2019 年 62 巻 7 号 p. 400-405
The non-destructive beam profile monitor is needed for high intensity accelerators to avoid radioactivation of the systems. A monitor system with sheet-shaped gas to measure two-dimensional (2-D) transverse beam profile nondestructively is under development. However, one of issues for realistic implementation of the monitor exists with non-uniform nature of the gas distribution. To obtain a correct beam profile, measurement of the gas distribution is indispensable because signal from the monitor is in proportional to both beam intensity and gas distribution. To measure the three-dimensional gas distribution, a system for analyzing the distribution of ions produced through gas interactions with beam has been developed. This system consists of an electron gun for producing ideal narrow beam, electrodes to form a parallel electric field toward micro-channel plate, and a phosphor screen. The experimental result by using a gas jet nozzle agreed well with the simulation.