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Beam Energy

To consider changes in error for 1.095 (BFIL=.94) and 1.240 (BFIL=1.064) GeV beams. This is for: 14 cm Pb VT collimator, theta_max 10.25, 25cm upstream, with a lintel, and global volume air.

In short, (1 = VT original, 2 = VT 14 geometry described above)
Geom 1 w/ helium 1 w/ air 2 w/ air 2 w/ air 2 w/ air
Beam Energy (GeV) 1.165 1.165 1.165 1.095 1.240
Rate (MHz) 872 816 810 926 702
< Q^2 > 0.0261 0.0261 0.0257 0.0228 0.0291
Error on Qweak (%) 4.19 4.27 4.30 4.35 4.30
Stat. Error (%) 3.28 3.38 3.44 3.61 3.29
Hadronic Error (%) 1.54 1.54 1.51 1.36 1.67
All other error (%) 2.10 2.10 2.09 2.00 2.18
Asymmetry (ppm) -0.2369 -0.2374 -0.2324 -0.1996 -0.2724
Stat. Error on Asymmetry (%) 2.18 2.25 2.30 2.51 2.11

Backgrounds for VT14_10.25_25cm_lin_air (no shielding wall)

Table 1: Results, weighted by cross section, photoelectric efficiency, and asymmetry.

Energy (GeV) 1.165 1.095 1.240
Elastic Photons (%) 0.1540 +/- 0.0048 0.1515 +/- 0.0048 0.1594 +/- 0.0049
Elastic Photons from coll. region (%) 0.0059 +/- 0.0006 0.0044 +/- 0.0005 0.0068 +/- 0.0007
Inelastic Photons (%) 0.0090 +/- 0.0007 0.0086 +/- 0.0008 0.0089 +/- 0.0007
Inelastic Electrons (%) 0.1052 +/- 0.0053 0.0785 +/- 0.0044 0.1731 +/- 0.0071
Moller Photons (%) 0.1399 +/- 0.0109 0.1161 +/- 0.0089 0.2293 +/- 0.0174
Moller Electrons (%) 0.9957 +/- 0.0742 1.0732 +/- 0.0741 1.0844 +/- 0.0820

Plots of the XY profile for the 3 beam energies (vt14 geom) shown below. The accepted profile is plotted.