Fall 2016 optic plans
Back to [Fall 2016 DVCS run plan]
Assuming we only need one setting for the new Q1.
This proposition has been made on the basis of Winter 2016 run plan, and experience of what happened and what was really used.
Proposition of LHRS run plan (still needs to be integrated with RHRS run plan)
| LHRS step | Approximate beam time | Goals |
| L1 (sieve) | 1h30 | 20 μA DIS with sieve slit on optics foils |
| L2 (NO sieve) | 1h - 1h30 | Delta Scan Elastic on LH2, 20 μA |
One pass program
Ebeam= 2.217 GeV
LHRS θe=17.5 deg
LHRS DAQ: S2+Cer (T3), Use LHRNEW for DAQ configuration. See [section 5.2 in DVCS shift howto] for complete procedure!.
Energy and position lock should be on.
The DVCS calorimeter HVs need to be off
==== Step L1: DIS on optics (WITH Sieve) ====
The DVCS calorimeter HVs need to be off
P0= 1.0 [GeV/c] (DIS)
If the LHRS goes to a new higher momentum setting, Q2 and Q3 need to
be cycled.
Simply leave the regulation ON for Q1.
Beam current : 20 μA
NO Raster
Q2= 0.205 GeV2
W= 1.720 GeV
| Target | Estimated Rates [Hz] | Estimated time | Actual rates [Hz] | Run number | #Event in the run |
| Optics | 300 | 1h (or at least 100k electron events) | |||
| C single foil | 60 | 20 min (or at least 72k electron events) |
==== Step L2: Delta Scan elastic (NO sieve) ====
The DVCS calorimeter HVs need to be off
If the LHRS goes to a higher momentum setting, Q2 and Q3 need to
be cycled.
Simply leave the regulation ON for Q1.
LHRS θe=17.5 deg
We are going to need to check the rates before we take these data, to be safe. But from experience from Winter 2016, 20 μA should be ok.
Run duration: 5-6 minutes each (It was enough during Winter 2016 experience) (We want at least 10k electron events in the LHRS).
Raster ON.
| Target: 15cm LH2 | |||||
| k' [GeV] | Delta P [%] | run number | number of trigger | ||
| 2.078 | 1.04 | ||||
| 2.038 | 1.02 | ||||
| 1.998 | 1.00 | ||||
| 1.958 | 0.98 | ||||
| 1.918 | 0.96 | ||||
Alternative Proposition of LHRS run plan at larger angle (still needs to be integrated with RHRS run plan)
| LHRS step | Approximate beam time | Goals |
| L1 (sieve) | 4h | 20 μA DIS with sieve slit on optics foils |
| L2 (NO sieve) | 1h30 | Delta Scan Elastic on LH2, 20 μA |
One pass program
Ebeam= 2.217 GeV
LHRS θe=35 deg
LHRS DAQ: S2+Cer (T3), Use LHRNEW for DAQ configuration. See [section 5.2 in DVCS shift howto] for complete procedure!.
Energy and position lock should be on.
The DVCS calorimeter HVs need to be off
==== Step L1: DIS on optics (WITH Sieve) ====
The DVCS calorimeter HVs need to be off
P0= 1.0 [GeV/c] (DIS)
If the LHRS goes to a new higher momentum setting, Q2 and Q3 need to
be cycled.
Simply leave the regulation ON for Q1.
Beam current : 20 μA
NO Raster
Q2= 0.82 GeV2
W= 1.537 GeV
| Target | Estimated Rates [Hz] | Estimated time | Actual rates [Hz] | Run number | #Event in the run |
| Optics | 25 | 3h (or at least 100k electron events) | |||
| C single foil | 5 | 1h (or at least 72k electron events) |
==== Step L2: Delta Scan elastic (NO sieve) ====
The DVCS calorimeter HVs need to be off
If the LHRS goes to a higher momentum setting, Q2 and Q3 need to
be cycled.
Simply leave the regulation ON for Q1.
LHRS θe=35 deg
We are going to need to check the rates before we take these data, to be safe. But from experience from Winter 2016, 20 μA should be ok with prescale ps3=1.
Run duration: 5 minutes each (We want at least 10k electron events in the LHRS).
Raster ON.
| Target: 15cm LH2 | |||||
| k' [GeV] | Delta P [%] | run number | number of trigger | ||
| 1.614 | 1.04 | ||||
| 1.584 | 1.02 | ||||
| 1.553 | 1.00 | ||||
| 1.521 | 0.98 | ||||
| 1.49 | 0.96 | ||||
