[Isotope-prod] LERF update

[Kevin Jordan]

HI All,
There were some challenges this morning; gun trip that recovered with out any problem, 1/4 RF false crowbar error, then zone 2 HPA but we were able to complete the 100 watt run on the Stack. This was exchanged with the solid graphite block around swing shift turn over. The radiation levels on opening the shielded hutch were ~1 rad on contact with majority likely 11C (20 min 1/2 life).
The machine was brought back up by Mike A. & Steve B. for the CW 1 kwatt to confirm that the graphite would not be damaged or reach excessive temperatures. A camera was positioned to monitor the actual temperature controllers (EPICS ADC was very noisy so this was just backup). This was confirmed by David H. & Adam S., the photos were indistinguishable from before & after!
Photos below show before and peak temperatures for the exposure, the lower two channels are not connected directly to the water lines but to the copper base next to the front face of the crucible and to the rear of the crucible (the solid graphite block lacked the screw-in plug so that sensor was not in contact with the block). During the Gallium irradiation I expect that sensor to go to perhaps 200C, again that is a thermally isolated sensor monitoring the true block temperature.

We await permission to proceed...
Kevin

[cid:2630DCCF-5F7E-48CB-8D15-A0BB3A564225-L0-001][cid:E6FEE900-225C-4E9D-98A6-470DB9FDED44-L0-001]
[cid:54C6E3E3-8633-43FC-81E2-6F01A8484FC6-L0-001]
Thermocouple tab attached to base of block


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