Log entry time 07:35:07 on January23,2009

Entry number 257403

Run Coordinator Report for Jan 22, 2009:

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               5.06                 Done

&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. Take positron runs for about 8 hours (Friday).

2. 13:00 (Friday) BigBite will be back to -ve polarity, L-HRS stays at -ve polarity.

3  Do Moller measurement.

3. Take 3He reference cell data for an hour.

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



Activities

- MCC tunes beam for the first two hours through the magnet MQA9A23 which was causing the BigBite

  HV trips. After that only one BB HV trip during Owl.

- 05:30 3He &pi+Vertical mode of production finishes.

- 05:30_06:40 3He reference cell data. The cell pressure stays constant at 125 psig during the run.

- 06:40 Call for controlled access to change BigBite polarity from - to + and to test the reference cell leak.

- 07:20 ARM finishes survey, tech-crew in the hall.

- 08:20 BigBite polarity change finishes. Target leak test continues.

- Target leak is found and repair is not possible in a couple of hours.

- 09:30 Beam permit

- After viewing beam through BeO and checking spot with different raster sizes positron production starts.

- 10:48- 11:05 BB HV trip recurs (3 times) due to a bad beam tuning, MCC says that ARC4 magnet is again a culprit.

- Due to beam problem positron runs with L-HRS as +ve polarity stops at 16:00 after accumulating 0.2 C of data.

- 16:00-17:40 Controlled access for the polarity change (+ to -) of L-HRS.

- No beam all Swing shift, Moller measurement will be done tomorrow (Jan 23) and must be done before Saturday Owl

  after which Hall B will be down for more than 3 weeks.

Beamtime Accounting:

         ABU        BANU    BNA   Comment

Owl      3.83       2.06    2.11  MCC beam tune 2 hr, hall access 1.25 hr

Day      5.06       1.70    1.24  Hall access first 1.5 hr, accelerator magnet problem

Swing    0.0        1.59    6.41  Controlled access, accelerator magnet problem