High intensity cyclotrons are widely applied in cutting-edge fields. A new high intensity H-cyclotron has been designed and commissioned at the China Institute of Atomic Energy (CIAE) for medical isotope production and potential neutron source research. This paper presents the development of high-quality-factor cavities for this proton cyclotron, integrating numerical simulations and experimental validations. A comprehensive analysis of key restrictive factors in cavity design led to two distinct schemes. Systematic investigations showed that for Scheme A (single-amplifier driven), central-plane electric field leakage and mechanical installation tolerances significantly impaired performance. Considering beam loading effects and RF system stability, Scheme B (dual-amplifier driven) was selected as the optimal solution. Prototype tests verified that the cavity achieves an unloaded quality factor over 6000 and an extracted beam current exceeding 1000 mu A, fully meeting predefined design specifications. This work lays a solid technical foundation for advancing compact high-current accelerator technology.

Medical cyclotrons serve as core equipment for clinical diagnosis and therapeutic applications in nuclear medicine. The electromagnetic compatibility (EMC) performance of their high-voltage power supplies is critical to ensuring the operational stability of the cyclotron, the normal functioningof surrounding medical devices, and overall system safety of the clinical system. In this study, EMC testing was performed on the high-voltage power supply of a medical cyclotron in strict accordance with YY 9706.102-2021, the Chinese national standard equivalent to the international standard IEC 60601-1-2:2007. The test results showed that the device passed most of the required immunity tests, while significant non-compliance issues were identified in both conducted emission (CE) and radiated emission (RE) measurements. Based on the frequency spectrum analysis of the CE test, noise at 0.17 MHz and 0.27 MHz was identified to be dominated by differential-mode (DM) interference, while the simultaneous over-limit emission on both L and N lines at 1.308 MHz and 1.476 MHz indicates that common-mode (CM) noise is dominant in this frequency band. For RE, multiple discrete emission peaks appeared in the $\mathbf{1 0 0 - 6 0 0 ~ M H z}$ frequency range, which are not integer multiples of the 30 kHz switching fundamental frequency of the power supply. This phenomenon originates from the coupling of high-frequency switching harmonics and structural resonance of the equipment. Considering the strict constraints on on-site rectification of medical high-voltage power supply systems, this work adopts a systematic research framework of “emission mechanism analysis-structural optimization design-numerical simulation evaluation”. Equivalent circuit models and three-dimensional electromagnetic field models were established using Simplorer and CST Studio Suite, respectively. A two-stage input filtering scheme for conducted emission suppression and a non-ideal shielding cabinet optimization scheme for radiated emission suppression were designed targeting the identified CE and RE issues separately, and simulation experiments were carried out to evaluate the rectification effectiveness of the proposed schemes.

The Beijing Radioactive Ion-beam Facility (BRIF), based on the Isotope Separation On-Line (ISOL) technique, consists of a 100 MeV proton cyclotron as the driving accelerator, a two-stage ISOL system for ion separation, a 13-MV tandem accelerator for post-acceleration, a superconducting linac for further boosting beam energies. It is capable of providing ISOL beams in the energy range from 60 to 300 keV, and post-accelerated beams in the energy range from 3 to 10 MeV/u for nuclei with mass numbers of A < 80. For nuclei with A up to 170, energies are still able to reach 3 MeV/u. This facility offers opportunities to address key questions of current interest in nuclear astrophysics, nuclear structure and reactions of unstable nuclei. In this review we present a comprehensive introduction to the BRIF and the typical experimental instruments installed on it, and then summarize current experimental results on unstable Na and Rb isotopes and future plan for development of the BRIF to improve its performance.

Vacuum surface flashover is a critical factor limiting the insulation reliability of ion source extraction systems. This study proposes a structural mitigation strategy based on the secondary electron emission avalanche (SEEA) theory. The electric field distribution at the metal–vacuum–dielectric triple junction is analyzed through finite element simulations, revealing strong local field distortion. A grooved plasma electrode design is introduced to suppress the peak electric field in this region. Simulation results confirm that the groove structure significantly reduces electric field intensity, thereby lowering flashover risk. Furthermore, the impact of groove geometry on vacuum conductance is assessed using molecular flow theory, highlighting a coupling constraint between field suppression and gas evacuation. The findings suggest that future designs should comprehensively balance electric field mitigation and vacuum performance.

Since 2016, a superconducting cyclotron (SC)-based proton therapy (PT) system has been designed, constructed, installed, and commissioned at the China Institute of Atomic Energy (CIAE). It includes a SC CYCIAE-230, a beamline with a fast energy selection system (ESS), a 360 degrees gantry, and a pencil beam scanning nozzle. Also, there is another beamline for proton irradiation, for example, used for space science research. This article will briefly introduce the overall design of the PT system. The results of the beam commissioning, from the cyclotron to the nozzle, will be emphasized. As early as September 2020, the proton beam's energy accelerated by the SC reached 231 MeV; the 360 degrees gantry had been tested by experts and found an isocenter better than 0.3 mm at any angle. After obtaining comprehensive commissioning permission in late November last year, we finished the test of the PT system with the following results: the energy of the cyclotron is 242 MeV, the energy range of the degrader is 71-242 MeV, the maximum average beam intensity extracted is 462 nA, and the measured efficiency of the beam from the central region to outside the cyclotron is 74%; it is 45 ms the time interval varying one energy step of the degrader and 51 units of the magnets. The results will be presented in detail in this article.

Based on the excellent radionuclide properties of 18F, amino acids labeled with radioactive nuclide 18F have shown its unique advantages in brain tumor imaging. A liquid target system with niobium as the target material and 18O(p, n)18F isotope was developed based on the 14 MeV cyclotron of the cyclotron research group of the Department of Nuclear Technology and Application, China Institute of Atomic Energy. In order to solve the problems of complicated structure and poor cooling effect of liquid target system cooled by helium, a liquid target system with direct water cooling is designed. The structure design process and material selection of liquid target are introduced in detail, and the stability of its transport system and control system is tested. The analysis results show that the liquid target system produced by this isotope has good stability. Under the irradiation of 20 μA beam intensity for 2 h, the yield of the product is 1.5 Ci. At present, it has been applied in Peking University, the system has good stability and repeatability, and has been highly praised by users.

The ion source is one of the key devices for the high-intensity cyclotron,which exerts influence on the beam intensity and applications of the machine.As part of the cyclotron research and development effort,China Institute of Atomic Energy(CIAE)has been developing arc discharge H ion sources based on volume production and multi-cusp magnetic configuration since 1997.In 2000,5.2 mA H-beam was reached and 15 mA H beam was achieved in 2010.After a long break,H ion source development started again in 2022 in order to improve performance of the main H-ion source of the CIAE 18 MeV cyclotron and to fulfill the requirement of future other high intensity proton beam cyclotrons for the high intensity H-ion.A new H-ion source and test stand was built at CIAE in 2023.The design of this new ion source was based on the experience on our previous 15-20 mA H-ion source and the source at TRIUMF.Major efforts included the study of the virtual filter magnetic field for filtering out fast electrons,multi-cusp confining magnetic field,four-half-circle ring filaments length and location,improvement of extraction structure and upgrading of vacuum system and power supplies.Up to now,more than 21 mA of H-beam were obtained at a high volt-age of 35 kV from a plasma electrode hole of 13 mm in diameter when the hydrogen flux was 25 sccm.At this output the maximum arc power available is only 4.5 kW and the e/H ratio is about 5.When the hydrogen flux is higher or extraction high voltage is higher,H-beam currents can reach 22 mA.However,the H-beam is very unstable with terrible sparks at extraction and acceleration gaps in this case,about five times a minute.This appears to be due to the lack of a differential pumping structure,which also results in an unexpectedly high hydrogen flux.In the experiment,the relationship between arc power and H-beam intensity was determined,also the optimal location of the four-filament structure was determined,which is obviously related to the virtual filter magnetic field distribution.At present,the emittance scanner is being processed and the measurement program is also updated and improved,the beam emittance has not been measured and analyzed at this stage.Subsequently,the vacuum chamber structure will be improved,the extraction structure also will be optimized to obtain brighter H-beam,and a long-lasting filament will be developed to reduce maintenance time.

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.

ABSTRACT A new double-gap buncher is designed for the CYCIAE-10 cyclotron in order to get the high-intensity proton beam with the order of mA. RF simulation is carefully performed to achieve a deep quantitative analysis of the equivalent capacitance and electrical field distribution. Uniform electrical field technology is verified by EM field simulation to get an electrical field uniformity of 94.67%. Type L matching circuit is used to transfer the loading reactance to 50 Ohms. Variable vacuum capacitor with 5–50 pF is selected for its small power loss and the convenience of commissioning. Dynamic calculation of the buncher and mechanical design are also presented in this paper. The open-loop bench test shows that 370 Vpeak RF voltage is established in the central electrode with power consumption of 37 W. Alternative redesign and online test are carried out, and more than 1 mA H− beams are achieved on the inner target, which verify the buncher design. Graphical Abstract

Superconducting synchrocyclotron for proton therapy has grown rapidly in recent years. Frequency modulation is considered as the unique technology of synchrocyclotron. In the process of theoretical cavity design of CIAE-230 MeV superconducting synchrocyclotron, the frequency modulation algorithm, based on the characteristic of cavity electromagnetic field distribution, is developed and then validated on the model cavity test. The rotor system works effectively at the speed of 7500 RPM, which indicates that the cavity modulation frequency reaches the kHz level. The interactive design related to the magnetic field is also introduced in this paper. The technical feasibility research on frequency modulation in this paper paves the way for the whole machine development.

Yttrium-86 (86Y, t1/2 = 14.7 h, 33% β+) is a nonstandard medical nuclide with a longer half-life than other standard nuclides such as gallium-68 for radiolabelling for PET (positron emission computed tomography) imaging. 86Y is compatible with DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and can be used to evaluate DOTA-chelated radiopharmaceuticals with long clearance half-lives, particularly therapeutic radiopharmaceuticals in several days. 86Y can be produced through 86Sr(p, n)86Y reaction, in which 86Sr-enriched SrCO3 powder is bombarded with low-energy protons. To handle the SrCO3 powder, a powder target for 86Y production in 14.6 MeV proton cyclotron was designed while maximizing yield, reliability and efficiency. To that end, the target's primary design parameters were traversed, simulated and optimized using computer algorithms to obtain advantageous parameter combinations. In this way, 86Y was produced on the powder target with high yield and successfully isolated with high purity (>97%) by solid-phase extraction via DGA resin for high-quality PET imaging and drug screening.

In this paper, the domestic and international demand and development trend of clinical diagnostic radionuclides are analyzed, and the medium and high-energy cyclotrons, adequate and systematic facilities, and preparation techniques required for the production of medical radionuclides based on solid targets are introduced. This paper focuses on the research and development carried out by some important medical institutions and scientific research institutes in China over the years in the aspects of medium and high-energy cyclotrons, beam transmission lines, high-power irradiation target stations and new medical isotope production processes etc. It also looks forward to some new directions for the development of medical radionuclides in China during the 14th Five-Year Plan period.

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.

A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). In order to provide high quality proton beams for instant radiopharrnaceutical distribution, and to produce a variety of radioactive ion beams taking use of the solid target, CYCIAE-14 adopts an injection system based on the external H+ ion source, axial injection, and spiral inflector with a designed high beam intensity, while most PET cyclotrons adopt internal ion source. With the different using for the cyclotron, there are two projects. One project with 200 mu A/14 MeV can be used for isotope production of C-11, O-18, N-13 and F-18. Another project with more than 400 mu A with 14 MeV can be used for more isotopes produced such as Cu-64, I-124 and Tc-99m. This paper will introduce the cyclotron of CYCIAE-14 with the two projects, and some experiments finished on the cyclotron will also be given in the paper, for example the F-18 and Zr-89 production, BNCT test.

At CIAE, we have been engaged in the development of isochronous accelerator for 60 years. From Cyclotron in the past to CW FFAG at present, isochronous accelerators have the technical advantages of high average beam intensity, fixed magnetic field and RF frequency, and low construction and operation costs. Therefore, the isochronous accelerator has been widely used. In this paper, a 100 MeV compact isochronous cyclotron CYCIAE-100 developed at CIAE in recent years is introduced. The successful commissioning of the cyclotron obtains a proton beam power up to 52 kW. Its stable operation provides dual-beam with the intensity ranges from 10 pA to 520 μA, and its applications are carried out annually for more than 30 users in different research fields. This paper also introduces a 2 GeV CW FFAG first proposed by CIAE. From the design of the 2 GeV CW machine, the energy limitation of the isochronous accelerator is increased from ∼1 GeV to 2 GeV, by our contribution of the beam dynamics study for high energy isochronous FFAG. The basic design of the key components, including HTS magnet, HP RF system, injection and extraction system, have also been explored. The preliminary conclusions suitable for engineering implementation are also presented.

In China, there is a strong demand of the medium-energy proton accelerators for proton therapy. A compact superconducting cyclotron named CYCIAE-230 is currently under construction at CIAE to provide 230 MeV proton beam. In this paper, the investigation and quantitative simulation of beam physics for CYCIAE-230 will be presented in detail, which mainly include: 1. The beam dynamics behavior in the ultra compact central region and the design challenges including the micro PIG ion source, the tips of magnetic poles and RF cavities; 2. the numerical simulation and optimization of the phase slip and tune diagram in acceleration region; 3. the orbit simulation in the extraction region, emphasizing on increasing the turn separation and the resonance study; 4. the fast intensity modulation, control of beam stabilization by a closed-loop feedback, and the basic algorithm for controlling the beam intensity, adjusting the phase and their implementations.

The term industrial ecology refers to the idea that nature can serve as a useful metaphor for industrial systems, which can be used to help industry become more efficient and more sustainable. Industrial symbiosis network (ISN) provides highly inter-dependent relationship between each two firms (members), exchanging materials and energy in a mutually advantageous manner to improve environmental, economic and social benefits in a regional level. Chemical industrial park is a practical form of industrial symbiosis network to emerge to achieve the goal of resource sharing among the participating chemical firms. To identify potential schemes for resource conservation and waste reduction, it is important to consider the process integration techniques, which allow industries for analysis and design of process and utility systems to increase both sustainability and profitability through reductions in energy, water and raw materials consumption, greenhouse gas emissions and waste generation. This work proposes sequential multi-objective pinch analysis (SMOPA) method based on the pinch analysis technique. The SMOPA proposes a sequential method to determine water and energy consumption, and carbon emission targets to achieve an optimal system. (1) Determine the minimum freshwater consumption, the minimum regeneration water and wastewater discharge; (2) Determine the minimum amount of hot and cold utilities; (3) Determine the minimum amount of clean energy and energy distribution in each region using carbon emission pinch analysis approach. The ISN case study is presented to illustrate the proposed method and the detailed

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.