Fission fragments yields and average total kinetic energy are fundamental nuclear data for nuclear energy applications and the study of nuclear devices. Certain fission products, such as 95 Zr, 99 Mo, 140 Ba, 144 Ce, and 147 Nd, serve as burnup monitors, assessing the number of fissions induced by neutrons on 235 U. However, current experimental data for these fission products worldwide are inconsistent, introducing significant uncertainty into related scientific research. In this study, we employed the Potential-driving Model to calculate the independent yields of 235 U and evaluate its advantages in such calculations. Additionally, we investigated the energy dependence of independent yields to select important products. Furthermore, we calculated the cumulative yields of 95 Zr, 99 Mo, 140 Ba, 144 Ce, and 147 Nd, and compared them with existing literature data to explore the energy dependence of fission products for 235 U. Given the lack of fission product yield data above 14.8 MeV, we extended our calculated incident neutron energy to 20 MeV, aiming to support future scientific research. The Geant4 physical model does not consider the influence of incident neutron energy on the average total kinetic energy of fission fragments; thus, we introduced the excitation function of the total kinetic energy of fission fragments recommended by Madland et al ., which effectively describes the experimental data of the average total kinetic energy of fragments formed in 235 U fission. In this paper, we comprehensively discuss the energy dependence of fission product yields and average total kinetic energy.

An improved high-yield compact D-D neutron generator has been developed for active neutron non-destructive interrogation at Lanzhou University in China. The generator has been meticulously designed based on the magnetic field distribution of the duoplasmatron ion source, the electric field distribution of the beam extraction acceleration system, beam transport, and target cooling system. The performance characteristics of the generator were measured under different deuterium beam energies and beam intensities. The experimental results indicated that the D-D neutron yield reached 1 x 109 n/s with the deuterium beam parameter of 210 keV/6.0 mA. The operational stability of the generator was assessed for 150 min, and the test results show that the generator has better stability in operation. This generator has potential applications in neutron radiography, active interrogation of special nuclear materials, and neutron activation analysis.

Proton recoil method can be used to experimentally measure fast neutron energy spectrum of non-pulsed neutron sources. The neutron energy spectrum unfolding algorithms based on the MLEM method, the GOLD deconvolution method, the Direct-D method, have been developed by using the EJ309 liquid scintillation detector. The degree of iteration by the mean square error (MSE) is proposed as a judgment criterion by according to the iterative accuracy, convergence speed and iteration efficiency. The developed neutron energy spectrum unfolding algorithms can unfolding the standard simulated mono-energetic neutron spectrum (2.5 MeV), 252Cf neutron spectrum, Am-Be neutron spectrum and the experimentally measured D-D neutron spectrum with higher precision as well as fewer iterations. The unfolded neutron spectra are in good agreement with the standard simulated neutron spectra and evaluated D-D neutron spectrum, which is revealed that the developed unfolding algorithms can unfolding neutron energy spectrum with reasonable accuracy.

Cyclotrons are indispensable scientific equipment and platforms for cutting-edge research and are widely applied in nuclear science and life science, as well as the innovative development of nuclear technology. The difficulties and corresponding key technologies of compact high-intensity proton cyclotron research are fourfold: the insufficient axial focusing force of a compact cyclotron frustrates improvements in beam energy and beam intensity; the smelting capacity of large-scale magnets and modern manufacturing restricts magnetic field accuracy, which affects the dynamic performance of high-intensity beams; high-beam dynamic loads and coupling resonance considerably influence the stable operation of cyclotrons; and high-intensity negative hydrogen ion sources, the coupling of multiple physical fields in the narrow space of the central region, and the high-precision six-dimensional matching of beam optics in the extraction region are also great challenges for compact high-intensity cyclotrons. To solve these problems, a strong focusing theory of radially modulated magnetic field gradients was innovatively created by a cyclotron team at the China Institute of Atomic Energy (CIAE), and a parallel computing algorithm and software for multi-cluster high-intensity beam dynamics were also invented. These innovations extend the acceleration energy limit of compact cyclotrons and help increase beam intensity substantially under the restriction of space charges. A magnet shimming algorithm for isochronous fields and nonideal harmonic fields, based on the shape function of odd and even triangles, was developed to improve axial focusing effectively and solve problems in magnet engineering. Key RF technologies, such as suppression of "transmission line-resonator" system coupling oscillation and dynamic loading changes, were researched, and then a long-term operation with high stability was achieved for the entire machine. A high-intensity cyclotron prototype with strong focusing was built based on these innovations, effectively promoting the beam intensity of miniaturized cyclotrons from 50-100 mu A to 300-500 mu A. Subsequently, more than ten high-intensity compact cyclotrons have been developed at the CIAE, and these cyclotrons can provide beam intensity at the mA order after necessary upgrades. The main performance indexes of the cyclotrons, such as intensity, injection efficiency, and extraction efficiency, are world-class. Cyclotron applications are also applied in the projects of the CIAE, National Space Science Center, Irradiation Hardening Application Technology Innovation Center, and Peking University and contribute much to scientific research. We provide proton beams for similar to 100 units to perform scientific and technological research related to nuclear technology and its applications. The research and applications prompt the development of high-intensity proton cyclotrons.

在230 MeV超导回旋加速器中,磁场调节棒及其驱动系统是束流调试的重要辅助装置.为满足束流对中和束流引出所需的磁场,设计并研制了16套磁场调节棒及其驱动装置.机械执行机构采用美国Thomson公司的精密直线执行器,其重复定位精度为±0.01 mm,位置传感器采用德国Novotechnik公司的直线位移电子尺,其重复精度为0.002 mm.此外,运动控制采用PLC加直线位移传感器负反馈闭环的方案.在实际工况下,系统定位精度达到0.05 mm,重复精度达到±0.02 mm,优于设计要求.此外,对该系统进行了静电放电测试、电快速瞬变脉冲群测试和浪涌抗扰度测试,结果满足医用电气设备电磁兼容标准YY 0505-2012/IEC 60601-1-2:2004的要求.该驱动系统的研制,克服了在强电离辐射、高磁场强度、狭小安装空间的特殊环境中达到高定位精度和高重复精度的难点,对优化束流的径向进动、减小加速区域的相干振荡振幅、提高引出区的束流引出效率等具有重要意义.

LHC provides a chance to study the physical processes of γγ collision and γ p collision mode by adding a forward detector. In this paper, we investigate J/ψ-pair photoproduction in NRQCD framework at the LHC with γγ collision mode. We calculate the contributions from ${~}^{3}S_{1}^{1}$ , ${~}^{3}S_{1}^{(8)}$ , ${{~}^{1}}S_{0}^{(8)}$ , ${~}^{3}P_{J}^{(8)}$ Fock states, and find that contribution from the colour octet ${{~}^{1}}{S_{0}^{8}}$ ${~}^{3}P_{J}^{(8)}$ and ${~}^{3} P_{J}^{(8)}{~}^{3}P_{J}^{(8)}$ channels dominates this process with forward detector acceptance 0.0015 < ξ < 0.5. We present the differential cross section distributions of transverse momentum $p_{t}^{J/\psi }$ and rapidity yJ/ψ with forward detector acceptances 0.0015 < ξ < 0.5, analyse the signal for J/ψ decaying to a opposite-sign (OS) muon pair. The results show that this process has the potential to be detected at the 13 TeV LHC with forward detector acceptance 0.0015 < ξ < 0.5.

The Integrated Modular Avionics (IMA) has become a popular aircraft avionics system, and ARINC653 is a standard interface for IMA architecture of aircraft avionics equipment, and real-time scheduling for ARINC653 partition Operating System (OS) is a key issue. There are lots of scheduling algorithms for ARINC653 partition OS based on a single-core processor. This paper presents a partition scheduling proposal based on parameter configuration and designs a scheduling algorithm based on multi-core Load Proportional Round-Robin (MLPRR). The algorithm calculates the task weight according to the load ratio of the task and completes the scheduling of the task on the multi-core processor to meet the real-time requirements of the multi-core partition OS. Experimental results show that MLPRR is feasible and efficient.

中国原子能科学研究院目前正在研制用于硼中子俘获治疗(BNCT)的强流质子回旋加速器,该加速器设计引出能量14 MeV、质子束流强大于1 mA.相比引出流强为400μA的PET回旋加速器,BNCT强流质子回旋加速器对中心区相位接收度和轴向聚焦的要求更高.为实现mA量级的束流的加速和引出,BNCT强流质子回旋加速器采取了增加负氢束流注入能量、增大磁铁镶条孔径、使用用于增大D ee盒头部张角的阶梯状结构及调整加速间隙的入口和出口高度等一系列中心区结构优化设计,有效地提高了中心区的相位接收度,改善了轴向电聚焦.在新的离子源注入能量下通过数值计算得到实测场下的轴向电聚焦和间隙高度的关系,选取合适的间隙高度获得最佳的轴向聚焦,从而确定了mA量级束流的注入和加速的中心区结构.同时在设计中考虑空间电荷效应的影响,计算了不同流强下的束流尺寸变化.中心区结构在实测磁场下的优化设计计算结果表明,BNCT强流质子回旋加速器中心区的束流对中好于0.5 mm,相位接收度大于40°,中心区最高可接收流强3 mA.目前,新的中心区结构已进入机械加工阶段.

由于等时性固定场交变梯度加速器具有连续束、强聚焦等优点,逐渐成为研究热点.等时性固定场交变梯度加速器的物理设计问题可归结为具有多个设计目标、可调节变量与条件限制的最优化问题.多目标进化算法的发展给复杂的最优化问题提供了解决方案.将多目标进化算法应用于等时性固定场交变梯度加速器的优化中可提高设计效率.为了验证该优化方法的有效性,针对70 M eV与1 GeV等时性固定场交变梯度加速器进行了物理设计优化,并达到了预期设计目标.

A 230 MeV compact superconducting cyclotron CYCIAE-230 is being constructed by the China Institute of Atomic Energy, which can be used for proton therapy and space radiation physics research. The technology of magnetic field measurement, shimming and processing is the primary task to realize the isochronous acceleration of cyclotron. The CYCIAE-230 has high magnetic field, high field gradient and dense rotation orbits. Therefore, the isochronous field and tune diagram need to be amended simultaneously. The first harmonic is also shimmed at the same process to ensure a good extraction efficiency by using precessional extraction. The precision of field measurement, shimming and processing is much higher and the algorithm is much more difficult than those in normal temperature cyclotron. In addition, the compact structure of the magnet has very narrow installation space, which makes the design of the mapper more difficult. The process of main magnet construction includes strict control of room temperature and electromagnetic compatibility (EMC), precise measurement of magnetic field, comprehensive research of beam dynamics and multi-dimensional numerical control (NC) processing under the control of complex algorithms. In this paper, the magnetic field measurement, shimming and processing of the main magnet will be illustrated in detail.

Proton beam with an average power of 5 MW-10 MW have important applications in particle physics towards the intensity frontier, as well as in the advanced energy, and material science. The fixed field alternating gradient (FFAG) accelerator combines the advantages of existing accelerators, which has a higher limitation of beam energy than high power cyclotron and has a higher beam-to-grid efficiency than existing high power linac and synchrotron, thus is considered as a good candidate for high power proton machine. By utilizing the strong focusing and large acceptance features of FFAG in the theoretical framework of the fixed field and fixed frequency of isochronous cyclotron, a continue wave FFAG capable of producing 2 GeV/3 mA protons (with an beam power of 6 MW) has been proposed in China Institute of Atomic Energy (CIAE). Due to the beam loss of high power proton beams, the resulting high radiation will deposit a large amount of radiation dose and heat load on the superconducting (SC) magnet. As the high temperature superconductors (HTS) have a much larger thermal margin due to high critical temperature (> 90 K) and high upper critical field (>100 T) than the traditional low temperature superconductors, and have been also considered have the lower overall construction costs and power consumption than the conventional magnet, currently the HTS magnet is the favorable solution for the 2 GeV FFAG magnet design. In this paper, the lattice design along with the requirements on the F-D-F magnet of the 2 GeV FFAG design is briefly introduced first. Then, the design of the F-D-F magnet is outlined. The details of the HTS coil design utilizing ReBCO conductor and operating at ~30 K is also included.

China Institute of Atomic Energy has developed a 230 MeV compact superconducting cyclotron CYCIAE-230 to meet the demands of proton therapy in China. Physical design requires a strict control of the average field error and first harmonic in the main field. A processing method of inclined 45° continuous cutting on the two pole sides is at the first time proposed to shim the field in compact superconducting cyclotron. For a spiral magnet pole, the field generated by the 45° continuous cutting on edges is relatively complicated to be calculated precisely by finite element method. In this paper, the analytical model of the linear equation for field shimming calculation is established. The shape function caused by the local cutting is solved by the magnetic saturation approximation. And then the shimming process is built with an iterative procedure based on the ridge regression method. The shimming algorithm is applied in CYCIAE-230, which achieve good results to reduce the shimming times and further the construction period. The process of the shimming algorithm and the corresponding shimming effect in CYCIAE-230 will be presented in detail.

经过60年的发展,中国原子能科学研究院(CIAE)独立自主地开展了基于PIC技术的强流回旋加速器束流动力学的大规模并行计算的核心算法研究,开发了CYCPIC2D、CYCPIC3D和OPAL-CYCL等强流回旋加速器束流动力学模拟程序,搭建了专用的高性能并行化计算机群PANDA.本文以CIAE已建成及在研的不同类型的回旋加速器为例,总结了回旋加速器基本束流动力学的分析方法和主要计算结果,并介绍了CIAE在回旋加速器束流动力学与多物理场模拟技术方面的发展与应用.

中国原子能科学研究院(CIAE)自1958年首台回旋加速器成功出束以来,已经历了60余年的回旋加速器创新与发展,并由此带动了我国核科学技术基础研究和应用技术的发展.本文在简要回顾回旋加速器前30年发展历程的基础上,重点阐述后30年围绕紧凑型回旋加速器的科技创新和应用,主要包括100MeV强流质子回旋加速器、医用小型回旋加速器、质子治疗超导回旋加速器及高功率等时性圆型加速器等多种先进的质子加速器研发.

为了测量超导回旋加速器主磁场,设计了一套磁场测量仪控制系统.该系统实现了半径r方向和角度θ方向的运动,并完成对核磁共振仪和数字积分器的实时数据采集.半径方向的定位精度达到10 μm,角度方向定位精度达到20 s.测量仪完成一次测量时间只需4 h,已在台架上完成磁场测量全过程的测试,还可应用于其他相关测量领域.

A superconducting cyclotron named CYCIAE-230 is designed and under construction at the China Institute of Atomic Energy, Beijing, China, to provide a 230-MeV proton beam for cancer therapy. The cryogenic system has been completed and the machining of the magnet will be finished soon. The shimming procedure will be performed to obtain the final isochronous field, which requires the field measurement precision to be 5 × 10 –5 . A search-coil sensor based mapping system was developed to satisfy the measurement accuracy requirements, including a nuclear magnetic resonance probe to precisely measure the field at the cyclotron center and a moving search coil to obtain the field differences. Moreover, a Hall probe is integrated in the system to verify the field data. The system allows the probe motion and data acquisition to be performed automatically. In this paper, the field mapping requirements are listed, the design and calibration of the coil is described, and the field mapping system, including mechanical structure and control system, is presented in detail.

In order to meet the requirement of proton beam energy for single event effect testing,a 300 MeV/A H2+ superconducting cyclotron was designed at China Institute of Atomic Energy.The cyclotron applies superconducting coil to reduce the size of main magnet and provides variable energy proton beams by stripping extraction H2+ ions.Beam extraction dynamics was studied by adjusting the stripping point and analyzing the proton trajectory and beam envelop,and the physical design of extraction was accomplished.The results show that the cyclotron is able to extract variable energy protons in 205-240 MeV and 265-300 MeV continuously,and retain the ability of mono-energy extraction at lower energy range.

Several small cyclotrons have been constructed at CIAE to extract 14-MeV proton beam from 100 to 400 μA for various medical applications, e.g., isotope production. The magnet mapping and shimming for the isochronous field is commonly an iterative process, which is critical for a commercial cyclotron to save the manufacturing time and reduce the cost. A numerical method is established to get the isochronous field by cutting the shimming bars at both sides of the sector pole. The method has been employed to shim the magnet for two small cyclotrons in CIAE. During the shimming process for the second cyclotron, this method has been developed to reduce the number of iterations and overall time for field mapping with the experience from the first cyclotron and accurate results of three-dimensional finite-element simulation. The shimming result shows that it satisfies the requirement of isochronism and focusing characteristics. In this paper, the development of the method is presented in detail, and the improvement for the shimming procedure is illustrated with the shimming data for the two small cyclotrons.