GTS meeting 3 14 17
- What is the expected rotation angle of the magnetized beam:
- Fay Presentation: media:17-03-14-magnetization -exVsim.pptx
- Geoff Krafft and Reza Kazimi, Comments on Slit Rotation Measurements: media:Comments_Slit_Rotation_Measurements.docx
- Latest drawings with new names for beamline elements: media:haysg_JL0038343-MAGNETIZED_BEAM_LDRD_ASSY.pdf
- What we have learned so far:
- MCRGT01 corrector gets misaligned each time magnets are on: attracted to MFGGT02 solenoid next to it. Need to hold it firmly on beamline.
- 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.
- Do we want to keep the anode biased at +280 V all times (and while running beam)?
- What is the direction of magnetic field in beamline solenoids? should be the same as gun solenoid which points in downstream direction.
- DO NOT TURN MAGNET ON WHILE GUN AT HV:
Now on the MLDGT01 Solenoid Magnet control screen, if for any reason the Current Readback is 0 and the gun voltage is nominal 300 kV , a pop-up screen with the following message will appear:
WARNING: Magnet current 0 Amps, Gun voltage 300 kV. To set the magnet current: 1. Set the gun voltage to 200 kV and wait until it reached that value 2. Turn on the magnet and set current to desired set point. Verify current read back reached desired set point. 3. Set gun voltage to nominal 300 kV. 4. Beam ops may continue with any magnet current setting. Every time the magnet current is set to 0 Amps, repeat procedure.