Transversity Run Plan 1st Order

07/18/2008, by Xiaodong Jiang

Commissioning Part

  0. Beam delivery, one pass beam, initial checks.

      Start up conditions:
      HRS_L at 16 degree, negative mode, P_HRS=xxx.xx GeV/c
      BigBite at 30 degree, 1.5 m drift (target to front surface of
      BigBite magnet), 710 A current.

      Beam tuned through Compton magnets.
      Compton detector initial check.
      Harp scan require that beam sigma_x: 100~200 micron, sigma_y:100~200 micron.
      Check lumi-monitors, beam position monitors, beam charge monitors.
      HAPPEX feedback working.

      Moller run.

      check beam steering by BigBite magnet.
      Target cell alignment check. Move beam around (through grid locations on BPMA and BPMB)
      and check detctor rates.
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   1. One pass beam, E0=1.234 GeV, polarized, 5 days total.

      HRS_L@16 degree, negative mode, quasi-elastic kinematics, P_HRS=xxx.xx GeV/c

     i, Carbon hole targets beam-target alignment check, HRS singles.
        Verify that beam goes through middle of holes on carbon targets.

    ii, HRS_L single arm detector shakedown, carbon multi-foil target.
        RICH, A1, Gas Cherenkov, S2M and Leadglass blocks. Check DAQ, HRS scalers,

   iii, HRS_L sieve slit runs, carbon multi-foil target, double-check optics (optional).

    iv, HRS@16 degree, He3 delta-production kinematics, P_HRS=xxx.xx GeV/c

      a. Carbon multi-foil run.

      b. Pol. He3 target, transverse in-plane polarization, transv. asy.
          at delta-production  measurement.

      c. tests of target spin flip while in step-b.

     v. HRS@16 degree, He3 elastic kinematics, P_HRS=xxx.xx GeV/c.

       a. Rotate target to Long., Pol. He3 elastic Asymmetry calibration.

       b. Reference cell run, He3 pressure curve. Run He3 gas 20~130 psi.

       c. Reference cell N2 runs, with different gas pressure, 20~130 psi..


    At the same time, BigBite at 30 degree, 710A magnet current,

     i, detector shakedowns, carbon multi-foil targets.
        Wirechambers, gas Cherenkov, preshower+shower, scintillators.
        Wirechamber HV scan, threshold scan.
    ii, check beam helicity sorted scalers, synk-check of HRS and BigBite scalers.
   iii, check Lumi-monitors. Synk-check of Lumi and BigBite scalers.

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    2. One pass beam, E0=1.24 GeV, polarized, HRS@58.1 degree in positive
       mode, P_HRS=0.62. BigBite at 30 degree, 710 A current.

    i. Carbon multi-foil run.

   ii, H(e,e'p) coincidence run, with reference cell H2 gas ~130 psi. I~15 uA.

        Check coincidence trigger. Coin. Time-of-flight, S2M t0 offsets.
        Beam RF timing signal check.
        Expected T5 rate is roughly:xxx.xx Hz.

   iii, change BigBite magnet current (in 20% steps to ~20% of Max.) to have
        elastic electron event spread over several rolls of blocks.
Shower+preshower
        hardware gain adjustement. Sotfware gain calibration.
        Check trigger thrshold.

    iv, BigBite sieve slit run, H(e,e') single arm, with Coin T5 taken at
        the same time.  This provide one set of optics calibration at
        E'=1.05 GeV for BigBite.

     v, While BigBite sieve slit in, take one run with carbon multi-foil target, BigBite field off.

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   3. Two pass beam, E0=2.400 GeV, un-polarized, HRS@46.1 degree in
      positive mode, P_HRS=1.25 GeV/c.

     i. Carbon multi-foil run.

    ii, H(e,e'p) coincidence, with reference cell H2 gas ~130 psi. I<15 uA.
        Expected T5 rate is roughly:xxx.xx Hz.

   iii, Change BigBite magnet current (in 20% steps to ~20% of Max.) to have
        elastic electron event spread over several rolls of blocks. for sotfware
        gain calibration around E'=1.80 GeV.
        Check trigger thrshold.

    iv. BigBite sieve slit run, H(e,e') single arm, with Coin T5 taken at
        the same time.  This provide one set of optics calibration at
        E'=1.80 GeV for BigBite.

     v, While BigBite sieve slit in, take one run with carbon multi-foil target, BigBite field off.
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   4. E0=5.900 GeV, polarized beam, pre-production check out (1 day).

     i, Beam tune through Compton magnet, Compton detector commisioning.
    ii, Moller run.
   iii. Beam position vs BigBite background rate check.

    iv. Coincidence trigger check, P_HRS=-2.4 GeV/c NEGATIVE mode, at 16 degree.
        Software check for coin-tinme of flight corrections.
        With enough confidence, shrink TOF window from 100 ns to ~60 ns(?)

     v. Pol. He3 target, transvers in plane polarization, spin-flip check.
        The DAQ goal is to take at least 1 kHz (100 Hz coin.+900Hz
singles)
        with 90% live time,

Production part

   5. Production, target transverse polarized, in-plane and verticle.
      With reference cell runs in between, H2 gas 130 psi, N2 gas 130 psi.

   6. Around Thanksgiving, change target cell.

   7. Production, target transverse polarized, in-plane and verticle.
      With reference cell runs in between, H2 gas, N2 gas.

   8. Complete data taking, switch over to d2n, change cell, with Long.
      target polarization setup.

   9. One pass beam again, polarized, He3 elastic asymmetry calibration.

  10. d2n production ...