Run coordinator daily report December 6th, 21:00

Since yesterday we have made good and steady progresses though struggling with :
- computers that keep on crashing ( X servers freezing, analysis machine locking up, coda (daq)  crashing ).  Paul King has written a set of advices to minimize coda crashes due to incorrect settings. . The night shifters had the worst time ever pretty much since the beginning of the week. Kudos to the night proud workers.
- beam delivery  being intermittent. Well in a sense we are choosing so : in order to provide data to our G0 beam task force we have to interrupt our data taking on a regular basis. Let us keep in mind that those interruption are to our benefit and we must be careful to take good and consistent data. Again we will try to take at least one half hour run at 40 uA (with charge feedback on, position feedback off  and PZT voltage at 5V) each shift and perform a Ia calibration once a day.
- harp scans being overall a pain  :   The four super harps available in hall C are operational with ~ 8 uA pulsed un-rastered beam. In this configuration, we planed to use them to calibrate the BPMs as well as to center the beam relative to the magnet axis. Unfortunately, the data are inconsistent , this could be due to a survey error. Greg Smith is very concerned and argue for a realignment of the girder. This could lead to a full shift of downtime maybe on Tuesday. Please read and comment his entry. Note that this down time could be coupled with the re-tunning of the injector or with the beam studies that are planned on Wed. swing shift. Practically, this mean that we cannot center for sure the beam inside the magnet, we cannot perform bcm calibration (relevant to compute absolute positions), we may have to hold on the halo monitor calibration. Target people are very reluctant to take tungsten data because they are uncomfortable with the alignment.  Finally with the harps, we have tried to perform a calibration of the raster, but in this configuration there is no signal... The pmts  that the beam group have installed  to read the harp in case they do not give signal (instead of reading the wries directly), are not read by any ADC yet. I'll try to push for that to happen...

The day shift was spend mostly in beam data taking:
- RHWP, IA and PZT scans and also test of the position feedback using the bpm in the injector.  Kaz will analyze the data.
- Y.C Chao (ACC ) performed F-OPT measurements. In this process, he uses the common PZT to displace the beam. The common PZT is wiggled at 30 Hz (uncorrelated with the helicity).  Chao then use the machine bpm to characterize the adiabatic damping and the orthogonality. This week-end he is doing to test : squeed quad study (change the optics of  specific magnetic elements) , stability studies (same measurement over time).
- beam spot size. The beam spot size was increased by a factor of 3 in each directions. The size of the intrinsic spot of the beam is now ~ 150 um well within our specs of < 200 um. This size brings us to conditions comparable to what we had last year.  The preliminary results I talked about yesterday have been informed.
- 120 Hz data taking. Jason Lenoble is working on the analysis of the data. Preliminary results have been posted, Jason is working on the interpretation. Also we have checked that the 120 Hz trigger is not compatible with charge feedback.

During the swing shift :
-a careful and complete calibration of the bcm was performed.
-the fly-swatter was inserted in order to test the linearity of the luminosity detectors. Greg Smith established that 40 uA can be shoot at the fly-swatter which is a good news. The fly-swatter produces something like 15% of the rates seen by the lh2 target. this is too bad because I had in mind to do deadtime studies with a solid target... Anyway some data will be taken with this target during the luminosity detector study.

The plans for 24 h :
- do luminosity detector checkout with the fly-swatter in ( Jianglai's test)
- take at least one hour of TE data with the fly-swatter and lh2 target in
- remove fly-swatter
- deadtime measurement : put lh2 target in, request a 3*3 mm^2 raster, pump speed at 40 uA
                                               : perform CMU's test
-change faulty ADC that ruined the calibration of octant 2,4 and 6  and  repeat HV calibration for octant 2,6 and 8.
 
 

your RC,

Julie