1. Compton Run
Liping Gan
June 18, 2004

2. Goals
A few short runs on 0.5% R.L. 9Be target with different beam intensity to study photon flux effect (~2 h).
A clean run on 0.5% 9Be target (~20 h)
Cross section measurement
Energy calibration
Short run on 5% R.L. 12C (~1-2 h)
Check Z dependence
Normalization to the PrimEx physics target
Cross check the system error of setup
Take single arm data during production run

3. 9Be 0.5% R.L. target, Ne=8.72X1022 e/cm2 Q~107 γ/sec
One E-counter, ΔE/E=3X10-3
For Eγ=4 GeV
Rate=0.2Hz
#event=14400 for 20 hours

4. 12C 5% R.L. target, Ne=6.42X1023 e/cm2 Q~107 γ/sec
two E-counter, ΔE/E=6X10-3
For Eγ=4.8 GeV
Rate=2.8 Hz
#event=10080 for 1 hours

5. 207Pb 5% R.L. target, Ne=7.58X1022 e/cm2 Q~107 γ/sec
two E-counter, ΔE/E=6X10-3
For Eγ=4.8 GeV
Rate=0.33 Hz
#event=1200 for 1 hours

6. Special requirement for trigger
Make coincidence of tagger MOR and two-cluster on Hycal.
PS magnet off
Open additional E-counters at Eγ: 2GeV, 3GeV, 3.5GeV, in order to increase the Compton events hitting on lead glass part of HYCAL
Set HYCAL cluster energy deposition threshold 200 MeV level.