Design and operation experiences of a multi-wire detector under high beam power environment

BackgroundMulti-Wires detector (MW) is widely used in beam profile measurements. However, wire deformation and even wire broken have also happened frequently during the MW operation due to beam power deposition on the wire under high beam power environment.PurposeThis study aims to investigate the influences of the beam parameters and detector design, especially wire tension structure, on the wire temperature and wire deformation arising therefrom.MethodsFirstly, based on the backward Euler method with adaptive steps, a numerical algorithm was developed to conduct temperature simulation of MW. Then, verification experiments with various beam parameters and detector design of MW were performed in an ion source platform at Institute of Modern Physics (IMP), Chinese Academy of Sciences, and the wire deformation caused by temperature was reproduced and observed at HIMMWW (Heavy Ion Medical Machine at WuWei city, China) complex. Finally, comparative analysis was conducted on the relevant results to find the appropriate beam parameters and detector design.Results & ConclusionsExperimental results show that temperature plays an essential role on wire deformation if none tension mechanism is implemented on wire structure. Based on numerical simulations, experiments verifications and operation experiences, a fixed wire tension maintained by welding is appropriate while the wire temperature is below 1 300 K, which also provides a simple construction and a low cost. After exceeding 1 300 K, pre-tensioning by a spring is essential to support the wire with a constant tension to avoid deformation.