The Super Proton Synchrotron at CERN is equipped with a scraping system for halo cleaning at beam transfer to the Large Hadron Collider. The system is composed of movable graphite blades mechanically swept through the beam to remove tails immediately before beam transfer. Due to the mechanical movement, beam particles are intercepted by a small volume of material with consequent concentration of energy deposition and high thermal loads. The blades were tested with beam to verify their resistance to the most extreme scraping conditions. Even though the beam was prematurely dumped by the beam loss monitoring system, the microstructural analysis of the blades following the test found signs of material sublimation. The test setup was reproduced in simulation to reconstruct the levels of energy deposition actually reached in the blades during the test; values are compatible with local material sublimation, in agreement with the microstructural analysis. Simulations were carried out by coupling the sixtrack tracking code, used for single particle beam dynamics in circular accelerators for high energy physics, to the fluka Monte Carlo code, for particle-matter interactions. The time evolution of the beam intensity measured during scraping and the distribution of losses around the ring were used for an extensive benchmark of the simulation tool against measurements taken during the test. This work presents the endurance test together with simulation results and the benchmark of the simulation tool. The quantitative agreement between simulations and measurements proves the quality of the analyses and the maturity of the simulation tool, which can be reliably used to predict the performance of cleaning systems in circular accelerators.

中文翻译：

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CERN超级质子同步加速器的束刮系统的表征

欧洲核子研究组织的超级质子同步加速器配备有刮擦系统，用于在将光束转移到大型强子对撞机时进行光晕清洁。该系统由可移动的石墨叶片组成，这些叶片机械地扫过梁，以在梁传输之前立即清除尾部。由于机械运动，束粒子被少量材料拦截，从而导致能量沉积集中和高热负荷。用梁对刀片进行了测试，以验证其对最极端刮擦条件的抵抗力。即使光束被光束损失监测系统过早抛弃，在测试后对叶片的微观结构分析也发现了材料升华的迹象。测试设置在模拟中进行了重现，以重建在测试过程中叶片中实际达到的能量沉积水平。值与局部材料升华兼容，与微观结构分析一致。模拟是通过耦合小号IX吨架跟踪代码，用于为高能物理环形加速器单粒子束动力学，向Fluka公司蒙特卡洛代码，用于颗粒物质的相互作用。刮削期间测得的光束强度的时间演变以及环周围损耗的分布被用作模拟工具相对于测试期间进行的测量的广泛基准。这项工作介绍了耐久性测试以及仿真结果和仿真工具的基准。模拟和测量之间的定量一致性证明了分析的质量和模拟工具的成熟度，可以可靠地预测圆形加速器中清洁系统的性能。