Ikegami K, Ueno A, Oguri H, Namekawa Y, Ohkoshi K
J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan.
Rev Sci Instrum. 2010 Feb;81(2):02A717. doi: 10.1063/1.3277158.
Dependence of various shapes of lanthanum hexaboride (LaB(6)) filaments on H(-) ion currents (I_H(-)'s) was examined by using the first Japan Proton Accelerator Research Complex (J-PARC) test ion source. It is almost the same with the J-PARC H(-) ion source (J-PARC-IS) except for the maximum arc current (290 A instead of 400 A). An I_H(-) of 35.2 mA was extracted by using a cylindrical double-spiral LaB(6) filament with a diameter of 29.5 mm and a length of 35.5 mm, which is the same one used in J-PARC-IS. It increased to 43.4 mA with a flat triple-hairpin LaB(6) filament. The I_H(-) is considered to be increased by the enlargement of the high density plasma region near the plasma electrode aperture and the reduction of the LaB(6) filament unemission area located in the high density plasma region.
利用日本首台质子加速器研究设施（J-PARC）测试离子源，研究了六硼化镧（LaB₆）灯丝各种形状对H⁻离子流（I_H⁻）的依赖性。它与J-PARC H⁻离子源（J-PARC-IS）几乎相同，只是最大弧电流不同（为290 A而非400 A）。使用直径为29.5 mm、长度为35.5 mm的圆柱形双螺旋LaB₆灯丝提取出35.2 mA的I_H⁻，该灯丝与J-PARC-IS中使用的相同。使用扁平三发夹LaB₆灯丝时，I_H⁻增加到43.4 mA。I_H⁻被认为是由于等离子体电极孔径附近高密度等离子体区域的扩大以及位于高密度等离子体区域的LaB₆灯丝未发射面积的减小而增加的。
