Compact Laser Photocathode Driven Accelerator for the Plasma Wake Field Accelerator Program at UCLA.

摘要

The plasma wake field accelerator requires a plasma density of 5 x 10 to the 13th power to 5 x 10 to the 14th power/cc in order to achieve a significant wake field amplitude (eE > 10 Mev/m/nCoul). Our earlier attempts with RF produced plasmas and BaO coated cathodes resulted in plasma densities which approached 9 x 10 to the 12th power cc. In this report, we will describe the preliminary measurements of a plasma produced by an indirectly heated Lanthanum Hexaboride cathode. The main advantages of Lanthanum Hexaboride (LaB6) are that: (1) LaB6 has a high emission current density (20 A/sq cm at 1700 C; (2) it has a low evaporation rate (almost two order of magnitudes lower than tungsten); and (3) it is immune to accidental exposure to air.