Minutes of A0 photoinjector group meeting
                        Monday September 20 th, 2004


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


* Next meeting: Monday October 04th 10:30 CDT, in WH10


* Plan for next week:

Since there is uncertainty on when the LCW will be back (TeV-related 
shutdown), We will decide about the schedule as soon as the LCW is 
back: the plan are then:
    - 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.
    


Discussions:

* Achievements of last week:

- we did not run most of the week due to the TeV LCW 
    water not having the proper resistivity. This 
    problem was due to mis-communication within the water 
    group.
   

- more work on the laser:
      - Jianliang and Rodion have been working on measuring 
        transverse spot sizes of the laser at several location. 
	In the meanwhile Christian Boffo (technical division) 
	did some vibration measurement of the laser room floor 
	and laser table. It was found that the vibration level 
	on the oscillator table is 3 times higher than those 
	of the floor -- this need to be investigated further. 
	
* Other discussion:

      - Steve Lidia (LBL) gave a talk on LBL plan on laser 
        R&D for low emittance electron injectors for light 
	source linac. A copy of his slides are at:
	


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