Standard Beamline Quadrupole Specification

From GlueXWiki
Revision as of 15:04, 21 January 2008 by Jonesrt (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Below is the spec for a standard JLAB QP magnet. At 19amps, it can just make the field spec for the Hall D tagger.

Bore3.81 cm1.5 in
Length30.48 cm 
Max B'l75 kGat 18 A (design current)
 82 kGat 19 A (depends on cable run)

Response from G. Yang:
To get the proper vertical focusing for the 2D microscope readout at the focal plane at 3 GeV [9 GeV photons], the quadrople should have a field gradient of ~0.8 kG/cm and a length of 30.48 cm, or an integrated field gradient of 25 kG. If we intend to move the microscope to 5 GeV or higher-energy electron positions, the field gradient should only be slightly larger. So the capacity of the standard JLab QP magnet is fine.

Remaining questions are:

  1. The difference between the 25 kG requirement stated above and the 80 kG stated in the specification. Why was such a large margin built into the specification?
  2. How does cable run length control whether or not the quadrupole can reach 82 kG? Isn't that a power supply issue?
  3. What are the inner diameters of standard pipe sizes that fit through this bore? Can we find one that meets the 30±2 mm ID in the specification?