Author :
Benson, S. ; Beard, K. ; Biallas, G. ; Boyce, J. ; Bullard, D. ; Coleman, J. ; Douglas, D. ; Dylla, F. ; Evans, R. ; Evtushenko, P. ; Hernandez-Garcia, C. ; Grippo, A. ; Gould, C. ; Gubeli, J. ; Hardy, D. ; Hovater, C. ; Jordan, K. ; Klopf, M. ; Li, R. ;
Abstract :
Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.
Keywords :
accelerator RF systems; beam handling techniques; electron accelerators; electron beams; free electron lasers; linear accelerators; synchrotron radiation; wakefield accelerators; CW powers; JLAB IR FEL driver accelerator; RF heating system; beam vacuum chambers; beamline; cathode lifetime; driver ERL; electron beam powers; free-electron laser; high power laser operation; laser optics; magnetic component stability; phase space distributions; reproducibility; resistive wall; synchrotron radiation; wake-field; Acceleration; Laser beams; Laser stability; Power system management; Quality management; Radio frequency; Reproducibility of results; Space charge; Space heating; Vacuum systems;
