Cooling plate assembly for plasma window positioned in beam accelerator system

Abstract

A beam accelerator system operable to produce medical isotopes, the system comprising: an ion accelerator generating an ion beam; a low pressure chamber; an anode adjacent and fluidly connected to the low pressure chamber; a plasma window adjacent and fluidly connected to the anode; and a cathode enclosure adjacent and fluidly connected to the plasma window. The plasma window has a plurality of plates, each plate having an aperture aligned with an aperture in one or more adjacent plates to form a plasma channel. One or more of the plurality of plates includes a unitary plate having apertures therein and one or more cooling channels that enter the unitary plate on a first side of the unitary plate and exit the unitary plate on a second side of the unitary plate. One or more cooling channels penetrate through the thickness of the integral plate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. application No. 17 / 951,975, filed on September 23, 2022, the entire contents of which are incorporated herein by reference.

[0003] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

[0004] This disclosure was developed with government support under Contract No. DE-AR0001377 awarded by the U.S. Department of Energy. The Government has certain rights in this disclosure. Background Art

[0005] field

[0006] The present disclosure relates generally to cooling plates for plasma window systems, and in particular plasma window systems used in beam accelerator systems, such as gaseous target neutron production systems. Technical Background

[0008] Beam accelerator systems are used to produce medical grade radioisotopes used by doctors in nuclear medicine. Generally, a beam accelerator system includes an ion accelerator that produces a high energy ion beam that is directed to a target chamber through a plasma window. For example, in a gaseous target neutron production system, the high energy ion beam is directed to a gaseous target. The generation of the high energy ion beam and its movement to the target requires a lot of energy and generates a lot of heat.

[0009]

[0006] Therefore, a need exists for components of beam accelerator systems, such as gaseous target neutron production systems, that help reduce the cost and energy required to produce radioisotopes. Summary of the invention

[0010] According to one embodiment, a beam accelerator system operable to produce medical isotopes comprises: an ion accelerator that produces a high-energy ion beam; a low-pressure chamber; an anode that is adjacent to and fluidically connected to the low-pressure chamber; a plasma window that is adjacent to and fluidically connected to the anode; and a cathode housing that is adjacent to and fluidically connected to the plasma window, wherein: the plasma window comprises a plurality of plates, each plate having a hole that is aligned with the holes in one or more adjacent plates to form a plasma channel; and one or more of the plurality of plates comprises an integral plate and one or more cooling channels, the integral plate having a hole therein, the one or more cooling channels entering the integral plate at a first side of the integral plate and exiting the integral plate at a second side of the integral plate, wherein the one or more cooling channels extend through the thickness of the integral plate.

[0011] According to another embodiment, a beam accelerator system operable to produce medical isotopes includes: an ion accelerator that produces a high-energy ion beam; a low-pressure chamber; an anode adjacent to and fluidly connected to the low-pressure chamber; a plasma window adjacent to and fluidly connected to the anode; and a cathode housing adjacent to and fluidly connected to the plasma window, wherein: the plasma window includes a plurality of plates, each plate having a hole that is aligned with the holes in one or more adjacent plates to form a plasma channel; and one or more of the plurality of plates includes a first cooling channel and a second cooling channel, the first cooling channel and the second cooling channel extending through the one or more plates. thickness, a first cooling channel and a second cooling channel entering the one or more plates at a first side of the one or more plates and exiting the one or more plates at a second side of the one or more plates, wherein the first cooling channel enters the one or more plates at the first side of the one or more plates, extends adjacent to the first side of the hole, turns in a first direction to extend adjacent to the second side of the hole, turns in a second direction and extends to exit the one or more plates at the second side of the one or more plates, and the second cooling channel enters the one or more plates at the first side of the one or more plates and extends to a third side of the hole, turns in the first direction to extend adjacent to the third side of the hole, turns in the second direction to extend adjacent to a fourth side of the hole, and exits the second side of the one or more plates.

[0012] According to another embodiment, a beam accelerator system operable to produce medical isotopes, the beam accelerator system comprising: an ion accelerator that produces a high energy ion beam; a low pressure chamber; an anode adjacent to and fluidly connected to the low pressure chamber; a plasma window adjacent to and fluidly connected to the anode; and a cathode housing adjacent to and fluidly connected to the plasma window, wherein: the plasma window comprises a plurality of plates, each plate having a hole, the hole being aligned with the hole in one or more adjacent plates to form a plasma channel; and one or more of the plurality of plates comprising a first cooling channel, a second cooling channel, and a third cooling channel, the first cooling channel The channel, the second cooling channel and the third cooling channel extend through the thickness of the one or more plates, wherein: the first cooling channel enters the one or more plates at a first side of the one or more plates, extends to a first side of the hole and is divided into a second cooling channel and a third cooling channel; the second cooling channel extends along a first direction adjacent to the first side of the hole to a second side of the hole, turns to a second direction and extends adjacent to the second side of the hole, and exits the one or more plates at the second side of the one or more plates; and the third cooling channel extends along a third direction adjacent to the first side of the hole to a third side of the hole, turns to a second direction and extends adjacent to the third side of the hole, and exits the one or more plates at the second side of the one or more plates.

[0013] Additional features and advantages will be set forth in the detailed description which follows, and in part will be apparent to those skilled in the art from that description, or may be learned by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings.

[0014] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 schematically depicts a gaseous target neutron production system according to embodiments disclosed and described herein;

[0016] Figure 2A schematically depicts a low pressure chamber, anode, plasma window, cathode housing, and cathode according to embodiments disclosed and described herein;

[0017] Figure 2B schematically depicts a cross section of a low pressure chamber, an anode, a plasma window, a cathode housing, and a cathode according to embodiments disclosed and described herein;

[0018] Figure 3 schematically depicts a cross section of an anode, plasma window, and cathode housing according to embodiments disclosed and described herein;

[0019] Figure 4 schematically depicts a front view of a plate having two parallel cooling channels according to embodiments disclosed and described herein;

[0020] Figure 5 schematically depicts an elevation view of a plate having a block of refractory metal according to embodiments disclosed and described herein;

[0021] Figure 6 schematically depicts a top view of a plate having two parallel cooling channels according to embodiments disclosed and described herein;

[0022] Figure 7 schematically depicts a front view of a plate having an L-shaped cooling channel design according to embodiments disclosed and described herein;

[0023] Fig. 8A schematically depicts a front view of a plate having a U-shaped cooling channel design according to embodiments disclosed and described herein;

[0024] Figure 8B schematically depicts a front view of a plate having an inverted U-shaped cooling channel design according to embodiments disclosed and described herein;

[0025] Fig. 9 schematically depicts a front view of a plate having an O-shaped cooling channel design according to embodiments disclosed and described herein;

[0026] Fig. 10A graphically depicting temperature and pressure drop versus flow rate for a plate with two parallel cooling channels having a smooth interior according to embodiments disclosed and described herein;

[0027] Fig. 10B graphically depicting temperature and pressure drop versus flow rate for a plate having two parallel cooling channels inside a vortex design according to embodiments disclosed and described herein;

[0028] Fig.11 graphically depicting temperature and pressure drop versus flow rate for a plate having an L-shaped cooling channel design according to embodiments disclosed and described herein;

[0029] Fig.12 graphically depicting hole temperature versus flow rate for a plate having a cooling channel design according to embodiments disclosed and described herein;

[0030] Fig.13 graphically depicting cooling channel temperature versus flow rate for a plate having a cooling channel design according to embodiments disclosed and described herein; and

[0031] Fig.14 Graphically depicted is cooling channel pressure drop versus flow rate for a plate having a cooling channel design according to embodiments disclosed and described herein. Specific embodiments

[0032] Reference will now be made in detail to embodiments of a cooling plate for use in a plasma window of a beam accelerator system, which embodiments of the cooling plate are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0033] According to an embodiment, a plasma window is positioned in a gaseous target neutron production system to operate as a windowless vacuum barrier to separate a low pressure beamline and a high pressure gaseous target chamber. The plasma window allows the system to have an increased gaseous target pressure, a shortened target length, and an increased current delivered to the target (e.g., the target gas present in the target chamber). In view of this, a beam accelerator system equipped with a plasma window enables an increase in the achievable neutron flux by up to two orders of magnitude compared to a conventional beam accelerator system.

[0034] refer to Figure 1, an embodiment of a beam accelerator system 100 operable to produce medical isotopes, the beam accelerator system 100 includes an ion accelerator 110 that produces a high energy ion beam 111, which is directed to a low pressure chamber 120. In an embodiment, the low pressure chamber operates under vacuum or near vacuum conditions, for example, at 1 Torr or less, 0.1 Torr or less, 0.01 Torr or less, 1×10 -3 torr or lower, 1×10 -5 torr or lower, 1×10 -6 torr or lower. The anode 130 is positioned adjacent to and fluidically connected to the low pressure chamber 120 and is separated from the cathode housing 150 by a plasma window 140. The plasma window 140 is adjacent to and fluidically connected to both the anode 130 and the cathode housing 105. In an embodiment, the anode 130 may be an anode plate. The cathode housing 150 is configured to accommodate a plurality of cathodes 151, which will be described in more detail below. The beam accelerator system 100 also includes a target chamber 160 for accommodating a target gas (e.g., deuterium, tritium, helium, or argon). The target chamber 160 and the cathode housing 150 are pressurized so that the cathode housing 150 is on the high pressure side of the beam accelerator system 100 and the anode 130 is present on the low pressure side (e.g., vacuum side) of the beam accelerator system 100. Due to the pressure difference between the low pressure side of the beam accelerator system 100 and the high pressure side of the beam accelerator system 100, the gas generated by the ion accelerator 101 and the gas present in the low pressure chamber 120 do not pass through the anode 130 and enter the plasma window 140 or the cathode housing 150. It should be understood that Figure 1 For illustration purposes only and not drawn to scale.

[0035] Conventionally, accelerating ions into a gaseous target chamber (e.g., target chamber 160) requires a large and expensive pumping infrastructure to maintain the low pressure required for ions to be accelerated from ion accelerator 110 while maximizing the pressure in target chamber 160. Figure 1 In the depicted embodiment, the target chamber 160 is adjacent to and fluidly coupled to the cathode housing 150. The target chamber 160 can be operated at a pressure that exceeds one million times the pressure present in the beamline 110, for example, 30 Torr or more, 50 Torr or more, 100 Torr or more, 500 Torr or more, 1000 Torr or more, or any value within a range of any two of these values. Larger ion beam sizes and higher current ion beams require more pumping due to the conductivity of the ion beam through the channel and into the target. Therefore, the beam size and overall yield of the system are therefore limited by the diameter of the channel into the target chamber.

[0036] The use of a plasma window 140 between the anode 130 at low pressure and the cathode housing 150 at high pressure allows a greater pressure reduction factor relative to conventional channels, facilitating the use of larger diameter and higher power ion beams. The benefits of pressure reduction also reduce overall pumping costs due to the reduction in conductivity and the pumping hardware required to maintain the pressure differential.

[0037] Figure 2A 1 is a side view of the low pressure chamber 120, the anode 130, the plasma window 140, the cathode housing 150 and the cathode 151. Figure 2A As shown, the plasma window 140 includes a plurality of plates adjacent to and connected to each other. In an embodiment, the plasma window 140 includes 4 to 8 plates, such as 5 to 7 plates, or 6 plates. As described above, the plasma window 140 is positioned between the anode 130 and the cathode housing 150, and the plasma window 140 is connected to both the anode 130 and the cathode housing 150. The cathode housing 150 is configured to support a plurality of cathodes 151. In an embodiment, the cathode housing is configured to support four cathodes, three cathodes, or two cathodes. In an embodiment where the cathode housing 150 is configured to support four cathodes, the cathodes 151 may be positioned about 90° apart from each other in the cathode housing 150. In an embodiment where the cathode housing 150 is configured to support three cathodes, the cathodes 151 may be positioned about 120° apart from each other, and in an embodiment where the cathode housing 150 is configured to support two cathodes, the cathodes 151 may be positioned about 180° apart from each other.

[0038] Figure 2B yes Figure 2A 1. A cross-sectional view of a low-pressure chamber 120, an anode 130, a plasma window 140, and a cathode housing 150 depicted in FIG. In an embodiment, the anode 130 is a grounded plate that includes a nozzle 131 that is fluidly connected to the low-pressure chamber 120. The nozzle 131 is also fluidly connected to a channel 132 positioned in the anode 130. As will be discussed in more detail below, the nozzle 131 and the channel 132 in the anode 130 operate to converge an ion beam from the low-pressure side of the beam accelerator system 100 to the plasma window 140. To this end, in one or more embodiments, the anode and / or the low-pressure chamber 120 is mounted to a pumping system and is fluidly connected to the pumping system.

[0039] Still reference Figure 2B, the plasma window 140 includes five adjacent plates 142 that are connected to each other and separate the anode 130 from the cathode housing 150. It should be understood that embodiments of the plasma window 140 may include more or less than five plates 142. Each plate 142 of the plasma window 140 includes a circular hole at or near the geometric center of the plate 142. The circular holes of each plate 142 are aligned around the central axis so that when multiple plates 142 are aligned and connected, the coaxial circular holes in the plates 142 form a plasma channel 141 through which the high-energy ion beam will travel from the anode 130 to the cathode housing 150. It should be understood that in embodiments, the holes in the plates 142 do not have to be perfectly circular and can be any shape that can accommodate the transmission of the high-energy ion beam. In embodiments, the plates 142 of the plasma window 140 are electrically floating and cooled with a fluid such as water, which will be discussed in more detail below. By configuring the plates 142 to be electrically floating, the voltage gradient across the plasma channel 141 is not as steep as when the plates 142 are grounded; this can aid in the transmission of the high energy ion beam across the plasma channel 141. In one or more embodiments, a separator can be positioned between portions of adjacent plates 142. In an embodiment, the separator can include a boron nitride gasket (not shown) closest to the plasma channel 141, a fluororubber O-ring surrounding the boron nitride gasket, and a polyvinyl chloride gasket surrounding the fluororubber O-ring.

[0040] Still reference Figure 2BAs described above, the cathode housing 150 is configured to support a plurality of cathodes 151. The cathode housing 150 also includes a cathode target region 153, which is fluidically coupled to the target chamber 160, and the target gas contained in the target chamber 160 is also present in the cathode target region 153. Each cathode 151 includes a cathode needle 152 extending from the cathode 151 into the cathode target region 153. The cathode 151 applies a voltage (e.g., a voltage in the range of 150V to 250V, such as 200V) across multiple points in the cathode target region 153 via the cathode needle 152 to initiate and / or maintain heating and ionization of a portion of the target gas, thereby forming a viscous plasma 310. In some embodiments, the cathode 151 applies a voltage to initiate and maintain the formation of the viscous plasma 310. However, other methods of initiating the formation of the viscous plasma 310 are also contemplated, such as using one or more starting coils, such as a Tesla coil, to apply an initial voltage. Although not depicted, such a starting coil may be mounted on one or more plates 142 of the plasma window 140. In addition, in embodiments including an initial coil, the cathode 151 can still apply voltage to maintain the viscous plasma 310. The cathode target region 153 of the cathode housing 150 is fluidly coupled to the target chamber 160 through the gas inlet 154, and both the target region 160 and the cathode target region 153 operate at a significantly higher pressure than the anode 130 and the low pressure chamber 120. The target region 160 and the cathode target region 153 can be pressurized by a pumping system or similar device. It should be understood that in some embodiments, the cathode target region 153 is a portion of the target region 160, that is, the portion of the target chamber 160 closest to the cathode needle 152.

[0041] Now refer to Figure 3 Describes the transmission of the high energy ion beam from the anode 130 through the plasma window 140 to the cathode housing 150, Figure 3 1 is a cross-sectional view of the anode 130, the plasma window 140 and the cathode housing 150. As mentioned above, in an embodiment, the anode 130 can be an anode plate including a cathode housing 150 and a cathode housing 150. Figure 3 1 and 2. A nozzle 131 fluidly connected to the nozzle 131 (not shown), and a channel 132 fluidly connected to the nozzle 131. Figure 3The plasma window 140 depicted in FIG. 1 includes five adjacent plates 142 having circular holes coaxially aligned to form a plasma channel 141. The plasma channel 141 is fluidly connected to the channel 132 of the anode 130 and the cathode target region 153 of the cathode housing 150. The target gas is introduced into the cathode target region 153, and a viscous plasma 310 is generated at the cathode needle 152 (or at one or more starting coils), which fills the plasma channel 141 and extends into the channel 132 of the anode 130. By filling the plasma channel 141 with the viscous plasma 310, a pressure barrier is created between the cathode housing 150 and the anode 130. However, ion accelerators (such as Figure 1 310. As shown, an ion beam of the type shown in FIG. 310 can be delivered through the viscous plasma 310. Thus, a pressure differential between the high pressure side of the beam accelerator system 100 and the low pressure side of the beam accelerator system 100 can be maintained while still being able to transmit a high energy ion beam through the beam accelerator system 100.

[0042] As described above, the plasma window 140 disclosed and described herein is effective in maintaining a pressure difference in the beam accelerator system 100, which can significantly reduce the costs (capital and operating costs) and space occupied by the pumping system required in the beam accelerator system that does not use one or more plasma windows 140. However, once the plasma channel 141 is filled with viscous plasma 310, cooling the plasma window 140 is a challenge. Specifically, it is conventional to use a constant power density on the plasma channel 141 regardless of the diameter of the plasma channel 141. However, as the diameter of the plasma channel 141 increases, the total power applied to the wall of the plasma channel 141 increases, resulting in extremely high temperatures. Therefore, the plate 142 of the plasma window 140 can be designed to improve the cooling of the plate 142 and the plasma channel 141. Such a design will be described as follows.

[0043] refer to Figure 4, a front view of a plate 142 used in a plasma window 140 according to one or more embodiments will be described. The plate 142 is generally square and has a circular hole 410 positioned near the geometric center of the plate 142. However, it should be understood that the shape of the plate can vary according to the embodiment. The body of the plate 142 is made of a thermally conductive metal, such as copper, silver, molybdenum, tungsten, or a related alloy. In addition, the plate can be a combination of materials. For example, the plate can be composed of a majority of a copper matrix with a tungsten layer near the arc. In an embodiment, the plate 142 is made of copper. As described above, when a plurality of plates 142 are placed adjacent to each other, the holes 410 in each plate 142 are aligned to form a plasma channel of the plasma window, and the viscous plasma fills the plasma channel. Therefore, the diameter of the hole 410 in each plate 142 is approximately the size of the ion beam transmitted through the plasma channel. In an embodiment, the hole 410 has a diameter from 1.0mm to 10.0mm, for example, from 2.0mm to 8.0mm, from 3.0mm to 7.0mm, or from 4.0mm to 6.0mm. In an embodiment, the diameter of the hole can change along the plasma window to match the diameter of the change of the plasma window. In such embodiments, the diameter of the hole at one end of the plasma window is greater than the diameter of the hole at the opposite end of the plasma window. The diameter of the ion beam produced in the beam accelerator system according to the embodiment is several orders of magnitude larger than the electron beam less than one millimeter diameter used in the electron beam (e-beam) system. Therefore, in the electron beam system and the precision low current ion beam application, a much smaller hole diameter than the beam accelerator system according to the embodiment that produces a high current ion beam can be used, and, as mentioned above, the larger the hole diameter used, the more total power and heat transferred to the hole wall. That is, the plate 142 used in the plasma window of the ion beam accelerator system according to the embodiment has a cooling requirement completely different from the components used in the low current electron beam system and the low current ion beam system.

[0044] As mentioned above, the high energy ion beam has approximately the same diameter as the plasma channel, and therefore, the ion beam has approximately the same diameter as the hole 410 of the plate 142. This can result in a large amount of heat loading in the plate 142, especially around the hole 410, even when a thermally conductive metal such as copper is used to form the plate 142. In addition, portions of the viscous plasma that fills the plasma channel may contact the inner walls of the hole 410. Thermally conductive metals conventionally used in the industry, such as copper, may not be able to withstand the temperatures caused by contact with or even proximity to a viscous plasma. Therefore, in one or more embodiments disclosed and described herein, a ring of a refractory metal 411 (e.g., tungsten or molybdenum) may be used to form the inner walls of the hole 410, and thereby the inner walls of the plasma channel. In such embodiments, and with reference to Figure 5, a heat conductive metal plate 142a (e.g., a plate made of copper) can be integrally formed around a cylindrical block 411a of refractory metal, for example, by casting liquid heat conductive metal around the cylindrical block 411a of refractory metal. Once the heat conductive metal plate 142a is formed, the cylindrical block 411a can be processed to form a hole 410 having an inner surface of the refractory metal 411.

[0045] Reference again Figure 4 , and as mentioned above, when viscous plasma fills the plasma channel, a large amount of heat is generated, creating a large heat load around the hole 410 in the plate 142. This heat load may cause poor performance or even failure of the plate 142. Therefore, cooling channels 421 and 422 may be provided in the plate 142 near the hole 410. A cooling fluid (e.g., deionized water, etc.) is flushed through the cooling channels 421 and 422, thereby extracting heat from the portion of the plate 142 near the hole 410 into the cooling fluid. Each cooling channel 421 and 422 extends through the plate 142, so that the cold cooling fluid enters the plate 142 at inlets 421a and 422a of the cooling channels 421 and 422, respectively positioned on a first side of the plate 142, and leaves the plate 142 at outlets 421a and 422a of the cooling channels 421 and 422, respectively positioned on a second side of the plate 142. As Figure 4 As shown, the first cooling channel 421 is positioned on the first side of the hole (i.e., the left side along the -x direction), and the second cooling channel 422 is positioned on the second side of the hole 410 (i.e., the right side along the +x direction), and the first cooling channel 421 is substantially parallel to the second cooling channel 422. As used herein, "substantially parallel" is used to mean parallel with an acceptable manufacturing tolerance. In an embodiment, it is desirable to position the first cooling channel 421 and the second cooling channel 422 as close to the hole 410 as possible without compromising the structural integrity of the plate 142 and the hole 410. Figure 4 4, the first cooling channel 421 and the second cooling channel 422 are equidistant from the hole 410; however, in an embodiment, one of the first cooling channel 421 or the second cooling channel 422 may be positioned closer to the hole 410 than the other cooling channel. In addition, and according to one or more embodiments, the first cooling channel 421 may not be positioned parallel to the second cooling channel 422.

[0046] Cooling channels 421 and 422 may be machined into plate 142 by drilling, laser or water jet ablation, etc. Figure 6 , Figure 6 Depicting a top view of plate 142 , cooling channels are machined into the thickness t of plate 142 . Figure 6The inlet 421a of the first cooling channel and the inlet 422a of the second cooling channel are shown, which are adjacent to the hole 410 in the plate 142. By machining the cooling channel through the thickness of the plate 142, the integrity of the plate 142 is not compromised by seams or welds, which may cause weak points in the plate 142, which are traditionally present in plasma window plates. In this article, a plate without seams or welds is referred to as a "one-piece plate". As mentioned above, the plasma window in which the plate 142 is positioned is subject to significant pressure differences due to the plasma window separating the high pressure side of the beam accelerator system and the low pressure side of the beam accelerator system. In addition, the one-piece plate 142 is subject to high thermal loads. The pressure difference and thermal load may cause any seam in the one-piece plate 142 to fail. Therefore, the plate of one or more embodiments disclosed and described herein may include an one-piece plate. It should be understood that the use of the term "plate" in this disclosure may refer to an one-piece plate or a non-one-piece plate.

[0047] According to one or more embodiments, the cooling channels 421 and 422 have a circular cross section (eg Figure 6 ), and the diameters of the cooling channels 421 and 422 are determined according to the required cooling fluid throughput. In other embodiments, the cooling channels 421 and 422 may have a cross-section that is oval, square, rectangular, pentagonal, hexagonal, or octagonal. Of course, the cross-sectional dimensions (e.g., diameter) of the cooling channels 421 and 422 are limited by the thickness t of the plate 142.

[0048] In an embodiment, the inner surfaces of the cooling channels 421 and 422, respectively, may be smooth, allowing for a relatively laminar flow of the cooling fluid from the inlets 421a and 422a of the cooling channels 421 and 422, respectively, positioned at the first side of the plate 142, to the outlets 421b and 422b of the cooling channels 421 and 422, respectively, positioned at the second side of the plate 142. However, in other embodiments, the interior of the cooling channels 421 and 422 may have a vortex design that results in a turbulent flow of the cooling fluid from the inlets 421a and 422a of the cooling channels 421 and 422, respectively, positioned at the first side of the plate 142, to the outlets 421b and 422b of the cooling channels 421 and 422, respectively, positioned at the second side of the plate 142. The vortex design may be provided via a vortex-shaped insert present in the cooling channels 421 and 422, or by machining the cooling channels 421 and 422 to have an integral vortex design on the inner surfaces of the cooling channels 421 and 422. Compared to cooling channels 421 and 422 having smooth inner surfaces, the turbulence of the cooling fluid through the cooling channels 421 and 422 caused by the vortex design of the cooling channels 421 and 422 facilitates the transfer of heat from the hole 410 to the cooling fluid. However, the cooling channels 421 and 422 having smooth inner surfaces are easier to manufacture and have a smaller pressure drop across the cooling channels 421 and 422. The cooling effect is mainly provided by the cooling fluid flow rate and the turbulence within the cooling channels 421 and 422. The higher the flow rate within the cooling channels 421 and 422, and the stronger the turbulence, the better the cooling effect will be provided. However, the increased flow rate and turbulence within the cooling channels 421 and 422 result in a greater pressure drop. Therefore, the cooling effect and the pressure drop are balanced to achieve the desired effect.

[0049] Reference again Figure 4 , providing cooling channels 421 and 422 on opposite sides of the hole 410 provides good cooling of the hole wall directly located between the hole 410 and the cooling channels 421 and 422. However, in one or more embodiments, even when the interior of the cooling channels 421 and 422 has a vortex design, the portion of the hole wall along the centerline 430 and not directly located between the hole 410 and the cooling channels 421 and 422 may not be cooled by the cooling channels 421 and 422. Figure 4 The cooling channel design shown is fully cooled. That is, the farther the hole wall is from the cooling channel, the less cooling effect the portion of the hole wall receives. Therefore, additional embodiments of cooling channel designs that provide more uniform cooling of the hole wall are provided herein.

[0050] Figure 7 FIG. 1 is a front view of a plate 142 having an L-shaped cooling channel design. As described above, the plate 142 includes a hole 410 having an annular inner surface made of a refractory metal 411. Figure 7The depicted embodiment of the plate 142 includes a first cooling channel 721 and a second cooling channel 722. The first cooling channel 721 and the second cooling channel 722 each have an “L” shape. The first cooling channel 721 is positioned to the left of the second cooling channel 722 (ie, to the left in the −x direction).

[0051] At the first side of the plate 142 (i.e., the bottom in the -y direction) and the outlet 721b of the first cooling channel 721, the first cooling channel 721 is positioned at the first side of the hole 410 (i.e., the left side in the -x direction) and extends upward (i.e., in the +y direction) in the plate 142 so that the first cooling channel 721 passes through the first side of the adjacent hole 410 (i.e., the left side in the -x direction). When the first cooling channel 721 extends to the second side of the hole (i.e., the top in the +y direction), the first cooling channel 721 turns to the first direction (i.e., the right side in the +x direction) and extends along the second side of the hole 410 (i.e., the top in the +y direction). When the first cooling channel 721 extends to the fourth side of the hole 410 (i.e., the right side in the +x direction), the first cooling channel 721 turns to the second direction (i.e., upward in the +y direction) and extends toward the second end of the plate 142 (i.e., the top in the +y direction), and extends to the inlet 721a of the first cooling channel 721. use Figure 7 In the cooling channel design depicted in the embodiment of FIG. , the first cooling channel 721 provides cooling to a first side of the hole 410 (ie, the left side along the −x direction) and a second side of the hole 410 (ie, the top along the +y direction).

[0052] At the first side of the plate 142 (i.e., the bottom in the -y direction) and the outlet 722b of the second cooling channel 722, the second cooling channel 722 is located between the centerline 430 of the hole 410 and the first cooling channel 721. The second cooling channel 722 extends upward (i.e., in the +y direction) in the plate 142 to the third side of the hole 410 (i.e., the bottom in the -y direction). When the second cooling channel 722 reaches the third side of the hole 410 (i.e., the bottom in the -y direction), the second cooling channel 722 approaches the first side of the hole 410 (i.e., the left side in the -x direction) and turns to the first direction (i.e., the right side in the +x direction) to extend along the third side of the hole 410 (i.e., the bottom in the -y direction). When the second cooling channel 722 extends to the fourth side of the hole 410 (i.e., to the right in the +x direction), the second cooling channel 722 turns to the second direction (i.e., upward in the +y direction) in the plate 142 and extends along the fourth side of the hole 410 (i.e., to the right in the +x direction) until the second cooling channel 722 reaches the inlet 722a of the second cooling channel 722. Figure 7In the cooling channel design depicted in the embodiment of FIG. 4 , the second cooling channel 722 provides cooling to a third side of the hole 410 (ie, the bottom along the −y direction) and a fourth side of the hole 410 (ie, the right side along the +x direction).

[0053] Figure 7 The cooling channel design of the embodiment depicted in FIG. 4 provides cooling on four sides of the hole 410, with Figure 4 This is in contrast to the embodiment depicted in which cooling is provided to both sides of the hole.

[0054] Fig. 8A FIG. 1 is a front view of a plate 142 having a U-shaped cooling channel design. As described above, the plate 142 includes a hole 410 having an annular inner surface made of a refractory metal 411. Fig. 8A The embodiment of the plate 142 depicted in FIG. 8 includes a first cooling channel 821 that is divided into a second cooling channel 822 and a third cooling channel 823. The combination of the first cooling channel 821, the second cooling channel 822, and the third cooling channel 823 forms a "U" shape.

[0055] The first cooling channel 821 enters the plate 142 at the first side of the plate 142 (i.e., the bottom in the -y direction) and near the outlet 821b of the first cooling channel 821. In an embodiment, the longitudinal axis of the first cooling channel 821 is positioned approximately at the centerline 430 of the cross-section that bisects the hole 410. The first cooling channel 821 extends upward (i.e., in the +y direction) in the plate 142 to the hole 410. When the first cooling channel 821 reaches the first side of the hole 410 (i.e., the bottom in the -y direction), the first cooling channel 821 is divided into a second cooling channel 822 and a third cooling channel 823. In an embodiment, the second cooling channel 822 and the third cooling channel 823 are both approximately perpendicular to the first cooling channel 821.

[0056] The second cooling channel 822 extends horizontally along the first side (i.e., the bottom in the -y direction) of the hole 410 in the first direction (i.e., the left side in the -x direction) to the second side (i.e., the left side in the -x direction) of the hole 410. When the second cooling channel 822 extends to the second side (i.e., the left side in the -x direction) of the hole 410, the second cooling channel 822 turns to the second direction (i.e., upward in the +y direction) and extends along the second side (i.e., the left side in the -x direction) of the hole 410 toward the second side (i.e., the top in the +y direction) of the plate 142, and extends to the inlet 822a of the second cooling channel.

[0057] The third cooling channel 823 extends in the third direction (i.e., right along the +x direction) along the first side of the hole 410 (i.e., bottom along the -y direction) to the third side of the hole 410 (i.e., right along the +x direction). When the third cooling channel 823 extends to the third side of the hole 410 (i.e., right along the +x direction), the third cooling channel 823 turns to the second direction (i.e., upward along the +y direction) and extends along the third side of the hole 410 (i.e., right along the +x direction) toward the second side of the plate 142 (i.e., top along the +y direction), and extends to the second inlet 822a.

[0058] exist Fig. 8A The U-shaped cooling channel design of the embodiment depicted in FIG. 4 provides cooling to three sides of the hole 410 (i.e., the bottom side of the hole 410, the left side of the hole 410, and the right side of the hole 410). Fig. 8A One or two plates 142 adjacent to the plate of the U-shaped cooling channel design of the embodiment depicted in the drawings may have the same Fig. 8A , wherein two cooling channel inlets 822a and 823a are positioned on the second side of the plate 142 (i.e., the top along the +y direction), and a single cooling channel outlet 821b is positioned on the first side of the plate 142 (i.e., the bottom along the -y direction). However, in an embodiment, the plate 142 having the same U-shaped cooling channel design as the embodiment depicted in FIG. Fig. 8A One or more adjacent plates 142 of the U-shaped cooling channel design of the embodiment depicted in the drawings may have an inverted U-shaped cooling channel design, wherein two cooling channel inlets 822a and 823a are positioned on a first side of the plate 142 (i.e., at the bottom along the -y direction), and a single cooling channel outlet 821b is positioned on a second side of the plate 142 (i.e., at the top along the +y direction).

[0059] refer to Figure 8B , the inverted U-shaped cooling channel design will now be described. As described above, the plate 142 includes a hole 410 having an annular inner surface made of a refractory metal 411. Figure 8B The depicted embodiment of plate 142 includes a first cooling channel 821 that is divided into a second cooling channel 822 and a third cooling channel 823. The combination of the first cooling channel 821, the second cooling channel 822, and the third cooling channel 823 forms an inverted "U" shape.

[0060] At the top of the plate 142 (i.e., upward in the +y direction) and near the outlet 821b of the first cooling channel 821, the longitudinal axis of the first cooling channel 821 is positioned about the centerline 430 that bisects the cross-section of the hole 410. The first cooling channel 821 extends downward in the plate 142 (i.e., downward in the -y direction) to the hole 410. When the first cooling channel 821 reaches the fourth side of the hole 410 (i.e., the top in the +y direction), the first cooling channel 821 is divided into a second cooling channel 822 and a third cooling channel 823.

[0061] The second cooling channel 822 extends along the fourth side (i.e., the top in the +y direction) of the hole 410 in the first direction (i.e., the left in the −x direction) to the second side (i.e., the left in the −x direction) of the hole 410. When the second cooling channel 822 extends to the second side (i.e., the left in the −x direction) of the hole 410, the second cooling channel 822 turns to the second direction (i.e., downward in the −y direction) and extends along the second side (i.e., the left in the −x direction) of the hole 410 toward the first side (i.e., the bottom in the −y direction) of the plate 142, and extends to the inlet 822a of the second cooling channel 822.

[0062] The third cooling channel 823 extends along the fourth side of the hole 410 (i.e., the top in the +y direction) in the third direction (i.e., the right in the +x direction) to the third side of the hole 410 (i.e., the right in the +x direction). When the third cooling channel 823 extends to the third side of the hole 410 (i.e., the right in the +x direction), the third cooling channel 823 turns to the second direction (i.e., downward in the -y direction) and extends along the third side of the hole 410 (i.e., the right in the +x direction) toward the first side of the plate 142 (i.e., the bottom in the -y direction), and extends to the inlet 823a of the third cooling channel.

[0063] Figure 8B The inverted U-shaped cooling channel design of the embodiment depicted in FIG. 4 provides cooling for three sides of the hole 410 (i.e., the top of the hole 410, the left side of the hole 410, and the right side of the hole 410). This inverted U-shaped cooling channel design can be used with Fig. 8A The U-shaped cooling channel design depicted in FIG. 1 complements the U-shaped cooling channel design depicted in FIG. 1 , so that the top of the hole 410 is cooled in the various plates 142 and the bottom of the hole 410 is cooled in the various plates 142. For example, and in one or more embodiments, having Fig. 8A The U-shaped cooling channel design depicted in the figure can be used with a plate having Figure 8B The plates of the inverted U-shaped cooling channel design depicted alternate so that every other plate has a cooling hole at the top, and every other plate has a cooling hole at the bottom.

[0064] Fig. 9FIG. 1 is a front view of a plate 142 having an O-shaped cooling channel design. As described above, the plate 142 includes a hole 410 having an annular inner surface made of a refractory metal 411. Fig. 9 The embodiment of the plate 142 depicted in FIG. 4 includes a first portion of a first cooling channel 921 that is divided into a second cooling channel 922 and a third cooling channel 923 on a first side of the hole 410. The second cooling channel 922 extends around the first portion of the hole 410, and the third cooling channel extends around the second portion of the hole 410. The second cooling channel 922 and the third cooling channel 923 rejoin on the second side of the hole 410 into the second portion of the first cooling channel 921. The combination of the second cooling channel 922 and the third cooling channel 923 forms an annular "O" shaped cooling channel around the hole 410.

[0065] At the first side of the plate 142 (i.e., the bottom in the -y direction) and the outlet 921b of the first cooling channel 921, the longitudinal axis of the first cooling channel 921 is positioned approximately at the centerline 430 of the cross-section that bisects the hole 410. The first portion of the first cooling channel 921 extends upward (i.e., in the +y direction) in the plate 142 to the hole 410. When the first cooling channel 921 reaches the first side of the hole 410 (i.e., the bottom in the -y direction), the first cooling channel 921 is divided into a second cooling channel 922 and a third cooling channel 923. The second cooling channel 922 extends in an annular shape, adjacent to the second side of the hole 410 (i.e., the left side in the -x direction) and mimics the shape of the hole 410. The third cooling channel 923 extends in an annular shape, adjacent to the second side of the hole 410 (i.e., the right side in the +x direction) and mimics the shape of the hole 410. Near the third side of the hole 410 (i.e., the top along the +y direction), the second cooling channel 922 and the third cooling channel 923 combine to form a second portion of the first cooling channel 921, which extends upward (i.e., along the +y direction) toward the second side of the plate 142 (i.e., the top along the +y direction) and the cooling channel inlet 921a.

[0066] Fig. 9 The O-shaped cooling channel design of the embodiment depicted in FIG. 4 provides cooling to all sides of the bore 410 by having an annular second cooling channel 922 extending around the left side of the bore 410 and having an annular third cooling channel 923 extending around the right side of the bore 410 .

[0067] In any embodiments disclosed and described herein, at least a portion of at least one cooling channel is offset from the hole by less than 15.0 mm, such as less than 10.0 mm, less than 8.0 mm, less than 6.0 mm, or less than 5.0 mm. Thus, in embodiments, at least a portion of at least one cooling channel is offset from the hole by 0.5 mm to 15.0 mm, 5.0 mm to 15.0 mm, 10.0 mm to 15.0 mm, 0.5 mm to 10.0 mm, 5.0 mm to 10.0 mm, or 0.5 mm to 5.0 mm.

[0068] In any embodiments disclosed and described herein, the cooling channel can have a cross-sectional diameter greater than or equal to 0.5 mm and less than or equal to 5.0 mm, greater than or equal to 1.0 mm and less than or equal to 5.0 mm, greater than or equal to 2.5 mm and less than or equal to 5.0 mm, greater than or equal to 4.0 mm and less than or equal to 5.0 mm, greater than or equal to 0.5 mm and less than or equal to 3.0 mm, greater than or equal to 1.0 mm and less than or equal to 3.0 mm, or greater than or equal to 0.5 mm and less than or equal to 2.0 mm.

[0069] It should be understood that the plasma window 140 can be cooled using any of the embodiments described herein. In practice, the operation of the beam accelerator system 100 can include generating a viscous plasma 310 in the plasma channel 141. The viscous plasma 310 can be generated by applying a voltage to a target gas (contained in the target chamber 160 and the cathode target region 153, and can contain deuterium, tritium, argon, or helium), thereby heating and ionizing a portion of the target gas to form the viscous plasma 310. In some embodiments, the input voltage is applied by the cathode 151. In other embodiments, the input voltage is applied by one or more starting coils, such as Tesla coils, which can be mounted on one or more plates 142. The method then includes directing an ion beam 111 generated by the ion accelerator 110 from the low pressure chamber 120 through the viscous plasma 130 in the plasma channel 141 disposed in the plasma window 140, and entering the target chamber 160. In the target chamber 160, the ion beam 111 interacts with the target gas through a fusion reaction to produce neutrons. The method also includes cooling the plasma window 140, in particular the plates 142 of the plasma window 140, which are heated by the viscous plasma 310 in the plasma channel 141. Figures 4 to 9 As described, plate 142 may be cooled by directing a cooling fluid through one or more cooling channels to transfer heat from apertures 410 and plate 142 to the cooling fluid, thereby cooling apertures 410 and plate 142 .

[0070] As used herein, the terms "substantially," "approximately," and the like refer to the subsequently recited property or measurement within normal manufacturing tolerances and imperfections in the relevant art.

[0071] A first aspect includes a beam accelerator system operable to produce medical isotopes, the beam accelerator system comprising: an ion accelerator that produces a high energy ion beam; a low pressure chamber; an anode that is adjacent to the low pressure chamber and fluidly connected; a plasma window that is adjacent to the anode and fluidly connected; and a cathode housing that is adjacent to the plasma window and fluidly connected, wherein: the plasma window comprises a plurality of plates, each plate having a hole that is aligned with the holes in one or more adjacent plates to form a plasma channel; and one or more of the plurality of plates comprises an integral plate and one or more cooling channels, the integral plate having a hole therein, the one or more cooling channels entering the integral plate at a first side of the integral plate and exiting the integral plate at a second side of the integral plate, wherein the one or more cooling channels extend through the thickness of the integral plate.

[0072] The second aspect includes the beam accelerator system of the first aspect, wherein the one or more cooling channels include a first cooling channel and a second cooling channel, wherein the first cooling channel is substantially parallel to the second cooling channel, and the first cooling channel is positioned on a first side of the aperture and the second cooling channel is positioned on a second side of the aperture.

[0073] A third aspect includes the beam accelerator system of the second aspect, wherein at least one of the first cooling channel and the second cooling channel has a smooth inner surface.

[0074] A fourth aspect includes the beam accelerator system of the second aspect, wherein at least one of the first cooling channel and the second cooling channel has a vortex design on an inner surface.

[0075] A fifth aspect includes the beam accelerator system of the second to fourth aspects, wherein the first cooling channel and the second cooling channel have circular cross-sectional areas.

[0076] A sixth aspect includes the beam accelerator system of the first to fifth aspects, wherein the plurality of plates are formed of a thermally conductive metal selected from the group consisting of copper, silver, aluminum, and tungsten.

[0077] A seventh aspect includes the beam accelerator system of the first to sixth aspects, wherein an inner wall of the hole is formed of a refractory metal.

[0078] An eighth aspect includes the beam accelerator system of the first to seventh aspects, wherein the aperture has a diameter of 1.0 mm to 10.0 mm.

[0079] A ninth aspect includes the beam accelerator system of aspects one to eight, wherein at least one point of the one or more cooling channels is offset from the aperture by less than 15.0 mm.

[0080] The tenth aspect includes the beam accelerator system of the first to ninth aspects, wherein a diameter of the one or more cooling channels is greater than or equal to 0.5 mm and less than or equal to 5.0 mm.

[0081] The eleventh aspect includes a beam accelerator system operable to produce medical isotopes, the beam accelerator system comprising: an ion accelerator that produces a high energy ion beam; a low pressure chamber; an anode adjacent to and fluidly connected to the low pressure chamber; a plasma window adjacent to and fluidly connected to the anode; and a cathode housing adjacent to and fluidly connected to the plasma window, wherein the plasma window comprises a plurality of plates, each plate having a hole that is aligned with the hole in one or more adjacent plates to form a plasma channel, and one or more of the plurality of plates comprises a first cooling channel and a second cooling channel that extend through the thickness of the one or more plates. The first cooling channel and the second cooling channel enter the one or more plates at a first side of the one or more plates and exit the one or more plates at a second side of the one or more plates, wherein the first cooling channel enters the one or more plates at the first side of the one or more plates, extends adjacent to the first side of the hole, turns in the first direction to extend adjacent to the second side of the hole, turns in the second direction and extends to exit the one or more plates at the second side of the one or more plates, and the second cooling channel enters the one or more plates at the first side of the one or more plates and extends to a third side of the hole, turns in the first direction to extend adjacent to the third side of the hole, turns in the second direction to extend adjacent to the fourth side of the hole, and exits the second side of the one or more plates.

[0082] A twelfth aspect includes the beam accelerator system of the eleventh aspect, wherein a longitudinal axis of the first cooling channel is located along a centerline bisecting a cross-section of the aperture.

[0083] A thirteenth aspect includes the beam accelerator system according to the eleventh and twelfth aspects, wherein the plurality of plates are formed of a thermally conductive metal selected from the group consisting of copper, silver, aluminum, and tungsten.

[0084] A fourteenth aspect includes the beam accelerator system according to any one of the eleventh to thirteenth aspects, wherein an inner wall of the hole is formed of a refractory metal.

[0085] A fifteenth aspect includes the beam accelerator system according to the eleventh to fourteenth aspects, wherein the aperture has a diameter of 1.0 mm to 10.0 mm.

[0086] A sixteenth aspect includes the beam accelerator system according to aspects eleven to fifteen, wherein at least one point of the first cooling channel or the second cooling channel is offset from the aperture by less than 15.0 mm.

[0087] A seventeenth aspect includes the beam accelerator system according to any one of the eleventh to sixteenth aspects, wherein a diameter of at least one of the first cooling channel and the second cooling channel is greater than or equal to 0.5 mm and less than or equal to 5.0 mm.

[0088] The eighteenth aspect includes a beam accelerator system operable to produce medical isotopes, the beam accelerator system comprising: an ion accelerator that produces a high energy ion beam; a low pressure chamber; an anode that is adjacent to and fluidically connected to the low pressure chamber; a plasma window that is adjacent to and fluidically connected to the anode; and a cathode housing that is adjacent to and fluidically connected to the plasma window, wherein the plasma window comprises a plurality of plates, each plate having a hole that is aligned with the hole in one or more adjacent plates to form a plasma channel, and one or more of the plurality of plates comprises a first cooling channel, a second cooling channel, and a third cooling channel, the first cooling channel A channel, a second cooling channel and a third cooling channel extend through the thickness of the one or more plates, wherein the first cooling channel enters the one or more plates at a first side of the one or more plates, extends to a first side of the hole and is divided into a second cooling channel and a third cooling channel; the second cooling channel extends adjacent to the first side of the hole in a first direction to a second side of the hole, turns to a second direction and extends adjacent to the second side of the hole, and leaves the one or more plates at the second side of the one or more plates; and the third cooling channel extends adjacent to the first side of the hole in a third direction to a third side of the hole, turns to a second direction and extends adjacent to the third side of the hole, and leaves the one or more plates at the second side of the one or more plates.

[0089] A nineteenth aspect includes the beam accelerator system according to the eighteenth aspect, wherein the first direction and the third direction are substantially perpendicular to the first cooling channel.

[0090] A twentieth aspect includes the beam accelerator system according to the eighteenth aspect or the nineteenth aspect, wherein the second direction is substantially parallel to the first direction.

[0091] A twenty-first aspect includes the beam accelerator system according to any one of the eighteenth to twentieth aspects, wherein the plurality of plates are formed of a thermally conductive metal selected from the group consisting of copper, silver, aluminum, and tungsten.

[0092] A twenty-second aspect includes the beam accelerator system according to any one of aspects eighteen to twenty-first, wherein an inner wall of the hole is formed of a refractory metal.

[0093] A twenty-third aspect includes the beam accelerator system of aspects eighteen to twenty-second, wherein the aperture has a diameter of 1.0 mm to 10.0 mm.

[0094] A twenty-fourth aspect includes the beam accelerator system of aspects eighteen to twenty-third, wherein at least one point of the one or more cooling channels is offset from the aperture by less than 15.0 mm.

[0095] A twenty-fifth aspect includes the beam accelerator system of aspects eighteen to twenty-four, wherein a diameter of one or more cooling channels is greater than or equal to 0.5 mm and less than or equal to 5.0 mm.

[0096] The twenty-sixth aspect includes a beam accelerator system operable to produce medical isotopes, the beam accelerator system comprising: an ion accelerator that produces a high-energy ion beam; a low-pressure chamber; an anode that is adjacent to the low-pressure chamber and fluidly connected; a plasma window that is adjacent to the anode and fluidly connected; and a cathode housing that is adjacent to the plasma window and fluidly connected, wherein the plasma window comprises a plurality of plates, each plate having a hole that is aligned with the holes in one or more adjacent plates to form a plasma channel, and one or more of the plurality of plates comprises: a first portion of a first cooling channel, a second cooling channel, a third cooling channel, and a second portion of the first cooling channel, wherein the first portion of the first cooling channel enters the plate at a first side of the plate, extends to a first side of the hole, and is divided into a second cooling channel and a third cooling channel, the second cooling channel extends around the first portion of the hole, the third cooling channel extends around the second portion of the hole, the second cooling channel and the third cooling channel are combined on the second side of the hole to form the second portion of the first cooling channel, the second portion of the first cooling channel exits the plate on the second side of the hole, and the second cooling channel and the third cooling channel form an annular cooling channel around the hole.

[0097] A twenty-seventh aspect includes the beam accelerator system according to the twenty-sixth aspect, wherein the plurality of plates are formed of a thermally conductive metal selected from the group consisting of copper, silver, aluminum, and tungsten.

[0098] A twenty-eighth aspect includes the beam accelerator system according to the twenty-sixth to twenty-seventh aspects, wherein the inner wall of the hole is formed of a refractory metal.

[0099] A twenty-ninth aspect includes the beam accelerator system of aspects twenty-six to twenty-eight, wherein the aperture has a diameter of 1.0 mm to 10.0 mm.

[0100] A thirtieth aspect includes the beam accelerator system of aspects twenty-six to twenty-ninth, wherein at least one point of one or more cooling channels is offset from the aperture by less than 15.0 mm.

[0101] A thirty-first aspect includes the beam accelerator system of aspects twenty-six to thirtieth, wherein a diameter of one or more cooling channels is greater than or equal to 0.5 mm and less than or equal to 5.0 mm.

[0102] Example

[0103] The embodiments will be further illustrated by the following examples.

[0104] The examples provided below were modeled using COMSOL software.

[0105] Example 1

[0106] With Figure 4 The plate with the cooling channel design shown was modeled, where the hole diameter was set to 10 mm and the hole power was set to 1 kW / cm 2 ; The cooling channel diameter was set to 3 mm; The cooling channel was offset from the hole by 9.525 mm; and the cooling liquid was set to water with an inlet temperature of 20°C.

[0107] The above simulation was performed with the cooling channel having a circular cross-sectional shape and a smooth interior, and the simulation was performed again under the same conditions but with the interior of the channel having a circular cross-sectional shape and a vortex design on the interior of the cooling channel. Fig. 10A Results showing a simulation of a cooling channel with a smooth interior. Fig. 10B Shown are the results of a simulation with a swirl design on the interior of a cooling channel.

[0108] Fig. 10A The graph in provides a comparison of temperature (°C) on the left y-axis and cooling water flow rate (gal / min) on the x-axis for maximum hole temperature and maximum cooling channel temperature. Fig. 10A The graph in Figure 1 provides a plot of the pressure drop in the cooling channel (psi) on the right y-axis versus the cooling water flow rate (gal / min) on the x-axis. Fig. 10A As shown, the pressure drop begins to increase rapidly at flow rates between 2.5 gal / min and 3.0 gal / min, while the bore temperature and cooling channel temperature tend to level off around flow rates between 2.5 gal / min and 3.0 gal / min.

[0109] Fig. 10B The graph in provides a comparison of temperature (°C) on the left y-axis and cooling water flow rate (gal / min) on the x-axis for maximum hole temperature and maximum cooling channel temperature. Fig. 10B The graph in Figure 1 provides a plot of the pressure drop in the cooling channel (psi) on the right y-axis versus the cooling water flow rate (gal / min) on the x-axis. Fig. 10BAs shown, the pressure drop begins to increase rapidly at flow rates between 2.5 gal / min and 3.0 gal / min, while the bore temperature and cooling channel temperature tend to level off around flow rates between 2.5 gal / min and 3.0 gal / min.

[0110] Fig. 10A and Fig. 10B The comparison shows that in the case of a vortex design (such as Fig. 10B In the cooling channel with a smooth interior (as shown in FIG. 1 ), at a lower cooling fluid flow rate, the temperature of the hole and the cooling channel is lower than that of the cooling channel with a smooth interior (as shown in FIG. Fig. 10A However, compared with the cooling channel design with a smooth interior cooling channel (such as Fig. 10A Compared with the cooling channel design with a vortex design inside the cooling channel (as shown in Fig. 10B As shown in Figure 2, the pressure drop increases faster.

[0111] Example 2

[0112] With Figure 7 The plate of the L-shaped channel design shown was modeled, where the hole diameter was set to 10 mm and the hole power was set to 1 kW / cm 2 ; The cooling channel diameter was set to 3 mm; The cooling channel was offset from the hole by 9.525 mm; and The cooling liquid was set to water with an inlet temperature of 20° C. The interior of the cooling channel had a circular cross-sectional shape and a smooth inner surface.

[0113] Fig.11 The graph in provides a comparison of temperature (°C) on the left y-axis and cooling water flow rate (gal / min) on the x-axis for maximum hole temperature and maximum cooling channel temperature. Fig.11 The graph in Figure 1 provides a plot of the pressure drop in the cooling channel (psi) on the right y-axis versus the cooling water flow rate (gal / min) on the x-axis. Fig.11 As shown, the pressure drop starts to increase rapidly at flow rates between 2.5 gal / min and 3.0 gal / min, while the bore temperature and cooling channel temperature tend to level off around flow rates between 2.5 gal / min and 3.0 gal / min.

[0114] like Fig. 10B and Fig.11As shown in the comparison of , the L-shaped channel design trades peak aperture temperature for peak cooling channel temperature. The L-shaped channel design has a much higher pressure drop (~95psi) than the cooling channel design with a smooth cooling channel interior in Example 1, but the L-shaped cooling channel design does not have as much pressure drop as the cooling channel design with a vortex design cooling channel interior of Example 1 (~40psi). The L-shaped channel design also has a maximum dissipation of 10-kw per plate. Therefore, the L-shaped channel design results in an aperture temperature similar to the design in Example 1 with a vortex design cooling channel interior, but the L-shaped cooling channel design has a smaller pressure drop.

[0115] Example 3

[0116] The following cooling channel designs were simulated:

[0117] Figure 4 The cooling channel design of , but wherein the cooling channel has a square cross-sectional shape and a smooth inner surface; and

[0118] Fig. 8A A U-shaped cooling channel design is shown, wherein the cooling channel has a circular cross-sectional shape and a smooth inner surface.

[0119] In each of the above designs, the hole diameter was set to 10 mm; the hole power was set to 1 kW / cm 2 ; The cooling channel diameter was set to 3 mm; The cooling channel was offset from the hole by 9.525 mm; and the cooling liquid was set to water with an inlet temperature of 20°C.

[0120] Figure 12 to Figure 14 The results of the above simulations and the simulations of Examples 1 and 2 are graphically depicted. Figure 12 to Figure 14 , the cooling channel design of Example 1 with a smooth interior is represented as “circular”, the cooling channel design with a square cross-sectional shape is represented as “square”, the cooling channel design of Example 1 with a vortex design interior is represented as “circular (vortex)”, the U-shaped cooling channel design is represented as “U-tube”, and the L-shaped cooling channel design of Example 2 is represented as “L-channel”.

[0121] Fig.12 Plotted graphically are maximum well temperature (°C) along the y-axis versus flow rate (gal / min) along the x-axis. Fig.13 The maximum cooling channel temperature along the y-axis is graphically depicted versus the flow rate (gal / min) along the x-axis. Fig.14 Inlet pressure (psi) versus flow rate (gal / min) is graphically depicted along the y-axis.

[0122] The circular cross-section channel with a smooth interior and the square cross-section cooling channel result in the highest temperatures in both the hole and the cooling channel, but have little effect on pressure. The circular cross-section cooling channel with a vortex design interior and the U-shaped cooling channel design both facilitate the lowest temperatures in both the hole and the cooling channel, but both come at a significant "cost" of pressure drop. The L-shaped cooling channel design provides a middle ground, where the pressure drop is not as significant as the circular cross-section cooling channel with a vortex design interior and the U-shaped cooling channel design, but the L-shaped cooling channel design provides lower peak temperatures at both the hole and the cooling channel than the circular cross-section cooling channel with a vortex design interior and the U-shaped cooling channel design.

[0123] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Therefore, this specification is intended to cover modifications and variations of the various embodiments described herein, as long as such modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A beam accelerator system, include: an ion accelerator, the ion accelerator generating an ion beam; Low pressure chamber; an anode adjacent to and fluidly connected to the low pressure chamber; a plasma window adjacent to and fluidly connected to the anode; as well as a cathode housing adjacent to and in fluid connection with the plasma window, wherein: The plasma window comprises a plurality of plates, each plate having an aperture that aligns with apertures in one or more adjacent plates to form a plasma channel; and One or more of the plurality of plates include an integral plate having a hole therein and one or more cooling channels entering the integral plate at a first side of the integral plate and exiting the integral plate at a second side of the integral plate, wherein the one or more cooling channels extend through a thickness of the integral plate.

2. The beam accelerator system according to claim 1, in: The one or more cooling channels include a first cooling channel and a second cooling channel; The first cooling channel is substantially parallel to the second cooling channel; and The first cooling channel is positioned on a first side of the bore and the second cooling channel is positioned on a second side of the bore.

3. The beam accelerator system according to claim 2, in, At least one of the first cooling channel and the second cooling channel has a smooth inner surface.

4. The beam accelerator system according to claim 2, in, At least one of the first cooling channel and the second cooling channel has a swirl design on an inner surface.

5. The beam accelerator system according to claim 2, in, The first cooling channel and the second cooling channel have circular cross-sectional areas.

6. The beam accelerator system according to claim 1, in, The plurality of plates are formed of a thermally conductive metal selected from the group consisting of copper, silver, aluminum, and tungsten.

7. The beam accelerator system according to claim 1, in, The inner wall of the hole is formed of a refractory metal.

8. The beam accelerator system according to claim 1, in, The holes have a diameter of 1.0 mm to 10.0 mm.

9. The beam accelerator system according to claim 1, in, At least one point of the one or more cooling channels is offset from the aperture by less than 15.0 mm.

10. The beam accelerator system according to claim 1, in, The one or more cooling channels have a diameter greater than or equal to 0.5 mm and less than or equal to 5.0 mm.

11. A beam accelerator system, include: an ion accelerator, the ion accelerator generating an ion beam; Low pressure chamber; an anode adjacent to and fluidly connected to the low pressure chamber; a plasma window adjacent to and fluidly connected to the anode; as well as a cathode housing adjacent to and in fluid connection with the plasma window, wherein: The plasma window comprises a plurality of plates, each plate having an aperture that aligns with apertures in one or more adjacent plates to form a plasma channel; and One or more plates of the plurality of plates include a first cooling channel and a second cooling channel, the first cooling channel and the second cooling channel extending through a thickness of the one or more plates, the first cooling channel and the second cooling channel entering the one or more plates at a first side of the one or more plates and exiting the one or more plates at a second side of the one or more plates, wherein: the first cooling passage enters the one or more plates at the first side of the one or more plates, extends adjacent to the first side of the hole, turns in a first direction to extend adjacent to the second side of the hole, turns in a second direction and extends to exit the one or more plates at the second side of the one or more plates, and The second cooling passage enters the one or more plates at the first side of the one or more plates and extends to a third side of the hole, turns in the first direction to extend adjacent to the third side of the hole, turns in the second direction to extend adjacent to a fourth side of the hole, and exits at the second side of the one or more plates.

12. The beam accelerator system according to claim 11, in, The longitudinal axis of the first cooling passage is located along a centerline that bisects a cross-section of the bore.

13. The beam accelerator system according to claim 11, in, The plurality of plates are formed of a thermally conductive metal selected from the group consisting of copper, silver, aluminum, and tungsten.

14. The beam accelerator system according to claim 11, in, The inner wall of the hole is formed of a refractory metal.

15. The beam accelerator system according to claim 11, in, The holes have a diameter of 1.0 mm to 10.0 mm.

16. The beam accelerator system according to claim 11, in, At least one point of the first cooling channel or the second cooling channel is offset from the hole by less than 15.0 mm.

17. The beam accelerator system according to claim 11, in, A diameter of at least one of the first cooling channel and the second cooling channel is greater than or equal to 0.5 mm and less than or equal to 5.0 mm.

18. A beam accelerator system, include: an ion accelerator, the ion accelerator generating an ion beam; Low pressure chamber; an anode adjacent to and fluidly connected to the low pressure chamber; a plasma window adjacent to and fluidly connected to the anode; as well as a cathode housing adjacent to and in fluid connection with the plasma window, wherein: The plasma window comprises a plurality of plates, each plate having an aperture that aligns with apertures in one or more adjacent plates to form a plasma channel; and One or more of the plurality of plates comprises a first cooling channel, a second cooling channel, and a third cooling channel, the first cooling channel, the second cooling channel, and the third cooling channel extending through a thickness of the one or more plates, wherein: the first cooling channel enters the one or more plates at a first side of the one or more plates, extends to a first side of the hole and divides into the second cooling channel and the third cooling channel; the second cooling passage extending in a first direction adjacent to the first side of the aperture to a second side of the aperture, turning in a second direction and extending adjacent to the second side of the aperture, and exiting the one or more plates at a second side of the one or more plates; and The third cooling channel extends in a third direction adjacent to the first side of the hole to a third side of the hole, turns to the second direction and extends adjacent to the third side of the hole, and exits the one or more plates at the second side of the one or more plates.

19. The beam accelerator system according to claim 18, in, The first direction and the third direction are substantially perpendicular to the first cooling channel.

20. The beam accelerator system according to claim 18, in, The second direction is substantially parallel to the first direction.

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