JLab FEL DC Gun

Conference · Sat May 01 04:00:00 EDT 2010

OSTI ID:2002890

Hernandez-Garcia, Carlos; Benson, Stephen; Biallas, George; Boyce, James; Bullard, Donald; Coleman, James; Douglas, David; Evtushenko, Pavel; Gubeli, Joseph; Hannon, Fay; Jordan, Kevin; Klopf, John; Moore, Steven; Neil, George; Shinn, Michelle; Tennant, Christopher; Walker, R.; Williams, Gwyn; Zhang, S.

The Jefferson Lab (JLab) Energy Recovery Linac 10 kW IR Upgrade Free Electron Laser (FEL) is driven by a 350kV DC un-polarized photoemission electron gun. In 2003, an upgrade version of the earlier 1 kW IR Demo FEL gun delivered over 1000 Coulombs with a single Cs:GaAs wafer in one year of operation. Between 2004 and 2007 a second wafer delivered over 7000 Coulombs and up to 9 mA CW beam for FEL operations. Both wafers suffered surface damage with total loss of quantum efficiency in several occasions during high current operations. Since then, the electron gun has been refurbished two times due to field emission damage. Although presently operating at nominal 350kV, field emission has significantly decreased the photocathode lifetime.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 2002890
• Report Number(s): JLAB-FEL-09-1074; DOE/OR/23177-1005
• Country of Publication: United States
• Language: English