Minutes of A0 photoinjector (local) meeting Friday May 7th, 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 14th 4pm in "the Motel" * Plan for next week: - Monday: morning: quadrupole calibration with beam [Jason/Philippe] afternoon: laser work [Rodion/Jamie] - Tuesday: laser work [Rodion/Jamie] -- NORTH CAVE IS RUNNING - Wednesday: Plasma experiment [Matt et al.] - Thursday: Plasma experiment [Matt et al.] - Friday: Plasma experiment [Matt et al.] Discussions: * Achievements of last week: - Monday/Tuesday: - laser work: installation of the two pulse splitter in the cave. The LVDT of the movable mirror was calibrated with streak camera measurements[Rodion/Nick] - Two pulse studies in parallel with CTR interferometry "resolution tests" [Rodion/Daniel]. The R56 of the chicane was measured. - Wednesday/Thursday: - flat beam studies: again took data on angular momentum versus B-field on the cathode, for three sets of spot sizes. As last week, oscillator required many tweaking along the day to be kept stable. And it seems our easy stable point during the experiment resulted in a bandwidth of 15 Angstrom. We also did some test on setting up the round to flat beam transformation using quad strength a priory computed via simulations. Our test are not conclusive, probably due to the lack of knowledge of incoming sigma matrix, we will in the next week concentrate on the measurement/understanding the incoming beam. [Yin-e/Philippe] - Friday/Saturday: - Plasma experiment [Matt et al.]. * Discussion: - Rodion presented his analysis of the data on the measurement of the bunch compressor chicane R56 he found R56=84+/-11 mm, this is close to the design value of R56=84.3 mm [from J.P's Carneiro's thesis] when the beam is bent by the nominal 22.5 deg angle. Of course we need to make sure the current in the chicane was properly tuned, given the energy, to have a bending angle of 22.5 deg. - Daniel presented the autocorrelation measurements when the beam consists of two pulses (generated by splitting the photo- cathode laser beam). He operated the bunch compressor and 9-cell cavity to be about three degree before compression (based on simulation), measured the coherent transition radiation auto- correlation and try to reconstruct the bunch time profile from these measurement. To date Daniel was not able to observe the two-pulse structure in the reconstructed time profile. - Yin-e gave a report on the measurement done last Wednesday and Thursday: from the data she extracted the incoming angular momentum evolution versus the B-field on the cathode. Compared to her pac2003 paper, the measured angular momentum seems to be higher than the one expected given what we think is the B-field on the cathode. Further analysis is on-going. - Matt and Gil detailed the long term plan of UCLA at A0: this coming week they want to have as much as possible beam time and then will remove the plasma density transition trapping experiment. Nick will install back (in about two week from now) his plasma wakefield experiment and will do a probe/witness measurement of the plasma wakefield. UCLA will come back around September with a modified setup of the present experiment that will allow to take data on the under-dense plasma lens. - Jamie S. presented a plot of the evolution of the oscillator bandwidth over the past three year. The bandwidth dropped from 21-22 Angstr. to 18 Angstr. about a year ago for reason nobody understand. * 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)