2 GeV等时性加速器散焦磁铁的1∶4比例模型线圈低温系统研制  

Development of 1∶4 Scale Model Coil Cryogenic System of Defocus Magnet for 2 GeV Accelerator

作　　者：周洪吉 付伟 王川[1] 王国彪 李建晖 朱晓锋 张素平[1] 靳昭军 林军[1] 汪洋 蔡红茹[1] 刘景源[1] 贾运胜 张天爵[1] ZHOU Hongji;FU Wei;WANG Chuan;WANG Guobiao;LI Jianhui;ZHU Xiaofeng;ZHANG Suping;JIN Zhaojun;LIN Jun;WANG Yang;CAI Hongru;LIU Jingyuan;JIA Yunsheng;ZHANG Tianjue(China Institute of Atomic Energy,Beijing 102413,China;Citic Heavy Industries Co.,Ltd.,Luoyang 471000,China;Suzhou Bama Superconductive Technology Co.,Ltd.,Suzhou 215000,China)

机构地区：[1]中国原子能科学研究院,北京102413 [2]中信重工机械股份有限公司,河南洛阳471000 [3]苏州八匹马超导科技有限公司,江苏苏州215000

出　　处：《原子能科学技术》2025年第1期231-238,共8页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12135020)。

摘　　要：为了掌握大范围交变梯度高温超导磁铁设计、内凹螺旋形结构的高温超导磁体绕制固定等技术,验证关键技术可行性,中国原子能科学研究院(CIAE)启动了FDF聚焦结构中散焦磁铁的1∶4比例高温超导磁铁研制。为此设计并研制了以小型GM制冷机为冷源的一种冷箱与超导线圈恒温器一体式的氦气循环系统,该系统由2台GM制冷机提供冷量,一台常温循环泵实现氦气循环,整个系统在提供足够的制冷量的前提下,能够确保高温超导线圈的温度均匀分布。该系统可将1∶4比例高温超导线圈最低冷却到25.3 K,完成了超导线圈载流性能的测试和超导线圈磁场特性测试,达到了设计的工作电流和最高磁场。验证了大型无绝缘、干式高温超导线圈在真空状态下采用氦气循环传导冷却方案的可行性,并验证了磁体与低温系统长期稳定运行性能,为新一代等时性高功率固定场交变梯度(FFAG)加速器磁聚焦结构的研制奠定了基础。In order to meet the demands of megawatt-class high-power proton accelerators for various applications,such as advanced research of high brightness in fundamental physics,and long-life-time nuclear waste transmutation,a 2 GeV/6 MW fixed field alternating gradient(FFAG)accelerator has been proposed by the China Institute of Atomic Energy(CIAE).Considering the inevitable beam loss of the high-power proton beam and the thermal effect of the accelerator,a preliminary study of the hightemperature superconducting(HTS)magnet solutions for the FFAG accelerator was carried out.To demonstrate the feasibility of manufacturing a spiral-shaped HTS magnet with concave edges based on ReBCO tapes,a 1∶4 scaled HTS magnet was currently being developed at CIAE.Considering the required magnetic field,the working current density of the superconducting strip and the energy efficiency of the refrigeration system,the optimal working point of the 1∶4 scaled HTS magnet was selected in the 30 K temperature zone.However,on the one hand,the cryogenic system for the large accelerator superconducting magnet is complex and large scale.On the other hand,there is no precedent for the cooling of large HTS magnets in the 20-30 K temperature zone.Therefore,a helium circulation cooling system for the HTS coil was developed.The refrigerator and HTS coils in this cryogenic system were housed in the same cryostat.The cryogenic system was powered by a 2 GM refrigerator,and it used a room-temperature circulating pump to circulate helium gas.The system ensured uniform temperature distribution of HTS coils.Using this system,the 1∶4 scaled HTS coil is cooled to 25.3 K.Since the cryogenic helium pipeline volume of this system is relatively small,the influence of cooling and rewarming of the HTS coil on system pressure is controllable.As there is no longer helium needed in the cooling process,the system pressure avoids to become too high after the loss of excess.The current carrying performance of the HTS coil and magnetic field characteristics of the HT

关 键 词：FFAG加速器 高温超导线圈 氦气冷却 

分 类 号：TL5[核科学技术—核技术及应用]