Septum Magnet Status Report

1
Septum Magnet Status Report

• John J. LeRose

2
January 31, 20031st Septum (Right) Arrives at
JLab
3
Installed in the Hall March 2003

• Two major Problems
• Heat leak from the warm bore
• Temporarily solved by adding bore cooling (and
  cooling the N2 shield with He)
• Permanent repairs planned for early next fall
• Design changes incorporated into magnet 2

4
July 2003

• Field configuration has been verified
• NMRs worked for a while
• Precision measurement of B vs. I
• External field makes sense now

5
Since July

• Optical properties in Right with correct coil
  configuration look very good
• 2 (Left) Arrives August 2003 (some assembly
  required)
• Bore Tube and coil cooling modified in Right
  Septum
• Bore Tube installed in Left Septum
• Both Magnets installed in the Hall

6
qf
xf
7
Good news/Bad news

• Heat leaks to the warm bore are gone
• Left has a leak in its insulating vacuum
• The leak is small enough that we can live with it
  by pumping, etc.
• Keeping the coils cold over extended periods of
  time is proving difficult (but doable)
• We got to 197 Amps on the 1st serious training
  run
• then 197 and then 215 after that
• NMR field monitoring works
• BUT only in manual mode.
• Coils on the right magnet are sitting at 10K
  (theories abound)
• Slow controls not working on the Left Septum

8
Left Septum
9
As of yesterday afternoon

• Work in progress modifying the cryogenic plumbing
  to allow easy cooling and evacuating of the left
  shield and improved cooling to the right septum
  shield
• Completing spectrometer/septum/target vacuum
  connections
• Controls expert, Mike Nilles of BWXT will be
  here Tuesday

10
(No Transcript)