[Halla_parity] [PREX] Experiment status and rough plan

[camsonne at jlab.org]

Beam was resumed at beginning of owl shift.
There were a few small glitches which will need to be addressed :
- the HARP at BMP 4B did not show signal ( we will try to reboot the IOC
to see if that fixes it )
- the Compton dipole would not turn on so we went straight for the target
checks, Q2 and allignement checks.

We will try to address those during the access for the Moeller refill and
if it requires more time we will fix everything at the next longer down on
Tuesday.

Vacuum is behaving well though we have seen some fluctuations along with
some temperature fluctuations so we are keeping an eye on those and
looking back at the previous data to figure out exactly the cause.

http://www.jlab.org/~adaq/halog/html/1006_archive/100604071436.html

The magnets tripped after the cool down of the magnet Howard came back in
the get them back up and Left Q1 tripped once during.
http://www.jlab.org/~adaq/halog/html/1006_archive/100603201250.html
http://www.jlab.org/~adaq/halog/html/1006_archive/100603203023.html


The detector alignement seems fine though ADC amplitude in counting mode
is a bit smaller for right arm PREX detector

http://www.jlab.org/~adaq/halog/html/1006_archive/100604035539.html

and sieve is a bit fuzzy on left arm most likely because of VDC calibration.

http://www.jlab.org/~adaq/halog/html/1006_archive/100604060101.html



We eventually switched to production around 8 AM this morning, data is
being checked but look good so far.

The plan is to run production until Monday when we are planning to make a
Moller measurement.

There will be target operator training today at 3PM by John Lerose so if
you want to be target operator certified please plan to attend.

There also will be the usual experiment 3PM meeting, I will send a
separate reminder with the calling insructions.

There are still shifts needing to be filled so please consider taking some
additionnal shifts on the experiment.

http://hallaweb.jlab.org/parity/prex/shifts/

Best regards,

Alexandre Camsonne
Current PREX Hall A run coordinator