中国散裂中子源二期双spoke超导腔设计

周文中; 潘卫民; 葛锐; 贺斐思; 李中泉; 王子晗; 米正辉; 黄彤明; 戴劲; 马强; 徐妙富; 李梅; 王小龙; 刘佰奇; 张新颖; 刘华昌; 彭军; 王生

doi:10.11884/HPLPB202335.220266

中国散裂中子源二期双spoke超导腔设计

doi: 10.11884/HPLPB202335.220266

周文中^{1, 2, 3,},
潘卫民^{1, 3, ,},
葛锐^{1, 3},
贺斐思¹,
李中泉¹,
王子晗^{1, 3},
米正辉¹,
黄彤明¹,
戴劲¹,
马强¹,
徐妙富¹,
李梅¹,
王小龙^{1, 2},
刘佰奇¹,
张新颖¹,
刘华昌^{1, 2},
彭军^{1, 2},
王生^{1, 2, 3}

1.
中国科学院高能物理研究所，北京 100049
2.
散裂中子源科学中心，广东东莞 523803
3.
中国科学院大学，北京 100049

详细信息

作者简介:
周文中，zhouwz@ihep.ac.cn

通讯作者:
潘卫民，panwm@ihep.ac.cn

中图分类号: TL503.2
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- 文章访问数: 706
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- 被引次数: 0
出版历程
- 收稿日期: 2022-08-26
- 修回日期: 2023-01-01
- 录用日期: 2023-01-01
- 网络出版日期: 2023-02-04
- 刊出日期: 2023-03-01

Design of the China Spallation Neutron Source phase II double spoke resonator

Zhou Wenzhong^{1, 2, 3
,},
Pan Weimin^{1, 3
, ,},
Ge Rui^{1, 3},
He Feisi¹,
Li Zhongquan¹,
Wang Zihan^{1, 3},
Mi Zhenghui¹,
Huang Tongming¹,
Dai jin¹,
Ma qiang¹,
Xu Miaofu¹,
Li Mei¹,
Wang Xiaolong^{1, 2},
Liu Baiqi¹,
Zhang Xinying¹,
Liu Huachang^{1, 2},
Peng Jun^{1, 2},
Wang Sheng^{1, 2, 3}

1.
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
2.
Spallation Neutron Source Science Center, Dongguan 523803, China
3.
University of Chinese Academy of Sciences, Beijing 100049, China

摘要

摘要: 中国散裂中子源是中国第一台、世界第四台脉冲型散裂中子源，其已于2020年2月达到100 kW功率的设计指标，运行稳定高效，供束效率位于国际前列。中国散裂中子源二期升级方案中总束流功率将升级到500 kW，其中直线加速器段将采用超导加速腔结构，束流能量由80 MeV提高到300 MeV。其中在80～165 MeV能量段采用324 MHz双spoke超导腔，在165～300 MeV能量段采用648 MHz 6-cell椭球超导腔。采用CST、COMSOL等仿真软件完成324 MHz双spoke超导腔的电磁、机械设计及优化，达到实际运行指标要求。为了提高腔运行的稳定性，在腔的设计中对E_P/E_acc着重进行了优化，使其尽量降低。
- 双spoke超导腔 /
- 氦压灵敏度 /
- 洛伦兹力失谐 /
- 二次电子倍增 /
- 调谐灵敏度
Abstract: The China Spallation Neutron Source (CSNS), located in Dongguan city, is the country's first and only spallation neutron source. It is also the fourth spallation neutron source in the world. It achieved the design index of 100 kW power in February 2020, and its operation is reliable and efficient. The total beam power will be increased to 500 kW in the CSNS phase II upgrade design, where the linac beam energy will be boosted from 80 MeV to 300 MeV and the peak current intensity will be increased from 15 mA to 50 mA by incorporating a superconducting linear accelerator. The double spoke resonator (DSR) will be used in the energy range of 80 MeV to 165 MeV. In the energy range of 165 MeV to 300 MeV, 6-cell ellipsoidal cavity will be used. DSR has many advantages, such as large velocity acceptance, which allows the spoke cavity to be used for a wider range of velocities, small size, high shunt impedance and a high coupling degree, which allows the production error requirements to be relaxed and the frequency bandwidth to be broadened from neighboring modes, among others. The DSR performance, including electromagnetic properties and machine parameters, was simulated and optimized using CST, COMSOL and other simulation software, and it achieved the requirement of CSNS phase II upgrade project. To improve the operating stability of the cavity, the design focused on minimizing E_p/E_acc.
- double spoke resonator /
- pressure sensitivity /
- Lorentz force detuning /
- multipacting /
- tuning sensitivity

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图 1 双spoke腔的基本参数示意图

Figure 1. Schematic diagram of basic parameters of double-spoke cavity

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图 2 参数优化流程框图

Figure 2. Flow chart of parameter optimization

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图 3 E_p/E_acc=4.1时电场在内表面及轴向分布

Figure 3. Distribution of electric field on the internal surface and axis with E_p/E_acc =4.1

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图 4 双spoke腔TTF分布

Figure 4. TTF distribution of DSR

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图 5 MP易发生的位置及不同材料SEY曲线仿真

Figure 5. MP’s position and SEY simulation of different materials

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图 6 耦合器天线及Q_e仿真计算

Figure 6. Simulation calculation of coupler antenna and Q_e

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图 7 双spoke腔槽结构

Figure 7. The mechanical structure of DSR

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图 8 腔的应力分布与端盖半弧形加强筋结构

Figure 8. Stress distribution of DSR and cambered reinforcing ribs

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图 9 LFD系数的拟合

Figure 9. LFD coefficient of DSR

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图 10 双spoke腔本征机械频率及振动方式

Figure 10. Mechanical intrinsic frequency and vibration mode of DSR

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图 11 装置地地磁场分解

Figure 11. Decomposition of the earth magnetic field

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图 12 双spoke超导腔磁屏蔽结构和轴线剩余磁场分布

Figure 12. Design of magnetic shield and distribution of residual magnetic field in axis of DSR

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图 13 双spoke腔焊接示意图

Figure 13. Welding diagram of DSR

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表 1 双spoke腔主要电磁参数

Table 1. Main electromagnetic parameters of DSR

frequency/MHz	β₀	aperture/mm	E_p/E_acc	B_p/E_acc/(mT·MV⁻¹·m)	G/Ω	（R/Q）/Ω	operating gradient/(MV·m⁻¹)
324	0.5	50	4.1	9.2	120	410	7.3

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表 2 双spoke腔的基模频率和高次模频率

Table 2. Fundamental model frequencies and high order mode frequencies of double spoke resonator (DSR)

model	frequency/MHz
1	324
2	354
3	386
4	503
5	505
6	548
7	603
8	604
9	613
10	658

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表 3 材料在不同温度下的参数

Table 3. Material parameters at different temperatures

material	Young’s modulus/GPa		yield strength/MPa		limit strength/MPa		density/ (kg·m⁻³)	Poisson’s ratio
material	295 K	4 K	295 K	4 K	295 K	4 K	density/ (kg·m⁻³)	Poisson’s ratio
Ti	106	117	275	834	344	1117	4500	0.34
Nb	105	118	70	699	185	742	8560	0.39
Nb55Ti	62	68	476	476	545	545	6366	0.34

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表 4 各个模式振动方式

Table 4. Vibration direction of each model

model	vibration model	vibration frequency/Hz
1	z-axis rotation	3.0
2	y-axis rotation	3.4
3	z-axis rotation	13.7
4	transverse vibration	34.3
5	z-axis simultaneous vibration	167.6
6	z-axis anisotropic vibration	174.7
7	z-axis rotation	196.3

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