D2n kinematics

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Revision as of 12:52, 27 July 2020 by Brads (Talk | contribs) (1-pass running considerations)

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Run Plan (updated when needed)


Rough / High-level sketch of d2n kinematic settings

Reduced kinematics list to accommodate limited beam time (dropped 1/4 of kinematics)

      ---------  Beam Params ----------
            E_beam = 10.4 GeV/c
            I_beam = 30 uA
            P_targ = 0.50
            P_beam = 0.80
          ---------  HMS ----------
       E'    theta    x        Q2       W
 A     4.2   13.5     0.207    2.414   3.178
 B     4.2   16.4     0.305    3.554   2.993
 C     4.0   20.0     0.418    5.018   2.806    --  Only setting compatible with SOLID Cherenkov small-angle test.
          --------- SHMS ----------
       E'    theta    x       Q2      W
 X     7.5   11.0     0.527   2.866   1.859
 Y     6.4   14.5     0.565   4.240   2.036
 Z     5.6   18.0     0.633   5.701   2.046


  • Not shown is the 1-pass running (2--3'ish days)


Schedule Overview

  • We should expect to have 6 weeks of beam
    • Hall C will have priority over Hall A (if there are beam loading, machine stability issues)
  • Rough priorities:
  1. We plan to start at 5-pass with kinematics A and X (small angle)
    We will start at 5-pass with kinematics C and X (small angle on SHMS, large angle on HMS)
    • This will allow the SOLID Cerenkov prototype folks to setup before beam and run their small-angle test on the HMS side.
  2. Then move to kin A and Z (high-Q2 SHMS, small angle HMS)
  3. Scheduling of Kin B, Y and 1-pass running would depend on how the Accel/target/virus behaves

Non-"production" runs

  • Confirm we have all the optics we need!
    • Analyze and get the new matrices in the analyzer
    • Make sure we have empty target runs for all kinematics and all optics configurations to help disentangle beamline window contributions
  • Nail down estimates for ref cell running (N2, H2, 3He, empty)
  • Minimal/no positron running?
    • Perhaps measure the positron background in HMS at 20 degree and compare with model?


1-pass running considerations

  • Request pass change to 1-pass
    • Controlled Access to install collimator (RadCon)
  • Restore 1-pass beam to Hall
    • Moller measurement ASAP
    • Turn off hodoscope bars as before: HMS [1]; SHMS [2]
    • Last time there was an issue with the raster; make sure we know what needs to be done [3] [Mark, Bill Gunning?]
  • Begin production running following A1n 1-pass notes 1-pass_calibration_for_A1n_(Jan_2020)
  • 3He elastic and QE longitudinal Asymmetries (incl. pressure curve / ref cell running)
    • HMS setting: 11.7 deg, -2.1483 GeV/c
    • SHMS setting: 8.5 deg, -2.12860 GeV/c
  • Polarized 3He Delta Transverse Asymmetry
    • HMS setting: 11.7 deg, -1.75830 GeV/c (electron W=1.232)
    • SHMS setting: 8.5 deg, -1.79736 GeV/c (electron W=1.232)
  • Pol 3He Elastic Measurement (E12-06-121A)
    • Details Coming Soon