122 enters the target 60 and causes layer 121 to undergo a neutron-generating reaction. This is a Li-7(p,n)Be-7 nuclear reaction in the case where the neutron-generating layer 121 is composed of lithium-7. The neutron-generating layer 121 can alternatively be beryllium-9 and can generate neutrons with proton beams (Be9(p,n)B9) or deuterium beams (Be9(d,n)B10) of different energies. The substrate 123 can be a material with excellent thermal conductivity, such as copper or aluminum, to help remove the heat generated by the reaction.

[0048] Figure 2BThis is a side view of an example target assembly 65 that can form the terminal portion of HEBL 50. The target 60 (not shown) may be contained within or near end 67 of the assembly 65. A charged particle beam enters the assembly 65 at end 66 and proceeds in parallel to the opposite end 67, where it impacts the target 60. Various cooling channels 68 are directed to and exit from end 67 for inserting and removing coolant used to regulate the temperature of the target 60 during use. Numerous sensors may be included to monitor the temperature and radioactivity of the assembly 65 and its surroundings. A valve 77, exemplarily in the form of a gate valve, is also shown.

[0049] Figure 2C This is a cross-sectional view of the example target assembly 65. For clarity, components such as valve 77, coolant passages, and sensor connections are omitted. The sidewall 62 has a tubular shape and contains an internal space 64 at a vacuum or near-vacuum level. The target 60 is positioned at end 67 and secured in place by end cap 63. Variations of this configuration are possible, such as the target 60 being surrounded by the sidewall 62. A charged particle beam 61 is guided through the internal space 64 and scanned through the target 60 by a scanning magnet 74 located upstream of HEBL 50 (not shown). Neutrons produced by the target 60 will be emitted to a certain extent from virtually all directions of the target 60, but most neutrons will be emitted in a dispersed but generally forward-oriented path. Here it is depicted as a neutron beam 70 in its original form.

[0050] Example of a dipole magnet assembly

[0051] Figure 3 This is a perspective view depicting an example DMA 200, which includes a dipole deflecting magnet 205 and a channel assembly 300 positioned within the dipole magnet 205. The DMA 200 is an example of a magnet assembly that can be arranged in the beamline of a beam system to deflect the trajectory of a charged particle beam. For example, the DMA 200 can be implemented as... Figure 1B The dipole magnets 56 and / or 58 in the HEBL 50 of the neutron beam system 100B. Figures 10A to 10C Other examples of sub-beam systems utilizing one or more DMA 200s are described in the text.

[0052] For clarity, see reference. Figures 4A to 6B A description of the DMA 200 is provided to explain how it uses dipole magnet 205 to generate a uniform magnetic field for a charged particle beam, while using channel assembly 300 to support the vacuum for the charged beam. A discussion is also provided regarding how the SSP of the charged beam can compromise vacuum integrity. Following this discussion, see references... Figures 7A to 9CThis paper outlines a description of the DMA 200 integrated with different types of charged particle beam collectors. Charged particle beam collectors provide an efficient means of managing SSP collisions that may occur when a charged beam interacts with a uniform magnetic field generated by a dipole magnet 205.

[0053] Figures 4A to 4C These are various views depicting an example dipole deflecting magnet 205 that can be implemented in DMA 200. Figure 4A This is a perspective view of dipole magnet 205. Figure 4B This is a cross-sectional view of the dipole magnet 205 along the horizontal bisecting plane (horizontal plane 214-1). Figure 4C This is a cross-sectional view (section A-A') of the dipole magnet 205 along the perpendicular bisecting plane.

[0054] like Figure 4A As shown, the dipole magnet 205 includes a first electromagnetic coil 220-1, a second electromagnetic coil 220-2, and a guard 210 surrounding the first coil 220-1 and the second coil 220-2. While many different coil configurations can be utilized, in this example, the coils 220 are configured similarly to Helmholtz coils, but with a deformed loop shape opposite to a circular loop shape. Specifically, each coil 220 is substantially planar and includes a winding (e.g., a wire) with one or more turns in the deformed loop shape around the coil 220. Each coil 220 is configured to conduct current through its winding to generate a corresponding magnetic field. The coils 220 may include windings with any number of turns, such as 5 or more turns, 10 or more turns, 25 or more turns, 50 or more turns, 100 or more turns, etc. For the same current, a larger number of turns generally increases the strength of the magnetic field generated by each coil 220 due to the increased current density (current per unit area) through the coils 220.

[0055] The guard 210 is made of a magnetic ferrous metal and provides a flux return path for the magnetic field generated by the coil 220. For example, the guard 210 can be composed of cast iron, pure iron (e.g., 99.8% pure Fe), hydrogen-annealed pure iron (e.g., 99.95% pure Fe), or a suitable iron alloy having a desired set of magnetic properties. Therefore, the guard 210 can have a relative permeability of about 5000 or greater, such as about 10000 or greater, about 20000 or greater, about 50000 or greater, about 100000 or greater, or about 200000 or greater. This depends on the choice of ferrous metal and / or other considerations such as durability, machinability, cost, weight, size limitations, etc. Due to its relatively high permeability, the guard 210 can focus and redirect the magnetic field generated by the coil 220 to a specific region of the dipole magnet 205 with a specific magnetic field configuration. As explained in more detail below, the guard 210 is configured to focus the magnetic field generated by the coil 220 to produce a uniform magnetic field that can be used to deflect the trajectory of a beam of charged particles at a specific deflection angle.

[0056] In this example, the outer surface of the guard 210 is covered by a metal plate 206, which is secured to the guard 210 by removable fasteners 208 (e.g., nuts and bolts). The plate 206 provides protection against electromagnetic interference entering and / or leaving the dipole magnet 205, for example, in the form of Faraday shielding. For example, the plate 206 can limit the magnetic fields generated by the coil 220, causing them to circulate within the guard 210 rather than escape from the dipole magnet 205. As another example, the plate 206 can shield stray electric and / or magnetic fields generated by other beam optics components that can also be implemented in the beamline (e.g., other dipole magnets, quadrupole magnets, scanning magnets, etc.). A mounting element 207 is disposed on the plate 206, which allows the dipole magnet 205 to be positioned within the beamline, for example, by mounting to a ceiling or other supporting structure. Although Figures 4A to 4C As not shown, the dipole magnet 205 may also be equipped with a utility panel that includes, for example, voltage taps for the coil 220, a current monitor for the coil 220, a safety disconnect device (e.g., a fuse or circuit breaker) for protecting the coil 220 from voltage spikes from the power supply, and / or an active cooling system for providing liquid cooling to the coil 220.

[0057] like Figure 4B and Figure 4C As shown, coil 220 and guard 210 are arranged relative to a first axis 305-1, a second non-parallel axis 305-2, and arc 306. The first axis 305-1, the second axis 305-2, and arc 306 are coplanar, such that the first axis 305-1 and the second axis 305-2 intersect each other at intersection point 308, and are tangents to arc 306 at corresponding tangency points 307-1 and 307-2. Tangency points 307-1 and 307-2 represent the endpoints of arc 306, the radius of which is... The opposite deflection angle is And has a corresponding arc length Typically, the arc 306 coincides with the desired trajectory of the charged particle beam as it interacts with the uniform magnetic field generated by the dipole magnet 205. In some specific embodiments, the radius varies depending on the specific configuration of the dipole magnet 205. It can be approximately 500 mm to 1000 mm and the deflection angle... It can range from approximately 10 degrees to 170 degrees. In this example, the deflection angle... It is described as 90 degrees, but deflection angles of 45 degrees and 135 degrees are also common choices.

[0058] The first axis 305-1 and the second axis 305-2 span the horizontal plane 214-1, which constitutes the plane of symmetry of the dipole magnet 205. Each coil 220 is secured to the guard iron 210, for example, by a snap-fit ​​222, such that the first coil 220-1 is positioned above the horizontal plane 214-1 and the second coil 220-2 is positioned below the horizontal plane 214-1. This forms a magnetic field configuration similar to two stacked current loops (e.g., Helmholtz coils). Specifically, the first coil 220-1 and the second coil 220-2 are positioned relative to each other along the vertical axis 214-2 within a cavity 213 formed by the guard iron 210. The cavity 213 has a cross-section similar to the letter "H," which allows the guard iron 210 to redirect the edge magnetic field generated above the first coil 220-1 and below the second coil 220-2. Thus, the guard iron 210 provides a magnetic flux return path for the coils 220.

[0059] The guard iron 210 forms a first pole 211-1 and a second pole 211-2, each protruding perpendicularly into the cavity 213. Each pole 211 acts as a magnetic north or south pole to generate or terminate a uniform magnetic field within the cavity 213. The first pole 211-1 and the second pole 211-2 are aligned with each other along the vertical axis 214-2, such that a uniform magnetic field is generated between the corresponding pole faces 212-1 and 212-2. The pole face 212 is orthogonal to the vertical axis 214-2, thus generating a uniform magnetic field with a small gradient or no gradient in the positive or negative z direction. Generally, coil 220 conducts current of the same amplitude in the same clockwise or counterclockwise direction, so their magnetic fields constructively superimpose to produce a uniform magnetic field. Here, clockwise and counterclockwise are specified by the right-hand screw rule, such that the thumb points in the positive z-direction. Therefore, the clockwise current conducted in coil 220 produces a uniform magnetic field in the negative z-direction. The counterclockwise current in coil 220 generates a uniform magnetic field in the positive z direction. .about Figure 4C The cross indicates the direction in which current enters the paper, and the dot indicates the direction in which current exits the paper.

[0060] Coil 220 and guard 210 have a deflection angle along arc 306. The geometry of the coils is such that each coil 220 forms a deformed loop around the arc 306, while the guard 210 extends along the arc 306. In this way, a uniform magnetic field is generated between the pole faces 212 along the entire curved trajectory of the charged beam traveling in the horizontal plane 214-1. This typically provides a compact geometry for the dipole magnet 205 while continuously applying a calibrated Lorentz force to the charged beam, causing it to follow a trajectory along the arc 306. For ease of description, assume the charged beam is received along the first axis 305-1 in the positive y-direction and output along the second axis 305-2 in the negative x-direction. Therefore, the charged beam is subjected to a Lorentz force pointing towards the origin 309 of the arc 306. ,in and These represent the charge and velocity of the charged particles in the beam, respectively. In the case of a positively charged beam, the dipole magnet 205 generates a uniform magnetic field in the negative z-direction. In the case of a negatively charged beam, the dipole magnet 205 generates a uniform magnetic field in the positive z-direction. If the charged beam is received along the second axis 305-2 in the positive x-direction and output along the first axis 305-1 in the negative y-direction, the direction of the uniform magnetic field is reversed in each of these cases.

[0061] Note that while circular arc geometries have been described in detail, non-circular arc geometries (e.g., general arcs or open curves) can also be used with the example DMA 200, dipole magnet 205, and channel assembly 300 described herein. For example, a non-circular arc may correspond to the trajectory of a charged particle beam under a non-uniform magnetic field, such as along a magnetic field gradient. In this case, the coil 220 and guard 210 of the dipole magnet 205 can be configured with more complex geometries, such that the distance between the poles 211 in the z-direction increases (or decreases) along the trajectory of the charged beam. In some specific embodiments, the pole face 212 may also have a gradient portion in a direction orthogonal to the trajectory (e.g., in the A-A' direction), which can provide focusing of the charged particle beam.

[0062] Figures 5A to 5B These are cross-sectional views depicting two examples of a channel component 300 that can be implemented in DMA 200. Figure 5A A first example of the channel component 300A is shown. Figure 5B A second example of channel component 300B is shown. The second channel component 300B is configured similarly to the first channel component 300A, and therefore the two examples are described together with the differences stated where appropriate.

[0063] In the example described, channel assembly 300 is a welded component, such as a vacuum welded component, but the example is not limited to this. In some cases, channel assembly 300 can be formed using other manufacturing techniques, such as three-dimensional (3D) metal printing, although these methods may be more expensive than conventional welding methods.

[0064] Typically, a welded component is an assembly of multiple metal parts welded together. The channel assembly 300 can be made by welding metal parts that have been cut, bent, or otherwise manufactured to appropriate dimensions and shapes using any suitable welding technique, where such welding techniques can be based on the specific material selected for the channel assembly 300. As an example, if the channel assembly 300 is formed of stainless steel metal parts, welding techniques such as metal inert gas (MIG) welding, tungsten inert gas (TIG) welding, or manual metal arc (MMA) welding can be used.

[0065] Preferably, the channel assembly 300 is made of a non-magnetic metal (e.g., a non-ferrous metal) that is transparent to a magnetic field, for example having a magnetic field strength close to that of a magnetic field. The relative permeability. In this way, the channel assembly 300 does not significantly distort the uniform magnetic field generated by the dipole magnet 205, which would otherwise affect the trajectory of the charged particle beam propagating within the channel assembly 300. Such nonmagnetic metals can include, but are not limited to, austenitic stainless steel, copper, tin, aluminum, titanium, and each of their respective alloys. Austenitic stainless steel, copper, and copper alloys are particularly suitable for use in the channel assembly 300 due to their high melting point, wear resistance, and corrosion resistance, and their relative inexpensiveness compared to alternatives such as titanium and titanium alloys. Certain nonmagnetic nickel alloys, such as Incol nickel alloys, are also suitable for extreme environments and can be used in the channel assembly 300 in some specific embodiments.

[0066] When connected to other beam optics components in the beam tube or beamline, the channel assembly 300 supports a vacuum. One or more vacuum pumps (e.g., mechanical pumps and / or high-vacuum diffusion pumps) can be used to evacuate air from the beamline to create a suitable vacuum within the channel assembly 300. Depending on the configuration of the specific beam system, the vacuum may have approximately [value missing]. to approximately The pressure. For example, a mechanical pump can generate approximately The vacuum, and a high-vacuum diffusion pump can reduce the vacuum to approximately or Generally, a relatively high vacuum (with low pressure) is required to ensure that the high-power components of the beam system (e.g., accelerator 40) do not generate electric arcs during operation. Furthermore, for example, approximately... or The relatively high vacuum allows charged beams, for example, to be accelerated by accelerator 40 to reach the desired energies with little or no scattering of stray atoms. Scattering would cause the charged particle beam to diffuse and defocus, as well as produce unwanted SSPs.

[0067] More specifically, the channel assembly 300 is a housing forming respective channels around a first axis 305-1, a second axis 305-2, and an arc 306. Each channel provides a pathway for a charged particle beam to pass along the first axis 305-1, the second axis 305-2, or the arc 306 in a vacuum. As used herein, a channel refers to a different path through which a charged beam can pass through the channel assembly 300, with or without a magnetic field, wherein the channel extends between a pair of openings.

[0068] A first channel extends from a first opening 310-1 to a second opening 310-2 and provides a path for the charged beam along an arc 306. The first channel includes: (i) a first linear portion 302-1 extending from the first opening 310-1 along a first axis 305-1, (ii) a second linear portion 302-2 extending from the second opening 310-2 along a second axis 305-2, and (iii) an arcuate portion 303 between the first linear portion 302-1 and the second linear portion 302-2, wherein the arcuate portion 303 extends along an arc 306.

[0069] The second channel extends from the first opening 310-1 to the third opening 310-3 and provides a path for the charged beam along the first axis 305-1. The second channel includes: (i) a first linear portion 302-1, and (ii) a third linear portion 302-3 extending along the first axis 305-1 to the third opening 310-3.

[0070] The third channel extends from the fourth opening 310-4 to the second opening 310-2 and provides a channel for the charged beam along the second axis 305-2. The third channel includes: (i) a fourth linear portion 302-4 extending from the fourth opening 310-4 along the second axis 305-2, and (ii) a second linear portion 302-2.

[0071] Note that the channels are not completely separate, as they intersect each other and extend between a common opening 310. (See also...) Figure 5A and Figure 5B As shown, the channel configurations of the two example channel components 300A and 300B differ slightly, although they perform the same function. The first channel component 300A is generally easier to manufacture than the second channel component 300B, and therefore can be used when cost is a constraint. Conversely, the second channel component 300B is generally more compact and robust than the first channel component 300A, and therefore can be used when space and performance are limited.

[0072] for Figure 5AThe first channel assembly 300A is shown, surrounding a region 330 defined between a first axis 305-1, a second axis 305-2, and an arc 306. At least a portion of each channel is supported within region 330. In this case, the arcuate portion 303 of the first channel extends along the arc 306 and is defined between (i) a wall 301 of the channel assembly 300A forming the inner radius of the arcuate portion 303, and (ii) a support wall 325 positioned within the region 330 forming the outer radius of the arcuate portion 303. A plurality of support columns 324 are also positioned within region 330 to provide structural support for the channel assembly 300A when a vacuum is generated. The second channel is located in region 330 between a first linear portion 302-1 and a third linear portion 302-3. Similarly, the third channel is located in region 330 between a fourth linear portion 302-4 and a second linear portion 302-2.

[0073] for Figure 5B The second channel assembly 300B shown is substantially separate from the first, second, and third channels due to the absence of region 330. In this case, the arcuate portion 303 of the first channel extends along arc 306 and is defined between (i) the first wall 301-1 of the channel assembly 300B forming the inner radius of the arcuate portion 303, and (ii) the second wall 301-2 of the channel assembly 300B forming the outer radius of the arcuate portion 303. Here, the arcuate portion 303 has a width between the first wall 301-1 and the second wall 301-2. In some specific implementations, the width of the bow-shaped portion 303 The diameter can be approximately 40 mm to 100 mm. The second channel includes a first intermediate linear portion 314-1 between the first linear portion 302-1 and the third linear portion 302-3, wherein the first intermediate linear portion 314-1 extends along the first axis 305-1. The third channel includes a second intermediate linear portion 314-2 between the second linear portion 302-2 and the fourth linear portion 302-4, wherein the second intermediate linear portion 314-2 extends along the second axis 305-2.

[0074] In some implementations, the second and / or third channels of the channel assembly 300 may also provide channels for the beam, allowing measurements of the charged particle beam and / or other components of the beam system to be performed. For example, for a charged beam received at a first opening 310-1 and output at a second opening 310-2 (and / or a third opening 310-3), a beam tube equipped with an optical camera may be connected to a fourth opening 310-4. The optical camera may guide the beam along a second axis 305-2 to measure the charged beam and / or directly inspect the target.

[0075] A corresponding connector 312 is positioned at each opening 310 to allow connection of the beam tube or other beam optics components. For example, each connector 312 may be a flange, such as a vacuum flange, to provide a proper vacuum seal. For ease of design, the openings 310 shown herein have the same size and shape. For example, each opening 310 may have the same diameter or lateral dimension. It is a circular or rectangular shape. In some specific implementations, the diameter or lateral dimension of the opening 310 is... The opening 310 is in the range of approximately 30 mm to 80 mm. However, in other specific embodiments, the opening 310 may have different sizes and shapes, such as polygonal or elliptical shapes. Threads (or holes) 322 are arranged around the channel assembly 300 to allow the channel assembly 300 to be positioned within the DMA 200 or to attach other components, such as a charged particle beam collector, to the channel assembly 300.

[0076] While the example described includes three channels, channel components 300 with more or fewer channels can also be utilized in DMA 200, such as channel components 300 with one, two, four, five, six, or more channels. As an example, in some implementations, channel component 300 may include only a first channel, only a first channel and a second channel, or only a first channel and a third channel. As another example, in some implementations, channel component 300 may be configured for multiple different curved trajectories of the charged particle beam, for example, corresponding to multiple different intensities of magnetic fields. In this case, channel component 300 may include multiple curved channels extending along corresponding arcs of different radii. This may be appropriate when DMA 200 is configured to guide the charged particle beam at multiple different deflection angles.

[0077] Figures 6A to 6B It is a description including according to Figures 4A to 4C The configured dipole magnet 205 and according to Figure 5A A cross-sectional view of an example DMA 200A with a configured channel component 300A. Figure 6A This is a cross-sectional view of the DMA 200A along a horizontally bisected plane (horizontal plane 214-1). Figure 6B This is a cross-sectional view (section A-A') of the DMA 200A along the vertical bisecting plane.

[0078] The channel assembly 300A is positioned within the horizontal plane 214-1 of the cavity 213, between the first coil 220-1 and the second coil 220-2. An opening 310, aligned with the corresponding axis 305 and located outside the dipole magnet 205, is used for connection to the beam tube (or other beam optics component) at a corresponding connector 312. Therefore, when the DMA 200 is fixed in the beamline, the channel assembly 300A can receive a beam of charged particles along the first axis 305-1 at the first opening 310-1. Then, due to the uniform magnetic field generated by the dipole magnet 205... Due to the interaction, the charged beam follows a trajectory 340 along the arc 306. Because the dipole magnet 205 has a geometry consistent with the arc 306, a uniform magnetic field is generated between the pole faces 212 of the guard iron 210 throughout the entire arcuate portion 303 of the channel assembly 300A. Therefore, the charged beam travels along trajectory 340 through the first channel of the channel assembly 300A. Thereafter, the charged beam exits at the second opening 310-2 along the second axis 305-2. If the dipole magnet 205 does not apply a uniform magnetic field, the charged beam instead travels through the second channel of the channel assembly 300A and then exits at the third opening 310-3 along the first axis 305-1.

[0079] However, charged particle beams are not typically composed entirely of PSPs of the same kind with identical kinetic energies. As mentioned above, a non-negligible portion of the charged beam can include different kinds of SSPs and / or particles with different kinetic energies than the PSPs. Reiterating a relevant example, in a tandem accelerator configured to accelerate a hydrogen ion beam to produce a proton beam, due to the approximately 90% efficiency of the charge exchange process, the proton beam can comprise approximately 90% PSPs (protons with identical kinetic energies) and 10% SSPs (including protons with approximately half the kinetic energy of the PSPs). This occurs in the presence of a uniform magnetic field. In such cases, these SSPs will exhibit a cyclotron trajectory with a different radius than the PSP, thus following a modified trajectory, such as trajectory 341.

[0080] More precisely, for those with absolute momentum and charge The given state of the particle The radius of the particle's cyclotron orbit It is given by the following formula:

[0081]

[0082] in It is a particle state The momentum-to-charge ratio. In this case, the PSP is determined by the particle state. Establish indicators, and SSP is configured according to particle states. Establish indicators. Note that for non-relativistic particles, absolute momentum... It can also be relative to the mass of the particle. and absolute speed (or equivalent kinetic energy) ) to characterize For ease of description, it is assumed that the charged beam particles are in the non-relativistic limit. ,in It is the speed of light. Nevertheless, the example DMA 200, dipole magnet 205, and channel assembly 300 described herein can also be used for beams of charged particles composed of relativistic particles, such as those with momentum. and kinetic energy ,in It is the Lorentz factor for a specific particle state.

[0083] Generally speaking, the dipole magnet 205 generates a uniform magnetic field. This makes the radius of arc 306 equal to the PSP rotary track. The radii are consistent. Therefore, the amplitude generated by the dipole magnet 205 is calibrated to... A uniform magnetic field. However, for the same magnetic field amplitude... SSP's cyclotron orbit There is a deviation from the cyclotron trajectory of the PSP. This is because the SSP has a different momentum-charge ratio than the PSP. For example, for something of the same type as the PSP but with about half the kinetic energy... The SSPs have corresponding gyroscopes of approximately As described above, such an SSP will follow a modified trajectory (e.g., trajectory 341) and thus collide with the inner surface of the channel assembly 300A located in the impact zone 351.

[0084] Additional impact zones 352, 353, and 354 indicate other possible locations for the SSP to collide with the inner surface of the channel assembly 300A. Impact zone 352 may include a collision from an SSP of the same type as the PSP but with approximately three-quarters of the kinetic energy of the PSP, for example, such that... Impact zone 353 may include collisions from an SSP having the same charge and kinetic energy as the PSP but with approximately one and a half times the mass of the PSP, for example, such that... Impact zone 354 may include collisions from SSPs having the opposite charge to the PSP, which are deflected in the opposite (in this case, clockwise) direction under the same magnetic field. High-velocity SSP collisions at any of the impact zones 351 to 354 may damage the channel assembly 300A, for example, due to excessive heating and / or ion implantation, which could lead to beam system failure, for example, due to disruption or contamination of the vacuum supported by the channel assembly 300A.

[0085] However, SSPs incident at impact zones 351 and 352 are typically the most common, especially for beam systems in tandem accelerators that realize the conversion of negatively charged particle beams into positively charged particle beams, because this conversion is not 100% efficient. Therefore, the wall 301 extending along the arcuate portion 303 of the channel assembly 300A is very prone to degradation. See below for reference. Figures 7A to 9C As described, wall 301 can be replaced (or configured) with a charged particle beam collector to absorb these incident SSPs, which can significantly extend the lifespan of channel assembly 300A and mitigate safety concerns.

[0086] While an example charged particle beam collector has been described in the context of mitigating SSP collisions in impact zones 351 and 352, the beam collector is not limited thereto. The charged particle beam collector can also be configured for impact zones 353 and 354, and other configurations of the channel assembly 300, for example, with a different number of channels (e.g., one, two, four, five, six, or more channels). In any of these cases, the inner surface of the channel assembly 300 exhibiting a high rate of SSP collisions can be configured with the example beam collector described herein to mitigate degradation and improve vacuum integrity.

[0087] Example of a dipole magnet assembly with an integrated charged particle beam collector

[0088] Figures 7A to 7C It involves including according to Figures 4A to 4C Various views of the configured dipole magnet 205 and the channel assembly 300X with a detachable charged particle beam collector 360X. Figure 7A This is a perspective view of the Channel Component 300X. Figure 7B This is a cross-sectional view of the 300X channel component. Figure 7C This is a cross-sectional view of the DMA 200X.

[0089] Here, the wall 301 extending along the arcuate portion 303 of the first example channel assembly 300A has been replaced by a bundle collector 360X to absorb SSP impacts in impact zones 351 and 352. If the bundle collector 360X exhibits significant degradation due to SSP impacts, it can be removed for subsequent inspection, modification, or replacement. Therefore, the bundle collector 360X provides a high degree of modularity to the channel assembly 300X. For example, the bundle collector 360X can be replaced without unloading the channel assembly 300X from the bundle line.

[0090] More specifically, the channel assembly 300X is a housing formed by a housing 361 and a beam collector 360X. The beam collector 360X is detachably attached to the housing 361. The housing 361 has the same configuration as the first example channel assembly 300A, but without the wall 301. Therefore, in this example, the housing 361 is a welded part, such as a vacuum welded part, which can be manufactured using the same welding technology as the channel assemblies 300A and 300B described above and is made of the same material (e.g., a non-magnetic metal).

[0091] The beam collector 360X includes a support 362 configured to absorb the SSP and distribute the resulting heat load, for example, to make the temperature distribution fairly uniform within the support 362. In this example, the support 362 can be made of the same or a different type of metal as the housing 361, since the beam collector 360X is not welded in place. While different types of metals can be welded together, this typically involves more complex welding techniques and could compromise the vacuum supported by the channel assembly 300X. As an example, the support 362 can be made of a heat-resistant, non-magnetic metal with relatively high thermal conductivity (e.g., copper, copper alloys, or non-magnetic nickel alloys (e.g., Inconel alloys)), while the housing 361 can be made of a different non-magnetic metal (such as austenitic stainless steel).

[0092] Support member 362 is attached to top member 364-1 and bottom member 364-2 to provide proper alignment of support member 362 when beam collector 360X is secured to housing 361. Depending on the specific implementation, top member 364-1 and bottom member 364-2 may be made of the same or different materials as support member 362. For example, if top member 364-1 and bottom member 364-2 are welded to support member 362, they may be made of the same nonmagnetic metal as support member 362. Beam collector 360X can be removably secured to housing 361 using removable fasteners attached to corresponding threads (or holes) 322 of housing 361. For example, removable fasteners may include bolts, such as vacuum bolts, which provide a proper vacuum seal when beam collector 360X is secured to housing 361. Similar to housing 361 and support member 362, removable fasteners may be made of nonmagnetic metal, such as any nonmagnetic metal described herein.

[0093] When the bundle collector 360X is fixed, the support 362 forms the wall of the channel assembly 300X extending along the inner radius of the arcuate portion 303. The inner surface 363-1 of the support 362 faces the arc 306 and therefore the intended direction of the incoming SSP. In this example, the support 362 is flat such that the inner surface 363-1 has a surface normal that forms a relatively equal angle with the first axis 305-1 and the second axis 305-2. However, in other specific embodiments, the support 362 may also be bent to follow the curvature of the arc 306, similar to... Figures 8A to 8D Example bundle collector 360Y. Here, the inner surface 363-1 and the outer (opposite) surface 363-2 of the support 362 are substantially parallel to each other. In some specific embodiments, the support 362 may have a thickness of about 10 mm to 50 mm between the inner surface 363-1 and the outer surface 363-2. .

[0094] In some embodiments, the inner surface 363-1 of the support 362 is supported by a highly heat- and wear-resistant refractory metal layer. This can significantly extend the lifespan of the beam collector 360X. For example, the refractory metal layer can protect the support 362 from high-speed SSP impacts. Various techniques can be used to apply the refractory metal layer to the inner surface 363-1 of the support 362, such as 3D printing, explosive bonding (or welding), deposition techniques (e.g., sputtering or electroplating), etc. In some embodiments, the refractory metal layer has a thickness ranging from approximately 1 mm to 10 mm.

[0095] Typically, the refractory metal layer comprises one or more refractory metal elements. Specifically, the refractory metal layer can consist of pure refractory metal elements or alloys comprising different components including one or more refractory metal elements (and other additives). One or more refractory metal elements may include: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium. In some examples, the refractory metal layer is made of molybdenum or molybdenum alloys (e.g., titanium-zirconium-molybdenum (TZM)). Molybdenum and TZM are high-performance refractory metals with extremely high heat resistance and wear resistance, high thermal conductivity, while remaining cost-effective compared to alternatives such as tungsten and tungsten alloys.

[0096] like Figure 7B As shown, the outer surface 363-2 of the support 362 can support a cooling pipe 365 (e.g., configured as a cooling coil) for active cooling of the bundle collector 360X. The cooling pipe 365 is configured to conduct coolant to reduce (or regulate) the temperature of the bundle collector 360X. Examples of coolants may include, but are not limited to, water, deionized water, liquefied gas (e.g., liquid nitrogen), cooling gas, polyalkylene glycol (PAG), mineral oil (e.g., polyphenylene ether oil), nanofluids, etc.

[0097] Cooling pipe 365 is typically made of a material with high thermal conductivity to provide sufficient heat transfer between support 362 and the coolant. Such materials may include any of those listed above for support 362, such as nonmagnetic metals like copper or copper alloys. One or more inlets and one or more outlets of cooling pipe 365 may be attached to a coolant pump to circulate coolant through cooling pipe 365. Coolant circulation may be based on a thermal management system configured to regulate the temperature of bundle collector 360X within a specified range. For example, the thermal management system may include temperature sensors (e.g., infrared thermometers) to monitor the temperature of bundle collector 360X and use it as feedback to control the coolant flow rate and / or input temperature.

[0098] During installation, the cooling pipe 365 is in direct thermal contact with the support 362, thus allowing the cooling pipe 365 to remove heat from the support 362 via convective heat transfer. This can significantly improve the lifespan and performance of the beam collector 360X, for example, by minimizing radiative heat transfer that could lead to hot spot buildup. The cooling pipe 365 may be brazed to the outer surface 363-2 or pressure-loaded onto the outer surface 363-2 via a thermal interface material (TIM) therebetween. Preferably, the TIM has a relatively high thermal conductivity to provide improved thermal contact between the cooling pipe 365 and the support 362. In some specific embodiments, the TIM has a thermal conductivity of about 10 W / mK or greater, such as about 11 W / mK, about 12 W / mK or greater, about 13 W / mK or greater, about 14 W / mK or greater, about 15 W / mK or greater, or about 20 W / mK or greater. Examples of TIMs may include one or more inorganic particulate fillers, such as alumina, magnesium oxide, aluminum nitride, boron nitride, and diamond powder. Examples of TIMs may also include one or more metallic fillers, such as silver and indium alloys.

[0099] Although Figure 7B The image depicts a cooling pipe 365, but in some specific embodiments, the bundle collector 360X may alternatively include cooling channels formed in the outer surface 363-2 of the support 362, similar to... Figures 8A to 8D Example bundle collector 360Y. Further details of example bundle collector 360Y are provided below.

[0100] Figures 8A to 8D It involves including according to Figures 4A to 4C Various views of an example DMA 200Y with a configured dipole magnet 205 and a channel assembly 300Y having a welded charged particle beam collector 360Y. Figure 8A This is a perspective view of the 300Y channel component. Figure 8B This is a cross-sectional view of the 300Y channel component. Figure 8CThis is a perspective view of the charged particle beam collector at 360°. Figure 8D This is a cross-sectional view of the DMA200Y.

[0101] Here, the wall 301 extending along the arcuate portion 303 of the first example channel assembly 300A has been replaced by a beam collector 360Y to absorb the SSP in the impact zones 351 and 352. The channel assembly 300Y and... Figures 7A to 7C The previous example of the channel assembly 300X shown is similarly configured, except that the beam collector 360Y is welded in place rather than removable. Specifically, the channel assembly 300Y is a housing formed by the housing 361 and the beam collector 360Y.

[0102] The beam collector 360Y includes a support 362 configured to absorb the SSP and distribute the resulting heat load, for example, to make the temperature distribution fairly uniform within the support 362. In this example, the support 362 is typically made of the same nonmagnetic metal as the housing 361, as the support 362 is welded to the housing 361. As mentioned above, while different types of metals can be welded together, this typically involves more complex welding techniques and could compromise the vacuum supported by the channel assembly 300Y.

[0103] Support 362 forms the wall of channel assembly 300Y extending along the inner radius of the arcuate portion 303. The inner surface 363-1 of support 362 faces the arc 306 and therefore the intended direction of the incoming SSP. In this example, support 362 is curved such that the inner surface 363-1 follows the arc 306 at a substantially fixed distance. Due to its curved surface, support 362 has a generally compact form factor. However, in other embodiments, support 362 may be flat, similar to... Figures 7A to 7C The first example is a beam collector 360X. Here, the inner surface 363-1 and the outer (opposite) surface 363-2 of the support 362 are substantially parallel to each other. In some specific embodiments, the support 362 may have a thickness of about 10 mm to 50 mm between the inner surface 363-1 and the outer surface 363-2. .

[0104] The inner surface 363-1 of the support 362 supports a highly heat- and wear-resistant refractory metal layer 370, which, as described above, can significantly improve the lifespan of the beam collector 360Y. The refractory metal layer 370 can be applied to the inner surface 363-1 of the support 362 using various techniques, such as any of those listed above for the first example beam collector 360X. Similarly, the refractory metal layer 370 may comprise any one or more refractory metal elements listed above for the first example beam collector 360X, for example, in pure form or as an alloy. As a related example, the refractory metal layer 370 may be made of molybdenum or a molybdenum alloy (e.g., TZM).

[0105] Cooling channels 366 are formed in the outer surface 363-2 of the support 362 and are configured to conduct coolant for active cooling of the bundle collector 360Y. Examples of coolant may include any of those listed above for the first example bundle collector 360X. In some embodiments, the cooling channels 366 have a depth in the range of about 5 mm to 25 mm into the outer surface 363-2. For example, the cooling channels 366 may be machined into the outer surface 363-2 of the support 362 or otherwise formed by suitable manufacturing methods. A cap (not shown) may be provided over the cooling channels 366 to prevent coolant leakage as it circulates through the cooling channels 366.

[0106] Here, cooling passage 366 is connected to inlet 367-1 to receive coolant and to outlet 367-2 to discharge coolant. Inlet 367-1 and outlet 367-2 may be attached to a coolant pump to circulate coolant through cooling passage 366, as described with respect to the first example bundle collector 360X, which may be based on a thermal management system. Depending on the desired direction of coolant flow through cooling passage 366, inlet 367-1 may also be configured as an outlet, and outlet 367-2 may also be configured as an inlet. Figure 8A As most clearly shown, the cooling channel 366 follows a tortuous path in the second surface 363-2 to maximize the duration and thermal contact between the coolant and the support 362. Therefore, the cooling channel 366 can remove heat from the bundle collector 360Y through convective heat transfer and reduce the effects of radiative heat transfer.

[0107] Although Figures 8A to 8D The image depicts a cooling channel 366, but in some specific embodiments, the bundle collector 360Y may alternatively include one or more cooling pipes supported on the outer surface 363-2 of the support 362, similar to... Figures 7A to 7C Example bundle collector 360X.

[0108] Figures 9A to 9C It involves including according to Figures 4A to 4C Various views of the configured dipole magnet 205 and the DMA 200Z with a channel assembly 300Z having a port 384 for the insertion charged particle beam collector 360Z. Figure 9A This is a perspective view of the 300Z channel component. Figure 9B This is a cross-sectional view of the channel component 300Z. Figure 9C This is a cross-sectional view of the DMA 200Z.

[0109] Here, a bundle collector 360Z is configured along the wall 301 extending from the arcuate portion 303 of the first example channel assembly 300A to absorb SSPs in the impact zone 351. If the bundle collector 360Z degrades significantly due to SSP impacts, it can be removed for inspection, modification, or replacement. Therefore, the bundle collector 360Z provides a high degree of modularity to the channel assembly 300Z. For example, the bundle collector 360Z can be replaced without removing the channel assembly 300Z from the bundle line.

[0110] In this configuration, the beam collector 360Z is an insert 380 configured to absorb the SSP and distribute the resulting heat load, for example, such that the temperature distribution is fairly uniform within the insert 380. The insert 380 can be made of a nonmagnetic metal with high thermal conductivity and a high melting point, which may include any of those described elsewhere herein. In some embodiments, the insert 380 is composed of a refractory metal comprising one or more refractory metal elements, such as in pure or alloyed forms, similar to the refractory metal layers described above for beam collectors 360X and 360Y. In some embodiments, the insert 380 may have a thickness of approximately 5 mm to 25 mm.

[0111] When inserted through port 384 on wall 301, insert 380 is positioned on the inner surface 302-1 of wall 301 facing arc 306. Therefore, surface 381 of insert 380 faces the intended direction of the incoming SSP. Insert 380 can be removed through port 384 for inspection, replacement, and / or modification. Port 384 is welded to the outer (opposite) surface 302-2 of wall 301, allowing access to the interior of the channel assembly 300Z when it is secured in the harness. Flange 385 (e.g., vacuum flange) is mounted to port 384 and includes a wing nut 386 that can be loosened to access insert 380 and tightened to provide a vacuum seal for channel assembly 300Z.

[0112] Cooling channels (not shown) are formed within the volume of insert 380 and configured to conduct coolant for active cooling of insert 380. Examples of coolants include any of those listed above for bundle collectors 360X and 360Y. Thus, the cooling channels can remove heat from insert 380 via convective heat transfer. For example, insert 380 can be 3D printed using 3D metal printing technology to create embedded cooling channels. A dual liquid feeder 382 is connected to insert 380 to supply and receive coolant from the cooling channels. For example, dual liquid feeder 382 can be a standard KF25 dual liquid feeder or other appropriately sized dual liquid feeders. When insert 380 is inserted into channel assembly 300Z through port 384, the inlet and outlet of dual liquid feeder 382 are outside channel assembly 300Z. Therefore, the inlet and outlet of the dual liquid feeder 382 can be attached to a coolant pump to circulate coolant through the cooling channels of the insert 380 when the insert 380 is positioned within the channel assembly 300Z.

[0113] In some specific implementations, for example, if insert 380 is composed of copper or a copper alloy, surface 381 of insert 380 may support a refractory metal layer. Various techniques can be used to apply the refractory metal layer to surface 381 of insert 380, such as any of the techniques listed above for beam collectors 360X and 360Y. As an example, if insert 380 is 3D printed, the refractory metal layer can be printed onto its surface 381 during the same manufacturing process. In a similar manner, the refractory metal layer may include any one or more refractory metal elements listed above for beam collectors 360X and 360Y, for example, in pure form or as an alloy.

[0114] Additional examples of neutron beam systems

[0115] Figures 10A to 10C These are schematic diagrams of three examples of sub-beam systems 1000A, 1000B, and 1000C, each configured for BNCT. In these examples, the HEBL 50 of each beam system 1000 includes one or more DMAs 200 with an integrated charged particle beam collector 360. For example, each DMA 200 can be configured according to... Figures 7A to 9C The example DMA 200X, 200Y, or 200Z can be configured. The neutron beam system 1000 is an example of a beam system that can be used in a medical facility with multiple treatment rooms 400 for administering BNCT to different patients 80.

[0116] refer to Figure 10AThe beam system 1000A is configured to generate a charged particle beam 61 and propagate it toward one of two targets 60-1 and 60-2 to generate corresponding neutron beams 70-1 and 70-2. Neutron beams 70-1 and 70-2 are then directed to the corresponding patient bodies 80-1 and 80-2 to be irradiated. Patients 80-1 and 80-2 are located in corresponding treatment chambers 400-1 and 400-2 adjacent to targets 60-1 and 60-2.

[0117] The beam system 1000A includes a charged particle source 20, an LEBL 30, an accelerator 40, and an HEBL 50. Source 20 is configured to generate a charged particle beam 61, which is output to the LEBL 30. The LEBL 30 is configured to transmit the charged beam 61 from source 20 to accelerator 40. Accelerator 40 is configured to accelerate the charged particle beam 61 to higher energies. As described elsewhere herein, in some embodiments, accelerator 40 is a tandem accelerator configured to convert a negatively charged beam into a positively charged beam, for example, converting a negative deuterium ion beam into a deuterium nucleus beam, or a negative hydrogen ion beam into a proton beam. HEBL 50 extends from accelerator 40 to targets 60-1 and 60-2, which can be housed in corresponding target assembly portions of HEBL 50, see, for example... Figures 2A to 2C HEBL 50 transmits a charged particle beam 61 from the output of accelerator 40 to one of two targets 60-1 or 60-2, where the charged particle beam is converted into a corresponding neutron beam 70-1 or 70-2.

[0118] In this example, HEBL 50 includes a DMA200 located at a branch point between two branches 57-1 and 57-2. The DMA 200 is configured to receive a charged particle beam 61 along a first axis 305-1 and deflect the charged particle beam 61 by applying a uniform magnetic field of corresponding amplitude. And the charged beam 61 is output along the second axis 305-2 toward the first target 60-1. Alternatively, when the DMA 200 does not apply a magnetic field, the charged beam 61 is output along the first axis 305-1 toward the second target 50-2.

[0119] refer to Figure 10B , beam system 1000B and Figure 10A The beam system 1000A is similarly configured, but includes an additional DMA 200-2 positioned within the HEBL 50, thereby altering the orientation of the second branch 57-2. Here, the second DMA 200-2 is configured to receive the charged particle beam 61 (output from the first DMA 200-1) along the first axis 305-1, and deflect the charged particle beam 61 by a second angle by applying a uniform magnetic field with a corresponding amplitude. And along the third axis 305-3, a charged particle beam 61 is output toward the second target 60-2.

[0120] refer to Figure 10C , beam system 1000C and Figure 10B The beam system 1000B is similarly configured, but includes an additional DMA 200-3 positioned within the HEBL50, thus forming a third branch 57-3. Here, the third DMA 200-3 is configured to receive a charged particle beam 61 (output from the second DMA 200-2) along the first axis 305-1, and deflect the charged particle beam by a third angle by applying a uniform magnetic field with a corresponding amplitude. And along the fourth axis 305-4, a beam of charged particles 61 is output toward the third target 60-3.

[0121] In each of the example beam systems 1000A to 1000C, when beam 61 passes through the corresponding DMA 200-1, 200-2, or 200-3 at any deflection angle , or During deflection, SSPs are filtered from the charged particle beam 61. Specifically, the SSPs are absorbed by the corresponding beam collector 360 of each DMA 200, which helps maintain the vacuum integrity of the HEBL 50 by mitigating degradation caused by SSP collisions. Although Figures 10A to 10C The beam systems 1000A to 1000C provide some example configurations of DMA 200 in the beamline, and various other combinations of DMA 200 can also be used to guide the charged beam 61 to multiple different targets 60 along multiple different trajectories.

[0122] Figure 11 This is a flowchart of an example method 1100 for using a DMA to deflect and filter a charged particle beam, the DMA including a dipole deflecting magnet and a channel assembly configured with a charged particle beam collector. For example, it can be based on... Figures 7A to 9C Example DMA 200X, 200Y or 200Z can be used to configure the DMA to implement method 1100.

[0123] In short, method 1100 may begin by securing the DMA in the beamline of the beam system. For example, method 1100 may include mounting the dipole magnet from a ceiling or other support structure via mounting elements, and connecting the channel assembly to the beam tube via connectors positioned at corresponding openings. Method 1100 may further include, for example, evacuating air from the beamline using one or more vacuum pumps to create a suitable vacuum within the channel assembly. Depending on the configuration of the beam system, the vacuum may have a range from approximately To date The pressure. Method 1100 may further include activating (or initiating) the beam system to generate a beam of charged particles, accelerating the beam of charged particles, and outputting the beam of charged particles to a beamline, as described elsewhere herein.

[0124] Method 1100 continues to propagate the charged particle beam (1102) along the first axis toward the first opening of the channel assembly. The charged particle beam includes: (i) PSPs of the same kind and having the same kinetic energy, and (ii) SSPs of different kind and / or having different kinetic energies than the PSPs. For example, the charged particle beam may be a positively charged beam (e.g., a proton or deuterium beam) generated by converting a negatively charged beam (e.g., a negative hydrogen or deuterium ion beam) by a tandem accelerator. In the case of a proton beam, the PSP is protons, and the SSP may include protons with different kinetic energies (e.g., approximately half to three-quarters of the kinetic energy of the PSP), as well as other kinds of charged particles.

[0125] Method 1100 continues to use a dipole magnet to generate a uniform magnetic field (1104) within the channel assembly. For example, method 1100 may include conducting corresponding currents of the same amplitude and direction through each of a first and a second coil of the dipole magnet. Typically, the uniform magnetic field has an amplitude such that: (i) the PSP follows a trajectory through a first channel of the channel assembly, and (ii) at least a portion of the SSP follows a trajectory intersecting with a charged particle beam collector. The first channel extends from a first opening to a second opening and includes an arcuate portion extending along an arc. The amplitude of the uniform magnetic field is typically equal to the momentum-to-charge ratio of the PSP divided by the radius of the arc. Because the amplitude of the uniform magnetic field is calibrated for the PSP, the SSP follows a modified trajectory. As described elsewhere herein, the charged particle beam collector is configured to absorb at least a portion of the SSP following a trajectory intersecting with the beam collector.

[0126] Method 1100 continues to output the filtered charged particle beam (1106) from the second opening of the channel assembly along the second axis. The filtered charged particle beam includes PSPs.

[0127] In some specific implementations, method 1100 further includes circulating coolant through one or more cooling pipes or cooling channels (1108) of the charged particle beam collector. For example, method 1100 may include activating a coolant pump, for instance, according to a thermal management system, to circulate coolant, which provides active cooling of the charged particle beam collector during operation of the beam system. As described elsewhere herein, heat is carried away from the beam collector via convection through the coolant, which can significantly extend the lifetime of the beam collector and the operating time of the beam system.

[0128] Method 1100 may further include deactivating (or shutting down) the beam system and interrupting the vacuum. Method 1100 may further include removing, modifying, or replacing the charged particle beam collector and thereafter repeating method 1100.

[0129] In addition to the embodiments described in the appended claims and the embodiments described above, the embodiments numbered below are also innovative.

[0130] In a first set of embodiments, a channel assembly is provided, the channel assembly including: a housing, the housing including: (i) a shell, and (ii) a charged particle beam collector fixed to the shell, wherein: the housing forms a channel extending from a first opening to a second opening, the channel including an arcuate portion, and the charged particle beam collector including supports for at least some of the walls extending along the arcuate portion.

[0131] In some embodiments of the first group, the charged particle beam collector further includes a refractory metal layer supported on a first surface of a support member, the first surface facing the channel. The refractory metal layer may include one or more of the following: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium. For example, the refractory metal layer may be made of molybdenum or a molybdenum alloy. The molybdenum alloy may be titanium-zirconium-molybdenum. The refractory metal layer may have a thickness in the range of 1 mm to 10 mm. The refractory metal layer may be explosively bonded to the first surface of the support member. The refractory metal layer may be printed onto the first surface of the support member. The refractory metal layer may be deposited on the first surface of the support member via sputtering or electroplating. The first surface of the support member may be flat. The first surface of the support member may be curved.

[0132] In some embodiments of the first group, the charged particle beam collector further includes: one or more cooling tubes supported on a second opposing surface of a support, the cooling tubes being configured to conduct coolant. The one or more cooling tubes may be configured to cool coils. The one or more cooling tubes may be configured to convectively remove heat from the charged particle beam collector via the coolant. The one or more cooling tubes may be made of a non-magnetic metal. For example, the one or more cooling tubes may be made of austenitic stainless steel, copper, or a copper alloy. The one or more cooling tubes may be brazed to the second surface of the support. The one or more cooling tubes may be pressure-loaded onto the second surface of the support, with a thermal interface material present therebetween. The thermal interface material may have a thermal conductivity of 10 W / (m K) or greater. The thermal interface material may include alumina.

[0133] In some embodiments of the first group, the charged particle beam collector further includes a cooling channel formed in a second opposing surface of the support, the cooling channel being configured to conduct coolant. The charged particle beam collector may further include an inlet connected to the cooling channel to receive coolant; and an outlet connected to the cooling channel to discharge coolant. The cooling channel may be configured to convectively remove heat from the charged particle beam collector via coolant. The cooling channel may follow a tortuous path in the second surface of the support. The cooling channel may have a depth of at least 8 mm penetrating the second surface of the support.

[0134] In some embodiments of the first group, the coolant is water.

[0135] In some embodiments of the first group, the first and second surfaces of the support are parallel.

[0136] In some embodiments of the first group, the support has a thickness between 10 mm and 50 mm between the first surface and the second surface.

[0137] In some embodiments of the first group, the charged particle beam collector is detachably secured to the housing. The channel assembly may further include multiple detachable fasteners to detachably secure the charged particle beam collector to the housing. The detachable fasteners may include multiple bolts. The bolts may be vacuum bolts.

[0138] In some embodiments of the first group, the charged particle beam collector is fixed to the housing. For example, a support member may be welded to the housing.

[0139] In some embodiments of the first group, the housing comprises multiple metal parts. These metal parts may be welded together.

[0140] In some embodiments of the first group, the housing and support are made of one or more non-magnetic metals.

[0141] In some embodiments of the first group, the housing is made of the same metal as the support. For example, the housing and support may be made of austenitic stainless steel, copper, or a copper alloy.

[0142] In some embodiments of the first group, the housing is made of a different metal than the support. For example, the housing may be made of austenitic stainless steel, and the support may be made of copper or a copper alloy.

[0143] In a second set of embodiments, a channel assembly is provided, comprising: a housing forming a channel extending from a first opening to a second opening, the channel including an arcuate portion along which a wall of the housing extends; a port disposed on a first surface of the wall opposite the channel; and a charged particle beam collector positioned on a second surface of the wall facing the channel when inserted through the port. For example, the port may be welded to the first surface of the wall.

[0144] In some embodiments of the second group, the housing comprises multiple metal parts. These metal parts may be welded together.

[0145] In some embodiments of the second group, the housing is made of a non-magnetic metal. For example, the housing may be made of austenitic stainless steel, copper, or a copper alloy.

[0146] In some embodiments of the second group, the charged particle beam collector includes: an insert; and a cooling channel formed within the volume of the insert, the cooling channel being configured to conduct coolant. The cooling channel may be configured to convectively remove heat from the charged particle beam collector via the coolant. The coolant may be water. The charged particle beam collector may further include: a dual liquid feedthrough connected to the cooling channel, the dual liquid feedthrough including: (i) an inlet for receiving coolant, and (ii) an outlet for discharging coolant. When the charged particle beam collector is inserted through the port, the inlet and outlet of the dual liquid feedthrough may be outside the housing. The insert may have a thickness ranging from 5 mm to 25 mm. In some embodiments, the insert has been three-dimensionally (3D) printed.

[0147] The insert may be made of a refractory metal. It may include one or more of the following: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium. For example, the insert may be made of molybdenum or a molybdenum alloy. The molybdenum alloy may be titanium-zirconium-molybdenum.

[0148] The insert can be made of a non-magnetic metal. For example, the insert can be made of austenitic stainless steel, copper, or a copper alloy. The charged particle beam collector may further include a refractory metal layer supported on the surface of the insert. The refractory metal layer may include one or more of the following: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium. For example, the refractory metal layer may be made of molybdenum or a molybdenum alloy. The molybdenum alloy may be titanium-zirconium-molybdenum. The refractory metal layer may have a thickness in the range of 1 mm to 10 mm. The refractory metal layer may be printed on the surface of the insert. When the charged particle beam collector is inserted through the port, the surface of the insert may face the channel.

[0149] In some embodiments of the second group, the channel assembly further includes a flange mounted to the port. The flange may include a wing nut configured to seal the port.

[0150] In some embodiments of the first and second groups, the channel further includes: a first linear portion extending along a first axis to a first opening; and a second linear portion extending along a second axis intersecting the first axis to a second opening, wherein an arcuate portion extends between the first and second linear portions along an arc tangent to the first and second axes. This arc may be a circular arc. The angle between opposing arcs may be in the range of 10 degrees to 170 degrees. For example, the angle between opposing arcs may be 45 degrees, 90 degrees, or 135 degrees.

[0151] In some embodiments of the first and second groups, the channel is a first channel, and the housing forms a second channel extending from a first opening to a third opening, the second channel including: a first linear portion; and a third linear portion extending along a first axis to the third opening.

[0152] In some embodiments of the first and second groups, the housing forms a third channel extending from the fourth opening to the second opening, the third channel comprising: a fourth linear portion extending from the fourth opening along a second axis; and a second linear portion.

[0153] In some embodiments of the first and second groups, each opening has the same size and shape. For example, each opening may be circular or rectangular. Each opening may have a maximum lateral dimension in the range of 30 mm to 80 mm.

[0154] In some embodiments of the first and second groups, the channel assembly further includes a corresponding connector positioned at each opening and configured to secure the channel assembly in the wire harness. Each connector may be a flange. For example, each flange may be a vacuum flange.

[0155] In some embodiments of the first and second groups, the channel assembly is fixed in the beamline and configured to receive a charged particle beam along a first or second axis. The channel assembly may be configured to support a vacuum for the charged particle beam. The charged particle beam may include: (i) primary-state particles of the same kind and having the same kinetic energy; and (ii) secondary-state particles of a different kind and / or having different kinetic energies than the primary-state particles. The charged particle beam collector may be configured to absorb at least a portion of the secondary-state particles. In some examples, the primary-state particles are protons. The secondary-state particles may include protons.

[0156] In a third set of embodiments, a dipole magnet assembly is provided, comprising: a channel assembly according to any of the embodiments of the first or second set; and a dipole magnet configured to generate a magnetic field within the channel assembly.

[0157] In some embodiments of the third group, the magnetic field is a uniform magnetic field. The uniform magnetic field may have a direction orthogonal to the first and second axes. In some examples, the uniform magnetic field is generated within the arcuate portion of the first channel.

[0158] In some embodiments of the third group, the dipole magnet includes: a first coil; a second coil; and a guard surrounding the first and second coils. A channel assembly may be positioned between the first and second coils.

[0159] In a fourth set of embodiments, a beam system is provided, comprising: an accelerator; a target; and a beamline extending from the accelerator to the target, the beamline including a dipole magnet assembly according to any embodiment of the third set of embodiments. This beam system can be configured for boron neutron capture therapy (BNCT).

[0160] In a fifth set of embodiments, a method is provided for deflecting and filtering a beam of charged particles using a dipole magnet assembly according to any embodiment of the third set, the method comprising: propagating a beam of charged particles toward a first opening of a channel assembly, the beam comprising: (i) primary state particles of the same kind and having the same kinetic energy; and (ii) secondary state particles of a different kind and / or having different kinetic energies from the primary state particles; generating a magnetic field within the channel assembly using a dipole magnet such that: (i) the primary state particles follow a trajectory through a first channel of the channel assembly; and (ii) at least a portion of the secondary state particles follow a trajectory intersecting a charged particle beam collector of the channel assembly; and outputting a filtered beam of charged particles, the filtered beam comprising the primary state particles, from a second opening of the channel assembly.

[0161] In some embodiments of the fifth group, the charged particle beam collector is configured to absorb at least a portion of the secondary state particles.

[0162] In some embodiments of Group 5, the amplitude of the uniform magnetic field is equal to the momentum-to-charge ratio of the primary-state particles divided by the radius of the arc.

[0163] In some embodiments of Group 5, the primary state particle is a proton.

[0164] In some embodiments of Group 5, the secondary state particles include protons.

[0165] In some embodiments of Group 5, generating a magnetic field within the channel assembly using a dipole magnet includes conducting a corresponding current through each of the first and second coils of the dipole magnet. In some examples, the corresponding currents through each of the first and second coils have the same amplitude and the same direction.

[0166] In some embodiments of the fifth group, the method further includes circulating coolant through one or more cooling pipes of the charged particle beam collector.

[0167] In some embodiments of the fifth group, the method further includes circulating coolant through the cooling channel of the charged particle beam collector.

[0168] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of the claimed protection, which is defined by the claims themselves, but rather as descriptions of features that may be specific to particular embodiments of the invention. Certain features described in this specification in the context of independent embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually in multiple embodiments or in any suitable sub-combination. Furthermore, although features may be described above as functioning in certain combinations and even initially claimed in this way, in some cases, one or more features from the claimed combination may be removed from the combination, and the claims may be directed to sub-combinations or variations thereof.

[0169] Similarly, although the operations are depicted in a specific order in the accompanying drawings and described in the claims, this should not be construed as requiring such operations to be performed in the particular order shown or sequentially, or to perform all illustrated operations to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of the various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0170] Specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. For example, the actions recited in the claims can be performed in a different order and still achieve the desired result. As an example, the processes depicted in the drawings do not necessarily require the specific order or sequence shown to achieve the desired result.

Claims

1. A channel assembly, the channel assembly comprising: The housing includes: (i) a shell, and (ii) a charged particle beam collector fixed to the shell, wherein: The outer casing forms a channel extending from a first opening to a second opening, the channel including an arcuate portion, and The charged particle beam collector includes a support forming the outer shell with at least some of the walls extending along the arcuate portion.

2. The channel assembly of claim 1, wherein the charged particle beam collector further comprises: A refractory metal layer is supported on a first surface of the support member, the first surface facing the channel.

3. The channel assembly of claim 2, wherein the refractory metal layer comprises one or more of the following: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium.

4. The channel assembly of claim 3, wherein the refractory metal layer is made of molybdenum or a molybdenum alloy.

5. The channel assembly of claim 4, wherein the molybdenum alloy is titanium-zirconium-molybdenum.

6. The channel assembly according to any one of claims 2 to 5, wherein the refractory metal layer has a thickness in the range of 1 mm to 10 mm.

7. The channel assembly according to any one of claims 2 to 6, wherein the refractory metal layer is explosively bonded to the first surface of the support.

8. The channel assembly according to any one of claims 2 to 6, wherein the refractory metal layer is printed on the first surface of the support.

9. The channel assembly according to any one of claims 2 to 6, wherein the refractory metal layer is deposited on the first surface of the support by sputtering or electroplating.

10. The channel assembly according to any one of claims 2 to 9, wherein the first surface of the support is flat.

11. The channel assembly according to any one of claims 2 to 10, wherein the first surface of the support is curved.

12. The channel assembly according to any one of the preceding claims, wherein the charged particle beam collector further comprises: One or more cooling pipes are supported on a second opposing surface of the support member, and the one or more cooling pipes are configured to conduct coolant.

13. The channel assembly of claim 12, wherein the one or more cooling tubes are configured as cooling coils.

14. The channel assembly according to any one of claims 12 to 13, wherein the one or more cooling tubes are configured to carry away heat from the charged particle beam collector via convection through the coolant.

15. The channel assembly according to any one of claims 12 to 14, wherein the one or more cooling tubes are made of a non-magnetic metal.

16. The channel assembly of claim 15, wherein the one or more cooling tubes are made of austenitic stainless steel, copper, or a copper alloy.

17. The channel assembly according to any one of claims 12 to 16, wherein the one or more cooling tubes are brazed to the second surface of the support.

18. The channel assembly according to any one of claims 12 to 16, wherein the one or more cooling tubes are pressure-loaded onto the second surface of the support, wherein a thermal interface material is present therebetween.

19. The channel assembly of claim 18, wherein the thermal interface material has a thermal conductivity of 10 W / (m K) or greater.

20. The channel assembly according to any one of claims 18 to 19, wherein the thermal interface material comprises alumina.

21. The channel assembly according to any one of claims 1 to 11, wherein the charged particle beam collector further comprises: A cooling channel is formed in the second opposing surface of the support member, and the cooling channel is configured to conduct coolant.

22. The channel assembly of claim 21, wherein the charged particle beam collector further comprises: An inlet, connected to the cooling channel, is used to receive the coolant; and An outlet, which is connected to the cooling channel to output the coolant.

23. The channel assembly according to any one of claims 21 to 22, wherein the cooling channel is configured to carry away heat from the charged particle beam collector via convection through the coolant.

24. The channel assembly according to any one of claims 21 to 23, wherein the cooling channel follows a tortuous path in the second surface of the support.

25. The channel assembly according to any one of claims 21 to 24, wherein the cooling channel has a depth of at least 8 mm into the second surface of the support.

26. The channel assembly according to any one of claims 12 to 25, wherein the coolant is water.

27. The channel assembly according to any one of claims 12 to 26, wherein the first surface and the second surface of the support are parallel.

28. The channel assembly of claim 27, wherein the support has a thickness between 10 mm and 50 mm between the first surface and the second surface.

29. The channel assembly according to any one of the preceding claims, wherein the charged particle beam collector is detachably attached to the housing.

30. The channel assembly of claim 29, further comprising a plurality of removable fasteners for removably securing the charged particle beam collector to the housing.

31. The channel assembly of claim 30, wherein the removable fastener comprises a plurality of bolts.

32. The channel assembly of claim 31, wherein the bolt is a vacuum bolt.

33. The channel assembly according to any one of claims 1 to 29, wherein the charged particle beam collector is fixed to the housing.

34. The channel assembly of claim 33, wherein the support is welded to the housing.

35. The channel assembly according to any one of the preceding claims, wherein the housing comprises a plurality of metal parts.

36. The channel assembly of claim 35, wherein the plurality of metal parts are welded together.

37. The channel assembly according to any one of the preceding claims, wherein the housing and the support are made of one or more non-magnetic metals.

38. The channel assembly of claim 37, wherein the housing is made of the same metal as the support.

39. The channel assembly of claim 38, wherein the housing and the support are made of austenitic stainless steel, copper, or a copper alloy.

40. The channel assembly of claim 37, wherein the housing is made of a different metal than the support.

41. The channel assembly of claim 40, wherein: (i) the housing is made of austenitic stainless steel, and (ii) the support is made of copper or a copper alloy.

42. A channel assembly, the channel assembly comprising: The outer casing forms a channel extending from a first opening to a second opening, the channel including an arcuate portion. The wall of the outer casing extends along the arcuate portion; A port, the port being disposed on a first surface of the wall opposite the channel; and A charged particle beam collector, when inserted through the port, is positioned on a second surface of the wall facing the channel.

43. The channel assembly of claim 42, wherein the port is welded to the first surface of the wall.

44. The channel assembly according to any one of claims 42 to 43, wherein the housing comprises a plurality of metal parts.

45. The channel assembly of claim 44, wherein the plurality of metal parts are welded together.

46. ​​The channel assembly according to any one of claims 42 to 45, wherein the housing is made of a non-magnetic metal.

47. The channel assembly of claim 46, wherein the housing is made of austenitic stainless steel, copper, or a copper alloy.

48. The channel assembly according to any one of claims 42 to 47, wherein the charged particle beam collector comprises: Inserts; and A cooling channel is formed in the volume of the insert and is configured to conduct coolant.

49. The channel assembly of claim 48, wherein the cooling channel is configured to carry away heat from the charged particle beam collector via convection through the coolant.

50. The channel assembly according to any one of claims 48 to 49, wherein the coolant is water.

51. The channel assembly according to any one of claims 48 to 50, wherein the charged particle beam collector further comprises: A dual liquid feeder connected to the cooling channel, the dual liquid feeder comprising: (i) an inlet for receiving the coolant, and (ii) an outlet for discharging the coolant.

52. The channel assembly according to claim 51, wherein, When the charged particle beam collector is inserted through the port, the inlet and outlet of the dual liquid feeder are outside the housing.

53. The channel assembly according to any one of claims 48 to 52, wherein the insert has a thickness in the range of 5 mm to 25 mm.

54. The channel assembly according to any one of claims 48 to 53, wherein the insert has been three-dimensionally (3D) printed.

55. The channel assembly according to any one of claims 48 to 54, wherein the insert is made of a refractory metal.

56. The channel assembly of claim 55, wherein the insert comprises one or more of the following: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium.

57. The channel assembly of claim 56, wherein the insert is made of molybdenum or a molybdenum alloy.

58. The channel assembly of claim 57, wherein the molybdenum alloy is titanium-zirconium-molybdenum.

59. The channel assembly according to any one of claims 48 to 54, wherein the insert is made of a non-magnetic metal.

60. The channel assembly of claim 59, wherein the insert is made of austenitic stainless steel, copper, or a copper alloy.

61. The channel assembly according to any one of claims 48 to 54, wherein the charged particle beam collector further comprises: A refractory metal layer is supported on the surface of the insert.

62. The channel assembly of claim 61, wherein the refractory metal layer comprises one or more of the following: niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, or iridium.

63. The channel assembly of claim 62, wherein the refractory metal layer is made of molybdenum or a molybdenum alloy.

64. The channel assembly of claim 63, wherein the molybdenum alloy is titanium-zirconium-molybdenum.

65. The channel assembly according to any one of claims 61 to 64, wherein the refractory metal layer has a thickness in the range of 1 mm to 10 mm.

66. The channel assembly according to any one of claims 61 to 65, wherein the refractory metal layer is printed on the surface of the insert.

67. The channel assembly according to any one of claims 61 to 66, wherein, When the charged particle beam collector is inserted through the port, the surface of the insert faces the channel.

68. The channel assembly according to any one of claims 42 to 67, the channel assembly further comprising a flange mounted to the port.

69. The channel assembly of claim 68, wherein the flange includes a wing nut configured to seal the port.

70. The channel assembly according to any one of the preceding claims, wherein the channel further comprises: A first linear portion, the first linear portion extending along a first axis to the first opening; and The second linear portion extends along a second axis intersecting the first axis to the second opening. The bow-shaped portion is located between the first linear portion and the second linear portion, and the bow-shaped portion extends along an arc tangent to the first axis and the second axis.

71. The channel assembly of claim 70, wherein the arc is a circular arc.

72. The channel assembly of claim 71, wherein the angle between the opposing arcs is in the range of 10 degrees to 170 degrees.

73. The channel assembly of claim 72, wherein the angle between the opposing arcs is 45 degrees, 90 degrees, or 135 degrees.

74. The channel assembly according to any one of claims 70 to 73, wherein the channel is a first channel, and the housing forms a second channel extending from the first opening to a third opening, the second channel comprising: First linear part; and The third linear portion extends along the first axis to the third opening.

75. The channel assembly of claim 74, wherein the housing forms a third channel extending from the fourth opening to the second opening, the third channel comprising: A fourth linear portion extends from the fourth opening along the second axis; and The second linear part.

76. The channel assembly according to any one of claims 70 to 75, wherein each opening has the same size and shape.

77. The channel assembly of claim 76, wherein each opening has a circular or rectangular shape.

78. The channel assembly of claim 77, wherein each opening has a maximum lateral dimension in the range of 30 mm to 80 mm.

79. The channel assembly according to any one of claims 70 to 78, the channel assembly further comprising: A corresponding connector is positioned at each opening and configured to secure the channel assembly in the wire harness.

80. The channel assembly of claim 79, wherein each connector is a flange.

81. The channel assembly of claim 80, wherein each flange is a vacuum flange.

82. The channel assembly according to any one of claims 79 to 81, wherein the channel assembly is fixed in the beamline and configured to receive a beam of charged particles along the first axis or the second axis.

83. The channel assembly of claim 82, wherein the channel assembly is configured to support a vacuum for the charged particle beam.

84. The channel assembly according to any one of claims 82 to 83, wherein the charged particle beam comprises: (i) Primary state particles of the same kind and with the same kinetic energy; and (ii) Secondary state particles of a different kind and / or with different kinetic energies than the primary state particles.

85. The channel assembly of claim 84, wherein the charged particle beam collector is configured to absorb at least a portion of the secondary state particles.

86. The channel assembly according to any one of claims 84 to 85, wherein the primary state particle is a proton.

87. The channel assembly of claim 86, wherein the secondary state particle comprises a proton.

88. A dipole magnet assembly, the dipole magnet assembly comprising: The channel assembly according to any one of claims 1 to 81; and A dipole magnet configured to generate a magnetic field within the channel assembly.

89. The dipole magnet assembly of claim 88, wherein the magnetic field is a uniform magnetic field.

90. The dipole magnet assembly of claim 89, wherein, when also subject to claim 71, the uniform magnetic field has a direction orthogonal to the first axis and the second axis.

91. The dipole magnet assembly of claim 90, wherein the uniform magnetic field is generated within the arcuate portion of the first channel.

92. The dipole magnet assembly according to any one of claims 88 to 91, wherein the dipole magnet comprises: First coil; Second coil; and A protective iron surrounds the first coil and the second coil.

93. The dipole magnet assembly of claim 92, wherein the channel assembly is positioned between the first coil and the second coil.

94. A beam system, the beam system comprising: accelerator; target; and A beamline extending from the accelerator to the target, the beamline comprising a dipole magnet assembly according to any one of claims 88 to 93.

95. The beam system of claim 94, wherein the beam system is configured for boron neutron capture therapy (BNCT).

96. A method for deflecting and filtering a beam of charged particles using a dipole magnet assembly according to any one of claims 88 to 93, the method comprising: The charged particle beam propagates toward the first opening of the channel assembly, the charged particle beam comprising: (i) Primary-state particles of the same kind and with the same kinetic energy; and (ii) Secondary state particles of a different kind and / or with different kinetic energies than the primary state particles; The magnetic field is generated within the channel assembly using the dipole magnet, so that: (i) The primary-state particle follows a trajectory through the first channel of the channel assembly; and (ii) At least a portion of the secondary-state particles follow a trajectory intersecting the charged particle beam collector of the channel assembly; and A filtered beam of charged particles, comprising the primary state particles, is output from the second opening of the channel assembly.

97. The method of claim 96, wherein the charged particle beam collector is configured to absorb at least a portion of the secondary state particles.

98. The method according to any one of claims 96 to 97, wherein, when also subject to claim 90, the amplitude of the uniform magnetic field is equal to the momentum-to-charge ratio of the primary-state particle divided by the radius of the arc.

99. The method according to any one of claims 96 to 98, wherein the primary state particle is a proton.

100. The method of claim 99, wherein the secondary state particle comprises a proton.

101. The method according to any one of claims 96 to 100, wherein, when also dependent on claim 92, generating the magnetic field within the channel assembly using the dipole magnet comprises: The corresponding current is conducted through each of the first and second coils of the dipole magnet.

102. The method of claim 101, wherein the respective currents through each of the first and second coils have the same amplitude and the same direction.

103. The method according to any one of claims 96 to 102, further comprising, when also dependent on claim 12: The coolant is circulated through one or more cooling pipes of the charged particle beam collector.

104. The method according to any one of claims 96 to 102, further comprising, when also dependent on claim 21 or 48: The coolant is circulated through the cooling channel of the charged particle beam collector.

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