Commissioning Plan for g6c (August 16)

Commissioning Plan for g6c (August 16 and 17)
Establishing Beam:

1. Verify radiators are retracted.

2. Verify TASC is OUT of beam.

3. Pair Spectrometer Magnet OFF.
4. Put Drift Chamber HV OFF and leave it OFF till you have finished with the whole procedure.

5. Request MCC to set beam current to Ie = 5 nA

6. Adjust electron beam to be centered on the beamline as determined by the horizontal and vertical nano-Amp cavities: Refer to bpm value in page 2 in g6 logbook.

7. Tell the MCC that you are going to do a harp scan (which might make the BPM move around)

DO a harp scan to verify beam profile.

The signal/background should >= 10^4.
Print out harp scan results, and paste in log book.

8. Insert "Radiator A"

9. Put the photon beam profiler (positioned directly in front of TASC) in the beamline. Print out the beam profile and put in the log book.

10. Reduce beam current to 100 pA. Move photon profiler out of the beamline. Change to radiator C. Move TASC into the beam line. Center the beam on TAsC. Ask mcc to move the beam around in x and y (from 2c21 and 2c24) and look at the TASC counts.
11. Move TASC out of the beamline. Change to radiator A. Move photon beam profiler in. Turn on all HVs. Check that target is full.
12. Using Snapshot print scaler_g.adl EPICs screen which records count rates of upstream pmts, TOF, EC, start counters, PS, PC, TASC and beamline settings. Verify rates are comparable to previous comparable conditions.

13. Check the colimator position.

Radiators:

A= 3x10^-4 (Production)

B= 10^-4(Production backup)

C= 2x10^-5(Normalization)

D= 2x10^-5(Normalization backup)

!!! NOTE: No Beam > 100 pA with radiator C or D !!!
Tagger:

check and mark tagger dump spot.

check occupancies

monitor t-scalers

monitor e vs t histogram(with and without e.t coincidence)

check e.t coincidence

REDUCE T-tdc timing windows if e counts are too high

Start Counter:

monitor scalers

w and w/o HV booster

Pair Spectrometer:

PRIMEX team: The dipole current must be adjusted for the g6c photon energy range (4.8-5.2 GeV)

CLAS (DC, ToF, EC, CC, LAC):

check monitor histograms

Trigger:

Production trigger for g6c:

MOR(1-12T)· ST(2/3) ·CLAS(ANY_TWO_SECTORS_TOF)
Timing

Perform MOR/ST delay curves with St. HV booster off. Restricted production trigger bit 2 (EC >= 1). Trigger file: g6_com.cfg

Perform MOR/ST delay curves with St. HV booster on. Restricted production trigger bit 2 (EC >= 1). Trigger file: g6_com.cfg

Perform MOR-ST/TOF delay curves with St. HV booster on. Production trigger bit 1 for ASYNC1.

Perform MOR-ST/TOF delay curves with St. HV booster on. Production trigger bit 1 for ASYNC2.

Data rate tests:

Perform beam Intensity scans for I=10,20,30,40,50,60 nA and following two triggers with the ST counter HV booster on and off.

Trigger bit 1: g6c Production trigger (g6_prod.cfg)

Trigger bit 1: g6c commitioning trifgger (g6_com.cfg)

Monitor deadtime corrected MOR, PS, ST rates. Need MOR/PS, ST/PS, and (Level 1 rate)/PS.

Produce TR/MOR vs I curves, w and w/o ST counter HV booster.

Time Async2 g6c production trigger (g6c_prod_async2.cfg)

Measure Ripani trigger rate. (g6c_prod_ripani.cfg)

Take a pedestal run.

Load the pedestal values into ADC's by runnig pedman.

Calibration Run

Take one low intensity run at I = 1 nA. for approximately three hours. Make sure the thinnest (0.1%) p.s. converter is put in.

Normalization Run

Beam Intensity of 100 PA with radiator C, approximately 50000. Make sure the thinnest (0.1%) p.s. converter is put in.

Start Production