Tuesday
(half day / swing shifts) - Wednesday (owl/day/swing
shifts)
General comments :
For the last 24 hours, we've been
mostly working on checking the beam parity quality performing RHWP/IA/PZT
scans. The beginning of January 2nd engineering should be renamed as
"RIPs"
engineering run (!). The good thing is that more people have been
involved
in these measurements so that Kaz should be able to take a little rest.
The bad thing is that the parity quality of beam seems not to be stable.
After the re-matching of the accelerator tuesday afternoon, the parity
quality has improved compared to monday morning but we haven't been able
to reproduce so far the quality we had sunday night and in December
'03. Furthermore, we noticed tonight that the parity beam quality might
depend on Hall A beam current...
Also, since we've started in
January,
some oscillations in the beam current are observed.
At the scheduling meeting
today, I ask to perform as soon as possible the hallA(100uA)/HallC(40uA)
compatibility test because right now we are somehow trapped between
checking
beam parity quality at 40uA and taking background data at 20uA on the
empty
target which requires also parity beam quality... After the 4pm "Parity
Beam Quality task Force" meeting where we were told that the
compatibility
test will be performed tonight I agreed on a schedule with the Hall A RC
and the PD. In fact, we've been wasting some time because when they
reached
55uA they told us that they will try to keep on increasing the beam
current
in Hall A up to 100uA tonight. Therefore, we have postponed RHWP/IA/PZT
scans until they would reach 100uA or whatever maximum current where they
will stay because these measurements requires at least 2hrs and then 4hrs
of long feedback runs. As the estimation was unclear, after they solved
their separator problem, we decided to go back to 20uA on the empty
target.
As soon as Hall A will stay for long enough at the maximum achievable
current
then we will go back to RIP scans and we will ask for 40uA (no
target).
What has been done :
- New Halo Measurements : evrything looks fine after the re-matching of the accelerator (g0log #73111)
- The target FSD box has been updated so that we will be able to perform Al frame excursion whenever we'll have the opportunity (no usuable beam for asymmetry measurements and target experts available). This requires also to determine which beam current we would like to use.
- Since run 18956, we are running with 9 DMCH boards in the VXI crate. Signals from Octants 1, 3, 5, 7 - Detectors 14 and 15 are sent to NA and French electronics (9th DMCH board) at the same time. G0realtimemonitor and g0analysis handle the new data format. The TOF on g0realtimemonitor are from NA electronics. The decoding of the 9th board is including in g0analysis but some more work has to be done to adapt specific functions such as deadtime, asymmetry calculation, ... for the NA detector handled by the 9th board.
- New EPICS variables have been added : Temperatures in the electronics cage. These variables can also be checked within G0 General Tools Display in the counting room.
- Hall A Beam current is recorded into the datastream.
- Jianglai computed expected statistical errors on asymmetries from empty target (20uA, 7 days, 100% efficiency) : g0log entry #73047.
Issues :
- Beam parity quality results :
g0log entries #73016,
73017,
73123)
- HallA (100uA) /HallC (40uA)
compatibility
test with respective beam quality requirements.
- 4MHz Clock readout (g0log entry
#73107)
- Oscillations in beam current
since the beginning of January engineering run (g0log entry #72936,
#73015)