This has happened few times now that acromag channel for the can heater driver stopped updating according to the PID script and the can gets heated to a very high temperature. This pushes the temperature out of the ranges of the current AD590 temperature sensor board. I have changed the range of channel 2 (this was being used for out-of-loop) to ensure we can still see some meaningful temperature value when such incidents happen. I have replaced R18 from 100k to 27k. The updated table is:

Weird phenomenon?

• I'm not sure this problem occurs though. Right now the out-of-loop temperature sensor shows that the temperature of the can is 55 Degree Celsius.
• This is also not cooling down fast. Last time it took days for it to cool down to set value.
• The alignment of the cavities change vertically when the can temperature is significantly different from the set value of 34.38 Degree Celcius.
• This hinders them from locking properly unless I tune the alignment back. But when the can will cool down finally, they will be misaligned again.
• Also, I just refuse to believe it is actually that hot, but I check the voltage after the transimpedance amplifier in temperature sensor boards and two independent AD590s are reporting this.
• And anyways, why is the acromag output channel getting frozen anyways.
• That being said, this is an irreproducible but non-harmful problem yet, so lower priority than the FSS saga going on.