Minutes of A0 photoinjector (local) meeting Friday May 14th, 2004 http://home.fnal.gov/~piot/FridayMeeting/Minutes/ ------------------------------------------------------------------------ NOTE: WORK ON INTERLOCK IS SCHEDULED ON MONDAY MAY 17TH ALL THE DAY ------------------------------------------------------------------------ * Next meeting: Friday May 21th 4pm in "the Motel" * Plan for next week: - Monday: NO BEAM: work on interlock in parallel work on the laser [Rodion] if beam back early enough: quad calibration [Philippe/Jason] - Tuesday/Wednesday: Two-pulses experiment [Rodion/Dan] - Thursday/Friday: Flat beam [Yin-E/Philippe] Discussions: * Achievements of last week: - Monday: - took a first set of difference orbit to try to calibrate the quadrupoles with beam (or check the calibrations inferred from B-measurements provided by the Technical Division). No yet final data, our difference orbit scripts had to be debugged - Tuesday: - laser work: tuned the laser to try to maximize the output energy as required by the Plasma density transition trapping experiment [Rodion/Nick/Jamie] - Wednesday/Thursday/Friday: - Plasma density transition trapping experiment: The beam was propagated to the experiment still, the charge transmission is of the order of 50 %. The addition of a steerer downstream of the plasma chamber allowed a better diagnosis of the beam: the typical beam spot for a charge of ~6 nC as about 1 mm, that is a factor two above the required size. The pulse length is also, generally, a factor 2-3 above the requirement. So its seems there will be a need for reworking the beamline (i.e. thiner or other type window prior to the experiment). In any case the first round of test of the experiment is complete and the experiment will be dismounted as soon as Nick wake-field experiment is ready to go in the beamline (in one or two weeks). UCLA (Matt et al.) plan to come back in September. The first step will be to do some experiment on under-dense plasma lens using the same experimental set-up as the one that has been use by Matt et al. for the plasma density transition trapping experiment. * Discussion: - Nick presented some data on the stability of the laser multi-pass amplifier. Nick has been taking data and doing various test on the various laser components. Regarding the multi-pass he finds that reducing the number of pass and making up for the gain loss by increasing the voltage on the two-pass amplifier head reduces fluctuation below 10 %. - Jamie has wired the thermocouples installed in the oscillator and Multi-pass amplifier. The temperature of these two components are archived in the ACNET database. This will offer the possibility to correlate noise/instability/problem on the oscillator and multi-pass with temperature evolution. * Tasks concerning hardware H2/ Corrector HTBX06, Jamie [Aug. 2003] Steerer from UCLA was installed TUESDAY FEB 3 but was again found to be not working last Tuesday [checked/fixed 04/30 Jamie] H8/ calibration of upstream directional coupler and insulator (Markus need to speak to Tim and with Kai to schedule this STATUS?) H11/ Some of the toroid need cabling to have signal available out of the cave in the rack area (JAMIE, 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] H23/ laser spare components list (Jamie, RECEIVED A FIRST VERSION JAN-30-2004) -- NEED RODS Rods ordered [CLOSED ITEM] H25/ Software for the digital camera (Jason) H26/ trigger problem on a couple of CCD camera (->Kai will look into it 03/2004) H27/ The temperature sensors on the laser components need to be wired and archived on ACNET (Jamie 03/26/04) H28/ Problem with emittance measurement at X7 (Philippe 04/16/04) H29/ Need dayly monitoring of the laser parameters (Jamie/Rodion 04/23/04)