Optics Meeting Sep 13 2022 230PM ET
From Moller Wiki
1. Relative elastic C12 and Moller rates (Vassu)
David, Vassu, Kate, Paul S., Zuhal, Chandan, Ciprian, James, Brynna, Bill
- (Vassu)Two modifications to sieve holes: a) adjusted Sector 5 holes to have similar pattern to Sector 1, to avoid Moller/12C overlaps - this worked b) made all holes phi values as 0 or +-8 degrees. Looks good. Should also check that the holes don't overlap for the case of the other 12C optics target.
- (Vassu)Optimized rotation angles as +-15.94 degrees (as opposed to +-13.94 degrees). Checked that each hole in each sector is cleanly seen in at least one of the new rotations - yes. Here "green" rotation is nominal, red and black are cw and ccw from green with that rotation angle. Also still want a full 360/7 rotation to move green->green. This was checked with pass 1 data looking at GEM plane 4, which should be the most extreme case for azimuthal defocusing. Suggestion: make a 1D plot of rate vs. phi, to see edges of GEMs even more clearly with respect to the hole distributions. Also suggested to make an x,y plot with the correct aspect ratio for each GEM plane.
- (Vassu)Tables of rates for each each for each sector at each beam energy for both 12C and Moller. Rates look good, except for a few known holes which at certain passes have blocked acceptance. The ratio of 12C/Moller events is reasonable in all cases, so 12C events will not be swamped by Moller events at the trigger level.
- (Kate)Will have more low-energy gamma statistics soon; will look at vertices to see sources of the low-energy gammas, and then try the other low-energy Livermore libraries. Ideas on how to make simulation more efficient (don't digitize hits for all 4 GEM planes).
- (Kate)Have generated simulations with scintillator "ring" material to mock up effect of X_0 of the GEMs and scintillators, see effect on optics reconstruction.
Meeting ID: 972 5975 5403