[17p-S2_203-1~11] Next-generation electron sources and new developments in electron beam technology

2:05 PM - 2:35 PM JST(5:05 AM - 5:35 AM UTC)

[17p-S2_203-3] Proposal of a Thermionic and Electrostatic Emission Cathode Driven Under Space Charge Limiting by Overcoming Joule Heating

Hiroki Sato², Jonghyun Moon^1,2, 〇Yoichiro Neo^1,2 (1.RIE Shizuoka Univ., 2.Shizuoka Univ.)

Keywords:

thermionic-field emission,Space-charge limitted current,Langmuir-Child law

Field emission cathodes emit current from the nanoscale region, resulting in high current density at the emission sites. Consequently, the upper limit of the emission current is determined by Joule heating. By surface diffusion of liquid gallium (Ga) metal, the evaporation heat of Ga was utilized as a cooling process. This enabled emission current characteristics exceeding the conventional limit, reaching the space-charge-limited current. Detailed analysis was performed on the emission current dependence of the cathode temperature, as predicted from the energy distribution of emitted electrons and the simulated current-voltage characteristics considering space charge.