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(gamma,p) Run Plan

(gamma,p) Run Plan
4.1 GeV gamma d
No gamma d running is planned at 4.1 GeV.
4.1 GeV gamma p

Instructions

  1. Rates are low at this energy, run beam currents of 25 - 30 microA. Prescale T1, T3, T5 to 1, and T2 and T4 to 100 - 200 Hz each.
  2. With current and time suggested, we should get about the number of good events with good FPP scattering suggested - see online replay instructions.
  3. Avoid file splitting if possible. Stop and restart runs when needed.
  4. The time estimate is based on scheduled time with 50% availability. Do not significantly shorten runs if count rate is larger than expected. If count rate is below estimates, run up to about two times longer, unless we are behind schedule.
  5. Radiator-out hydrogen runs should be about 60% as long as radiator-in runs, except all dummy target runs should be for 20 - 30 minutes of data - do not worry about adjusting their time. 12C measurements are to determine y-target offsets, and should be run for 10 minutes each.
  6. For each angle / momentum setting, take a measurement on 12C solid target for ~10 minutes while the magnets are settling. This should be done with raster off. (This is used to check spectrometer offsets, which are not now regularly measured.)
  7. Comment: Pi+ background is kinematically allowed, and should have high rates at the larger angles.
Task Ie  Target  Radiator  th-e  p-e  th-h  p-h  FPP  Time Counts
(uA)  (%)  deg  GeV  deg  GeV  door  h or m good event+good FPP
ep for 1.667 GeV d(gp) false asym - 1 30 1H out 18.58 3.340 48.71 1.460 all 2 h ~7 M
" 20 12C " " " " " " 10 m ~10 k
ep for 1.667 GeV d(gp) false asym - 2 30 1H out 19.13 3.303 47.86 1.460 all 2 h ~7 M
" 20 12C " " " " " " 10 m ~10 k
ep for 1.667 GeV d(gp) false asym - 3 30 1H out 19.69 3.266 47.02 1.460 all 2 h ~7 M
" 20 12C " " " " " " 10 m ~10 k
120ocm 70 MeV off 20 12C out 21.34 3.087 45.31 1.581 all 10 m ~10 k
" 25 - 30 dummy " " " " " " 20 m -
" " 1H " " " " " " 3.5 h -
" " 1H 6% " " " " " 6.5 h -
" " dummy " " " " " " 30 m -
105ocm 70 MeV off 25 - 30 dummy 6% 28.03 2.667 37.28 2.069 all 30 m -
" " 1H " " " " " " 6.5 h -
" " 1H out " " " " " 3.5 h -
" " dummy " " " " " " 20 m -
" 20 12C " " " " " " 10 m -
90ocm 50 MeV off 20 12C out 35.90 2.219 30.251 2.583 all 10 m ~10 k
" 25 - 30 dummy " " " " " " 20 m -
" " 1H " " " " " " 3.5 h -
" " 1H 6% " " " " " 6.5 h -
" " dummy " " " " " " 30 m -
75ocm 35 MeV off 25 - 30 dummy 6% 45.66 1.761 24.08 3.086 all 30 m -
" " 1H " " " " " " 6.5 h -
" " 1H out " " " " " 3.5 h -
" " dummy " " " " " " 20 m -
" " 12C " " " " " " 10 m -