Momentum scan for BigBite Commision
Goal - The momentum scan in coinc with HRS produces over-defined protons of known momentum and angles set for the calibration
but shines only a limited part of the BB acceptance. We will therefor mix singles H(e,p) events in to the trigger.
Set beam at 1201 MeV (1st pass), 5-10 microAmp.
Make sure the singles rate at all BB scintillators are well below
1 Mhz each.
Set HRS(L) at A1 kinematics.
Establish a mix of coincidence trigger [HRS(L) (electron) * BB(proton) ] and singles BB (proton).
Get data for A1,A2,A3,A6,(G2) kinematics, for both H and C(normal) targets
Change energy from 1st pass th 2nd pass and get data for A4,A5,(C1,G1) kinematics.
Make sure all elements are working. Take enough beam to have ~10,000 per element, for off line analysis.
Analysis -
a) Identify electrons in HRS(L), protons in BB, Identify clean (e,e'p) and (e,p) events.
b) Get the expected momentum distribution using all possible methods and adjust fit/calculation parameters.
* Scintillator hit position.
* TOF Aux-E
* TOF target-E
c) Check dP/P for the different methods.
d) Look for the expected angle vs momentum correlation for the proton in BB.