Difference between revisions of "G2p optics"

Revision as of 23:25, 21 April 2012

Summary of Optics Plan

Define the following jobs:
 A. Acceptance calibration, sieve out, rasters on and off (large C12, no LHe) 
 B. Delta scan, (sieve in, C12, no LHe) 
 C. Beam position scan (Sieve in, large C12, no LHe, 8 points on x,y axis and 4 additional points at corner) 
 D. Pointing (Sieve in, CH2, need to refill LHe)

1. 0T @ 2.257:

Do A, move sieve in, do B and C(12 points), refill LHe do D.
At the end take elastic NH3 data to check NH3 thickness.
When finish: move sieve out; Ramp field up to 2.5T; Drain LHe

2. 2.5T, 90deg @ 2.257:

Do A, move sieve in, do B and C(12 points), refill LHe do D.
When finish: Ramp field up to 2.5T; Drain LHe out

3. 5.01T, 6deg @ 2.257:

Do B and C(8 points), refill LHe do D. 

4. 2.5T, 90deg @ 1.706:

Do A, move sieve in, do B and C(8 points), refill LHe do D.
When finish: Rotate target field to 6 deg; Ramp up to 5.01T; Darin LHe out

5. 5.01T, 6deg @ 1.706 GeV:

Here is the optics plan for gep at 1.706 GeV:
P0=1.691

Sieve IN:
target   config                   number of events or beam  time
C12    Sieve IN, No rasters      2 x 1M (10 minutes)
C12    Sieve IN, Both rasters    2 x 1M (10 min)
NH3    Sieve IN, Both rasters    3 x 7M (about 1 hours, which will give
                                 about 400 events when cut to 1x1 beam size)
**Escorted access to move sieve out (30 min)

C12    Sieve out, both rasters   30 minutes(about 10 M events for each
                                 arm, good for dilution)  

In total 2.5 ABU, 3 hours were allocated.

6. 5.01T, 90deg @ 2.257:

Do A, move sieve in, do B and C(8 points), refill LHe do D.
When finish: Turn off target field; Drain LHe, move sieve out.

7. 0T @ 1.159:

Do A, move sieve in, do B and C(8 points), refill LHe do D.
At the end take elastic NH3 data to check NH3 thickness.
When finish: move sieve out; Ramp field up to 2.5T; Drain LHe out

8. 2.5T, 90deg @ 1.159:

Do A, move sieve in, do B and C(8 points), refill LHe do D.
When finish: Ramp field up to 5.01T; Drain LHe out


Here is the optics plan for 1.1GeV with 2.5T at 90 degrees target field.
Before doing optics, beam center and slow raster size have to be determined.

No LHe, LHRS starts at -4% and right HRS start at -3.5%:

1. Delta scan:  C12, sieve in , no raster  (4 hours)
Left HRS: -4%, -3%, -2%, -1%, 0%, 1%, 2%, 3%, 4%
Right HRS: -3.5% -2%, 0%, 2%, 3.5%

NOTE: if running out of time, we will skip 3.5% in right arm
and 1%, 3% at left arm.  This can save about 1 hours.

**Ramp dipoles back to 0% when finish. (40 minutes)

2. Beam position scan: C12, delta=0; sieve in, slow raster only,  (40 minutes)
Config the slow raster to jump in the following way:
1)between (x=-5, y=-5) and (5,5)
2)between x=0, y=+/-5
3)between x=+/-5, y=0


3. Acceptance calibration, part 1:  C12, sieve in, delta=0  (10 minutes)
1) both rasters on

4. Pointing: CH2, sieve in ,delta=0, no rasters (30 minutes)
Take data till the H peak of a normal sieve hole can be fit.

**Escorted access to move sieve out when finish (30 minutes)
5. Acceptance calibration, part2:  C12, sieve out, delta=0 (20 minutes)
1) no rasters
2) both rasters


Estimated time: 7 hours

At the end of the optics, refill LHe, change to the 1st production point,
start dilution runs then polarize NH3 target.

9. 5.01T, 6deg @ 1.159:

Do B and C(8 points), refill LHe do D.

• Overall G2P|GEP optics plan
• 2.253GeV_0T_optics_runplan
• 2.253GeV_2.5T_90deg_optics_runplan
• 2.253GeV_5.0T_6deg_optics_runplan

• 1.706GeV_2.5T_90deg_optics_runplan
• 1.706GeV_5.0T_6deg_optics_runplan

• 1.159GeV_2.5T_90deg_optics_runplan

With new right septum

• 2.253GeV_2.5T_90deg_optics_runplan_new_right_septum

For commissioning:

• Procedure suggested by Vince
• Procedure suggested by Jin