ADS注入器II 热冲击损伤研究(英文)
Study on Thermal Shock Damage to Injector II of China ADS Project
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摘要: 由于束流脉冲无法控制而引起直线加速器的热冲击损伤是造成加速器无法完成聚束及偏转的主要因素，而对热冲击进行定量的热应力评估可以有效地避免RFQ、超导腔以及其他加速元件等加速器设备的损伤，这在研制强流直线加速器的过程中至关重要。本研究引用一种新颖的计算方法定量分析整个注入器的热冲击损伤并明确了三种不同材料高纯铌、无氧铜和不锈钢对应的加速器件的热冲击的特征。基于有限元方法对瞬态热应力进行分析，得出三种不同材料对应的加速器件在入射角度为90 度时的温度分析结果。对于所研制的注入能量低于10 MeV的强流直线加速器来讲，得到可允许的入射时间为20 µs。Because of injecting an out-of-control beam pulse, thermal shock damage to the accelerator may well cause a failure of focusing and steering elements. In order to prevent RFQ accelerator,superconducting cavities and other accelerator components from thermal damage, t is essential to conduct a quantitative evaluation of the thermal stresses induced in the material during the thermal shock. The present study in this paper proposed a novel method to evaluate the thermal stresses quantitatively, which can clarify the characteristics of thermal shock of several materials, such as OFHC, SUS304 and Niobium. Transitional thermal stress is investigated by three dimensional nite element method (FEM) to obtain the temperature distribution for three materials at the beam incident angle of 90°. Finally the simulation results prove that the machine protect system response time meets the requirement when the allowable injection time is de ned as 20 μs.Abstract: Because of injecting an out-of-control beam pulse, thermal shock damage to the accelerator may well cause a failure of focusing and steering elements. In order to prevent RFQ accelerator,superconducting cavities and other accelerator components from thermal damage, t is essential to conduct a quantitative evaluation of the thermal stresses induced in the material during the thermal shock. The present study in this paper proposed a novel method to evaluate the thermal stresses quantitatively, which can clarify the characteristics of thermal shock of several materials, such as OFHC, SUS304 and Niobium. Transitional thermal stress is investigated by three dimensional nite element method (FEM) to obtain the temperature distribution for three materials at the beam incident angle of 90°. Finally the simulation results prove that the machine protect system response time meets the requirement when the allowable injection time is de ned as 20 μs.
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