CERN Accelerating science

Article
Title	Comparison of 2 Cathode Geometries for High Current (2 kA) Diodes
Author(s)	Pichoff, N
Publication	2004
In:	22nd International Linear Accelerator Conference, Lubeck, Germany, 16 - 20 Aug 2004, pp.654
Subject category	Accelerators and Storage Rings
Abstract	AIRIX (FRANCE) and DARHT axis-1 (USA) are two high current accelerators designed for flash X-ray radiography. The electron beam produced (2 kA, 3.5 to 3.8 MV, 60 ns) is extracted from a velvet cold cathode. Specific calculations have demonstrated the influence of the cathode geometry on the emitted beam profile [1]. To check this assumption we have made two different experiments (DARHT March 2003 – AIRIX March 2004). We have compared the beam characteristics with two different geometries both theoretically and experimentally. The beam simulations have been done with 3 codes: a home-made code (M2V) and 2 commercial codes (PBGUNS and MAGIC). The extracted beam current and transverse profiles, for the first experiment, have been measured and compared to simulations results. In the second one, we have compared the beam’s extracted current and the energy spread.