1. GaAs Photocathode Performance
40 cm
Photocathode
Ball cathode
Drive Laser
GaAs Photocathode Performance
Photocathode QE~6% after initial activation
Photocathode delivers ~200 C between re-cesiations
Typical day of operations draws ~35 Coulombs
About 96% of previous QE is recovered with each re-cesiation
12 activated cathodes and close to 40 re-cesiations performed on a single GaAs wafer in one year

2. Demonstrated DC Photocathode Gun performance
Pulsed operation at 8 mA/pulse (110 pC/bunch) in 16 ms-long pulses at 2 Hz repetition rate
CW operation at 9.1 mA (75 MHz) with 122 pC/bunch
Routinely delivers 5 mA CW and pulse current at 135 pC/bunch for FEL operations
400 A peak current at wiggler
Vacuum environment: 4.0E-11 Torr, 99.9% H2

3. 7% QE % QE

4. Cathode camera image taken while running 7 mA CW

5. Transverse halo contributes to energy spread

6. 10 kW Upgrade FEL photocathode performance after vacuum improvements

7. RGA