直线加速器Kanthal合金高功率同轴负载设计及功率分布  

Simulation design and power distribution calculations of linac collinear load based on Kanthal alloy

作　　者：孙袁[1] 沈连婠[1] 王秀翠[1] 裴元吉[2] 

机构地区：[1]中国科学技术大学精密机械与精密仪器系,合肥230027 [2]中国科学技术大学国家同步辐射实验室,合肥230029

出　　处：《强激光与粒子束》2011年第10期2752-2756,共5页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(10775128)

摘　　要：为满足辐照直线加速器的小型化需求,提出利用同轴负载代替波导式负载结构的方案,其关键技术是利用涂敷在加速腔内壁的微波吸收材料直接吸收剩余微波功率。针对面吸收型负载材料Kanthal(Fe-Cr-Al)合金,采用2π/3模式6腔2周期谐振腔结构,运用CST仿真进行S波段同轴负载设计。对涂层涂敷位置及面积对负载腔工作频率和品质因子的影响进行了详细的仿真分析,并得到了满足2 856MHz工作频率的腔体尺寸补偿值;设计了一种6腔2周期同轴负载,单路衰减可达-18.63dB。吸波涂层及腔体铜壁表面功率损耗密度的计算结果表明,腔体周向功率损耗呈均匀分布,阑片表面呈抛物线型分布。In order to miniaturize irradiation accelerators,the collinear load is proposed to substitute for the waveguide load.The key technique is to dissipate the remnant power in load cavities which are coated with efficient microwave-absorbing materials on their inner walls.Taking advantage of a 2π/3 mode resonance structure,the S-band collinear load based on Kanthal（Fe-Cr-Al） which is a kind of surface-attenuating metal is studied in CST.The influences of the coating position and area on the operation frequency and cavity quality factor are analyzed.The compensation of cavity dimensions for tuning at 2 856 MHz is determined.A two-period collinear load composed of six cavities is designed,with one-way attenuation of-18.63 dB.The power density calculations of the coatings and copper walls reveal that the power distributes uniformly on the cavity circumference and appears parabolic along the radius on the disk surface.

关 键 词：直线加速器 同轴负载 Kanthal合金 腔体频率补偿 功率分配 功率分布 

分 类 号：TL53[核科学技术—核技术及应用]