Construction of a 300-keV compact ion microbeam system with a three-stage acceleration lens

加速レンズを用いた300keV小型イオンマイクロビームシステムの構築

石井 保行; 大久保 猛; 小嶋 拓治; 神谷 富裕

Ishii, Yasuyuki; Okubo, Takeru; Kojima, Takuji; Kamiya, Tomihiro

A 300-keV compact ion microbeam system has been constructed to form a submicron ion microbeam. This system consists of a gas-ion source and a three-stage acceleration lens. Since the three-stage acceleration lens was designed to play two roles of acceleration and focusing for ion beam simultaneously, no focusing devices such as focusing lens and beam line are needed outside of the system. Therefore, the system is downsized to about 1 m high and can be placed in a small experimental room. The beam sizes formed by the system were experimentally measured by changing the voltages of the third acceleration lens in the three-stage acceleration lens within the range of 150 keV. These beam sizes were also theoretically calculated using Munro code. The experimentally obtained value was almost same of the theoretically estimated value. It demonstrated that the three-stage acceleration lens effectively worked on the focusing lens as designed.