Where are the collimators?
During the summer of 2002 the collimator boxes were removed from the spectrometers and then reinstalled. All previous history of the collimator positions is no longer valid. The survey report A812 gives the new sieve and collimator offsets and A820 gives target to collimator/sieve distances. (survey report database)
Newest Results of
Measurements of the Locations of the Sieves and Large Collimators for the HRS
Spectrometers
(based on JLab Alignment Group DT #'s: A812 , September 18,2002 , and A820 October 4, 2002)
|
|
Δx (mm) |
Δy (mm) |
z (m) |
|
Right (formerly Hadron) Sieve |
-0.03 |
-0.05 |
1.1752 |
|
Right Large Collimator |
1.45 |
-0.03 |
1.1008 |
|
Left (formerly Electron) Sieve |
-0.89 |
0.05 |
1.1829 |
|
Left Large Collimator |
-2.21 |
0.01 |
1.1086 |
Δx is the horizontal displacement of the Sieve or Collimator from its ideal position. +x is to the left when facing the spectrometer.
Δy is the vertical displacement of the Sieve or Collimator from its ideal position. +y is up.
z is the distance from the ideal target position to the sieve or collimator.
Please send comments or questions to John LeRose: lerose@jlab.org