Difference between revisions of "GTS meeting 3 14 17"

Revision as of 16:15, 12 March 2017

With Gun solenoid off, beamlet from the slit on the second viewer is not exactly horizontal - camera may not be aligned?
The gun solenoid is not centered on the beam. It is significantly off in -45 degree direction (as seen on the viewers). That has to be addressed before we can take good data.
The gun HV being on or biased would not help the QE scans. It appears that the best way to measure the QE is with the anode biased and the puck grounded with the long manipulator.

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-* Measured QE ~ 3.5% with -100 V Gun bias. Was about 0.4% with -1 kV bias. This is to be compared to QE ~ 3.9% in Prep Chamber with -280 V bias before moving the photocathode to Gun.
+* What we have learned so far:
+# With Gun solenoid off, beamlet from the slit on the second viewer is not exactly horizontal - camera may not be aligned?
-* Gun vacuum improved when opening the gate valve to beamline
+# The gun solenoid is not centered on the beam. It is significantly off in -45 degree direction (as seen on the viewers). That has to be addressed before we can take good data.
+# The gun HV being on or biased would not help the QE scans. It appears that the best way to measure the QE is with the anode biased and the puck grounded with the long manipulator.
-* Beam to F-Cup
-* Plan to complete the second part of beamline in two weeks. We will have one-week down in about 2 weeks to install the second DP can, solenoid, ion precipitator and the BNNT diagnostic station.