Transcript Targets #1 & 2

We appear to have encountered a serious problem with the
target.
•
Demonstrator target installed in R78. Insulation failure led to
burnt out coil 13th February after few hundred pulses.
Stator extracted from drive removed from ISIS and used as
replacement. Failed in rather similar way 20th February. (May
already have had insulation damaged.)
Stator in ISIS performed >2M pulses last Autumn, but without
central tube welded to flanges. Could this also be vulnerable?
We are discussing with coil manufacturers and motor
engineers. (Need advice before take further action!)
Present plan:
•
•
•
•
–
–
–
–
–
–
Obtain coils with better insulation (double insulated?)
Thin mica (or similar) sheets between coils etc (without
compromising cooling)?
QA – High voltage breakdown tests on all coils before assembly.
Target shaft destroyed during disassembly – must obtain two new
shafts, chance to fix other problems. (Wing Lau contacted.)
Need two new pairs of flanges, new central tubes, for two drives.
Magnets, optics etc can be recovered from other drives.
Chris Booth
University of Sheffield
1