【作者】 闫芳； 李智慧；

【Author】 YAN Fang,LI Zhi-hui (Institute of High Energy Physics,Beijing 100049,China)

【机构】 中国科学院高能物理研究所；

【摘要】 中国加速器驱动次临界系统(C ADS)项目预计于2032年建成一个反应堆热功率为1000 MW的加速器驱动次临界洁净核能系统。驱动加速器采用RFQ及超导直线加速器将CW质子束加速到1.5 GeV,平均流强为10 mA。ADS对加速器的稳定性和可靠性有很严格的要求,为安全起见,设计流强采用实际流强的两倍(20 mA),而且采用了长漂移段的单元结构,以避免紧凑型结构在恒温器分段时破坏周期结构,导致发射度的增长。强流加速器空间电荷效应引发的共振机制,使束流横向和纵向的运动发生耦合,驱使束流通过横向和纵向温度的交换达到均温状态,并因此造成横向和纵向发射度交换,束流品质变差。ADS的流强指标并不高,但双倍的设计流强以及加速过程中变频之后流强进一步加倍以及长单元结构的选择,空间电荷的作用已经很显著。本工作讨论了均温设计的条件并结合"Hofmann"的稳定图给出了与流强无关的设计,为C ADS加速器的设计以及日后可能的流强升级提供了更多的自由度。更多还原

【Abstract】 The Chinese ADS project is proposed to build a 1000MW Accelerator Driven sub-critical System before 2032. The accelerator will be operating on CW mode with 10mA and the final energy is 1.5GeV.As for the crucial demand on the reliability and stability of the ADS accelerator,the design intensity of the linac is doubled(20mA)and the lattice design can not be too compact for leaving enough space to accommodate the cryomodule separation without breaking the lattice.For high current rf Linear accelerators,the space charge forces couple the longitudinal and transverse motions and drive the beam towards an equipartitioned state causing significant emittance growth and hence beam quality deterioration. Although the current specification of the ADS is not so high,but the space charge dominate significantly because of the doubled beam current and the frequency change during acceleration and the choices of long drift lattice.Hence the equipartitioning design has been considered and a stable region in Hofmann chart has been chosen here to give a robust design independent of the beam intensity.The design philosophy is discussed and preliminary design result is presented.更多还原