Log entry time 11:08:17 on January21,2009

Entry number 257115

Run Coordinator Report for Jan 20, 2009:

# Polarity status of the spectrometers: BigBite -ve (for e-), L-HRS +ve (for &pi+)

# &pi+Vertical  mode with the half-wave-plate IN

Charge Accumulated Summary So Far



                     Half Wave Plate     Charge Expected (C)  Charge Accumulated (C)   Comment

&pi- Vertical             IN                       3.5               0.86                 -

&pi- Vertical             OUT                      3.5               4.04                 Done   



&pi-Transverse            IN                       3.5               0.62                 -

&pi- Transverse           OUT                      3.5               4.38                 Done   



&pi+ Vertical             IN                       3.5               4.17                 Currently here

&pi+ Vertical             OUT                      3.5               3.72                 Done   



&pi+ Transverse           IN                       3.5               4.5                  Done

&pi+ Transverse           OUT                      3.5               3.66                 Done  



Overall Plans

1. Will do Moller measurement on Jan 22, 7 PM.

2. Will do positron runs on Thursday (Jan 22) Day/Swing and Swing/Owl(Friday) where



   Day/Swing [starting 07:00]: BigBite +ve polarity and L-HRS +ve

   Swing/Owl [starting 17:00]: BigBite +ve polarity and L-HRS -ve



3. Friday 07:30: BigBite will be back to -ve polarity, L-HRS stays at -ve polarity.

4. Will stay for about a week of production in &pi-Vertical mode.



Activities

- 09:00-17:25 Beam-study and restoration

- Opportunistic work in the hall during beam-study time: LHRS/BigBite trigger, 

  RICH, BigBite cherenkov, BigBite wire-chambers (gas check)

- Target internal temperature test and NMR/EPR work from counting room during the downtime

- After the restoration of beam, the BPM positions get changed: New settings: 

  BPMA (x, y) = (-1.0, 2.2)  BPMB (x, y) = (-0.4, 2.2)

  Old settings: BPMA (x, y) = (-1.4, 1.7)  BPMB (x, y) = (-1.0, 1.2)

- Confirmed from the analysis expert that the new BPM settings do not change any physics-result.

- More frequent BigBite HV trips.

- Compton signal and background at the same level due to Compton-lock in place, has to be unlocked

  to see them saperated (Fixed on Jan 21 08:20). Good Compton rate.

- Production on polarized 3He in &pi-Vertical mode.



Beamtime Accounting:

         ABU        BANU    BNA   Comment

Owl      7.34       0.14    0.55

Day      0.91       0.03    7.03   Beam-study 09:00-17:25

Swing    5.09       1.69    1.22   Frequent BigBite HV trips, beam tuning for BPM setting