【摘要】 束流粒子通过加速腔的基模加速,以达到所需的能量值。由于腔本身的多谐性,束流在超导腔里面会激发起高次模,其中其电场分布对粒子加速起到负面作用的,称之谓有害高次模,减小或抑制有害高次模是加速腔研究的一个重要环节,利用铝模型腔对超导腔的高次模抑制进行研究,给出测量结果,研究表明:铁氧体是很好的微波吸收材料,对于所研究的超导腔内的高次模有着良好的吸收效果。更多还原

【Abstract】 Higher-order modes (HOM’s) excited in the Superconducting Cavity (SCC) can be damped through many ways. Microwave absorbers, HOM’ s couplers, coaxial waveguides and other devices are used to achieve this aim. The recent status of the R&D on an 800MHz Prototype SCC being developed is presented in this paper. For the cavity, the HOM’ s damping by absorbers is obtained with the large beam duct. A low power measurement on a prototype cavity has been carried out and the Q-values of HOM’s are confirmed to be drastically reduced. Two types of ferrite as absorbers are investigated to achieve the function of damping the HOM’ s. The modes we concerned focus in the range of 0.8-2.7GHz. By means of changing the parameters of the ferrite used in the cavity, a conclusion about the damping is acquired . Measurements indicate that most of the HOM’ s in this range are effectively absorbed and damped at the presupposition that the basic mode is not affected. A few special modes are pointed out, which cannot be absorbed by means of absorbers because they cannot propagate out of the cavity. The two types of ferrite used in this project have similar property with the same value of B, equal to 1500Gs and the different values of e equal to 14, 16 respectively. In order to study the relation between the parameters of ferrite and the damping effect, further research will be carried out sequential-ly.更多还原