Minutes of A0 photoinjector group meeting
                        Monday July 26th, 2004

           http://home.fnal.gov/~piot/FridayMeeting/Minutes/
           

* Next meeting: Monday August 2nd, 2004

* Plan for next week:
 
Monday:
	Get the some data on the 81 MHz phase measurement
Tuesday:
	Install + test skew quads [Jamie Santucci]
Wednesday:
	Beam studies [Yin-e et al.]
Thursday:
	Beam studies [Steve(LBL) et al.]
Friday:
	Beam studies [Philippe et al.]

Discussions:

* Achievements of last week:

  - Monday North cave rf cold tests [Leo Bellantoni et al.]
  
  - Tuesday:
    - morning: Wildman et al.] fast phase shifter test for 
      proton driver, 
    - afternoon: bunch compression studies [Rodion/Daniel]: took 
      a set of data to confirm some early measurementds
  - Wednesday/Friday [Yin-e/Philippe], conitnue measurement of 
    CAM-dominated beam. Measured envlope, emittanve along the 
    beamline for different settings of the solenoids, L versus 
    charge for a given spot size on cathode and L versus spot 
    size on the cathode
   
  - Thursday [Steve LBL)] did some measurement of beam envelope 
    emittance along the beamline.     


* Other discussed items:

  - digital camera arrived but had problem with firmware version, 
    Markus had the bad camera returned and we should receive new 
    camera with latest version of firmware for all of them. 
  - Rodion reported his measurement on R56, he found a value 
    of 4.5 cm in discrepancies with the value predicted of 8.4 cm 
    for the nominal bending  angle of 22.5 deg (this is not under-
    stood and being looked at)
  - Sevral time in the week phase jum of the gun phase were observed, 
    to my [Philippe] knowledge all of them were correlated to work 
    on the 81 MHz phase measurement being done. 
  - Wednesday the gun amplitude had a big jump: nominal set point of 
    45 MV had to be crancked up to 85 MV to keep the gun E-field to 
    35 MV/m; next time this happen we should measure the voltage on 
    the klystron
    
* Tasks concerning hardware 

Sun Aug  1 10:43:44 CDT 2004
ACTION ITEM updated:

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)
H14/ air coil steerers, Kai will gather all the paper he has 
     and we will decide whether we can give this project to one of 
     the NIU engineering student
     (Kai, STATUS: nobody at NIU picked up this project...)
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]                            
H26/ trigger problem on a couple of CCD camera 
     (->Kai will look into it 03/2004)
H28/ Problem with emittance measurement at X7 (Philippe 04/16/04)
H29/ Need daily monitoring of the laser parameters (Jamie/Rodion 04/23/04)
     [OSCILLATOR BW AT 131.225.136.161:8000/~laser]
H32/ Digital camera from SONY(?): camera sent back waiting for new ones
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]

from Adrian Melissinos:

NEEDED LASER STUDIES:

1. Study of oscillator bandwidth versus length of 
   compressed pulse. Measure IR length using stepping 
   autocorrelator
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