Ion generation system with fiber grid for ion collection

Abstract

A method is provided that includes accelerating ions toward a carbon fiber lattice and trapping the ions in the carbon fiber lattice. In one embodiment, the method further includes combusting the carbon fiber lattice to obtain a residue including the ions. In one embodiment, the ions are ytterbium ions. In one embodiment, at least a portion of the ytterbium ions are ytterbium-176 ions, and the method further includes isolating the ytterbium-176 ions from other ytterbium ions prior to trapping the ytterbium-176 ions in the carbon fiber lattice.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 251,397, filed on October 1, 2021, which is hereby incorporated by reference in its entirety.

[0002] The present disclosure generally relates to the field of generation of heavy metal ions, for example, the generation of heavy metal ions used in medical applications. More specifically, the present disclosure relates to improving the efficiency of collecting and configuring ions that are accelerated out of an ion source with high extraction energy.

Background Art

[0003] In conventional techniques involving ion beams, it is usually intended to cause a high - energy collision between the ion beam and a substrate material so as to cause a change in the substrate material. The ions themselves in such a system are not efficiently retained by the substrate material and can be sputtered, sublimated, or scattered. Such systems and methods do not increase the collection efficiency of the ions themselves. In contrast, one goal of the present application is to collect the ions of an ion beam as a configured substance that can be collected, stored, transported, used, etc., for example in medical applications.

Summary of the Invention

Means for Solving the Problems

[0004] One embodiment of the present disclosure is a method. The method includes providing a lattice of carbon fibers, accelerating ions toward the lattice of carbon fibers, and capturing the ions with the lattice of carbon fibers. The method may also include burning the lattice of carbon fibers to obtain a residue containing the ions.

[0005] The ion may be a ytterbium ion. In some embodiments, the ion includes a ytterbium-176 ion, and the method also includes isolating the ytterbium-176 ion from other isotopes before capturing the ion in a carbon fiber lattice.

[0006] In some embodiments, accelerating ions toward a carbon fiber lattice involves imparting energy greater than 100V to the ions. Trapping ions in a carbon fiber lattice may involve decelerating the ions by deflecting them with multiple carbon fibers in the lattice.

[0007] In some embodiments, the method includes increasing the area of ​​the carbon fiber lattice that traps ions by operating an actuator to rotate or translate the carbon fiber lattice. The method may also include providing multiple layers of fibrous carbon material. Providing the carbon fiber lattice may include arranging the carbon fibers in multiple directions.

[0008] Another embodiment of the present disclosure is an ion generation system. The ion generation system may include an ion source configured to generate ions, a target having a fiber lattice, and an electrode positioned between the ion source and the target substrate, the electrode being configured to accelerate the ions toward the target substrate so that the ions are incident on the fiber lattice. The fiber lattice is configured to trap the ions. The ions may be ytterbium ions, such as ytterbium-176 ions.

[0009] The fiber lattice may contain multiple carbon fibers arranged in multiple directions. The target may contain multiple layers of the fiber lattice. The fiber lattice may contain graphite or carbon and may be configured to burn. After combustion of the fiber lattice, it may leave behind a residue containing ions.

[0010] In some embodiments, the electrode imparts energy exceeding 100V to the ions. In some embodiments, the target includes a mount, and the mount is configured to releasably fix the fiber lattice at a predetermined position with respect to the mount. The ion generation system may include an actuator operable to rotate the target. This specification also provides, for example, the following: (Item 1) Accelerating ions toward the carbon fiber lattice, The ions are captured in the carbon fiber lattice, Methods that include... (Item 2) The method according to item 1, further comprising burning the carbon fiber lattice to obtain a residue containing the ions. (Item 3) The method according to item 1, wherein the ion is a ytterbium ion. (Item 4) The method according to item 3, wherein at least a portion of the ytterbium ions are ytterbium-176 ions, and the method further comprises isolating the ytterbium-176 ions from other ytterbium ions before capturing the ytterbium-176 ions in the carbon fiber lattice. (Item 5) Isolating the aforementioned ytterbium-176 ion is possible. By applying a magnetic field to the ytterbium ions using a magnetic analyzer, the ytterbium ions are separated by mass from the other ytterbium ions, The other ytterbium ions are blocked using a mass-decomposition opening positioned between the magnetic analyzer and the carbon fiber lattice, wherein the ytterbium-176 ions pass through the mass-decomposition opening, and the blocking is performed. The method described in item 4, including the method described in item 4. (Item 6) The method according to item 1, wherein accelerating the ions toward the lattice of the carbon fibers includes giving the ions energy exceeding 100V. (Item 7) The method according to item 1, wherein trapping the ions in the carbon fiber lattice includes decelerating the ions by deflecting them with a plurality of carbon fibers in the carbon fiber lattice. (Item 8) The method according to item 1, further comprising increasing the area of ​​the carbon fiber lattice that captures the ions by operating an actuator to rotate or translate the carbon fiber lattice. (Item 9) The method according to item 1, wherein the carbon fiber lattice comprises multiple layers of fibrous carbon material. (Item 10) The method according to item 1, wherein the carbon fiber lattice includes carbon fibers arranged in multiple directions. (Item 11) An ion source configured to generate ions, A target with a fiber grid, An electrode disposed between the ion source and the target substrate, configured to accelerate the ions toward the target substrate so that the ions are incident on the fiber lattice, An ion generation system comprising, The fiber lattice is configured to capture the ions. The aforementioned ion generation system. (Item 12) The ion generating system described in item 11, wherein the ion is the ytterbium-176 ion. (Item 13) The ion generation system according to item 11, wherein the fiber lattice comprises a plurality of carbon fibers arranged in a plurality of directions. (Item 14) The ion generation system according to item 11, wherein the target comprises multiple layers of the fiber lattice. (Item 15) The ion generation system described in item 11, wherein the fiber lattice contains graphite. (Item 16) The ion generation system according to item 11, wherein the fiber lattice is configured to burn. (Item 17) The ion generating system according to item 11, wherein the fiber grid is configured to leave a residue containing the ions after the fiber grid has been burned. (Item 18) The electrode provides energy exceeding 100V to the ions in the ion generation system as described in item 11. (Item 19) The ion generation system according to item 11, wherein the target comprises a mount, the mount being configured to releasably fix the fiber grid to the mount in a predetermined position. (Item 20) The ion generation system according to item 11, further comprising an actuator capable of rotating the target.

[0011] This disclosure, in conjunction with the accompanying drawings, will be more fully understood from embodiments for carrying out the invention described below, where similar reference numerals refer to similar elements. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of an ion generation system according to an exemplary embodiment. [Figure 2] This is a schematic diagram of the target and voltage source of an ion generation system in an embodiment involving cations, according to an exemplary embodiment. [Figure 3] This is a schematic diagram of the target and voltage source of an ion generation system in an embodiment involving anions, according to an exemplary embodiment. [Figure 4] This is a block diagram of an ion generation system having a magnetic rotating device according to several embodiments. [Figure 5]This is an exploded view of the target fiber lattice of an ion generation system according to several embodiments. [Figure 6] These are perspective views of the target fiber lattice of an ion generation system according to several embodiments. [Figure 7] This is a top view of the target of an ion generation system according to several embodiments. [Figure 8] This is a top view of the fiber lattice target of the ion generation system, based on several experimental results. [Figure 9] This is a top view of the fiber lattice target of the ion generation system, based on several experimental results. [Modes for carrying out the invention]

[0013] Before proceeding to the figures illustrating specific embodiments in detail, please understand that this disclosure is not limited to the details or methodologies described or shown in the description or figures. Also, please understand that the terms used herein are for illustrative purposes only and should not be considered limiting.

[0014] Overall, the drawings illustrate systems and methods relating to ion generation systems, such as heavy metal ion generation systems, in various exemplary embodiments. Specifically, the drawings illustrate systems and methods relating to the efficient collection of ions (heavy metal ions, such as ytterbium ions containing ytterbium-176) at a target of an ion generation system so that the ions can be reconstituted as substances (for example, substances having high concentrations of ytterbium-176 or other desired isotopes) that can be collected, stored, transported, and used for various applications.

[0015] As detailed below, ions are generated in an ion source and extracted from the ion source as an ion beam with a high extraction energy, for example, 20kV to 80kV (e.g., 40kV to 60kV) (note that in this text, ionic kinetic energy is often expressed in volts, where 1 volt corresponds to 1 joule per coulomb, and in other conventions these values ​​may be expressed in keV). The ion beam may pass through a magnetic analyzer and a mass-resolved aperture. The magnetic analyzer uses a magnetic field to classify the ions by momentum (i.e., by atomic mass if all generated ions have the same charge), and the mass-resolved aperture is positioned relative to the beam and the magnetic analyzer to allow mainly the desired ions (e.g., ions of a desired isotope) to pass through while preventing other ions from passing through the aperture. Thus, only the desired ions, or an ion beam containing a high proportion of the desired ions, passes through the aperture. Therefore, the mass-resolved aperture isolates the desired ions or a high proportion of the desired ions. A target (target substrate, substrate, etc.) is positioned so that the beam of the desired ions is incident on the target.

[0016] The method described herein increases the ion deposition rate on the target and reduces the sputtering rate on the target, thereby increasing the proportion of ions that constitute neutral material (e.g., neutral material of the desired isotope) and reducing the rate of ion loss. Consequently, the overall efficiency of the entire ion generation system (e.g., power and resource consumption per unit of material produced) is improved. Ion accumulation on other undesirable surfaces of the ion generation system (which may otherwise occur due to ion scattering) is also minimized or prevented, thereby reducing downtime and maintenance of the ion generation system. Furthermore, the method herein reduces heat transfer to the target substrate (thermal load on the target, thermal energy load on the target), thus reducing or eliminating temperature control problems that may be caused by high-energy collisions on the target.

[0017] As detailed below, some of the advantages of this specification are achieved in part and / or in some embodiments by holding the target at a voltage that has the same polarity as the ions and is slightly lower in magnitude than the potential of the ion beam. As the ion beam approaches the target, the target voltage (and the electric field generated by that voltage) reduces the energy of the ion beam. For example, the target voltage may be selected to (at least partially) offset the energy supplied to the ion beam by the extraction electrode, so that when the ions reach the target, the energy of the ions is converted into thermal energy. In such cases, both the electronic stopping power of the ions at the target (i.e., the interaction between the ions and the target, the interaction between the electrons of the ions and the electrons of the target substrate) and the nuclear stopping power of the ions (i.e., the interaction between the atomic nuclei of the ions and the atomic nuclei of the target substrate) are reduced to zero or near zero. By reducing these interactions through the potential of the target, the ions adhere to the target and form a film rather than colliding with it at high energy and sputtering or scattering away.

[0018] The systems and methods described herein also provide a target material suitable for efficiently capturing ions incident on the target and readily reducing them to a residue containing a high concentration of the desired isotope / atom (i.e., from the ion beam). Specifically, as described in detail below, fibrous grids, e.g., grids of carbon fibers (e.g., graphite fibers), felt, mesh, etc., can be arranged so that the ion beam is incident on them. The fibrous grid can capture ions and readily combust (or undergo some other reaction) in the presence of oxygen to leave a residue containing, for example, a high concentration of the desired isotope. To enhance the target's collecting ability before it is necessary to interrupt the operation to collect the desired isotope from the target, the fibrous grid may be rotated or translated relative to the beam during the operation of the ion generation system. Thus, the various concepts described below, individually and collectively, enhance the efficiency of collecting the desired isotope.

[0019] Referring here to Figure 1, a block diagram of an ion generation system 100 according to an exemplary embodiment is shown. The ion generation system 100 includes an ion source 102, a drawer electrode(s) 104, a magnetic analyzer 106, a mass-resolution aperture 108, a target 110, and a voltage source 112 connected to ground 114 and the target 110. The ion source 102, the drawer electrode(s) 104, the magnetic analyzer 106, the mass-resolution aperture 108, and the target 110 are arranged sequentially so that ions generated in the ion source 102 pass sequentially through the drawer electrode(s) 104, the magnetic analyzer 106, and the mass-resolution aperture 108 before reaching the target 110. The ion generation system 100 is configured to efficiently collect desired ions at the target 110 as a neutral substance that can be extracted, stored, transported, etc., and ultimately used for some application, such as a medical application, as detailed below.

[0020] The ion source 102 is configured to generate ions. For example, the ion source 102 may be configured as a Bernas or Freeman ion source, including a filament that can operate to emit electrons that ionize a gas supplied into the ion source 102, such as a heavy metal gas like ytterbium vapor. Other metals (Lu, Tc, etc.) may also be used. The interaction between electrons and gas ionizes the gas and generates ions. In some embodiments, the ion source 102 generates cations (i.e., ions with positive polarity). In other embodiments, the ion source generates anions (i.e., ions with negative polarity). The ion source 102 includes an outlet slit or opening so that ions can be drawn out of the ion source 102. In some embodiments, the ion source 102 includes an auxiliary heater to protect the elements of the ion source 102 and to improve the uniformity of the ions drawn from the ion source 102, which is described in detail, for example, in U.S. Provisional Patent Application No. 63 / 122,699 filed on 8 December 2020, the entire disclosure of which is incorporated herein by reference.

[0021] The extraction electrode(s) 104 includes one or more electrodes configured and operating to supply an electric field for extracting ions from the ion source 102. Since ions have a charge of a first polarity (positive or negative in various embodiments), a voltage of opposite polarity at the extraction electrode(s) 104 extracts ions from the ion source as an ion beam. The extraction electrode(s) 104 may include one or more electrodes for accelerating, decelerating, shaping, and aiming the ion beam. By supplying an electric field that accelerates the ion beam emanating from the ion source 102, the extraction electrode(s) 104 imparts extraction energy to the ion beam equal to or similar in magnitude to the voltage at the extraction electrode(s) 104. For example, when an ion beam passes through the extraction electrode(s) 104, an electrode with a voltage of 55 kV may impart 55 kV of extraction energy to the ion beam (note that in many cases ionic energy is expressed in volts, and 1 volt corresponds to 1 joule per coulomb).

[0022] Therefore, an ion beam with a high extraction energy is supplied as the output of the extraction electrode(s) 104. In various embodiments, the high extraction energy may be in the range of 20kV to 80kV, for example, 40kV to 60kV (e.g., 55kV). In such embodiments, the voltage applied to the extraction electrode(s) 104 can be selected to provide the ion beam with the desired extraction energy in a particular scenario.

[0023] In the embodiment shown in Figure 1, the ion beam passes from the extraction electrode 104 to the magnetic analyzer 106. In other embodiments, the magnetic analyzer 106 is omitted. The magnetic analyzer 106 is configured to supply a magnetic field that generates a magnetic force on the ion beam. The magnetic force on each ion may be approximately equal, but the ion beam may contain ions of different isotopes, and therefore the masses of the ions may differ. The magnetic force provided by the magnetic analyzer 106 can cause separation of ions by mass. Therefore, after passing through the magnetic analyzer 106, different regions of the cross-section of the ion beam may contain ions of different isotopes, i.e., ions of different masses.

[0024] In Figure 1, the ion beam is shown to pass from the magnetic analyzer 106 to the mass-resolution aperture 108, which is configured to allow desired ions to pass through while preventing undesirable subsets of ions from passing through. Thus, the mass-resolution aperture 108 isolates the desired ions or a high proportion of desired ions. Specifically, the ions that can pass through the mass-resolution aperture 108 are mainly those of the desired isotope (or two desired isotopes), while ions of one or more other isotopes are blocked by the mass-resolution aperture 108. This is achieved by positioning the mass-resolution aperture 108 relative to the magnetic analyzer 106 and utilizing the isotopic separation provided by the magnetic analyzer 106. Various geometric arrangements are possible in various embodiments. Thus, in embodiments including the magnetic analyzer 106 and the mass-resolution aperture 108, the ion beam reaching the target 110 contains a high proportion of the desired isotope(s) and a low proportion of ions of different isotopes.

[0025] An ion beam from the mass-resolved aperture 108 is incident on the target 110. The target 110 is configured to receive and collect ions from the ion beam. The target 110 may include a substrate material suitable for receiving and retaining ions, which may be included as a film on the surface of the target 110 and / or embedded in the lattice structure of the target 110. For example, the substrate material of the target 110 may have a crystalline structure. As another example, the substrate material of the target 110 may include a carbon fiber material (e.g., carbon fiber cloth). The material(s) of the target 110 may also be selected so as to be able to hold the target 110 at a substantially constant voltage when ions are collected on the target 110, embedded in the target 110, or otherwise received in the target 110. The material(s) of the target 110 may also be selected so as to facilitate the deposition of ions on or within the target 110. To facilitate the collection of ionic substances that accumulate on the target 110 during the operation of the ion source 102, the target 110 may be removable and replaceable within the ion generation system 100.

[0026] The target 110 is shown to be connected to a voltage source 112, which is connected between the target 110 and ground 114. Other elements of the ion generation system 100 include appropriate electronic elements, such as a power supply, that enable the operation of the ion generation system 100. The voltage source 112 is configured to hold (retain, establish, maintain, etc.) the target 110 at a voltage (referred to herein as the target voltage) having the same polarity as the ion beam. For example, in a scenario in which the ion source generates cations, as shown in Figures 2-3 and discussed below, a positive voltage is applied to the target 110 by the voltage source 112, while in a scenario in which the ion source generates anions, a negative voltage is applied to the target 110 by the voltage source 112. In another embodiment, the target 110 is connected directly to ground so that the target 110 is not biased, as in the embodiment of Figures 2-3.

[0027] The target voltage is preferably lower than the extraction energy of the ion beam so that the ion beam can reach the target without being forced in the opposite direction by the target voltage. At the same time, the target voltage is preferably high enough to reduce the energy of the ion beam and large enough to minimize both the electron stopping power and nuclear stopping power of the ion beam at target 110 (this minimizes scattering or sputtering that would be caused by high-energy collisions between the ions and target 110). For example, the target voltage may be lower than the extraction energy by an amount corresponding to the thermal energy of the ions so that the energy of the ions is converted into thermal energy at the same time that the ions reach target 110. In various embodiments, the target voltage is lower than the extraction energy and greater than 95% of the extraction energy, for example, greater than 99% of the extraction energy (and simultaneously lower than the extraction energy). In some embodiments, the target voltage is about 100V lower than the extraction energy so that the ion beam has an energy of about 100V when it reaches the target (for example, subtracting the target voltage from the extraction energy is equal to about 100V). In one embodiment, the extraction energy is 55kV and the target voltage is 54.9kV.

[0028] In some embodiments, the voltage source 112 and target 110 are configured such that the voltage of target 110 is kept substantially constant as ions accumulate on target 110 (e.g., embedded in target 110 as a film on target 110) through the operation of the ion generation system 100 and the ions constitute a neutral substance (e.g., a desired isotope(s)). In some cases, target 110 may be removable from the ion generation system 100 to facilitate the extraction of the constituted ionized substance from target 110. In some such cases, the voltage source 112 is controlled to gradually reduce the target voltage to zero, thereby allowing target 110 to be detached from the voltage source 112 without destroying the ionized substance collected on target 110. In some embodiments, target 110 (or a part thereof) is removed for use in transporting and further processing of the ionized substance and replaced with a new target 110 (or a new part thereof) for subsequent operation of the ion generation system 100. In another embodiment, the ionized material may be extracted from the target 110 and collected in a container (or other collection and retention device) so that the target 110 can be reused in subsequent operations of the ion generation system 100 to collect further ions.

[0029] Referring now to Figure 2, a schematic diagram of the target 110 and voltage source 112 of the ion generation system 100 in an embodiment with a cation beam 150 according to an exemplary embodiment is shown. Figure 2 shows the cation beam 150 (i.e., a beam of positively charged ions) aimed at and incident on the target 110.

[0030] Since the cation beam 150 has positive polarity, the voltage across the target 110 is also given positive polarity. Figure 2 shows that the target 110 is connected to the positive terminal of the voltage source 112, and the negative terminal of the voltage source 112 is connected to ground 114. The voltage source 112 maintains the target 110 at a positive potential, that is, at a potential with the same polarity as the cation beam 150.

[0031] The positive potential of target 110 provides an electric field that resists the movement of the ion beam 150 toward target 110. The ion beam 150 must move across this electric field to reach target 110. In this way, the kinetic energy of the ion beam 150 is converted into the potential of the ions in the electric field generated by the positive potential of target 110. This can be thought of as the ions rolling uphill to reach target 110. As discussed above, the target voltage is selected and maintained so that the cation beam 150 is at a low energy, such as thermal energy, at the same time that the cations reach target 110. Once converted to thermal energy, the cation beam 150 no longer has the excess kinetic energy to move away from target 110 or cause sputtering or scattering, so the ions of the cation beam 150 adhere to target 110 and form a cation film 151, for example, as shown in Figure 2.

[0032] Referring now to Figure 3, a schematic diagram of the target 110 and voltage source 112 of the ion generation system 100 in an embodiment with an anion beam 152 according to an exemplary embodiment is shown. Figure 2 shows the anion beam 152 (i.e., a beam of negatively charged ions) aimed at and incident on the target 110.

[0033] Since the anion beam 152 has negative polarity, the voltage across the target 110 is also given negative polarity. Figure 3 shows that the target 110 is connected to the negative terminal of the voltage source 112, and the positive terminal of the voltage source 112 is connected to ground 114. The voltage source 112 maintains the target 110 at a negative potential, that is, at a potential with the same polarity as the anion beam 152.

[0034] The negative potential of target 110 provides an electric field that resists the movement of the ion beam 152 toward target 110. The ion beam 152 must move across this electric field to reach target 110. In this way, the kinetic energy of the ion beam 152 is converted into the potential of the ions in the electric field generated by the negative potential of target 110. This can be thought of as the ions rolling uphill to reach target 110. As discussed above, the target voltage is selected and maintained so that the anion beam 152 becomes low energy, such as thermal energy, at the same time that the anions reach target 110. Once converted to thermal energy, the anion beam 152 no longer has the excess kinetic energy to move away from target 110 or cause sputtering or scattering, so the ions of the anion beam 152 adhere to target 110 and form an anion film 153, as shown in Figure 3, for example.

[0035] Therefore, the ion generation system 100 is configured to efficiently generate and collect ions as the constituent ionized material. As described above, by setting the target 110 to the target voltage, a high proportion of the ions incident on the target 110 adhere to the target 110, for example, forming a film on the target 110. Thus, the efficiency of the ion generation system 100 is improved by collecting a high proportion of the desired ions generated by the ion source 102. Furthermore, since the rate of sputtering or scattering of material is low or zero, the accumulation of material on other undesirable surfaces within the ion generation system 100 is substantially prevented, thus reducing downtime, cleaning, and maintenance of the ion generation system 100. In addition, the electron stopping power or nuclear stopping power (i.e., interatomic collisions) of high-energy ions on the target significantly increases the thermal energy of the target, but the embodiments herein use the potential provided by the voltage source 112 to reduce the energy of the ions, thus avoiding the accumulation of thermal energy on the target.

[0036] Referring now to Figure 4, schematic diagrams of apparatus 200, including a vacuum chamber 202, an ion generation system 204, and a magnetic rotation device 206, are shown according to several embodiments.

[0037] The ion generation system 204 is shown to include an ion beam generator 208 and a target 210. The ion beam generator 208 is configured to generate an ion beam and direct the ion beam toward the target 210 so that the ion beam is incident upon the target 210. The ion beam generator 208 may include, for example, the ion source 102, extraction electrode 104, magnetic analyzer 106, and / or mass resolution aperture 108 in Figure 1. The target 210 may be configured in the same way as, for example, the target 110 in Figure 1.

[0038] As shown in Figure 4, the target 210 is connected to a magnetic rotating device 206. The magnetic rotating device 206 includes an internal plate (first plate) 212, an external plate (second plate) 214, and a motor 216. The internal plate 212 is inside the vacuum chamber 202 (inside the vacuum chamber 202, within the vacuum chamber 202, contained within the vacuum chamber 202) and is located inside 218 of the wall 220 of the vacuum chamber 202. The external plate 214 is outside the vacuum chamber 202 (outside the vacuum chamber 202, outside the vacuum chamber 202, not contained within the vacuum chamber 202) and is located outside 222 of the wall 220. The motor 216 is mechanically connected to the external plate 214. The target 210 is mechanically connected to the internal plate 212.

[0039] Motor 216 is operable to drive the rotation of the outer plate 214. Motor 216 may be an electric motor, such as a stepping motor, which converts electricity into rotational motion. Motor 216 is connected to the outer plate 214 so that the operation of motor 216 applies torque to the outer plate 214, causing the outer plate 214 to rotate around its axis. The rotational drive shaft of motor 216 can be aligned with the axis of the outer plate 214 and directly transmit torque to the outer plate 214 to cause the outer plate 214 to rotate. Motor 216 may be controllable to rotate the outer plate 214 at various speeds. In some embodiments, motor 216 operates to rotate the outer plate 214 at a rate of about 1 revolution per minute.

[0040] The outer plate 214 includes one or more magnets (e.g., permanent magnets), and the inner plate 212 also includes one or more magnets (e.g., permanent magnets) corresponding to one or more magnets in the outer plate 214. Exemplary arrangements of magnets in the inner plate 212 and the outer plate 214 are shown in Figures 3 to 6 and will be described with reference to them. The magnets in the outer plate 214 and the inner plate 212 are arranged such that the outer plate 214 exerts an attractive force on the inner plate 212, and vice versa. For example, one or more magnets in the outer plate 214 may be arranged to have positive magnetic polarity in the direction of the wall 220, while one or more magnets in the inner plate 212 may be arranged to have negative magnetic polarity in the direction of the wall 220 (or vice versa), so that the magnets attract each other and the inner plate 212 and the outer plate 214 are attracted by magnetic force. The magnets provide a magnetic field strong enough to exert an attractive force across the wall 220 of the vacuum chamber 202. In some embodiments, the thickness of the wall 220 may be about 0.5 inches.

[0041] Due to the magnetic attraction between the magnets of the outer plate 214 and the magnets of the inner plate 212, the rotation of the outer plate 214 by the motor 216 causes the rotation of the inner plate 212. In the shown embodiment, the inner plate 212 rotates in sync with the rotation of the outer plate 214 due to its magnetic coupling with the outer plate 214. This allows rotational motion and torque (e.g., angular kinetic energy) to be transmitted across the walls 220 of the vacuum chamber 202 without compromising the integrity of the hermetic seal of the vacuum chamber 202 (e.g., without requiring mechanical engagement between the inner plate 212 and the outer plate 214, which may be difficult to hermetically seal). As shown in Figure 4, since the target 210 is mounted on the inner plate 212, the rotation of the inner plate 212 causes the target 210 to rotate. Although the embodiments herein refer to rotation, in another embodiment, the motor 216 is positioned to cause a corresponding translation of the internal plate 212 and target 210 by translating the external plate 214 (for example, in one or two dimensions). The operation of the motor 216 causes motion of the target 210, for example, rotation of the target 210.

[0042] As shown in Figure 4, the ion beam generator 208 directs the ion beam onto the target 210 such that the ion beam is offset relative to the target's axis of rotation. Therefore, as the target 210 rotates due to the operation of the magnetic rotating device 206, the point or region on which the ion beam enters the target 210 changes. As the target 210 rotates over time, the ion beam enters different parts of the target 210 over time, thereby increasing the total area of ​​the target 210 exposed to the ion beam. The movement of the target 210 exposes a wider area of ​​the target 210 to the ion beam, making it possible to capture ions and / or isotopes from the ion beam. Thus, the target 210 can capture more material compared to embodiments with a static target 210, which allows the apparatus 200 to operate continuously for a longer period until the target is full (saturated, etc.). Rotating the target can also help reduce temperature gradients across the target, which may be undesirable.

[0043] The magnetic rotating device 206 is also configured to transfer heat to or from the vacuum chamber, for example, to remove heat from the target 210 and control the temperature of the target 210. As shown, both the internal plate 212 and the external plate 214 are positioned in contact with the wall 220 of the vacuum chamber 202. The internal plate 212 and the external plate 214 may include materials with high thermal conductivity (e.g., low resistance to heat flow passing through them), such as metals such as steel. The wall 220 may be made of a similar material. The internal plate 212 and the external plate 214 are in thermal contact with each other through the wall 220. Such thermal contact is maintained by the attractive force between the magnets of the internal plate 212 and the external plate 214, which can draw the internal plate 212 and the external plate 214 toward each other and bring them into contact with the wall 220. The target 210 is shown to be positioned on the internal plate 212. This forms a heat transfer path from the target 210 to the external plate 214.

[0044] In the embodiments shown, the apparatus 200 also includes a cooling system 224 that is thermally in communication with the outer plate 214. The cooling system 224 may include a refrigeration cycle (e.g., including a compressor, condenser, expansion valve, and evaporator) configured to remove heat from the outer plate 214. For example, the cooling system 224 may supply a cooled fluid via one or more coils or other heat exchangers that are thermally in communication with the outer plate 214. Cooling the outer plate 214 increases the heat flow away from the target 210, which may be desirable in embodiments where the collision between the ion beam and the target 210 imparts thermal energy to the target 210. In another scenario (e.g., another use of the magnetic rotating device 206), the cooling system 224 may include, or may be replaced by, a heating system configured to impart thermal energy to the outer plate 214 in order to transfer thermal energy (heat) into the vacuum chamber 202 via the inner plate 212.

[0045] Referring now to Figure 5, exploded views of target 110 (or target 210) or a part thereof (e.g., its fiber lattice) are shown according to several embodiments. In the embodiment of Figure 5, target 110 includes a first lattice 400 and a second lattice 402, which form target 110 as a fiber lattice. The first lattice 400 and the second lattice 402 can be stacked as layers to form target 110. In another embodiment, a different number of lattices (layers) (e.g., one, three, four, five, etc.) are included in target 110. In various embodiments, the fiber lattice can be formed as carbon felt or foamed carbon.

[0046] The first lattice 400 includes a plurality of fibers arranged in a plurality of directions (indicated as two orthogonal directions). The plurality of fibers may be woven together or otherwise joined to form the first lattice 400. The second lattice 402 also includes a plurality of fibers arranged in a plurality of directions (indicated as two orthogonal directions), and these fibers may be woven together or otherwise joined to form the second lattice 402. The first lattice 400 and the second lattice 402 may be positioned relative to each other such that the fibers of the first lattice 400 are parallel to the fibers of the second lattice 402, or they may be oriented in a different way such that the fibers of the first lattice 400 form a non-orthogonal angle with respect to the fibers of the second lattice 402. In some embodiments, the first lattice 400 and the second lattice 402 are composed of fibers that appear substantially solid to the naked eye but are submicroscopic.

[0047] For example, the fibers of the first lattice 400 and the second lattice 402 of carbon fibers, as shown in Figure 5, may be made of carbon. In some embodiments, the fibers are made of graphite, for example, some or all of the fibers of the first lattice 400 and the second lattice 402 are graphite fibers. The fiber material is preferably of high purity (e.g., 95% or more carbon) so that when burned (in the presence of oxygen), the carbon fibers themselves leave little or no solid residue. In a vacuum (e.g., inside the vacuum chamber 202 during the operation of the apparatus 200, where oxygen is substantially absent), the carbon fibers are configured to withstand high temperatures (e.g., temperatures above 200°C, above 300°C, above 800°C) without substantially deforming, melting, etc.

[0048] The first lattice 400 and the second lattice 402 are configured to capture ions incident on them (for example, ions from the ion beam supplied by the ion beam generator 208 in Figure 4). Due to the arrangement of multiple fibers, ions are deflected (scattered, collided, etc.) by the multiple fibers so that after colliding with the target 110 once, their kinetic energy is reduced until the ions remain in the target 110 (e.g., converted into thermal energy) without scattering away from the target 110. The arrangement of fibers is partially porous so that some ions can pass through the outer surface of the first lattice 400, thus reducing the amount of energy accumulated on the surface of the first lattice 400 and allowing ions to scatter multiple times without escaping from the target 110 (e.g., without evaporating and disappearing from the target 110). Therefore, compared to a flat plate or block of material, the lattice structure provides an increased surface area and an overlapping geometric structure, which can facilitate the capture of ions incident on target 110 at a high rate (e.g., over 40%, and over 90% in some arrangements). Thus, the first lattice 400 and the second lattice 402 allow for the efficient collection of desired isotopes at target 110.

[0049] The first lattice 400 and the second lattice 402 are also configured to burn (in the presence of oxygen) or otherwise react to leave a residue containing a high concentration of the desired isotope (e.g., reduced to a residue). For example, in the fiber lattice structure of Figure 5, the surface area-to-mass ratio of the target 110 is increased compared to a solid block or plate of carbon or graphite, which allows for the relatively easy combustion of the first lattice 400 and the second lattice 402 (e.g., compared to a solid block of graphite that does not normally burn). For example, while the target 110 is held in a vacuum where there is virtually no oxygen present during the operation of the ion generation system 100 (which prevents complete combustion of the target 110), the target 110 captures the desired isotope (in the first lattice 400 and the second lattice 402 in the embodiment of Figure 5). The target 110 can then be removed from the vacuum for the process of extracting the isotope from the fiber lattice (e.g., the target 210 can be removed from the vacuum chamber 202 in the embodiment of Figure 4). Outside the vacuum, oxygen is present, which enables the combustion of carbon fibers. Next, the fiber lattice (e.g., a first lattice 400 and a second lattice 402) can be burned to reduce it to a residue having a high concentration of the desired isotope. After combustion, the carbon dissipates as a gas, so the remaining material consists of the desired isotope, which can be oxidized during the extraction process. For example, in some embodiments, after the combustion of the target, a powder of ytterbium oxide (e.g., ytterbium-176 oxide) remains as a powder (e.g., a white powder).

[0050] Referring now to Figure 6, perspective views of the fiber grid 500 of target 110 (or target 210) according to several embodiments are shown. In various embodiments, the fiber grid 500 can be used as a substitute for the first grid 400 and the second grid 402 of Figure 5, or can be used in combination with the first grid 400 and / or the second grid 402 of Figure 5.

[0051] As shown in Figure 6, the fiber grid 500 contains multiple fibers arranged in an intertwined network, and thus the fiber grid 500 may feature an open-cell foam. As in the embodiment of Figure 5, the multiple fibers may be carbon fibers and / or graphite fibers. The fiber grid 500 is configured to capture ions (e.g., from an ion beam generated by the ion beam generator 208 in the embodiment of Figure 4) so ​​that the desired isotopes are collected in the fiber grid 500. Due to the fibrous structure of the fiber grid 500, ions can be deflected by multiple fibers until, after colliding with the fiber grid 500, they remain stationary in the fiber grid 500 without scattering away from it. The fiber grid 500 also has a high surface area-to-mass ratio, which facilitates the easy combustion of the fiber grid 500, reducing it to a residue with high concentrations of the desired isotopes.

[0052] Referring now to Figure 7, a top view of a target 210 (or target 110) according to several embodiments is shown. In the embodiments shown, the target 210 is shown to include a first grid 400 (a second grid 402 may be included in some embodiments, but is hidden behind the first grid 400 and not visible from the viewpoint of Figure 7, for example), a backing plate 600, a mount 602, and a bolt (or other connecting member, e.g., screw, clip, connector, etc.) 604, wherein the mount 602 is formed in a ring shape and is positioned so that the first grid 400 is located between the mount 602 and the backing plate 600, and the bolt 604 connects the mount 602 to the backing plate 600.

[0053] When the bolt 604 is tightened, the mount 602 holds the first grid 400 (or other fiber grid, e.g., fiber grid 500) to the backing plate 600, thereby fixing the first grid 400 in place relative to the backing plate 600. When the bolt 604 is loosened, the first grid 400 can be released from the mount 602, and thus the first grid 400 can be removed in order to collect the collected isotopes from the first grid 400.

[0054] In some embodiments, the backing plate 600 is connected to, or is part of, the internal plate 212 of the magnetic rotating device 206 (actuator) shown in Figure 4. In such embodiments, the operation of the motor 216 driving the external plate 214 causes the internal plate 212, the backing plate 600, the mount 602, and the fiber grid (e.g., the first grid 400) to rotate. This allows the fiber grid to rotate around an axis, for example, increasing the surface area of ​​the fiber grid (e.g., the first grid 400) into which the ion beam is incident.

[0055] Figure 7 shows an embodiment in which a beam of ytterbium ions with an energy of 60 kV is generated and directed to the first lattice 400, causing the first lattice 400 to capture ytterbium ions / atoms. Figure 7 shows the combustion region 606 in which ytterbium is captured by the first lattice 400. In the embodiment shown, during ion capture, the ion beam causes partial combustion of the first lattice 400. Figure 7 also shows that by moving the first lattice 400 (e.g., by the rotation described above) while the ion beam is incident on the first lattice 400, it may be possible to use a larger portion of the first lattice 400 to capture ions, thus increasing the total amount of the desired isotope / atom collected.

[0056] Referring to Figure 8, the upper parts of the first lattice 400 and the second lattice 402 (partially obscured by the first lattice 400) are shown based on experimental results. In the embodiment of Figure 8, an ion beam of ytterbium with an energy of approximately 5 kV was incident on the first lattice 400 and the second lattice 402 (some ions passed through the first lattice 400 and reached the second lattice 402). The burning region 700 indicates where ions were collected in the first lattice 400 and the second lattice 402. The experiment in Figure 8 demonstrates that ytterbium can be captured by the first lattice 400 and the second lattice 402. Figure 8 also shows that rotating the first lattice 400 and the second lattice 402 exposes more of the fiber lattice material to the ion beam, increasing the total amount of the desired isotope collected by the fiber lattice.

[0057] Referring now to Figure 9, the upper parts of the first lattice 400 and the second lattice 402 (partially obscured by the first lattice 400) are shown from another experimental result. In the embodiment of Figure 9, a ytterbium ion beam with an energy of approximately 0.3 kV was incident on the first lattice 400 and the second lattice 402 (some ions passed through the first lattice 400 and reached the second lattice 402). The burning region 800 indicates where ions were collected in the first lattice 400 and the second lattice 402. Comparing the experiments in Figures 8 and 9, the beam with an energy of approximately 0.3 kV showed increased capture compared to the beam with an energy of approximately 5 kV (as evidenced by the larger burning region 800 compared to the burning region 700). Thus, as previously stated with reference to Figures 1 to 3, Figures 8 and 9 demonstrate the advantage of reducing the ion energy before collision with the target 110. Figure 9 also shows that rotating the first lattice 400 and the second lattice 402 exposes more of the fiber lattice material to the ion beam, increasing the total amount of desired isotopes collected by the fiber lattice. Thus, the various features described herein contribute to the efficient capture of desired isotopes / atoms in the fiber lattice material, making it easy to obtain a residue rich in the desired particles from the fiber lattice material.

[0058] The above discussion has provided a general overview of the physical principles related to the operation of the ion generation system 100 and the effect of the target voltage on the ion beam. However, it should be understood that the behavior of ion beams is complex, and that additional or alternative theoretical or experimental results may be used to provide further explanations or alternative explanations of the various advantages of the systems and methods described herein. For example, experimental results have shown that the advantages described herein can be obtained by applying a target voltage of the same polarity as the ion beam to the target 110, as described above, and that desired isotopes such as ytterbium-176 can be efficiently captured by the fiber lattice material described herein.

[0059] The terms “approximately,” “about,” “substantially,” and similar terms as used herein are intended to have a broad meaning consistent with the common and accepted usage of those skilled in the art to which the subject matter of this disclosure belongs. Those skilled in the art to consider this disclosure should understand that these terms are intended to enable the description of specific features described and claimed, and not to limit the scope of these features to the exact numerical values ​​or ideal geometric shapes provided. Accordingly, these terms should be construed as indicating that any modifications or changes of substance or materiality to the subject matter described and claimed are also deemed to fall within the scope of the disclosure set forth in the appended claims.

[0060] As used herein, the terms “coupled” and their variations mean joining two members to each other directly or indirectly. Such joining may be static (e.g., permanent or fixed) or movable (e.g., removable or detachable). Such joining may be achieved by directly linking the two members to each other, by using a separate intervening member and any additional intermediate member linked to each other, or by using an intervening member integrally formed with one of the two members as a single structure. When "coupled" or its variations are modified by additional terms (e.g., directly coupled), the general definition of "coupled" as shown above is modified by the plain language meaning of the additional terms (e.g., "directly coupled" means joining two members without any separate intervening members), resulting in a narrower definition than the general definition of "coupled" as shown above. Such coupling may be mechanical, electrical, or fluid.

[0061] References to the position of elements in this specification (e.g., “top,” “bottom,” “above,” “below”) are used solely to describe the orientation of various elements in the drawings. It should be noted that the orientation of various elements may differ in other exemplary embodiments, and that such variations are also intended to be included in this disclosure.

[0062] The drawings and descriptions may illustrate a specific order of method steps, but unless otherwise specified above, the order of such steps may differ from the order illustrated and described. Also, unless otherwise specified above, two or more steps may be performed simultaneously or partially simultaneously. Such variations may depend, for example, on selected software and hardware systems and the designer's choice. All such variations are included within the scope of this disclosure. Similarly, software embodiments of the described methods may be implemented by standard programming techniques with rule-based logic and other logic for performing various connection steps, processing steps, comparison steps, and decision steps.

Claims

1. The method involves accelerating ions toward a carbon fiber lattice, wherein the ions are ytterbium ions. The ions are captured in the carbon fiber lattice, Methods that include...

2. Accelerating ions toward the lattice of carbon fibers, The ions are captured in the carbon fiber lattice, To obtain a residue containing the aforementioned ions, the carbon fiber lattice is burned, Methods that include...

3. The method according to claim 1, wherein at least a portion of the ytterbium ions are ytterbium-176 ions, and the method further comprises isolating the ytterbium-176 ions from other ytterbium ions before capturing the ytterbium-176 ions in the carbon fiber lattice.

4. Isolating the aforementioned ytterbium-176 ion is possible. By applying a magnetic field to the ytterbium ions using a magnetic analyzer, the ytterbium ions are separated by mass from the other ytterbium ions, The other ytterbium ions are blocked using a mass-decomposition opening positioned between the magnetic analyzer and the carbon fiber lattice, such that the ytterbium-176 ions pass through the mass-decomposition opening. The method according to claim 3, including the method described in claim 3.

5. The method according to claim 1, wherein accelerating the ions toward the lattice of the carbon fibers includes providing the ions with energy exceeding 100V.

6. The method according to claim 1, wherein trapping the ions in the carbon fiber lattice includes decelerating the ions by deflecting them with a plurality of carbon fibers in the carbon fiber lattice.

7. Accelerating ions toward the lattice of carbon fibers, The ions are captured in the carbon fiber lattice, By operating an actuator to rotate or translate the carbon fiber lattice, the area of ​​the carbon fiber lattice that captures the ions is increased. Methods that include...

8. The method according to claim 1, wherein the carbon fiber lattice comprises a plurality of layers of fibrous carbon material.

9. The method according to claim 1, wherein the carbon fiber lattice includes carbon fibers arranged in multiple directions.

10. An ion source configured to generate ions, wherein the ions are ytterbium ions, A target with a fiber grid, An electrode disposed between the ion source and the target substrate, wherein the electrode is configured to accelerate the ions toward the target substrate so that the ions are incident on the fiber lattice, An ion generation system comprising, An ion generation system in which the fiber lattice is configured to capture the ions.

11. The ion generation system according to claim 10, wherein the ion is ytterbium-176 ion.

12. The ion generation system according to claim 10, wherein the fiber lattice includes a plurality of carbon fibers arranged in a plurality of directions.

13. The ion generation system according to claim 10, wherein the target comprises a plurality of layers of the fiber lattice.

14. An ion source configured to generate ions, A target with a fiber grid, An electrode disposed between the ion source and the target substrate, wherein the electrode is configured to accelerate the ions toward the target substrate so that the ions are incident on the fiber lattice, An ion generation system comprising, The fiber lattice is configured to capture the ions, The aforementioned fiber lattice is an ion generation system containing graphite.

15. The ion generation system according to claim 10, wherein the fiber lattice is configured to burn.

16. The ion generation system according to claim 10, wherein the fiber grid is configured to leave a residue containing the ions after the fiber grid has been burned.

17. The ion generation system according to claim 10, wherein the electrode provides energy exceeding 100V to the ions.

18. The ion generation system according to claim 10, wherein the target comprises a mount, the mount being configured to releasably fix the fiber grid to the mount in a predetermined position.

19. An ion source configured to generate ions, A target with a fiber grid, An electrode disposed between the ion source and the target substrate, wherein the electrode is configured to accelerate the ions toward the target substrate so that the ions are incident on the fiber lattice, An actuator capable of rotating the aforementioned target, An ion generation system comprising, An ion generation system in which the fiber lattice is configured to capture the ions.

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