Oguri H, Ueno A, Ikegami K, Namekawa Y, Ohkoshi K
J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan.
Rev Sci Instrum. 2010 Feb;81(2):02A715. doi: 10.1063/1.3266138.
A cesium-free H(-) ion source driven with a LaB(6) filament is being operated at the Japan Proton Accelerator Research Complex for approximately three years without any serious trouble. In the beam commissioning or supply runs, the ion source has been operated in two different modes such as low current mode of 5 mA and high current mode of 30 mA. The total interruption time during the runs due to the ion source failure is approximately 50 h, which correspond to the ion source availability of 99%. After a long-term operation, the surface of the filament and the plasma electrode become discolored with dark partially. The result of surface analysis with field emission scanning electron microscope showed that most of the dark material is formed with boron. At the beam test performed in the interval of the run, we demonstrated that the H(-) current increased by miniaturizing the LaB(6) filament.
一种由LaB₆灯丝驱动的无铯H⁻离子源在日本质子加速器研究中心运行了约三年，没有出现任何严重问题。在束流调试或供能运行中，离子源以两种不同模式运行，即5 mA的低电流模式和30 mA的高电流模式。运行期间由于离子源故障导致的总中断时间约为50小时，这对应着离子源99%的可用性。经过长期运行后，灯丝表面和等离子体电极部分变黑变色。场发射扫描电子显微镜的表面分析结果表明，大部分深色物质是由硼形成的。在运行间隔期间进行的束流测试中，我们证明通过使LaB₆灯丝小型化，H⁻电流增加了。
