The China Fusion Engineering Test Reactor (CFETR) will be a superconducting tokamak featuring sixteen toroidal field (TF) coils; a full-size TF coil, based on a national scientific research project, has been designed and is currently being built. The first cool-down test of the TF coil is foreseen to take place in 2025. During the entire cool-down process, it is necessary to ensure that the temperature difference between any two positions of the TF coil is <50 K to avoid irreversible damage to the coil caused by excessive thermal stress. However, the maximum temperature (Tmax) within the TF coil cannot be directly and accurately obtained through experimental measurements; therefore, the thermal hydraulic analysis is crucial to prepare the cool-down strategy of the coil. In this paper, the first cool-down analysis of one CFETR TF coil is completed using the 4C code. The code is based on a 1D model of the helium flow inside the cable-in-conduit conductors coupled to a set of 2D cross sections of the steel structures, where the heat conduction is modeled. The thermal coupling between the turns and the pancakes, as well as the coupling between winding and casing, is also considered. The maximum temperature evolution within the magnet is computed and the optimized cool-down strategy (inlet temperature, inlet and outlet pressure evolution) is proposed.

The Central Solenoid Model Coil (CSMC) has been manufactured and assembled as part of the R&D projects for the China Fusion Engineering Test Reactor (CFETR), and will be tested at ASIPP. The measurement of the current sharing temperature (T-cs) of the coil at maximum operating current of 47.65 kA is proposed to assess the performance of the coil. The T-cs is defined as the point where the electric field locally reaches 10 mu V/m. During the T-cs test, voltage taps measure the voltage of each cooling channel of the CSMC. Reliable thermal-hydraulic predictions are necessary to estimate the total voltage across a cooling channel when the local electric field is 10 mu V/m, supporting the definition of the T-cs loop heating strategy. A predictive analysis of the T-cs tests for the CSMC is carried out, using the GANDALF code. An optimum heating scenario, based on the staircase strategy is developed to reduce cryogenic costs.

Since the last IAEA-FEC in 2021, significant progress on the development of long pulse steady state scenario and its related key physics and technologies have been achieved, including the reproducible 403 s long-pulse steady-state H-mode plasma with pure radio frequency (RF) power heating. A thousand-second time scale (similar to 1056 s) fully non-inductive plasma with high injected energy up to 1.73 GJ has also been achieved. The EAST operational regime of high beta(P) has been significantly extended (H-98y2 > 1.3, beta(P) similar to 4.0, beta(N) similar to 2.4 and n(e)/n(GW) similar to 1.0) using RF and neutral beam injection (NBI). The full edge localized mode suppression using the n = 4 resonant magnetic perturbations has been achieved in ITER-like standard type-I ELMy H-mode plasmas with q(95) approximate to 3.1 on EAST, extrapolating favorably to the ITER baseline scenario. The sustained large ELM control and stable partial detachment have been achieved with Ne seeding. The underlying physics of plasma-beta effect for error field penetration, where toroidal effect dominates, is disclosed by comparing the results in cylindrical theory and MARS-Q simulation in EAST. Breakdown and plasma initiation at low toroidal electric fields (<0.3 V m(-1)) with EC pre-ionization is developed. A beneficial role on the lower hybrid wave injection to control the tungsten concentration in the NBI discharge is observed for the first time in EAST suggesting a potential way toward steady-state H-mode NBI operation.

The Central Solenoid Model Coil (CSMC) has been manufactured as part of the R&D projects for the China Fusion Engineering Test Reactor (CFETR), and it will undergo testing in the second half of 2024. For the safety operation of magnet, predictive analyses are required to study thermal-hydraulic behavior of the CSMC during the quench. In this paper, the different quench initial position is detailed studied, for example, quench initiates at the peak magnetic field region and the lowest magnetic field region. In addition, the different quench disturbances are considered, such as (disturber length 0.01 m and disturber time 3 ms), (disturber length 1 m and disturber time 3 ms), and (disturber length 6 m and disturber time 100 ms). In all cases, the designed quench protection system is satisfied with the present design criteria concerning the hot spot temperature and the maximum helium pressure.

Within the framework of the comprehensive research facility for fusion technology (CRAFT) activities, a prototype toroidal field (TF) coil has been designed and will be manufactured at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), in Hefei. The main purpose is to develop and validate the manufacturing technologies of the large-scale superconducting coils of the China Fusion Engineering Test Reactor (CFETR). To ensure the safe operation of the CFETR device, the Gandalf-Fluent tool and the 4C code are employed to evaluate the performance of the superconducting magnets, and their thermal-hydraulic simulation results are compared with each other. The comparison shows that the thermal coupling between turns and pancakes and the transient model of the thermal coupling to the casing structures, accounted for in 4C but neglected in Gandalf-Fluent, have a significant effect on the temperature profile. Then a detailed reassessment of the minimum temperature margin (Delta T-mar(min)) is carried out using the 4C code. The results show that the Delta T-mar(min) is similar to 1.0 K (if a realistic value for the inter-turn and inter-pancake coupling parameter is assumed), lower than the design requirement of 1.2 K, and it deserves the attention of the designers.

Tokamak superconducting TF coils experience severe structural and thermal loads during operation. Hence optimizing the design of the conductor and the coil is crucial, making it inevitable to repeatedly try different conductor and WP configurations, and then perform structural analyses for the magnet. However, due to the fact that the magnet is huge in size, meanwhile the WP constituents are heterogeneous, complex and small in dimension, it is generally unrealistic to perform a global 3D structural analysis on a magnet model with detailed WPs. Smeared WPs with equivalent homogeneous properties are therefore commonly used to build the finite -element model. Usually, the smeared properties of WP are calculated by finite-element analyses, which are time costly and cumbersome. Here the ANN approach is proposed to calculate the WP smeared properties. First, the conductor and WP configurations are summarized, and a universal representative WP model is developed. Then, 4322 training cases are calculated by finite-element analyses with ANSYS. Next, the ANN model is built and the training cases are fed into it, after 298 iterations the ANN achieves convergence with excellent per-formance. Finally, the effectiveness of the trained ANN is demonstrated. Our results indicate that the ANN approach of calculating the WP smeared properties is reliable and can reduce the calculation time by 5 order of magnitude than the finite-element analysis.

The SC200 superconducting cyclotron for hadron therapy is developed by collaboration of ASIPP (Hefei, China) and JINR (Dubna, Russia). However, the spatial shift of superconducting coils in a cyclotron will lead to the deviation of the magnetic from the requirements. It has an adverse effect on the acceleration of the beam. This article studies the effect of the tilt and horizontal offsets on the magnetic field in cyclotron. These two offsets can be detected by measuring the first harmonic of radial and axial components of the magnetic field on the midplane, respectively. Additionally, it is proved that the mixed offset of superconducting coils can be decomposed into these three fundamental offsets: vertical offset, tilt, and horizontal offset. Experimental data also indicate that this method can substantially reduce the first harmonic of the radial component of the magnetic field in the required area, which means that the superconducting coils are aligned in space.

The toroidal field (TF) coil is a crucial system in China Fusion Engineering Test Reactor (CFETR). The operating safety of the magnet will strongly depend on the heat load and the capability of the coolant to remove it. The adequate cooling design of the TF coil case can effectively establish thermal shielding to prevent the heat flux from the TF coil case to the winding. An orthogonal scheme is applied to optimize the cooling design. The effect of the parameters of the cooling channels on the heat transfer from case to conductors is studied, such as the channel numbers N, the distance between the cooling channel and the edge P, the diameter of the pipe D, and the mass flow rate M. Compared with the original design, the optimization design significantly improves the cooling capacity.

China Fusion Engineering Test Reactor (CFETR) has received much attention over the past several years, aiming at bridging the gap between the International Thermonuclear Experimental Reactor (ITER) and the Demonstration Fusion Reactor (DEMO). The toroidal field (TF) coils play an important role in the tokamak, which provide the main magnetic field to confine the plasma. In order to evaluate the feasibility of superconducting magnets used in CFETR, it is important to predict the magnet performance in terms of temperature margin during normal operation conditions. The simulations confirm the need to increase the mass flow rate, or decrease the hydraulic length of high field windings. The results show that the proposed reduction of hydraulic length is more effective to increase the minimum temperature margin.

SC200 cyclotron is a compact superconducting cyclotron for proton therapy developed by the ASIPP (Hefei, China)-JINR (Dubna, Russia) collaboration. In this paper, some beam dynamics simulations are done to evaluate the magnetic field of SC200 measured by mapping system. Magnetic field is optimized by shimming bars and coils to make sure beam can be accelerated to the entrance of extraction system. The optimization of isochronism of magnetic field, beam radial oscillation caused by imperfect first harmonic of magnetic field, magnetic vertical focusing force and radial magnetic field at median plane are presented. The tolerance of imperfect average magnetic field bump and radial magnetic field are studied by beam dynamics simulation.

The toroidal field (TF) coil is a crucial system in the tokamak, which provides the main magnetic field to confine the plasma. One TF coil of the China Fusion Engineering Test Reactor (CFETR) will be constructed with the support of the Chinese government in the next five years. In order to study the quench behavior of the CFETR TF coil, the assumed quench initiation at the maximum and minimum temperature margin position of the TF coil is analyzed, and the effect of the quench detection threshold on the hot spot temperature is studied. It is found that 0.5 V quench detection voltage leads to hot spot temperature above 250 K in the low-field region. In order to meet the design criteria of the hot spot temperature, the quench detection voltage should be less than 0.2 V.

回旋加速器中的超导磁体由于加工和安装误差会在垂直方向上存在偏移现象.该现象导致加速器内磁场偏离设计,影响束流的有效加速.目前测量超导磁体的垂直偏移主要依靠机械测量和力学传感器监控,这些方法只能在工程上确定超导磁体是否对中,而最后的对中效果仍需要通过磁场测量确认.基于中俄正在联合研制的200 MeV超导质子回旋加速器SC200,详细阐述直接利用其中平面平均径向场相对变化计算超导磁体垂直偏移的过程.对比模拟和实验的数据表明,该方法能够将主加速区中平面的平均径向场控制在±1 Gs以内,即实现了超导磁体在垂直方向上的对中,为SC200的研制奠定了扎实的基础,也为其他回旋加速器中超导磁体的位置调整提供了参考.

A set of gas nitriding coating device suitable for the electrostatic deflector (ESD) of cyclotron is designed. Using this device, the TiN coating on small electrode of titanium alloy coupons was carried out in the mixture of nitrogen and ammonia. The effects of nitriding temperature and time on the reaction results were studied, the results of the coating experiment were analyzed, and the surface treatment parameters suitable for gas nitriding TiN coating on the surface of the titanium alloy electrode of the ESD were obtained. X-Ray Diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize and analyze the properties of nitrided coatings. And a high voltage discharge experiment was performed on the sample to measure its dark current. The results show that under atmospheric pressure, annealing temperature of 900 °C, and holding time of 8 h, the coating conditions of titanium alloy electrode materials has the best performance.

China fusion engineering test reactor (CFETR), based on ITER technology and bridged between ITER and DEMO, has been supported by China government to start technologies R&D and engineering design. The field of CFETR at plasma core is 6.5 T, maximum field of TF coil is about 14.8 T. TF coil is wound by Nb3Sn and NbTi CIC conductors. Coil weight is about 650 tons with height about 21.7 m and width about 12.3 m. Prototype TF coil manufacture design consists of mechanical & electro-magnetic design and analysis, conductor design and analysis, coil AC loss analysis, thermal–hydraulic analysis and coil cooling, quench detection and coil protection, coil winding, case manufacture, and coil assembling. The TF prototype coil is one sub-task of the CRAFT project, which will last for 5 year and 8 months and is constructed by ASIPP and SWIP cooperatively. The preliminary design of the TF prototype coil has been finished at the present stage. In this paper, the basic design requirements of TF magnet are introduced firstly. Next, the preliminary design and analysis of the TF coil is described, which includes the winding package (WP) design, the coil case (CC), the conductor design and analysis, the electromagnetic, mechanical and AC losses analysis. Then the process and tooling design for the WP and CC manufacturing and assembling is presented. Finally, a summary and a plan are given.

中国聚变工程实验堆(CFETR)是中国新一代聚变装置,环向场(TF)磁体系统是托卡马克关键部件之一.根据TF线圈冷却要求,给出CFETR TF线圈盒冷却的初步设计.通过开展2D模拟分析TF线圈盒冷却通道数量、质量流量、位置等参数对冷却效果的影响.模拟结果表明,增加冷却通道数量可显著减少导体热流量;而增加质量流量对冷却效果的提高不明显.线圈盒内腿段盖板(AP)组件冷却通道由16条增加至30条后,绕组热流量降低至2.01 W/m,减小了约37％.同时,模拟发现缩短冷却通道与拐角间的距离,可显著提升冷却效果.

The SC200 cyclotron is the critical component of the proton therapy system, which is being jointly developed by the Institute of Plasma Physics Chinese Academy of Sciences (ASIPP), Hefei, China, and the Joint Institute for Nuclear Research (JINR), Dubna, Russia. It is an isochronous cyclotron to accelerate H+ ions and extract proton beam energies of 75-200 MeV with the maximum beam intensity of 1 mu A. The maximum magnetic field intensity of the SC200 cyclotron is 4.6 T, and the accuracy of measurements for the average isochronous field is required to be better than 10(-4). The magnetic gap decreases from 37 mm at cyclotron center to 9 mm at the pole edge. Hence, the difficulty of designing a magnetic field measurement system is increased because of the required magnetic field accuracy and the narrow gap between the poles. A measurement system has been developed to measure the magnetic field distribution in the median plane of the cyclotron by the SENIS Hall probe. After the Hall probe is calibrated by NMR, the measurement accuracy can reach +/- 4 x 10(-4) under the magnetic field intensity of 5 T. The position of the Hall probe will be monitored by grating and optical encoder, respectively, so as to ensure its correct positions. To verify the performance of the mapping system, it has been tested in the SC200 cyclotron with the designed vacuum degree. The test results showed that the mapping system can run smoothly and meet the measurement requirements of the SC200 cyclotron.

The China Fusion Engineering Test Reactor (CFETR) Central Solenoid (CS) Model Coil is being fabricated by the Institute of Plasma Physics Chinese Academy of Sciences, and will be cryogenically tested in 2021. In order to validate the structural integrity of the CS Model Coil under seismic loads, response spectrum (RS) and time history analyses have been carried out. This paper first introduces the manufacturing progress of the CS Model Coil and the structure of the CS Model Coil. Then, the RS analysis is perfomed with the complete-quadratic-combination (CQC) modal combination rule. Finally, time history analyses under the artificial Hefei wave and the modified El Centro wave are conducted. The seismic response of the CS Model Coil is described and the obtained maximum von-Mises stresses are respectively 30.9 MPa and 34.0 MPa for the RS and time history analysis. These stresses are mainly caused by the horizontal excitations, and are lower than the allowable stress limit.

A comprehensive research facility project was approved in December 2018 with funding of 345 million EUR, to support the research and development of the China Fusion Engineering Test Reactor (CFETR). As part of this project, a full-size CFETR toroidal field (TF) coil will be designed, manufactured and tested by the Institute of Plasma Physics Chinese Academy of Sciences. Two options are being explored in parallel for the TF coil design, using either circle-in-square or rectangular cable-in-conduit conductors (CICCs). The rectangular CICC has been reported to have some merits for a DEMO TF coil, as reported in designs of the EU-DEMO and K-DEMO. First this paper presents the progress in the conceptual design of the CFETR TF coil with rectangular CICCs, according to the most recent reference single-null configuration and radial build of CFETR. Then, electromagnetic analyses are performed to give the magnetic field distributions, toroidal field ripple, in-plane and out-of-plane Lorentz loads. Finally, 3D global and 2D local mechanical analyses are conducted, and the detailed mechanical behavior of the TF coil is illustrated and discussed. Our analyses indicate that the present TF design is reasonable, considering the ITER criteria, and provides valuable insight into the mechanical behavior of the CFETR TF coil system.

er to detect the beam quality of the SC200 superconducting cyclotron,measure the beam at the extraction reference and the acceptance of the accelerator is realized.This article mainly introduces the design that use the scintillation screen at the extraction reference to measure the beam profile,position and use the Faraday cup to measure the current intensity with 2.5 level accuracy.The remoted controlling of probes and the acquisition and processing of signal based on LabVIEW and PLC.

Background Considering the nonlinearity of magnet material, the homogeneity of the material and the accuracy of the finite element numerical simulation, sufficient safety margin of the sector is left in the design of the main magnet. In order to obtain ideal isochronous magnetic field after the machining and assembling the magnet, the shimming procedure is necessary according to the actual measured magnetic field. It can ensure the safe implementation of the project. [Purpose] This study aims at the magnet shimming method that is very important for the design and manufacture of the main magnet of cyclotron. [Methods] First of all, the influence of different cutting parameters of magnet pole on the magnetic field in the middle plane was investigated by using the finite element analysis software TOSCA. Then the superposition effect of adjacent grooves on magnetic field was considered to give a numerical method for calculating the shimming value of the sectors. [Result&Conclusion] The feasibility of magnetic field shimming method was verified by simulation, which provides an effective basis for actual magnetic field shimming in the future.