Beam Diagnostic Study and Development of Laser Based Photo Neutralization Beam Profile monitor system in High intensity Proton Accelerator.

为了提高高强度质子加速器的束流强度和束流质量，研制了束流诊断系统。在J-PARC直线加速器中构建了激光光中和光束轮廓监测仪。确定了光束电流、位置和轮廓，得到了基于激光的光束轮廓监测仪的技术指标。评价了收集光离电子的磁场空间分布。馈通容器和真空容器由耐辐射材料组成，用于高强度操作。通过对光束诊断系统的微调，获得了大电流、低发射度的负离子束。在Linac排土线上测定了残余气体撞击负离子束的中性粒子组分。光束诊断系统在高强度光束操作中发挥了重要作用，这些成果对于激光轮廓监测的发展是必不可少的。

In order to improve the beam intensity and quality of high intensity proton accelerator, the beam diagnostic systems have been developed. A laser based photo neutralization beam profile monitor was constructed in J-PARC Linac. Beam current, position and profile had be confirmed to obtain the specifications of laser based beam profile monitor. Spatial profile of magnetic field to collect the photo ionized electrons was evaluated. Feedthrough and vacuum vessels were composed of radiation resistant materials for high intensity operation. Large current and low emittance negative ion beam have been obtained by fine tuning using the beam diagnostic system. Neutral particle component of negative ion beam by residual gas impact was also measured in Linac dump line. Beam diagnostic system have been played important role for high intensity beam operation, and these results are indispensable for development of laser based profile monitor.