A single particle effect simulation irradiation device based on a heavy ion cyclotron

Abstract

The present invention relates to a single particle effect simulation irradiation device based on a heavy ion cyclotron, belonging to the technical field of radiation hardening. The device includes a mixed beam switching module, a beam line beam expansion module, a diagnostic target chamber and an irradiation target chamber. A beam current on-line monitoring module is provided in the diagnostic target chamber, and a beam current measurement module is provided in the irradiation target chamber. They are all connected through pipelines. The mixed beam switching module is used to quickly provide a single ion beam current. After being expanded by the beam line beam expansion module, a large-area uniform single ion beam current is obtained. The expanded single ion beam current is irradiated onto the device under test in the irradiation target chamber. During the irradiation process, the fluence / fluence rate and beam spot uniformity of the single ion beam current are monitored by the beam current on-line monitoring module, and the beam current energy and fluence rate are measured by the beam current measurement module. Using the device provided by the present invention can solve problems such as the generation of a large-area uniform beam spot, extraction to the irradiation target chamber for irradiation, and rapid sample change.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiation hardening, and particularly relates to a single event effect simulation irradiation device based on a heavy ion cyclotron. Background Art

[0002] The single event effect of space radiation refers to the phenomenon that a single high-energy charged particle in space hits the sensitive part of a microelectronic device. Due to ionization, the device generates extra charges or causes atomic displacement of the material, resulting in a change in its logical state, interference or failure of its function. With the development of the space industry, the hazards caused by the single event effect have become increasingly significant. According to relevant statistical data, among the failures of spacecraft, the failures related to the space radiation environment account for 71% of the total number of failures, and the single event effect accounts for 55% of the radiation failures.

[0003] Ground simulation experiments are an important means to study the single event effect. The single event effect experiment requires a relatively low particle fluence rate, a relatively large beam spot area, and high uniformity requirements. Therefore, it is necessary to build a special beam line to meet these requirements and solve the key technologies such as the generation of a large-area uniform beam spot, extraction to the irradiation target chamber for irradiation, and rapid sample replacement. Summary of the Invention

[0004] To solve the defects existing in the prior art, the purpose of the present invention is to provide a single event effect simulation irradiation device based on a heavy ion cyclotron. Using this device can solve the key technologies such as the generation of a large-area uniform beam spot, extraction to the irradiation target chamber for irradiation, and rapid sample replacement.

[0005] To achieve the above purpose, a technical solution adopted by the present invention is:

[0006] A single event effect simulation irradiation device based on a heavy ion cyclotron, characterized in that the device includes a mixed beam switching module, a beam line beam expansion module, a diagnostic target chamber, and an irradiation target chamber. A beam current online monitoring module is arranged in the diagnostic target chamber, and a beam current measurement module is arranged in the irradiation target chamber. The mixed beam switching module and the beam line beam expansion module, the beam line beam expansion module and the diagnostic target chamber, and the diagnostic target chamber and the irradiation target chamber are all connected by pipelines;

[0007] The device under test is placed in the irradiation target chamber. The mixed beam switching module is used to quickly provide the single ion beam current required for radiation. The beam line beam expansion module expands the single ion beam current to obtain a large-area uniform single ion beam current, and the expanded single ion beam current irradiates the device under test in the irradiation target chamber;

[0008] During the irradiation process, the fluence / fluence rate and beam spot uniformity of the single ion beam are supervised through the beam on-line supervision module, and the beam energy and fluence rate before irradiating the device under test are measured through the beam measurement module.

[0009] Furthermore, for the single particle effect simulation irradiation device based on a heavy ion cyclotron as described above, the irradiation target chamber is a horizontal target chamber, a push-pull type slide rail is arranged in the irradiation target chamber, and a sample holder for installing the device under test is arranged on the push-pull type slide rail.

[0010] Furthermore, for the single particle effect simulation irradiation device based on a heavy ion cyclotron as described above, the mixed beam switching module includes an ECR ion source and a cyclotron. The ECR ion source is used to mix and ionize various gases injected into it to form a mixed ion with a high ionization state, and at the same time extract and form a mixed ion beam. The mixed ion beam is injected into the cyclotron along the axial direction of the cyclotron; by finely adjusting the high-frequency frequency of the cyclotron, the required single ion beam can be quickly sorted out.

[0011] Furthermore, for the single particle effect simulation irradiation device based on a heavy ion cyclotron as described above, the mass-to-charge ratios of the various gases injected into the ECR ion source are approximately the same, and at the same time, the requirements for the linear energy transfer density of single particles are met.

[0012] Furthermore, for the single particle effect simulation irradiation device based on a heavy ion cyclotron as described above, the beam line beam expansion module is mainly sequentially provided with a first quadrupole magnet, a first octupole magnet, a second quadrupole magnet, and a second octupole magnet along the optical path. The first quadrupole magnet and the second quadrupole magnet both include four magnetic poles uniformly distributed on a circle perpendicular to the beam direction, and coils are serially installed on the four magnetic poles; the first octupole magnet and the second octupole magnet both include eight symmetrically installed magnetic poles, and coils are serially installed on the eight magnetic poles. The single ion beam is deflected at a set angle through the beam line beam expansion module, so as to form a proton beam with a set area and uniformity on the target.

[0013] Furthermore, for the single particle effect simulation irradiation device based on a heavy ion cyclotron as described above, the beam on-line supervision module uses an S-Mon supervision detector to supervise the beam fluence / fluence rate and beam spot uniformity during the irradiation process.

[0014] Furthermore, for the single particle effect simulation irradiation device based on a heavy ion cyclotron as described above, the beam measurement module uses a gold-silicon surface barrier detector to measure the energy of the extracted beam.

[0015] Further, for the single - particle effect simulation irradiation device based on a heavy - ion cyclotron as described above, the beam measurement module uses multiple plastic scintillator detectors to measure the fluence rate of the extracted beam.

[0016] Further, for the single - particle effect simulation irradiation device based on a heavy - ion cyclotron as described above, the proportional - coefficient conversion method is used to indirectly measure the total fluence of the device under test. The specific proportional - coefficient conversion method is as follows:

[0017] Before irradiating the device under test, move the plastic scintillator detector to the beam center, turn on the beam switch to start irradiation detection. At this time, the plastic scintillator detector and the S - Mon monitoring detector are irradiated simultaneously. The fluence proportional coefficient K is:

[0018]

[0019] where N S1 is the count of the plastic scintillator detector, N SMon is the count of the S - Mon monitoring detector, and S is the collimation hole area of the plastic scintillator detector;

[0020] After that, move the plastic scintillator detector to the beam - avoiding position, and move the device under test to the beam center position. At this time, the device under test and the S - Mon monitoring detector are irradiated simultaneously. Use the count of the S - Mon monitoring detector to inversely deduce the total fluence F DUT :

[0021] F DUT =K×N′ SMon

[0022] where F DUT represents the total fluence of the device under test during irradiation, and N’ SMon represents the count of the S - Mon monitoring detector during the irradiation of the device under test.

[0023] Using the single - particle effect simulation irradiation device based on a heavy - ion cyclotron of the present invention has the following remarkable technical effects:

[0024] 1. By using the particle - beam switching method combining an ECR ion source and a cyclotron, the switching of ion - beam species can be completed within the order of minutes;

[0025] 2. By using the beam - expanding method combining two quadrupole magnets and two octupole magnets to achieve the homogenization of the single - ion - beam spot in the X and Y directions, a proton beam with large - area homogenization can be obtained;

[0026] 3. The design of the large-sample irradiation target chamber enables single-shot multi-sample irradiation. The rapid sample change based on the vacuum system ensures batch irradiation, overall guaranteeing the accurate and efficient progress of the experiment. Brief Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the overall structure of a single-event effect simulation irradiation device based on a heavy-ion cyclotron provided in an embodiment of the present invention;

[0028] In the figure: 1 - ECR ion source; 2 - cyclotron; 3 - first quadrupole magnet, 4 - first octupole magnet, 5 - second quadrupole magnet; 6 - second octupole magnet; 7 - diagnostic target chamber; 8 - irradiation target chamber. Detailed Embodiment

[0029] The present invention will be further described below in combination with specific embodiments and the accompanying drawings of the specification.

[0030] In view of the problems mentioned in the background art, the present invention proposes a single-event effect simulation irradiation device based on a heavy-ion cyclotron, which can solve key technologies such as the generation of a large-area uniform beam spot, extraction to the irradiation target chamber for irradiation, and rapid sample change.

[0031] Figure 1 It is a schematic diagram of the structure of a single-event effect simulation irradiation device based on a heavy-ion cyclotron provided in an embodiment of the present invention. The device includes two major parts: hardware and software. The hardware part includes a mixed beam switching module, a beam line beam expansion module, a diagnostic target chamber 7, and an irradiation target chamber 8. A beam current online monitoring module is arranged in the diagnostic target chamber 7, and a beam current measurement module is arranged in the irradiation target chamber 8. The mixed beam switching module and the beam line beam expansion module, and the beam line beam expansion module and the diagnostic target chamber 7 are connected by pipelines. The device under test is placed in the irradiation target chamber 8. The mixed beam switching module is used to quickly provide the single ion beam current required for simulating radiation. The beam line beam expansion module expands the single ion beam current to obtain a large-area uniform single ion beam current, and the expanded single ion beam current irradiates the device under test in the irradiation target chamber 8; during the irradiation process, the online monitoring of the fluence / fluence rate and beam spot uniformity of the single ion beam current is realized through the beam current online monitoring module, and the measurement of the beam current energy and fluence rate before irradiating the device under test is realized through the beam current measurement module. The software part includes the operation control program interfaces of each module and the corresponding computer control system. The following will separately describe each module of the hardware in detail.

[0032] For the ground simulation test of single-event effect, since it is necessary to switch multiple different ions, change the ion species of the ion source, preheat, etc., and each ion requires adjustments such as magnetic field and high frequency, which takes several hours. For single-event tests that require frequent switching of ion beam species, it is necessary to minimize the time required to change ion species to improve test efficiency. To address this technical problem, in this invention, the hybrid beam switching module combines an ECR ion source and a cyclotron, and uses the cocktail injection method to achieve single-particle irradiation, shortening the beam switching time of single particles from several hours to minutes, realizing rapid switching of single-particle beam currents.

[0033] The hybrid beam switching module includes an ECR ion source 1 and a cyclotron 2, which are used to rapidly switch the single-particle beam current required for the test. The ECR ion source 1 is used to mix and ionize multiple gases injected into it to form a mixed ion with a high ionization state, and then use the cocktail injection method to simultaneously extract them to form a mixed ion beam current, which is simultaneously injected into the cyclotron 2; the cyclotron 2 accelerates the mixed ion beam current injected into it, and quickly sorts out the required single-ion beam current by finely tuning the high-frequency frequency.

[0034] The working principle of the cocktail injection method is as follows: Select several gases with very close charge-to-mass ratios and inject them into the ECR ion source for mixing. After being ionized by the ECR ion source 1, ions with a high ionization state are formed, and they are simultaneously extracted to form a mixed ion beam current; the mixed ion beam current extracted from the ECR ion source 1 is injected into the cyclotron 2 along the axis of the cyclotron 2. Since the charge-to-mass ratios of multiple ions are very close, their requirements for magnetic field and high frequency are close to each other, and they can be accelerated simultaneously with similar orbits. By using the high resolution of the cyclotron 2 and slightly changing the magnetic field or electric field by finely tuning the magnetic field or frequency of the cyclotron 2, the required single-ion beam current can be quickly sorted out. This method compresses the time for changing ion species to the order of ten minutes.

[0035] It should be noted that the mixed gas needs to select ions with very close charge-to-mass ratios and simultaneously meet the requirements of the linear energy density transmission of single particles.

[0036] The beam line beam expansion module uses two quadrupole magnets and two octupole magnets to expand the single-ion beam current, realizing the uniformity of the single-ion beam spot in the X and Y directions and obtaining a proton beam current with a set area uniformity. As Figure 1As shown in the figure, the beam current expansion module is arranged after the cyclotron 2. Along the optical path, a first quadrupole magnet 3, a first octupole magnet 4, a second quadrupole magnet 5 and a second octupole magnet 6 are mainly arranged in sequence. Among them, the four magnetic poles of the first quadrupole magnet 3 and the second quadrupole magnet 5 are evenly distributed on a circle perpendicular to the beam current direction. The coils are installed in series on the four magnetic poles and are wound by hollow water-cooled copper tubes; the coils of the first octupole magnet 4 and the second octupole magnet 6 are symmetrically installed on the eight magnetic poles and are wound by hollow water-cooled copper tubes. The combined action of the two quadrupole magnets and the two octupole magnets deflects the single ion beam current at a set angle, obtains a as good as possible uniform distribution on the target, and forms a proton beam current with a set area and uniformization.

[0037] In a preferred embodiment of the present invention, the effective length of the first quadrupole magnet 3 is 400 mm, and the maximum field gradient is 8 T / m; the effective length of the second quadrupole magnet 5 is 400 mm, and the maximum field gradient is 6 T / m; the effective length of the first octupole magnet 4 is 400 mm, and the maximum field gradient is 6 T / m; the effective length of the second octupole magnet 6 is 400 mm, and the maximum field gradient is 2 T / m. Using TURTLE software to simulate the beam current distribution on the target, the beam spot area on the target is 20 cm × 20 cm, the uniformity is better than 91%, and the beam current utilization rate is 47%.

[0038] The beam current on-line monitoring module is installed in the diagnostic target chamber 7, and an S-Mon monitoring detector is used to monitor the beam current fluence / fluence rate and beam spot uniformity during the irradiation process.

[0039] The beam current measurement module is installed in the irradiation target chamber 8. It mainly includes a gold-silicon surface barrier detector for measuring the extracted beam current energy and multiple plastic scintillator detectors for measuring the extracted beam current fluence rate, and assists in adjusting the beam current according to the measured beam current parameters.

[0040] The basic structure of the gold-silicon surface barrier detector is to evaporate a layer of gold on a piece of N-type silicon. The layer of silicon close to the gold film has the characteristics of P-type silicon. The reverse-biased P-N junction formed in this way is close to the surface layer, and the junction region is the sensitive region of the detector. The commonly used fluence rate range during the ion irradiation experiment is 1E3 - 3E4 ion / cm 2 / s. According to the measurement requirements, the present invention uses multiple plastic scintillator detectors to measure the fluence rate of the extracted beam current (for example, 4 multiple plastic scintillator detectors). The multiple plastic scintillator detectors are respectively installed in different directions, and the beam spot uniformity can also be reflected according to the counts of the multiple plastic scintillator detectors.

[0041] The present invention uses a proportional coefficient conversion method to indirectly measure the total fluence of the device under test. The specific proportional coefficient conversion method is as follows: Before irradiating the device under test, move the plastic scintillator detector in the irradiation target chamber 8 to the beam center, turn on the beam switch to start irradiation detection. At this time, both the plastic scintillator detector and the S-Mon monitoring detector in the diagnostic target chamber are irradiated, and the fluence proportional coefficient K can be obtained as follows:

[0042]

[0043] where N S1 is the count of the plastic scintillator detector, N SMon is the count of the S-Mon monitoring detector, and S is the collimation hole area of the plastic scintillator detector.

[0044] After that, move the plastic scintillator detector in the irradiation target chamber 8 to the beam avoidance position, move the device under test to the beam center position, turn on the beam switch. At this time, both the device under test and the S-Mon monitoring detector are irradiated, and the total fluence F on the device under test is obtained by back-calculating the count of the S-Mon monitoring detector DUT :

[0045] F DUT = K × N' SMon

[0046] where F DUT represents the total fluence of the device under test during irradiation, and N' SMon represents the count of the S-Mon monitoring detector during the irradiation of the device under test.

[0047] The irradiation target chamber 8 is a horizontal target chamber. A push-pull type slide rail is arranged in the irradiation target chamber 8, and a sample holder for installing the device under test and the plastic scintillation detector is arranged on the slide rail. During use, the sample holder can be quickly withdrawn from the irradiation target chamber 8 by means of automatic or manual push-pull of the slide rail to install and replace the detector and the sample device. The designed space of the irradiation target chamber 8 can accommodate single-time multi-sample irradiation.

[0048] A single particle effect simulation irradiation device based on a variable energy heavy ion cyclotron provided by the present invention uses a particle beam switching method combining an ECR ion source and a cyclotron, and can complete the switching of ion beam species within a time scale of minutes; uses a beam expansion method combining two quadrupole magnets and two octupole magnets to achieve the homogenization of the single ion beam spot in the X and Y directions, and can obtain a large-area homogeneous proton beam; the design of the large sample irradiation target chamber allows single-time multi-sample irradiation; the fast sample replacement based on the vacuum system ensures batch irradiation, and overall ensures the accurate and efficient progress of the test.

[0049] The above embodiments are only illustrative examples of the present invention. The present invention can also be implemented in other specific ways or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described embodiments should be considered illustrative rather than restrictive in any aspect. The scope of the present invention shall be defined by the appended claims, and any changes equivalent to the intention and scope of the claims shall also be included within the scope of the present invention.

Claims

1. A single event effect simulation irradiation device based on a heavy ion cyclotron, characterized in that: The device comprises a mixed beam switching module, a beam line expansion module, a diagnostic target chamber (7) and an irradiation target chamber (8); a beam online monitoring module is provided in the diagnostic target chamber (7); a beam measurement module is provided in the irradiation target chamber (8); the mixed beam switching module and the beam line expansion module, the beam line expansion module and the diagnostic target chamber (7), and the diagnostic target chamber (7) and the irradiation target chamber (8) are connected via pipelines; The device to be tested is placed in the irradiation target chamber (8), the mixed beam switching module is used to quickly provide the single ion beam required for radiation, the beam line expansion module expands the single ion beam, thereby obtaining a large-area uniform single ion beam, and the expanded single ion beam is irradiated onto the device to be tested in the irradiation target chamber (8); During the irradiation process, the single ion beam fluence, fluence rate and beam spot uniformity are monitored by the beam online monitoring module, and the beam energy and fluence rate of the device under test before irradiation are measured by the beam measurement module; The mixed beam switching module comprises an ECR ion source (1) and a cyclotron (2). The ECR ion source (1) is used to mix and ionize multiple gases injected therein to form mixed ions in a highly ionized state, and simultaneously extract mixed ion beams to form mixed ion beams. The mixed ion beams are injected into the cyclotron (2) along the axial direction of the cyclotron (2); and the required single ion beams are quickly sorted out by fine-tuning the high-frequency frequency of the cyclotron (2). The beam line expansion module is mainly provided with a first quadrupole magnet (3), a first octapole magnet (4), a second quadrupole magnet (5) and a second octapole magnet (6) in sequence along the optical path, wherein the first quadrupole magnet (3) and the second quadrupole magnet (5) both include four magnetic poles evenly distributed on a circle perpendicular to the beam direction, and coils are installed in series on the four magnetic poles; the first octapole magnet (4) and the second octapole magnet (6) both include eight symmetrically installed magnetic poles, and coils are installed in series on the eight magnetic poles, and the single ion beam is deflected at a set angle by the beam line expansion module, thereby forming a uniform proton beam with a set area on the target.

2. The single event effect simulation irradiation device based on heavy ion cyclotron according to claim 1, characterized in that: The irradiation target chamber (8) is a horizontal target chamber. A push-pull slide rail is provided in the irradiation target chamber (8). A sample holder for mounting a device to be tested is provided on the push-pull slide rail.

3. The single event effect simulation irradiation device based on heavy ion cyclotron according to claim 1, characterized in that: The beam online monitoring module uses an S-Mon monitoring detector to monitor the beam flux / fluence rate and beam spot uniformity during the irradiation process.

4. The single event effect simulation irradiation device based on heavy ion cyclotron according to claim 3, characterized in that: The beam measurement module uses a gold-silicon surface barrier detector to measure the energy of the extracted beam.

5. The single event effect simulation irradiation device based on heavy ion cyclotron according to claim 4, characterized in that: The beam measurement module uses a plurality of plastic scintillator detectors to measure the fluence rate of the extracted beam.

6. The single event effect simulation irradiation device based on heavy ion cyclotron according to claim 5, characterized in that: The proportional coefficient conversion method is used to indirectly measure the total radiation dose of the device under test. The proportional coefficient conversion method is specifically as follows: Before irradiating the device under test, the plastic scintillator detector is moved to the center of the beam, and the beam switch is turned on to start irradiation detection. At this time, the plastic scintillator detector and the S-Mon monitoring detector are irradiated at the same time, and the fluence proportional coefficient K is: Among them, N S1 is the plastic scintillator detector count, N SMon is the S-Mon monitoring detector count, S is the collimation hole area of the plastic scintillator detector; Then, the plastic scintillator detector is moved to the beam avoidance position, and the device under test is moved to the center of the beam. At this time, the device under test and the S-Mon monitoring detector are irradiated at the same time, and the total fluence F on the device under test is obtained by reverse calculation using the counting of the S-Mon monitoring detector. DUT : F DUT =K×N′ SMon Among them, F DUT Indicates the total radiation dose of the device under test, N' SMon Indicates the count of the S-Mon monitoring detector during the irradiation process of the device under test.

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