Minutes of A0 photoinjector group meeting
                        Monday Nov 01 st, 2004


     
      minutes at: http://nicadd.niu.edu/fnpl/Operation/Minutes/


* Next meeting: Monday Nov 8th, 10:30 CDT, in WH10



* Plan for next week:

    - resume operation 
    - run beam 1 nC for HOM-based beam alignment
    - test CCD digital camera optics on an OTR screen
    - when e- beam cannot be run, laser work/study are 
      scheduled.
    
* Last week activity

- Work on the laser, did some off-line analysis of the fiber 
  launcher, discover T of 50 % (instead of 15 %) boosted up 
  to 80% with new lens. Since a few days, the bandwidth lower. 
  (1 or 2 days). 
- Intensity fluctuation: 40% last week! prevented to do decent
  measurement on HOM. Multi-pass power supply tripped several time
- a lot of problem with water cooling 

- LCW upgrade: bunch of independent chillers, causing downtime water 
  header + return header, with heat exchanger, 
- digital camera: sensitivity of digital camera is only 4 lux compared 
  to 0.8 lux for Cohu camera. [Philippe, Yin-e]

- took some data for calibrating the UV diode in the cave (this is 
  is conjunction to quadtum efficiency measurements) [Ray, Jianliang, Rodion]


plan for next week:


ACTION ITEM updated:
Thu Oct 1st 16:07:11 CDT 2004

H8/ calibration of upstream directional coupler and
    insulator (Markus need to speak to Tim and with Kai to
    schedule this STATUS?)
H13/ Pulse stacker, what do we do? (Rodion)
H21/ the laser uniformity problem can this be due to the new (since
     late summer) tight focusing in the doubling crystal area to
     improve conversion efficiency? On going work [Rodion]
H28/ Problem with emittance measurement at X7 (Philippe 04/16/04)
H32/ Digital camera from SONY(?): [Philippe/Yin-e]
     to be TESTED with OTR [Sep 27]
H33/ laser fluctuation since June 1st week [FIXED?]
H34/ Need more work on power supply + devise a way to measure
     the current being put out to the magnet [Jamie]
H35/ A0 cryosystem contamination
H36/ laser room/table vibration studies


#.36

from Adrian Melissinos:

NEEDED LASER STUDIES:

1. Study of oscillator bandwidth versus length of
   compressed pulse. Measure IR length using stepping
   autocorrelator [Done week of AUG 23rfd 2004]
2. beam profile (wavefront) studies both in IR and UV
   in laser room and on virtual cathode. Use spatial filters
3. study of doubling and quadrupling efficencies with old
   and new crystal, take a tuning curve

POSSIBLE LASER UPGRADE PROJECTS

1. Measure IR pulse length before compression (use diode?)
   implement cw autocorrelation
2. Install new beamline between multipass and 2-pass --
   install spatial filter, rebalance 2-pass amplifiers
3. Relay imaging UV from laser room to cave
4. _harware_: replacing all coolers with new system IV +
   use existing system III as back-up
5. pulse stacker studies, new pulse stacker R&D