Difference between revisions of "Qweak Elastic GEM Profile"

Revision as of 16:30, 15 May 2009

Elastic electron scattering profile at Z=-528 and Z=-558, the two limits of the GEM keep out zone.

the 35 cm target is at Z = -650 cm

If [math]\theta = [/math] 6 degrees and Z = -528-(-650)+35/2 = 139.5 cm then Y = Z \tan(6) =14.6 cm

If [math]\theta = [/math] 6 degrees and Z = -558-(-650)-35/2 = 74.5 cm then Y = Z \tan(6) = 7.8 cm

IIf [math]\theta = [/math] 11 degrees and Z = -528-(-650)+35/2 = 139.5 cm then Y = Z \tan(11) =27.12 cm

If [math]\theta = [/math] 11 degrees and Z = -558-(-650)-35/2 = 74.5 cm then Y = Z \tan(11) = 14.48 cm

GEM detector would need to span from 7.8 cm to 27.12 cm to catch elastic electrons which hit a scintillator moved 6 cm radially out from its present location.

The previous profiles prior to this latest change in the collimator when overlayed on top of each other looked like:

The electron profile closest to the beam pipe center appears to be about 8 cm away from the beam pipe center now instead of about 7.5 cm.

@@ Line 2: / Line 2: @@
 the 35 cm target is at Z = -650 cm
 If <math>\theta = </math> 6 degrees and Z = -528-(-650)+35/2 = 139.5 cm then Y = Z \tan(6) =14.6 cm
@@ Line 10: / Line 11: @@
 If <math>\theta = </math> 11 degrees and Z = -558-(-650)-35/2 = 74.5 cm then Y = Z \tan(11) =  14.48 cm
+; GEM detector would need to span from 7.8 cm to 27.12 cm to catch elastic electrons which hit a scintillator moved 6 cm radially out from its present location.
 Profiles generated by Neven using Katherine's Euclid file ([[Media:qweak_gw_5-dec-07.euclid.txt]])  representing the collimator design dated 8/8/07 from [http://www.iac.isu.edu/mediawiki/index.php/Collimator Paulo's Drawing "Hall -V QWEAK EXPERIMENT COLLIMATOR BUNKER SETUP UPSTREAM CLEANUP COLLIMATOR" # 67503-E-00021].