Title :
Measurements of reduced corkscrew motion on the ETA-II linear induction accelerator
Author :
Allen, S.L. ; Brand, H.R. ; Chambers, F.W. ; Chen, Y.J. ; Coffield, F.E. ; Deadrick, F.J. ; Griffith, L.V. ; Lager, D.L. ; Mauer, W.J. ; Nexsen, W.E. ; Paul, A.C. ; Sampayan, S. ; Turner, W.C.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
Abstract :
The ETA-II linear induction accelerator is used to drive a microwave free-electron laser (FEL). Corkscrew motion, which previously limited performance, has been reduced by: (1) an improved pulse distribution system which reduces energy sweep, (2) improved magnetic alignment achieved with a stretched wire alignment technique (SWAT), and (3) a unique magnetic tuning algorithm. Experiments have been carried out on a 20-cell version of ETA-II operating at 1500 A and 2.7 MeV. The measured transverse beam motion is less than 0.5 mm for 40 ns of the pulse, an improvement of a factor of 2 to 3 over previous results. Details of the computerized tuning procedure, estimates of the corkscrew phase, and relevance of these results to future FEL experiments are presented.<>
Keywords :
collective accelerators; electron accelerators; particle beam diagnostics; 2.7 MeV; 40 ns; ETA-II; computerized tuning; energy sweep; linear induction accelerator; magnetic alignment; magnetic tuning algorithm; microwave free-electron laser; pulse distribution system; reduced corkscrew motion; stretched wire alignment technique; transverse beam motion; Acceleration; Electron beams; Laboratories; Laser tuning; Linear accelerators; Magnetic fields; Motion measurement; Pulse measurements; Voltage; Wire;
Conference_Titel :
Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0135-8
DOI :
10.1109/PAC.1991.165198
