RF Gun Photocathode Research at SLAC

Conference · Wed May 16 04:00:00 EDT 2012

OSTI ID:1043873

Jongewaard, E; Akre, R; Brachmann, A; Corbett, J; Gilevich, S; Grouev, K; Hering, P; Lewandowski, J; Loos, H; Montagne, T; Sheppard, J C; Stefan, P; Vlieks, A; Weathersby, S; Zhou, F

LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: US DOE Office of Science (DOE SC); Basic Energy Sciences (BES)
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1043873
• Report Number(s): SLAC-PUB-15020
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
Accelerators
ACCPHY
XFEL
CHEMISTRY
COPPER
ELECTRON BEAMS
ELECTRON GUNS
LASERS
LIFETIME
PHOTOCATHODES
PHOTOEMISSION
PLASMA
QUANTUM EFFICIENCY
RF SYSTEMS
SPECTROSCOPY
STANFORD LINEAR ACCELERATOR CENTER