The China Institute of Atomic Energy (CIAE) is developing a proton cyclotron with an energy of 9.5 MeV and a current of 100 mu A. To evaluate the performance of the cyclotron, the beam dynamics study has been conducted. Static and dynamic orbit analyses combined with phase-space matching were used to assess its beam acceptance and acceleration capability. Particle tracking simulations were employed to calculate characteristics such as radial centering and axial focusing, and the structure was optimized accordingly. The extracted beam parameters were controlled by adjusting the tilt angle of the stripping foil. The phase acceptance of this cyclotron exceeds 60 degrees, and the beam size at the liquid target is 1.35 mm & times; 2.01 mm. The cyclotron has entered the beam commissioning stage, with measured beam currents of 107 mu A at the internal target and 65 & micro;A of extracted beam current at the Faraday cup after stripping.

To address the heavy reliance on imported medical cyclotrons in China，the China Institute of Atomic Energy has independently developed a 10 MeV ultra-compact cyclotron，aiming at achieving localized and low-cost production of medical radioisotopes. The device incorporates key technologies including shallow-valley magnets，an integrated high-frequency and vacuum system，single-pass axial shimming，and an internal Penning ion source. It has a compact footprint of less than 1.4 m3 and a total weight under 7.5 tons，and is designed for high integration and intelligent operation and maintenance. Under working conditions of 10 MeV proton energy with 80 μA beam current，the cyclotron maintained stable operation for 2 h，yielding 18F with an activity of over 3 Ci. This output is sufficient for approximately 15 patient doses，fulfilling the clinical demand. The results demonstrate that this accelerator is reliable，user-friendly，and suitable for in-hospital production of short-lived medical radioisotopes such as 18F and 68Ga.

We propose a machine-learning-based optimization method for phase selection of shaper and buncher section in synchronous-phase RF linear accelerators. Firstly, the dataset is established by simulation and the BackPropagation (BP) neural network is trained as a surrogate model to analyze the effects of buncher and RF cavity phases on beam quality. Subsequently, the Particle swarm optimization algorithm (PSO) is used to find optimal accelerating phases that satisfy the beam quality requirements. The results show that the Mean-Square Error (MSE) of the surrogate model is less than 0.01, while the Root-Mean-Square Error (RMSE) between the optimized and target values of beam quality is as low as 0.041. Besides, the optimization time per iteration is reduced to approximately 5 ms, outperforming genetic algorithms (GA) in both speed and accuracy. The machine learning methods can quickly and accurately find parameters that satisfy physical designs. We are considering applying this method to the real project of high-energy ion implanter development, which can hopefully reduce the complexity of the traditional calculating steps and improve work efficiency significantly.

The compact cyclotron CYCIAE-100, developed by the China Institute of Atomic Energy (CIAE), can generate a continuous proton beam with an energy of 100 MeV. To meet the pulsed beam requirements for nuclear data measurements, a beam pulsing system was developed. A chopper was installed in the injection line to convert the continuous beam from the ion source into a pulsed beam with a frequency adjustable from the MHz range to lower frequencies. Two phase selectors were used to limit the beam's phase width, and a dual extraction method was employed to reduce beam overlaps in the extraction region, thus achieving quasi-single-turn extraction. The design and fabrication of the chopper and phase selectors were completed, and experimental tests were conducted. The experimental results demonstrated that the pulse width was successfully compressed to less than 5 ns, ensuring sufficiently high energy resolution and providing the conditions for nuclear data measurement experiments.

Electron–positron colliders operating in the GeV center-of-mass range, or tau-charm energy region, have been proved to enable competitive frontier research due to several unique features. With the progress of high-energy physics in the last two decades, a new-generation Tau-Charm factory, called the Super Tau-Charm Facility (STCF), has been actively promoted by the particle physics community in China. STCF has the potential to address fundamental questions such as the essence of color confinement and the matter–antimatter asymmetry within the next decades. The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5 × 1034 cm−2 s−1 that is optimized at a center-of-mass energy of 4 GeV, which is approximately 50 times that of the currently operating Tau-Charm factory—BEPCII. The STCF accelerator has two main parts: a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams. As a typical third-generation electron–positron circular collider, the STCF accelerator faces many challenges in both accelerator physics and technology. In this paper, the conceptual design of the STCF accelerator complex is presented, including the ongoing efforts and plans for technological research and development, as well as the required infrastructure. The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan (2026–2030).

Magnetic field shimming is crucial for achieving isochronous acceleration in a cyclotron. Matrix methods based on least square fitting are commonly used to calculate the cutting curve of a shimming bar. However, this matrix method becomes inapplicable when dealing with cases of nonlinear shimming effects. An algorithm based on the Gauss-Newton iteration method to address shimming problems with nonlinear effects has been proposed. Numerical and experimental results demonstrate the effectiveness and accuracy of this algorithm. It has been applied to a compact positron emission tomography (PET) cyclotron developed at China Institute of Atomic Energy (CIAE).

As the research work about irradiation effect and neutron measurement requires high-energy neutron with the development in the fields of space exploration, medical treatment and high-energy physics investigation, a beamline of quasi-monoenergetic neutron in the range of 30 similar to 50 MeV based on a proton cyclotron with a maximum energy of 50 MeV is under construction and preparation. We studied the design of this quasi-monoenergetic neutron beamline with a focus on target chamber and collimator. Comprehensive comparison on characters of thermodynamic and nuclear physics between lithium and beryllium was conducted, and lithium was chosen as target material by better performance on quasi-monoenergetic neutron peak. Relevant parametric simulations of lithium thickness were carried out in consideration of efficiency and quality of neutron generation which shows the change on height and width of quasi-monoenergetic neutron peak. Energy loss of incident proton caused by titanium film and argon gas was estimated to provide a reference for the mechanical design of target chamber. Evaluation has been done to show the variation of neutron spectra and fluxes at different positions from the target along with collimators of different lengths, and the collimator length was determined to be 2 m in view of flux and ratio of quasi-monoenergetic neutron peak. All work provides a data reference for the building and operation of the quasi-monoenergetic neutron beamline.

The low-energy beam transport section is an important part of particle accelerators whose design and optimization process usually requires substantial computation resources and time investment. We applies Latin hypercube sampling method to construct a Kriging surrogate model and verifies its accuracy. The results show that the root-mean-square (RMS) error of the overall prediction is below 0.01. The given output beam parameters are optimized by genetic algorithm, and the corresponding component parameters are determined reversely. The results indicate that 89% of the optimization deviations are below 0.001 while 100% of the optimization deviations are below 0.01. This method has high predictive accuracy and fast response time, significantly reducing the design and matching time of the low-energy transport section, and is expected to be applied to cyclotron injection, automated beam tuning, and other fields in the future.

With the development of nuclear science and technology, the application of PET medical radionuclides is increasing, and the demand is increasing. But the Ge-Ga generators used to provide 68Ga medical radionuclide are all dependent on imports. In order to carry out the research of Ge-Ga generator technology, we will carry out the pilot experiments of 68Ge production.In the study, the simulated production of medical radionuclide 68Ge based on FLUKA Monte Carlo program. The end of bombardment (EOB) yields of 68Ge with 100 μA, 200 μA and 500 μA beam intensity were calculated by 14 MeV, 30 MeV and 70 MeV proton beams irradiating Ga targets enriched with 69Ga for 1 hour, 12 hours and 24 hours, respectively. The changes of EOB yields and the activity of radionuclides on the targets were analyzed. After 24 hours irradiation by 30 MeV/500 μA proton beam, the EOB yield of 68Ge nuclide is 3.13×1010 Bq, which is similar to the EOB yield with 24 hours irradiation by 70 MeV/500 μA proton beam, which is 4.54×1010 Bq. There are fewer radioactive impurities on the target and higher input and output benefit with 30 MeV proton beams. Therefore, the proton energy for 68Ge nuclide production is 30 MeV.The research could provide some theoretical basis and support for 68Ge production pilot experiment and mass production.

In some radioisotope production experiments，100 MeV high-current proton cyclotron is required to extract a single-turn beam to meet the experimental requirements，but at present，there is a serious problem of turn overlap when the beam is extracted，and a beam screening device needs to be designed to improve the quality of the drawn beam. The beam screening device has a frame structure and slit motion system based on the cyclotron，and a control system based on PLC design to control the stepper motor and use the electronic ruler and PID control algorithm to achieve closed-loop control. After many times of operation and debugging，the motion accuracy of the mechanical device is ±0.2 mm，and the beam screening can be realized during the operation of the accelerator，which has reference significance for the design and manufacture of the cyclotron beam screening device.

The precise measurement and error compensation technique of the main magnetic field in cyclotron accelerator are important research directions and key components in the construction of the device. Due to factors such as internal defects in the iron material and mechanical processing errors, the non-ideal magnetic field generated by the main magnet of the cyclotron accelerator usually deviates from the required isochronous magnetic field distribution and contains a certain amplitude of harmonic magnetic field. Therefore, in the process of developing a cyclotron accelerator, it is necessary to perform multiple shimming on the non-ideal magnetic field, and ultimately achieve the required distribution by correcting the actual magnetic field. Compared with traditional magnetic field compensation algorithms, this paper proposes an algorithm based on a multivariate linear regression model, incorporating the calculation of the first harmonic magnetic field. This algorithm achieves simultaneous quantitative shimming for both temporal errors in the magnetic field and first harmonic errors, eliminating the need for a separate iterative process for shimming the first harmonic magnetic field. In order to avoid increasing the finite element calculation workload, this paper uses a 1/4 magnet model in the new algorithm to obtain the shape function for the first harmonic magnetic field and the average magnetic field. Simplifying the full model finite element calculation of the main magnet to a 1/4 model can save approximately 80% of CPU time. By using the algorithm proposed in this paper, after three iterations of shimming, the isochronism error of the magnetic field in the 16 MeV cyclotron at the China Institute of Atomic Energy is reduced to the order of 10-4, and the integral sliding phase control of particles is controlled within ±14°, while the magnitude of the first harmonic of the magnetic field is reduced to within 6 Gs. The transverse free oscillation frequency of the magnetic field was also adjusted, improving the axial focusing frequency at large radius positions, allowing the beam to pass through dangerous resonances only at low energy positions and quickly move away from resonance positions. Through the first shimming process, the magnitude of the first harmonic of the magnetic field is reduced, minimizing the coupling of the beam phase space in the transverse direction and avoiding major harmful resonances. Experimental studies have shown that this algorithm has the characteristics of low computational cost for shape function calculations, high shimming accuracy, and a small number of iterations. The algorithm in this article can be further expanded to realize the shimming calculation of any high-order harmonic magnetic field error of the cyclotron.

This study focuses on the simulation of target preparation, dissolution, and separation- purification processes for the production of the vital medical radioactive isotope 68Ge using medium-high energy cyclotrons. It encompasses the preparation and quality inspection of gallium-nickel alloy targets, target dissolution, the establishment of analytical detection methods, and the optimization of simulation conditions for the separation and purification of 68Ge. Initially, gallium-nickel alloy targets were prepared on copper backing plates by optimizing the electrodeposition process conditions. Analytical detection methods were then established using inductively coupled plasma mass spectrometry (ICP-MS). Subsequently, the dissolution process of the gallium-nickel alloy targets was studied using an electrochemical anodic oxidation method. Finally, the combined use of Tulsimer CH-90 chelating resin and Sephadex G25 gel resin was employed to optimize the simulation conditions for the separation and purification of 68Ge, completing the process simulation study. The results indicate that the prepared gallium-nickel alloy targets have a smooth and flat surface with a uniform composition distribution, containing 74.7% gallium and 25.3% nickel, and have a thickness of 179 mg/cm2, suitable for medium-high energy proton irradiation above 30 MeV. The established ICP-MS internal standard method enables accurate quantitative detection of germanium and impurity elements. The electrochemical method allows for simple and rapid dissolution of the gallium-nickel alloy layer without heating. The combined use of chelating resin and gel resin for separation and purification yields germanium-containing sample solutions with high recovery rates and purity. Through the aforementioned process simulation studies, a simulated process flow for target preparation, target dissolution, analytical detection, and separation-purification has been established, providing technical support for the production of 68Ge using medium-high energy cyclotrons.

68Ge is the parent nuclide of radioactive nuclide 68Ga used in positron emission tomography (PET) diagnostic imaging，which is converted into 68Ga by a 68Ge/68Ga generator for clinical diagnostic imaging applications. Currently，there are 13 kinds of 68Ga labeled radiopharmaceuticals in China that have entered clinical practice and have good application prospects in tumor imaging such as high-grade endocrine tumors and prostate cancer. Therefore，with the approval and widespread use of 68Ga radiopharmaceuticals，68Ge has broad application prospects in both domestic and international markets.In addition,68Ge can also be widely used as a calibration source for PET scanners.China Institute of Atomic Energy (CIAE) plans to build a 75 MeV cyclotron with the maximum beam current of 800 μA and the proton energy range of 75 MeV. It will be used to focus on the production of 68Ge nuclide.This article used the Monte Carlo program FLUKA to simulate in detail the production of 68Ge nuclides yield，reaction products，the variation of impurity nuclide production with cooling time，and long-life nuclides affecting separation processes by irradiating gallium nickel alloy targets and niobium gallium capsule targets in medium to high energy proton cyclotron.The simulation results can provide the useful reference for the production，separation，and purification of 68Ge in medium to high energy cyclotron.

A set of nozzle equipment for proton therapy is currently under development at China Institute of Atomic Energy (CIAE). To facilitate the off-line commissioning of the whole equipment, a set of ionization chamber signal generation system, known as the test electronics, was designed. The results showed that the system can simulate the beam position, beam fluence (which exhibits a positive correlation with the dose), and other related analog signals generated by the proton beam when it traverses the ionization chamber. Moreover, the accuracy of the simulated beam position is within ± 0.33 mm, and the accuracy of the simulated beam fluence signal is within ± 1%. The test electronics can output analog signals representing environmental parameters. The test electronics meets the design requirements, which can be used for the commissioning of the nozzle system as well as the treatment control system without the presence of the proton beam.

With the rapid development of nuclear science and technology, medical radioisotopes play an increasingly important role in nuclear medicine, and are widely used in the diagnosis and treatment of cardiovascular and cerebrovascular diseases, tumors and other diseases. Accelerator production of medical radioisotopes has the advantages of flexibility, efficiency, system safety and high nuclide activity, and is one of the important production methods to ensure the safe and stable supply of medical radioisotopes. In 2021, China Atomic Energy Authority together with seven other ministries, jointly released the “Medium - and Long Term Development Plan for Medical Isotopes (2021−2035)”, which clarifies that there are 14 important medical isotopes that China needs to focus on developing before 2035, of which 9 isotopes can be produced by accelerators. This article mainly introduces the production and application overview of accelerators for the 9 important medical isotopes listed in the plan. The 9 important medical isotopes include the imaging nuclides 123I, 124I, 64Cu, 68Ga, 89Zr and the therapeutic nuclides 186Re, 103Pd, 225Ac ,223Ra .Among them,225Ac、68Ge and 223Ra are the focus of isotope production in medium and high energy accelerators, and also are the main development trend of accelerator production radioisotopes. This study provides a comprehensive review of the nuclear properties, applications, reaction cross-sections, yields, and production methods of the diagnostic and therapeutic nuclides mentioned above, providing reference for the production of related nuclides.

通过理论分析和仿真模拟对中国原子能科学研究院一台100 M eV强流质子回旋加速器的束流切割器进行了优化设计,并同时研制出两套束流切割器进行实测对比,选定最佳方案.该切割器波形选择为回旋加速器高频频率的16分频2.8 M Hz正弦波,具有结构紧凑体积小、螺旋谐振器Q相对较高、加载切割电压较高且功率损耗低、无需水冷等特点,同时配套研制了一套开口形状为正方形的选束狭缝装置.最后在实验终端成功获得了能量为100 M eV、重复频率为5.6 M Hz的脉冲质子束.该切束器的成功研制不仅满足了核数据测量的应用需求,还极大地推动了回旋加速器束流脉冲化技术的发展.

GeV-class proton beam with an average power of several megawatts has many important applications in particle physics towards the intensity frontier, as well as in the advanced energy and material science. There are three different types of constructed accelerators for high power proton beam production: The cyclotron, linear accelerator and rapid-cycling synchrotron. The highest beam power of these accelerators currently is 1.4 MW. Studies have shown that the energy efficiency of the PSI cyclotron is about two times of the other types. Thus, the isochronous accelerator is a good technical route to develop proton machines with high beam power and high power efficiency. The isochronous fixed-field alternating gradient accelerators (FFAGs) scheme is a promising candidate for next-generation GeV-class high power proton driver. There are two bottle-neck problems in the development of GeV/mA class FFAG: As an isochronous accelerator, radial tune of isochronous FFAG is approximately increasing with beam energy in a linear way, and thus the integer resonance crossing problem becomes an inevitable problem. Single turn extraction with very low beam losses is also a verry important issue of high power isochronous FFAG. To the author’s knowledge, high beam extraction efficiency for beam energy of GeV-class is still unresolved. To solve those problems, an idea of integer resonance suppressor (IRS) which intentionally introduces the third harmonic magnetic field was proposed. One IRS is made up of two pair of coils, and each pair has independent power supply to generate the required harmonic magnetic bump. IRS can not only inhibit the radial oscillation and beam size blowup caused by integer resonance crossing but also contribute to a controllable coherent oscillation which is helpful to beam extraction with high efficiency. In the CYCIAE-FFAG design, νr=3 resonance is the lowest order resonance. Third harmonic field of only 1 Gs (1 Gs=10-4 T) can drive large coherent oscillation and then the following intrinsic resonance 3νr=10 will lead to serious beam size blowup effect. However, IRS can compensate the driving error and minimize the coherent oscillation before reaching the detrimental resonance. IRS provides a possibility of relaxing the requirement of magnet manufacture and installation. Our simulations show that third harmonic field of 10 Gs is acceptable with proper IRS settings. In the PSI 590 MeV ring cyclotron, beam is eccentrically injected to give rise to coherent oscillation. However, in CIAE-FFAG design, the beam was injected centrally and controllable amplitude of coherent oscillation was introduced in the integer resonance crossing process. The IRS scheme makes it possible to have knobs to adjust the amplitude and phase of coherent oscillation, which will be much easier to enlarge the turn separation. Taking the CYCIAE-FFAG project for example, simulations in this paper show that IRS can not only reduce the beam size growth rate to less than 5%, but also enlarge the turn separation to 3 cm. That is to say, IRS not only acts as resonance suppressor, but also plays the role of separation optimizer between the last and second last turn. The result shows that IRS is a potential solution for resonance crossing and extraction problems of GeV/mA class circular accelerator.

Fixed-Field Alternating Gradient accelerators (FFAG, also known as FFA) are promising candidates for next-generation GeV-class proton driver with average beam power of several megawatts. In isochronous accelerators, radial tunes are approximately increasing with beam energy in a linear way, and thus the integer resonance crossing problem becomes the major bottleneck of GeV-class isochronous FFAG design. In 2019, China Institute of Atomic Energy (CIAE) proposed an isochronous FFAG conceptual design with capability of producing 2GeV/6MW continuous wave (CW) proton beam. However, this conceptual design shows that the beam size is blown up at high energy region due to the third harmonic magnetic field caused by imperfections. The reason is that the integer resonance vr=3 causes a large coherent oscillation, and this large amplitude is not compatible with the following third order intrinsic resonance 3vr=10. In order to correct the large coherent motion before reaching the 3vr=10 resonance, we propose an idea of integer resonance suppressor (IRS) which intentionally introduces the third harmonic magnetic field. Our calculation shows that third harmonic field of 10Gs is acceptable with proper IRS settings, meaning that the requirements of magnet manufacture and installation can be relaxed. The increased imperfection tolerances will make magnet manufacture and installation much easier.

基于加速器高阶传输映射的非线性效应解析分析,具有物理图像清晰、守辛、准确的优点,但其缺点是适用范围较窄.为了扩展非线性效应解析分析的适用范围,提出一种模拟李指数运算过程的神经网络层并构建了用于预测带电粒子非线性行为的新型神经网络.经过大量粒子跟踪数据的学习,可用于预测带电粒子复杂的非线性运动行为,并从中提取线性传输矩阵与表征非线性运动的指数因子.为了验证该新型神经网络的有效性,跟踪一段由薄透镜磁铁组成的磁聚焦结构得到大量的训练数据,并对所提出的神经网络进行训练.训练后的神经网络在测试数据集上表现良好,测试数据的损失函数方均根小于8×10-4,达到了预测带电粒子非线性行为的目的.

聚焦于核技术应用领域中射线产生装置、放射性同位素技术、核探测技术,概述了电子加速器、质子/重离子加速器、中子发生器等重要射线产生装置与放射性同位素制备、放射性药物、放射源以及核探测技术等的国内外研究现状,分析了国内射线装置与放射性同位素技术的发展趋势及前景.