Title :
Time-dependent degradation of an ion-focused ATA beam
Author :
Fawley, W.M. ; Boyd, J.K. ; Caporaso, G.J. ; Chambers, F.W. ; Chong, Y.P. ; Hildum, J.S. ; Lee, P. ; Orzechowski, T.J. ; Rogers, D.R. ; Struve, K.W. ; Weir, J.T.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
Abstract :
Detailed measurements of the time-dependent beam quality of an ATA (Advanced Test Accelerator) pulse transported on a KrF laser-photoionized benzene channel were performed. It was found that the tail portion (τ⩾20-30 ns) of the pulse becomes severely degraded both at high currents (I>3 kA) and at long transport distances. Nonaxisymmetric channel ion motion is suspected as the predominant source of the problem. The authors discuss various experiments which varied laser properties (timing, fluence, profiles), background ion pressure, and electron beam current in order to study the physics behind this degradation
Keywords :
beam handling equipment; beam handling techniques; focusing; particle accelerators; KrF laser-photoionized benzene channel; background ion pressure; degradation; electron beam current; fluence; ion-focused ATA beam; laser properties; nonaxisymmetric channel ion motion; profiles; tail portion; time-dependent beam quality; timing; transport distances; Degradation; Ion accelerators; Ion beams; Laser beams; Life estimation; Optical pulses; Particle beams; Performance evaluation; Pulse measurements; Testing;
Conference_Titel :
Particle Accelerator Conference, 1989. Accelerator Science and Technology., Proceedings of the 1989 IEEE
Conference_Location :
Chicago, IL
DOI :
10.1109/PAC.1989.73489
