FSU – Water Damage
Water Damage
NMR had a failure with the air dryer system that caused water to enter the airlines of system all the way thru the shim coil. Had to replace the following:
- All system air solenoids
- Shim Coil
Also had to clean the upper barrel for proper spinning.
Shim Coil was replaced with an Oxford 23/54 coil vs. Varian 27/54. This coil is 10 mm longer and has a different 50 pin connector. Needed to build an adapter for cable and use a 10 mm spacer.
Cryo Shim Quench
after repairs and coil replacement, fond that cryo line was greater than 1.2 KHz wide. After reviewing He fill procedure with customer, determined that they must have quenched a cryoshim due to hot gases during the fill.
Trained the customer on proper fill procedure and RRI mapped and cryoshimed magnet. Was able to achieve RT lineshape specs after successful 3D Gradient shimming.
| Cryo Shim | Value (Amps) | |
|---|---|---|
| Z1 | +4.660 | |
| Z2 | +5.080 | Z2 value may be reversed. See notes in magnet book. |
| Z3 | +8.000 | |
| X | -4.257 | |
| Y | -11.914 | |
| ZX | +3.700 | |
| ZY | +1.600 | |
| XY | -6.010 | (S2 on ISS10) |
| X2-Y2 | +2.110 | (C2 on ISS10) |
RF Amp Testing
After running pw90 specs, found that both Hi Band and Low Band had low output. Ran RF gain test and found the gain of the High Band AMP was 41 dB (vs 49-53 dB) and the Low Band AMP was 46.4 dB (vs 55-60 dB). Recommend repairing amp modules.
| Xmtr | Attn/SW | AMP Out | Probe | |
|---|---|---|---|---|
| CH1(H1) | 7.8 | 0.3 | 41.1 | 40 |
| CH2(C13) | 9.4 | 2.9 | 46.4 | 44.8 |
Customer Training
Recommend user operator training by Don Emerson and Don Frank that includes operation, application and technical aspects of the NMR system.