Systems and methods for using exchangeable ion beam targets - Patents.com

Abstract

To provide systems and methods employing interchangeable ion beam targets.SOLUTION: Provided herein are multiple systems and multiple methods for generating multiple different monoenergetic neutron energies using multiple interchangeable ion beam targets. In certain embodiments, each of the multiple ion beam targets is configured to generate a monoenergetic energy value that is at least 100 kiloelectron volts (keV) different from the other ion beam targets. In some embodiments, the multiple ion beam targets comprise LiF, TiD1.5-1.8, TiT1-2, ErD1.5, ErT, or Li.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Application No. 62 / 869,337, filed July 1, 2019, which is incorporated herein by reference in its entirety.

[0002] Provided herein are systems and methods for generating a variety of monoenergetic neutron energies using a plurality of interchangeable ion beam targets. In certain embodiments, each of the plurality of ion beam targets is configured to generate a monoenergetic energy value that differs from the other ion beam targets by at least 100 kiloelectron volts (keV). In some embodiments, the plurality of ion beam targets include LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li. [Background technology]

[0003] Neutron radiography and tomography are proven techniques for non-destructive testing and quality control of manufactured parts in aerospace, energy, automotive, defense and other sectors. Like x-rays, when neutrons pass through an object, they provide information about the internal structure of that object. Neutrons can easily pass through many high density materials, providing detailed information about the interior materials. This includes many low density materials. This property is crucial for many parts requiring non-destructive evaluation, including jet engine turbine blades, satellite parts, munitions, aircraft and spacecraft parts, and composite materials. Summary of the Invention

[0004] Provided herein are systems and methods for generating a variety of monoenergetic neutron energies using a plurality of interchangeable ion beam targets. In certain embodiments, each of the plurality of ion beam targets is configured to generate a monoenergetic energy value that differs from the other ion beam targets by at least 100 kiloelectron volts (keV) (or differs by 10-90 keV). In some embodiments, the plurality of ion beam targets include LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li.

[0005] In some embodiments, provided herein are systems for generating a plurality of monoenergetic neutron energy targets, the systems comprising: a) an ion source configured to produce an ion beam; b) an accelerator operatively coupled to the ion source and configured to receive the ion beam and accelerate the ion beam to generate an accelerated ion beam; c) a target station comprising a target holding mechanism; and d) a plurality of interchangeable ion beam targets, each of the plurality of interchangeable ion beam targets i) configured to be held by the target holding mechanism, and ii) configured to generate a plurality of neutrons when struck by the accelerated ion beam, the plurality of interchangeable ion beam targets collectively providing a plurality of neutrons having monoenergetic neutron energy values ​​in a range ranging from at least 300 kiloelectron volts (keV) (or at least 150-250 keV).

[0006] In a specific embodiment, each of the plurality of interchangeable ion beam targets is selected from the group consisting of LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5, ErT and / or Li, LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT and / or Li, or LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT, and / or Li. In other embodiments, each of the plurality of switchable ion beam targets iii) has a unique thickness among the plurality of ion beam targets. In further embodiments, the plurality of switchable ion beam targets collectively provide a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 1 MegaelectronVolt (MeV) (e.g., at least 1...1.5...2.0...4.5...7.0...or 9.0 MeV). In certain embodiments, the plurality of switchable ion beam targets collectively provide a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 10 MegaelectronVolts (e.g., at least 10...12...15...or 20 MegaelectronV).

[0007] In certain embodiments, the monoenergetic neutron energy of each of the plurality of exchangeable ion beam targets differs from one another by at least 100 keV (e.g., at least 100...200...400...800...or 2000 keV). In further embodiments, the monoenergetic neutron energy of each of the plurality of exchangeable ion beam targets differs from one another by at least 500 keV. In some embodiments, the plurality of exchangeable ion beam targets includes at least three ion beam targets (e.g., at least 3, 4, 5, 6, 7, 8, or 9). In other embodiments, the plurality of exchangeable ion beam targets includes at least six ion beam targets (e.g., at least 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15). In certain embodiments, the plurality of interchangeable ion beam targets include: i) a first ion beam target that generates a monoenergetic neutron energy value of about 300 keV, ii) a second ion beam target that generates a monoenergetic neutron energy value of about 1 MeV, iii) a third ion beam target that generates a monoenergetic neutron energy value of about 2.5 MeV, iv) a fourth ion beam target that generates a monoenergetic neutron energy value of about 4 MeV, v) a fifth ion beam target that generates a monoenergetic neutron energy value of about 6 MeV, and vi) a sixth ion beam target that generates a monoenergetic neutron energy value of about 14 MeV. In some embodiments, monoenergetic neutron energy values ​​between the aforementioned values ​​are employed (e.g., 700 keV, 2.3 MeV, 3.1 MeV, 5.2 MeV, and 12.3 MeV).

[0008] In some embodiments, the plurality of systems further comprises a control system, the control system comprising software configured to vary incident ion energy of the accelerated ion beam based on which of the plurality of interchangeable ion beam targets is held by the target holding mechanism. In other embodiments, the plurality of systems further comprises a test facility configured to scan an item with the plurality of neutrons. In certain embodiments, the item is selected from the group consisting of a space system, a space instrument, an aircraft part, an infrastructure, and a transportation system part. In certain embodiments, the plurality of systems further comprises a collimator. In other embodiments, the target station further comprises a water cooling system.

[0009] In some embodiments, provided herein are methods including: a) inserting a first target from a set of at least two ion beam targets into an ion beam accelerator that generates an accelerated ion beam; b) operating the ion beam accelerator for a length of time such that the accelerated ion beam impacts the first target, thereby generating a plurality of neutrons having a first monoenergetic neutron energy value; c) removing the first target from the ion beam accelerator; d) inserting a second target from the set of at least two targets into the ion beam accelerator; and e) operating the ion beam accelerator for a length of time (and at a particular energy) such that the ion beam impacts the second target, thereby generating a plurality of neutrons having a second monoenergetic neutron energy value that differs from the first monoenergetic neutron energy value by at least 100 kiloelectron volts (keV). In other embodiments, the second monoenergetic neutron energy value differs from the first monoenergetic neutron energy value by at least 500 kiloelectronvolts (keV) (eg, at least 500...1000...2000...10,000 keV).

[0010] In some embodiments, the at least two ion beam targets include at least three ion beam targets, and the method further includes: f) removing the second target from the ion beam accelerator; g) inserting a third target from the set of at least three targets into the ion beam accelerator; and h) operating the ion beam accelerator for a length of time such that an ion beam impacts the third target, thereby producing a plurality of neutrons having a third monoenergetic neutron energy value that differs from both the first and second monoenergetic neutron energy values ​​by at least 100 kiloelectron volts (keV). In further embodiments, the third monoenergetic neutron energy value differs from both the first and second monoenergetic neutron energy values ​​by at least 500 kiloelectron volts.

[0011] In some embodiments, the at least three ion beam targets include at least four ion beam targets, and the method further includes: i) removing the third target from the ion beam accelerator; j) inserting a fourth target from the set of at least four targets into the ion beam accelerator; and k) operating the ion beam accelerator for a length of time such that an ion beam impacts the fourth target, thereby producing a plurality of neutrons having a fourth monoenergetic neutron energy value that differs from all of the first, second, and third monoenergetic neutron energy values ​​by at least 100 kiloelectron volts (keV). In some embodiments, the fourth monoenergetic neutron energy value differs from all of the first, second, and third monoenergetic neutron energy values ​​by at least 500 kiloelectron volts. In some embodiments, the steps are repeated for a fifth, sixth, seventh, or more ion beam targets.

[0012] In some embodiments, each of the plurality of ion beam targets is selected from the group consisting of LiF, TiD 1.5-1.8 , TiT1-2 ,ErD 1.5 , ErT or Li, LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li, or LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT, or Li. In other embodiments, each of the at least four ion beam targets has a unique thickness among the first, second, third, and fourth ion beam targets. In further embodiments, the at least four ion beam targets collectively provide a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 5 or 10 megaelectron volts (MeV) (e.g., at least 5...7...10...15...20...or 30 MeV). In certain embodiments, the method further comprises scanning an item with the plurality of neutrons having a first monoenergetic neutron energy value between steps b) and c) (or between steps g) and h), or between steps j) and k). In some embodiments, the item is selected from the group consisting of a space system, a space instrument, an aircraft part, an infrastructure, and a part of a transportation system. In certain embodiments, each of the at least two, or at least three, or at least four ion beam targets produces a different monoenergetic neutron energy value selected from the group consisting of about 300 keV, about 1 MeV, about 2.5 MeV, about 4 MeV, about 6 MeV, and about 14 MeV.

[0013] In some embodiments, provided herein are systems comprising: a) a computer processor; b) a non-transitory computer memory including one or more computer programs and a database, the one or more computer programs including accelerator system operation software; and c) an ion beam accelerator system including one or more of the following subsystems in operative communication with the non-transitory computer memory: i) a target station including a target holding mechanism configured to hold one of a plurality of ion beam targets; and ii) a beam generating subsystem that generates an ion beam having an intensity adjusted by the accelerator system operation software based on which of the plurality of ion beam targets is present within the ion beam accelerator system, the ion beam accelerator system being capable of being automatically adjusted by the accelerator system operation software to capture a particular ion beam target present within the ion beam accelerator system selected from the plurality of ion beam targets. [Brief description of the drawings]

[0014] The patent or patent application contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. [Figure 1] 1 shows an exemplary schematic diagram of an accelerator system installed at a test facility. [Diagram 2] FIG. 1 shows an exemplary box diagram of the accelerator system, test facility and control components. [Figure 3A] 1 illustrates an exemplary portion of an accelerator system including a target station in a non-cross-sectional view. [Figure 3B] Certain components of an exemplary portion of an accelerator system including a target station are shown in cross-sectional view. [Figure 4A]An exemplary embodiment is shown in which a beam dump blocks the beam line so that it cannot then strike the target. [Figure 4B] It shows how the beam dump can be retracted to allow the beam to continue on to the collimator and target. [Diagram 5] 1 illustrates a cross-sectional view of an exemplary target station. [Figure 6A] FIG. 2 illustrates a top view of an exemplary target-retaining flange for use in the systems herein. [Figure 6B] 1 illustrates a cross-sectional view of an exemplary target-retaining flange for use in the systems herein. [Figure 7] 1 illustrates a cross-sectional view of an exemplary target station. [Figure 8] 1 illustrates an exemplary four-finger collimator and holding mechanism. [Figure 9] Neutron energy spectrum target modeling for 2 cm from a p-LiF target at 300 keV is shown, showing the flux vs. energy relationship for various target thicknesses. [Figure 10] Neutron energy spectrum target modeling for 2 cm from a p-LiF target at 400 keV is shown, showing the flux vs. energy relationship for various target thicknesses. [Figure 11] Neutron energy spectrum target modeling for 2 cm from a p-LiF target at 500 keV is shown, showing the flux vs. energy relationship for various target thicknesses. [Figure 12] Neutron energy spectrum target modeling for 2 cm from a p-LiF target at 1 MeV is shown, showing the relationship between flux and energy for various target thicknesses. [Figure 13]Neutron energy spectrum target modeling for 2 cm from a p-LiF target at 2.5 MeV is shown, showing the relationship between flux and energy for various target thicknesses. [Figure 14] Neutron energy spectrum target modeling for 2 cm from a p-LiF target at 3.9 MeV is presented, showing the flux vs. energy relationship for various target thicknesses. [Figure 15] Neutron energy spectrum target modeling for 2 cm from a d-TiD1.5 target at 4 MeV is shown, showing the flux vs. energy relationship for various target thicknesses. [Figure 16] Neutron energy spectrum target modeling for 2 cm from a d-TiD1.5 target at 6 MeV is shown, showing the flux vs. energy relationship for various target thicknesses. [Figure 17] Neutron energy spectrum target modeling for 2 cm from a d-LiF target at 15 MeV is shown, showing the flux vs. energy relationship for various target thicknesses. [Figure 18] Neutron energy spectrum target modeling for 30 cm from a p-LiF target at 300 keV is shown, showing the relationship between flux and energy for various target thicknesses. [Figure 19] Neutron energy spectrum target modeling for 30 cm from a p-LiF target at 400 keV is shown, showing the relationship between flux and energy for various target thicknesses. [Figure 20] Neutron energy spectrum target modeling for 30 cm from a p-LiF target at 500 keV is shown, showing the relationship between flux and energy for various target thicknesses. [Figure 21]Neutron energy spectrum target modeling for 30 cm from a p-LiF target at 1 MeV is shown, with flux vs. energy for various target thicknesses. [Figure 22] Neutron energy spectrum target modeling for 30 cm from a p-LiF target at 2.5 MeV is shown, with flux vs. energy for various target thicknesses. [Figure 23] Neutron energy spectrum target modeling for 30 cm from a p-LiF target at 3.9 MeV is shown, with flux vs. energy for various target thicknesses. [Figure 24] Neutron energy spectrum target modeling for 30 cm from a d-TiD1.5 target at 4 MeV is shown, showing the relationship between flux and energy for various target thicknesses. [Diagram 25] Neutron energy spectrum target modeling for 30 cm from a d-TiD1.5 target at 6 MeV is presented, showing the relationship between flux and energy for various target thicknesses. [Figure 26] Neutron energy spectrum target modeling for 30 cm from a d-LiF target at 15 MeV is shown, showing the relationship between flux and energy for various target thicknesses. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Provided herein are systems and methods for generating a variety of monoenergetic neutron energies using a plurality of interchangeable ion beam targets. In certain embodiments, each of the plurality of ion beam targets is configured to generate a monoenergetic energy value that differs from the other ion beam targets by at least 100 kiloelectron volts (keV). In some embodiments, the plurality of ion beam targets include LiF, TiD 1.5-1.8, TiT 1-2 ,ErD 1.5 , ErT or Li.

[0016] In certain embodiments, provided herein is a single neutron system with various neutron energies for use in radiation effects testing and neutron scanning. In certain embodiments, systems and parts are scanned for radiation and / or internal defects, including but not limited to space systems and equipment (e.g., satellites and satellite parts), materials and parts that may be subject to radiation damage, materials and parts that may be subject to radiation damage, functional / electronic systems used in civil nuclear power plants (e.g., equipment nuclearization), infrastructure (e.g., lightning hardening), systems that may be sensitive to natural radiation environments (e.g., atmospheric neutrons), especially in terms of reliability (e.g., vehicles), and systems that need to handle threats from directed energy weapons (e.g., High Power Microwave). In some embodiments, the systems and embodiments herein allow for evaluation of the behavior of a component under a number of different neutron irradiation values ​​(e.g., 14 MeV, 6 MeV, 4 MeV, 2.5 MeV, 1 MeV and 300 keV neutron irradiation). In Table 1, exemplary neutron energies with corresponding exemplary neutron fluxes are provided.

[0017] [Table 1]

[0018] In certain embodiments, multiple different ion beam targets are used that can be exchanged within a single accelerator system. In some embodiments, LiF targets of different thicknesses are used (e.g., for 300 keV, 400 keV, 500 keV, 1 MeV, 2.5 MeV and 15 MeV neutrons in Table 1). In certain embodiments, TiD1.5 targets of different thicknesses are used (e.g., for 4 MeV and 6 MeV neutrons in Table 1). Any type of suitable accelerator system can be used herein, such as an adjustable commercial tandem accelerator system provided by National Electrostatics Corporation (NEC). The performance specifications of an exemplary accelerator system are shown in Table 2 below.

[0019] [Table 2]

[0020] In certain embodiments, the systems herein use a single beamline, while in other embodiments, multiple beamlines are used with multiple target stations. In certain embodiments, a pure lithium ion beam target is used.

[0021] Any type of suitable ion source may be used with the systems herein. In certain embodiments, a proton or deuteron ion source (e.g., with a toroidal discharge chamber) is used. In certain embodiments, the ion source power supply and two molecular pumps (e.g., 650 l / s turbo) with gate valves (isolation valves) and backing pumps are biased up, e.g., to -60 kV. In certain embodiments, two 4.2 kVA rated isolation transformers are used to deliver AC power to the ion source pumps and power supplies. In some embodiments, an insulating fluid is pumped in a closed loop from ground potential to the ion source for cooling. In certain embodiments, one or more of the following system components are used: extractor, acceleration gap, and einzel lens assembly; pre-acceleration tube; bias isolation power supply; Y-steerer; faraday cup; and process control and power supplies.

[0022] In certain embodiments, magnetic field deflection is used to mass analyze the ion beam from the ion source in conjunction with a low energy beamline in the system. In some embodiments, an electrostatic X-Y steerer and an Einzel lens are provided to direct the mass analyzed beam to the accelerator stripper tube. In certain embodiments, the system uses one or more of the following: inflection magnets; lenses, beam steerers; Faraday cups; beam profile monitors; and controllers.

[0023] Any type of suitable accelerator may be used in the methods and systems herein. In certain embodiments, the accelerator is a tandem electrostatic accelerator (e.g., capable of delivering energies of 0.4-6.0 MeV for singly charged ions). In some embodiments, four high performance charging chain systems are installed in the column to provide a conservative 600 μA current to the high voltage terminals. The charging chains efficiently deliver current to the gas with much less energy loss than would be the case for belts. As a result, high charging currents can be provided with relatively modest power inputs without introducing difficult cooling problems. In certain embodiments, the accelerating tubes are of robust metal and ceramic construction and are bakeable to moderate temperatures. They can be operated at pressures approximately 100 times lower than those typically achieved in tubes sealed with organic cement. This is advantageous for high current applications where backflow electrons from ionization of gas molecules can provide a total current drain many times greater than the ion beam current. The tube does not require ramp fields or high tube pressures to allow successful operation. In certain embodiments, the vacuum system with the accelerator is made of all metal and ceramic construction (e.g., excluding the ion source, turbomolecular pumps, and gate valves) and is capable of ultra-high vacuum operation. In some embodiments, the design goal for this vacuum system is to achieve a vacuum of 1×10 in the absence of an ion beam. -8 Torr and 5 × 10 -8 Torr. In certain embodiments, the acceleration system includes at least one of the following components: a tank, a column, a terminal, a shorting rod system, a charging system, a voltage stabilization system, an acceleration tube and a vacuum system, a potential distribution, and an insulating gas (e.g., Sf6).

[0024] In certain embodiments, the post-acceleration beamline includes the necessary components to steer and focus the proton / deuteron beams into various targets for neutron production, in some embodiments, the system provides interchangeable target disks on a target assembly into a single permanent target station, as described further below.

[0025] In certain embodiments, the systems and methods herein use a target station in which various targets can be placed. An exemplary target station is shown in FIG. 3 as mounted on a portion of an accelerator system. In certain embodiments, when the target is not being irradiated, the beam will hit a beam dump controlled by an air actuated linear feedthrough as shown in FIG. 4A (e.g., 100% of the beam is collected into the beam dump and the current is measured). In certain embodiments, the beam dump can be retracted to allow the beam to continue on (e.g., into a four finger collimator as shown in FIG. 4B). In some embodiments, when the beam current hits the collimator (e.g., a four finger collimator), it is measured and subtracted from the beam dump current measurement to calculate the exact beam current on the target. As shown in FIG. 4A, the beam passes through the four finger collimator and hits the neutron generating target.

[0026] In certain embodiments, at least one viewport is included as part of the target station, allowing the target to be visualized (e.g., as shown in cross-sectional view in FIG. 5). In some embodiments, target health monitoring is performed indirectly by measuring at least one of the following: the use of an energy-resolving planar silicon charged particle detector mounted within the target retaining flange, the output from this detector and an external long detector being used in concert to monitor neutron output; target chamber pressure; fast gate valve position; target coolant flow in; target coolant flow out; target coolant temperature in; target coolant temperature out; an nominal neutron flux.

[0027] In some embodiments, the replaceable ion beam target herein is placed in a target holding flange as shown in FIG. 6. Typically, the heat load is very high on the target, making it difficult to achieve sufficient and uniform cooling by mounting the target in a cooled target holder. Thus, in some embodiments, direct water cooling of a tantalum substrate, which typically contains a thin target material, is employed. Two exemplary designs of ion beam targets are as follows: First, in certain embodiments, a single integrated target assembly consisting of a tantalum disk with internal cooling lines is used to hold the target. The target is mounted and held rigidly in place by a water cooling line that is a vacuum coupling radiation (VCR) type fitting. The cooling water system, in certain embodiments, has features that ensure that water is completely removed from the water line before changing the target assembly. Second, in some embodiments, the target is composed of a thin (~3 mm) tantalum disk and an ion beam target mounted and sealed to a target holder that exposes the backside of the target directly to the cooling water. In certain embodiments, the target relies on an all-metal "O-ring" seal. In this case, the target holder present in the target holder flange is not usually replaced with the target change. However, regular maintenance / replacement is generally adopted. The distance between the LiF or TiD1.5 (or other materials such as pure lithium) target surface and the open space outside the vacuum chamber available for component irradiation is about 15 mm in certain embodiments. Furthermore, the outer surface of the target station where the components are irradiated is flat and free or protruding in some embodiments, which allows for the placement of large components directly towards the irradiation surface of the target station.

[0028] In certain embodiments, the target station design employs one beam line impinging on a single target to produce the desired reaction. The target may be replaced with another target for various reactions. In some embodiments, the procedure for changeover involves the following steps: 1) close the standard gate valve between the target and the fast valve that isolates the pumping station from the target area; 2) vent the target area; 3) remove the back target flange, the four-finger collimator will stay in place unless it is serviced; 4) remove the target by loosening the two VCR-type nuts that attach the water cooling lines or by removing the target disk; 5) install the new target in the back flange by tightening the two VCR-type nuts; 6) reinstall the back target flange onto the four-finger collimator flange; 7) open the valve to the roughing pump, rough the target chamber, close the valve to the roughing pump; and 8) open the gate valve to the pumping stage (interlock may be performed only when sufficient pressure is achieved and the roughing pump valve is closed). In certain embodiments, the zero length flange that holds the four-finger collimator is attached by its own bolt pattern and remains securely attached to the target chamber during normal target changes (e.g., it would only be removed when the four-finger collimator requires servicing). In certain embodiments, the outer flange is a modified aluminum conflat with a stainless knife edge. In general, the majority of the time for a target change will be to remove and reinstall the conflat flange, which is the backing plate. In certain embodiments, the back flange is provided with a "quick door" with a single clamping mechanism and a polymer O-ring (e.g., which would be changed periodically due to neutron damage). In certain embodiments, if a conflat seal is employed, a vertical conflat gasket attachment is employed.

[0029] A comprehensive modeling study on the neutron energy and flux parameters shown in Table 1 above and shown again below (as Table 3) was conducted during development of the embodiments herein.

[0030] [Table 3]

[0031] The results of this modeling are shown in Figures 9-26. Note that in addition to the LiF and TiD1.5 modeled in Figures 9-26, pure lithium targets can also be used. In a particular embodiment, titanium with 1.5 deuterium atoms interstitially per titanium atom (TiD1.5) is used to maximize the flux of the DD reaction. There is often an inherent tradeoff between narrower energy bands and higher neutron flux, and vice versa. For many reactions, the modeling work shows various target thickness options to demonstrate the tradeoff. Other target thicknesses are also possible, depending on prioritization of energy spectrum vs. total flux. In this exemplary modeling, all reactions have a beam current of 175 uA. Both LiF and TiD1.5 are thin film deposition (solid) onto a tantalum backing.

[0032] In certain embodiments, an integrated control system is used with the neutron generating systems herein, including independent safety and / or control systems. In certain embodiments, software components are included in the control system, allowing changes to be made to accommodate different targets being swapped in and out. In certain embodiments, the software control automates the system sufficiently to allow an operator to select a particular ion beam target, and the system automatically compensates for the required distance of the ion beam to the target, and the intensity of the ion beam.

[0033] 1 shows an exemplary schematic diagram of an accelerator system installed at a test facility, where portion 10 shows a neutron generating target assembly, portion 20 shows a high energy beam transport assembly, portion 30 shows an ion beam accelerator, and portion 40 shows a low energy beam transport assembly. Also in this figure, portion 50 shows an ion source, portion 60 shows an auxiliary control cabinet, portion 70 shows radiation shielding, and portion 80 shows radiation shielding.

[0034] FIG. 2 shows an exemplary box diagram of the accelerator system, test facility and control components. As shown in this diagram, the monoenergetic neutron system is composed of the following components: an ion source (e.g., a TORVIS ion source), low energy beam transport components, an accelerator (e.g., a tandem accelerator), high energy beam transport, and a target station. The target station may be configured for LiF and TiD1.5 targets, for example. Also shown in this diagram is an integrated control system that controls all of the aforementioned components. The integrated control system is controlled by an operator who interacts with the system via a control console at the operator station.

[0035] 3 shows an exemplary portion of an accelerator system including a target station. The diagram shows that the beam (arrows) coming from the focusing and steering station passes through a turbo pump, a valve (e.g., a VAT Series 750 fast accelerator gate valve), and then enters a target chamber with a collimator (e.g., a four-finger collimator with calorimetric and current measurement systems) and a target (e.g., one of multiple interchangeable targets).

[0036] Figure 4A shows an example embodiment where a beam dump blocks the beam line in the target chamber so that it cannot then strike the target. Figure 4B shows how the beam dump can retract to allow the beam to continue on to the collimator and target. The beam dump is water cooled. When the beam is captured by the beam dump, it can be measured by a collimator (e.g., a four-finger collimator).

[0037] 5 shows a cross-sectional view of an exemplary target station. A collimator is shown in front of the target (e.g., a four-finger collimator).

[0038] FIG. 6 shows a top view (6A) and a cross-sectional view (6B) of an exemplary target retention flange for use in the systems herein. The outer ring ConFlat has alignment pins and can be constructed from stainless steel. The ConFlat flange can be constructed, for example, from stainless steel explosively bonded to aluminum. The target is mounted and held rigidly in place by a water cooling line that is a Vacuum Coupled Radiation (VCR) type fitting.

[0039] 7 shows a cross-sectional view of an exemplary target station, in which interleaved non-contact collimator leaves are shown above the ion beam target.

[0040] FIG. 8 shows an exemplary four-finger collimator and retention mechanism. The retention mechanism connections can be brazed ceramic for thermal and electrical insulation. A standard CF flange seal is shown along with four insulating cooling circuits for calorimetric measurements, and a pair of alignment pins. A four-finger collimator with a central tantalum proton sink and outer copper heat sinks is shown.

[0041] All publications and patents provided herein are incorporated by reference in their entirety. Various modifications and variations of the described structures and methods of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with certain preferred embodiments, it should be understood that the invention as claimed is not to be unduly limited to such specific embodiments. Indeed, various modifications to the described embodiments of the invention that are obvious to those skilled in the relevant arts are intended to be within the scope of the invention.

[0042] This disclosure also includes the following numbered clauses:

[0043] 1. 1. A system for producing a plurality of different monoenergetic neutron energies, comprising: a) an ion source configured to generate an ion beam; b) an accelerator operably coupled to the ion source and configured to receive the ion beam and accelerate the ion beam to generate an accelerated ion beam; c) a target station including a target holding mechanism; d) a plurality of interchangeable ion beam targets, each of the plurality of interchangeable ion beam targets comprising: i) configured to be held by the target-holding mechanism; and ii) generating a plurality of neutrons having a unique monoenergetic neutron energy value among the plurality of interchangeable ion beam targets when struck by the accelerated ion beam; the plurality of replaceable ion beam targets; Equipped with A system, wherein the plurality of interchangeable ion beam targets collectively provide a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 300 kiloelectron volts (keV) when struck by the accelerated ion beam.

[0044] 2. Each of the plurality of interchangeable ion beam targets comprises: LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li, LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li; Or LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li, 2. A system as described in clause 1.

[0045] 3. Each of the plurality of interchangeable ion beam targets comprises: iii) having a unique thickness among the plurality of ion beam targets; 2. A system as described in clause 1.

[0046] 4. 13. The system of claim 1, wherein the plurality of interchangeable ion beam targets collectively provide a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 1 megaelectronvolt (MeV).

[0047] 5. 13. The system of claim 1, wherein the plurality of interchangeable ion beam targets collectively provide a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 10 megaelectron volts.

[0048] 6. 2. The system of claim 1, wherein the monoenergetic neutron energies of each of the plurality of interchangeable ion beam targets differ from each other by at least 100 keV.

[0049] 7. 2. The system of claim 1, wherein the monoenergetic neutron energies of each of the plurality of interchangeable ion beam targets differ from each other by at least 500 keV.

[0050] 8. 13. The system of claim 1, wherein the plurality of interchangeable ion beam targets includes at least three ion beam targets.

[0051] 9. The plurality of interchangeable ion beam targets include: i) a first ion beam target producing monoenergetic neutron energy values ​​of about 300 keV; ii) a second ion beam target producing monoenergetic neutron energy values ​​of about 1 MeV; iii) a third ion beam target producing a monoenergetic neutron energy value of about 2.5 MeV; iv) a fourth ion beam target producing a monoenergetic neutron energy value of about 4 MeV; v) a fifth ion beam target producing a monoenergetic neutron energy value of about 6 MeV; and vi) a sixth ion beam target producing a monoenergetic neutron energy value of about 14 MeV; 2. The system of claim 1, comprising:

[0052] 10. Further comprising a control system; The system of claim 1, wherein the control system comprises software configured to vary the incident ion energy of the accelerated ion beam based on which of the plurality of interchangeable ion beam targets is held by the target holding mechanism.

[0053] 11. 13. The system of claim 1, further comprising a test facility configured to scan an item with the plurality of neutrons.

[0054] 12. 12. The system of claim 11, wherein the items are selected from the group consisting of space systems, space equipment, aircraft parts, infrastructure, materials and parts susceptible to radiation damage, and parts of transportation systems.

[0055] 13. 13. The system of claim 1, further comprising a collimator.

[0056] 14. 13. The system of claim 1, wherein the target station further comprises a water cooling system.

[0057] 15. a) inserting a first target from a set of at least two ion beam targets into an ion beam accelerator that generates an accelerated ion beam; b) operating the ion beam accelerator for an amount of time such that an accelerated ion beam impacts the first target, thereby producing a plurality of neutrons having a first monoenergetic neutron energy value; c) removing the first target from the ion beam accelerator; d) inserting a second target from the set of at least two targets into the ion beam accelerator; e) operating the ion beam accelerator for an amount of time such that the ion beam impacts the second target, thereby producing a plurality of neutrons having a second monoenergetic neutron energy value that differs from the first monoenergetic neutron energy value by at least 100 kiloelectron volts (keV); A method comprising:

[0058] 16. 16. The method of clause 15, wherein the second monoenergetic neutron energy value differs from the first monoenergetic neutron energy value by at least 500 kiloelectron volts.

[0059] 17. the at least two ion beam targets include at least three ion beam targets; f) removing the second target from the ion beam accelerator; g) inserting a third target from the set of at least three targets into the ion beam accelerator; h) operating the ion beam accelerator for an amount of time such that the ion beam impacts the third target, thereby producing a plurality of neutrons having a third monoenergetic neutron energy value that differs from both the first and second monoenergetic neutron energy values ​​by at least 100 kiloelectron volts (keV); 16. The method of claim 15, further comprising:

[0060] 18. 18. The method of claim 17, wherein the third monoenergetic neutron energy value differs from the first and second monoenergetic neutron energy values ​​by at least 500 kiloelectron volts.

[0061] 19. the at least three ion beam targets include at least four ion beam targets; i) removing the third target from the ion beam accelerator; j) inserting a fourth target from the set of at least four targets into the ion beam accelerator; k) operating the ion beam accelerator for an amount of time such that an ion beam impacts the fourth target, thereby producing a plurality of neutrons having a fourth monoenergetic neutron energy value that differs from all of the first, second and third monoenergetic neutron energy values ​​by at least 100 kiloelectron volts (keV); 18. The method of claim 17, further comprising:

[0062] 20. 20. The method of claim 19, wherein the fourth monoenergetic neutron energy value differs from the first, second and third monoenergetic neutron energy values ​​by at least 500 kiloelectron volts.

[0063] twenty one. Each of the plurality of ion beam targets is LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li, LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 , ErT or Li; Or LiF, TiD 1.5-1.8 , TiT 1-2 ,ErD 1.5 21. The method according to any one of clauses 15 to 20, wherein the compound essentially consists of ErT or Li.

[0064] twenty two. 20. The method of claim 19, wherein each of the at least four ion beam targets has a unique thickness among the first, second, third and fourth ion beam targets.

[0065] twenty three. 20. The method of claim 19, wherein a ensemble of the at least four ion beam targets provides a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 10 megaelectronvolts (MeV).

[0066] twenty four. 16. The method of claim 15, further comprising between steps b) and c) scanning an item with the plurality of neutrons having a first monoenergetic neutron energy value.

[0067] twenty five. 25. The method of claim 24, wherein the items are selected from the group consisting of space systems, space equipment, aircraft parts, infrastructure, and parts of transportation systems.

[0068] 26. 20. The method of claim 19, wherein each of the at least four ion beam targets produces a different monoenergetic neutron energy value selected from the group consisting of about 300 keV, about 1 MeV, about 2.5 MeV, about 4 MeV, about 6 MeV and about 14 MeV.

[0069] 27. a) a computer processor; b) non-transitory computer memory containing one or more computer programs and a database, the one or more computer programs including accelerator system operating software; and c) a plurality of subsystems in operative communication with said non-transitory computer memory, including: i) a target station including a target holding mechanism configured to hold one of a plurality of ion beam targets; and ii) a beam generation subsystem that generates an ion beam having an intensity that is adjusted by the accelerator system operating software based on which of the plurality of ion beam targets is present within the ion beam accelerator system; wherein the ion beam accelerator system can be automatically adjusted by the accelerator system operating software to capture a particular ion beam target present within the ion beam accelerator system selected from the plurality of ion beam targets; A system comprising:

Claims

1. a) inserting a first target from a set of at least two ion beam targets into an ion beam accelerator that generates an accelerated ion beam; b) operating the ion beam accelerator for an amount of time such that an accelerated ion beam impacts the first target, thereby producing a plurality of neutrons having a first monoenergetic neutron energy value; c) removing the first target from the ion beam accelerator; d) inserting a second target from the set of at least two targets into the ion beam accelerator; e) operating the ion beam accelerator for an amount of time such that an ion beam impacts the second target, thereby producing a plurality of neutrons having a second monoenergetic neutron energy value that differs from the first monoenergetic neutron energy value by at least 100 kiloelectron volts (keV); A method comprising:

2. 2. The method of claim 1, wherein the second monoenergetic neutron energy value differs from the first monoenergetic neutron energy value by at least 500 kiloelectron volts.

3. the at least two ion beam targets include at least three ion beam targets; f) removing the second target from the ion beam accelerator; g) inserting a third target from the set of at least three targets into the ion beam accelerator; h) operating the ion beam accelerator for an amount of time such that an ion beam impacts the third target, thereby producing a plurality of neutrons having a third monoenergetic neutron energy value that differs from both the first and second monoenergetic neutron energy values ​​by at least 100 kiloelectron volts (keV); The method of claim 1 further comprising:

4. 4. The method of claim 3, wherein the third monoenergetic neutron energy value differs from the first and second monoenergetic neutron energy values ​​by at least 500 kiloelectron volts.

5. the at least three ion beam targets include at least four ion beam targets; i) removing the third target from the ion beam accelerator; j) inserting a fourth target from the set of at least four targets into the ion beam accelerator; k) operating the ion beam accelerator for an amount of time such that an ion beam impacts the fourth target, thereby producing a plurality of neutrons having a fourth monoenergetic neutron energy value that differs from all of the first, second and third monoenergetic neutron energy values ​​by at least 100 kiloelectron volts (keV); The method of claim 3 further comprising:

6. 6. The method of claim 5, wherein the fourth monoenergetic neutron energy value differs from the first, second and third monoenergetic neutron energy values ​​by at least 500 kiloelectron volts.

7. Each of the plurality of ion beam targets is LiF, TiD １．５－１．８ , TiT １－２ , ErD １．５ 7. The method of claim 1, comprising: ErT or Li.

8. The method of claim 5 , wherein each of the at least four ion beam targets has a unique thickness among the first, second, third and fourth ion beam targets.

9. 6. The method of claim 5, wherein a ensemble of the at least four ion beam targets provides a plurality of neutrons having monoenergetic neutron energy values ​​ranging from at least 10 megaelectronvolts (MeV).

10. 2. The method of claim 1, further comprising between steps b) and c) scanning an item with the plurality of neutrons having a first monoenergetic neutron energy value.

11. The method of claim 10 , wherein the item is selected from the group consisting of a space system, a space instrument, an aircraft part, an infrastructure, and a part of a transportation system.

12. 6. The method of claim 5, wherein each of the at least four ion beam targets produces a different monoenergetic neutron energy value selected from the group consisting of 300 keV, 1 MeV, 2.5 MeV, 4 MeV, 6 MeV and 14 MeV.

13. a) a computer processor; b) a non-transitory computer memory containing one or more computer programs and a database, the one or more computer programs including accelerator system operating software; and c) a plurality of subsystems in operative communication with said non-transitory computer memory, including: i) a target station comprising a target holding mechanism configured to hold one of a plurality of ion beam targets; and ii) a beam generation subsystem that generates an ion beam having an intensity that is adjusted by the accelerator system operating software based on which of the plurality of ion beam targets is present within the ion beam accelerator system; wherein the ion beam accelerator system can be automatically adjusted by the accelerator system operating software to capture a particular ion beam target present within the ion beam accelerator system selected from the plurality of ion beam targets; A system comprising:

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