Dec runplan
E08-027/E08-007 Commissioning Runplan
Goal : Commission the beamline diagnostics (BCM, BPM, tungsten calorimeter, super-harp slow and fast rasters, Moller polarimeter), the septa magnets, the spectrometer detector stack, the 3<math>^{rd}</math> arm detector and all associated control/DAQ systems for E08-027 and E08-007. The polarized target, local dump and FZ chicane magnets will not be commissioned at this time.
Contents
Task I : Initial Delivery (9 shifts)
The initial delivery of beam to Hall A will be directed by Accelerator Ops, with assistance from the Hall A shift crew. This includes delivery of beam to the dump, commissioning of the BPMs, calibration with the Harp and power up of the rasters.
Full details are provided at:
- Initial Delivery Testplan (Y. Roblin). Some further details are here.
- Tungsten Calorimeter Testplan (M. Ahmad)
Start up configuration
- Three pass beam, E0 =1.721 GeV, polarized, no raster.
- Current: Initially pulsed up to 8<math>\mu</math>A pulsed, then up to 5 <math>\mu</math>A CW.
- Spectrometers at 12.5 degrees, <math>P_0=1.720</math> MeV (carbon elastic).
- Carbon Target: OUT.
- Sieve slits : OUT.
- Septa settings: 5.69 degrees.
- Compton chicane: OFF (straigt-thru).
- Polarized Target chicane : OFF and degaussed. (straigt-thru).
- Tungsten Calorimeter : Retracted.
Collab responsibilities:
- Request slow raster radius : 1 cm. Fast raster : 1 x 1 mm<math>^2</math>.
- Checkout Happex BPM crate. ( Resp: A. Camsonne, P. Zhu)
- Request slow energy lock. Monitor Happex asymmetry feedback.
- Confirm final beam energy for delivery.
- Shift will need to run spot++.
- Start Detector checkout parasitically using scattering from <math>^4</math>He flowing in the target chamber.
Task II : Moller Commissioning (2 shifts)
Test plan of Sasha Glamazdin for Moller measurement at three-pass beam.
- Moller settings, HV adjusment - 2 hours
- The first Moller quad scan - 1 hour
- The third Moller quad scan - 1 hour
- Moller target scan - 30 min
- New DAQ dead time test - 2 hours
- Restore the beam parameters - 30 min
Hall A Shift Responsibilities:
- Determine absolute beam helicity signs in Hall A.
- Large asymmetry run. 1 hour. (Resp: Alex).
- Record beam half-wave plate IN/OUT changes during data taking.
- Verify that Wien filter angle and beam half-wave plate status are in EPICS data stream.
Task III: HRS/Detector Checkout
Some of these tasks can be performed parasitically to previous tests. There should be some usuable rate coming from the helium in the PVC pipe.
Hall A Shift Responsibilities:
- Verify that FZ1 and FZ2 chicane magnets are configured for no deflection (‘straight-thru’ mode).
- Insert 10 mil carbon foil target. ( Resp: Ed )
- Spectrometer Magnets ( Resp: Jack, John )
- Test Quad and Septa cycling. 3 hours.
- Septa field correspondence to HRS. ( Resp: Jixie, Min.)
- Set momentum to carbon elastic setting, <math>P_0=1720</math> MeV.
- Request CW beam at 1 <math>\mu</math>A. No raster.
- Adjust prescalers to obtain deadtime less than 10%. Verify DAQ rate is greater than 4 kHz.
- Continuos online replay. Take 2 M good events per run, but atleast 15 mins for each run. No run longer than 1 hour.
- High rate DAQ tests. 3 hours. ( Resp: Vince, Ryan).
- Minimize DAQ readout time, reduce deadtime.
- Record deadtime as a function of DAQ rate. Change rate via current or prescalers.
- Trigger Checkout. ( Resp: Alex, Vince, Ryan, Melissa).
- Check deadtime via the scalers.
- Verify that all scalers are incrementing.
- Check for double pulsing.
- Check scalers: detector, triggers, charge, etc. ( Resp: Pengia, Vince).
- Online dead time calculation make sense from the scalers. (Use SRC deadtime software.)
- Lumi checkout ( Resp: Kalyan, Pengia).
- 3rd Arm checkout( Resp: Kalyan, Chao, Jixie). Prior to beam perform Hall probe measurement of magnetic fields at PMT location, and Mu-metal shield optimization.
- Put Al shielding in place before locking-up the Hall.
- Detector checkout with beam (check rates, helicity scalers, bcm, deadtime measurement etc..)
- HV adjustment if any (done with cosmics already)
- Threshold check (unfortunately, we don’t have remote threshold control, so need to go to the hall each time we change threshold)
- Check trigger (dE.AND.E) rates and understand optimal conditions to run vis-a-vis prescales vs deadtime.
- Check to see if buffering can implemented ( This in principle can be done before beam come to the hall)
- Helicity ( Resp: Chao, Pengia).
- HRS Detectors ( Resp: Alex, Vince, Melissa, Ryan) : 6 shifts.
- VDC ( Resp: Ryan).
- Gas Cerenkov ( Resp: Melissa)
- Gas shed checkout procedure (Resp: Jack)
- PMT HV gain-matched.
- All ADC and TDC channels have signal?
- Compare NPE to old short tank results.
- Pion rejector / Calorimeter ( Resp: Melissa).
- PMT HV gain-matched.
- All ADC and TDC channels have signal?
- Scintillator ( Resp: Ryan).
- Timing offset of S1 S2M.
Task IV: Optics Commissioning : 3 shifts
( Resp: Jixie Zhang, Min, Chao). This will be a limited commissioning of the spectrometer and septa optics. To be performed only if time available.
By Jixie: The sieve slits are not in position in this commissioning. What we can do here are the following:
- Beam cross scan (OPs will steer with correctors and quads) 2 shifts
Try to change beam position with slow raster. At each beam position, take data for delta=0.
- Verify initial optics database. iterate. 1 shift.
Make a delta scan when beam position at (x=0,y=0), set delta to -4%, -2%, 0, +2%, +4%
V: Carbon Inelastic Spectrum and False Asymmetry
( Resp: Karl)
- Acceptance scan. Sequentially shift momentum setting by factor 1/3. 1 shift.
- Adjust Prescaler to bring deadtime below 10%. Prescaler should be approximately in range 1-10.
- Take full spectrum of carbon, covering the elastic and accessible inelastic region. See Table below for kinematic settings. Take 2M good events per setting, with a minimum time spent on each point of one hour.
E<math>_0</math> | P<math>_0</math> | W | Minimum Time (hr) |
1.72 | 1.720 | 0.98 | 1 |
1.72 | 1.680 | 1.02 | 1 |
1.72 | 1.556 | 1.07 | 1 |
1.72 | 1.431 | 1.17 | 1 |
1.72 | 1.317 | 1.26 | 1 |
1.72 | 1.211 | 1.34 | 1 |
1.72 | 1.115 | 1.40 | 1 |
1.72 | 1.025 | 1.46 | 1 |
1.72 | 0.943 | 1.51 | 1 |
1.72 | 0.868 | 1.56 | 1 |
1.72 | 0.798 | 1.60 | 1 |
1.72 | 0.735 | 1.64 | 1 |
1.72 | 0.676 | 1.67 | 1 |
1.72 | 0.622 | 1.70 | 1 |
1.72 | 0.572 | 1.73 | 1 |
1.72 | 0.526 | 1.75 | 1 |
1.72 | 0.484 | 1.77 | 1 |
1.72 | 0.445 | 1.79 | 1 |
1.72 | 0.410 | 1.81 | 1 |