these were responding the right way last run. None of the cables or chassis were replaced during the SAM other than the cryomodule. For these two cavities, it is as if we are running with no interlock on the window temperature. Set point for the trip is positive and the readback is negative. This will never trip even if it exceeds -4V
The BSList that was performed to verify mitigation:
https://tasklists.jlab.org/bslist/tasks/120407
Lowered to 50 and 65% respectively and got nuissance diffuser trips even without the ion chamber current dropping anywhere near the dynamic threshold (see fig 1). I bumped both up 15%, to 65 and 80 % for IC 1 and 2 respectively. I then lowered threshold for IC 1, which doesn't trip all the way down to 20% (fig 2). The behavior seemts to point to something being odd with IC 2? Final settings in fig 3
On the next maintance day, I would like to work with this chassis one more time before closing out this ATLiS / Epass.
Since we had to remove the attenuator boards, the signal read back levels are clipping. I think that I have a solve for this, but it involves swapping out the internal ADC boards with a modified version. I am working with the fab shop to do these changes on some spare boards. My plan would be to perform the board swap in situ (with chassis power off of course) and see if this takes care of the clipping.
Start of shift: xB at 320 nA on H2, xC at 40 uA on 10cm Dummy
Cavity tripped out on detune angle according to the waveform browser. Sitting in SEL the TDETA is highly unstable and trying to transition into SELA/SELAP would cause the tuner to tune the cavity off resonance.
Took a look at CRFPPmin and CRFPPmax, looks like they're both maxed at 180. If this is just oscillating then I don't think it's any surprise that the TDETA is showing the same behavior.
We've bypassed it for now.
| Shift | Owl |
|---|---|
| CEBAF Program | |
| MCC Crew Chief | Price |
| MCC Operators | Howard, Chaudhary, Christian |
| Program Deputy | Nissen |
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