Physics design for the C-ADS main linac based on two different injector design schemes

The China ADS (C-ADS) project proposes to build a 1000 MW Accelerator Driven sub-critical System around 2032. The accelerator will work in CW mode with 10 mA in beam current and 1.5 GeV in final beam energy. The linac is composed of two major sections: the injector section and the main linac section. There are two different schemes for the injector section. The Injector-Ⅰ scheme is based on a 325 MHz RFQ and superconducting spoke cavities of the same RF frequency and the Injector-Ⅱ scheme is based on a 162.5 MHz RFQ and superconducting HWR cavities of the same frequency. The main linac design will be different for different injector choices. The two different designs for the main linac have been studied according to the beam characteristics from the different injector schemes.     

中国加速器驱动次临界系统主加速器初步物理设计

中国加速器驱动次临界系统（C-ADS）计划采用一个平均流强为10 mA的连续波质子加速器作为次临界堆的驱动器,驱动加速器的束流功率为15 MW,最终能量1.5 GeV,其中主加速器是驱动加速器的一个重要部分,完成束流能量从10 MeV到1.5 GeV的加速,所有加速腔均采用超导结构。为了避免频繁束流中断对反应堆的损坏,设计要求驱动加速器在运行过程中束流可以中断的次数非常有限,因此加速器在设计过程植入了容错机制,尝试了各种可能的方法以最大程度地满足C-ADS加速器的高可靠性和稳定性的要求。介绍了C-ADS主加速器的基本设计: 总长度306.4 m, 束流的归一化RMS发射度增长控制在5%以内。总结了各个重要参数选择过程中的考虑以及整个加速段多粒子跟踪模拟的束流动力学结果。     

中国加速器驱动次临界系统主加速器初步物理设计

中国加速器驱动次临界系统（C-ADS）计划采用一个平均流强为10 mA的连续波质子加速器作为次临界堆的驱动器,驱动加速器的束流功率为15 MW,最终能量1.5 GeV,其中主加速器是驱动加速器的一个重要部分,完成束流能量从10 MeV到1.5 GeV的加速,所有加速腔均采用超导结构。为了避免频繁束流中断对反应堆的损坏,设计要求驱动加速器在运行过程中束流可以中断的次数非常有限,因此加速器在设计过程植入了容错机制,尝试了各种可能的方法以最大程度地满足C-ADS加速器的高可靠性和稳定性的要求。介绍了C-ADS主加速器的基本设计: 总长度306.4 m, 束流的归一化RMS发射度增长控制在5%以内。总结了各个重要参数选择过程中的考虑以及整个加速段多粒子跟踪模拟的束流动力学结果。     

Conceptional design of a heavy ion linac injector for HIRFL-CSRm

A room temperature heavy ion linac has been proposed as a new injector of the main Cooler Storage Ring(CSRm) at the Heavy Ion Research Facility in Lanzhou(HIRFL), which is expected to improve the performance of HIRFL. The linac injector can supply heavy ions with a maximum mass to charge ratio of 7 and an injection kinetic energy of 7.272 MeV/u for CSRm; the pulsed beam intensity is 3 emA with the duty factor of 3%. Compared with the present cyclotron injector, the Sector Focusing Cyclotron(SFC), the beam current from linac can be improved by 10–100 times. As the pre-accelerator of the linac, the 108.48 MHz 4-rod Radio Frequency Quadrupole(RFQ) accelerates the ion beam from 4 keV/u to 300 keV/u, which achieves the transmission efficiency of 95.3% with a 3.07 m long vane.The phase advance has been taken into account in the analysis of the error tolerance, and parametric resonances have been carefully avoided by adjusting the structure parameters. Kombinierte Null Grad Struktur Interdigital H-mode Drift Tube Linacs(KONUS IH-DTLs), which follow the RFQ, accelerate ions up to the energy of 7.272 MeV/u for CSRm. The resonance frequency is 108.48 MHz for the first two cavities and 216.96 MHz for the last 5 Drift Tube Linacs(DTLs). The maximum accelerating gradient can reach 4.95 MV/m in a DTL section with the length of17.066 m, and the total pulsed RF power is 2.8 MW. A new strategy, for the determination of resonance frequency,RFQ vane voltage and DTL effective accelerating voltage, is described in detail. The beam dynamics design of the linac will be presented in this paper.