DC EMITTING CHARACTERISTICS OF A SINGLE CRYSTAL LAB6 THERMIONIC CATHODE

摘要：

A diode-type electron gun is used to investigate the DC emitting characteristics of a single crystal LaB6 thermionic cathode. The emitting area is a planar 2-mm-diameter, achieving transmitted currents up to 175 mA and the current density 5.57A/cm2. Comparing the measured current with Longo equation, which is accurate and applicable in the regime of practical operation. The circumstance has an effect on the emitting ability of cathode, when the vacuum is more than 7×10-4 Pa, and the current density apparently becomes lower. Aggradation and diffusion of LaB6 to pyrolytic graphite make the resistance of the heater lower. Experimental results show that DC emitting current density is lower than pulsed emitting due to the finite diffusion velocity of atom La and the surface adsorption of remainder-gas.

作者: WANG Han-bin LI Ming LIU Xi-san

作者单位: Institute of Applied Electronics,CAEP,P.O.Box 919-1014,Mianyang 621900,China

会议类型: 国际会议

会议名称: 17th International Conference on High-Power Particle Beams(第17届高功率离子束国际会议)

会议地点: 西安

会议语种:英文

页码: 427-430

在线出版日期: 2008-07-06（万方平台首次上网日期，不代表论文的发表时间）