GTS meeting 10 09 17

• Remaining tasks before shutdown:

1. Slit-Viewer emittance measurement: Slit1 and Viewer3 with focus lens
2. Measure lifetime with a larger laser size (~rms=0.5 mm)
3. Measure lifetime for: 0 A, 50 A, 100 A, 150 A, 200 A, 300 A, 400 A (Gun HV=300 kV, I=3.0 mA) - Done - [1]
4. Lifetime vs biased anode

• Why is photocathode lifetime limited (100 - 300 C)?

1. Laser heating and QE decay
2. Laser size too small?

• What is means to measure emittance, by Cristhian Valerio, Universidad de Sinaloa, Mexico

1. Media:PastedGraphic-2.tiff
2. Media:PastedGraphic-3.tiff
3. Media:PastedGraphic-4.tiff
4. But if the laser spot is off center, we are limited to measure the "system" emittance, rather than the intrinsic emittance, which would require the laser spot at the center of the cathode.Media:PastedGraphic-1.pdf