Star-fst-l mailing list

["Visser, Gerard" <gvisser AT indiana.edu>]

hi Xu,

    There's two possibilities I think. Could be that the ARM board has a failure and is supplying too much voltage to the PPB. That would make it run hotter. This seems unlikely, but it is trivial to try swapping the ARM sometime today/soon. (If that doesn't fix it, I'd put the old one back so you don't have to redo the timing adjustments.)

    More likely it is just some mechanical problem, screw loose on the cooling connection there. Nothing to do till someday when poletip is open, next summer hopefully. In this case, I would just use the thing, it will probably not break. I cannot promise that there is zero risk of damaging the FST module but I think it is less than 10% risk, considering the overall run duration it is probably better to try it than to sit out a year for this module. But you and Zhenyu should rule. I expect the regulators on PPB (and everything else) will keep working fine unless they just totally break due to overheating, so data should be good from this module (I think). It is not impossible though that it is doing something strange and causing the pedestal shift you saw. I'd still just try to use it, I see no better course of action here.

     Gerard

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From: Xu Sun <sunxuhit AT gmail.com>
Sent: Wednesday, November 17, 2021 10:16 AM
To: Visser, Gerard <gvisser AT indiana.edu>
Subject: Re: [Star-fst-l] Increase the cooling flow speed

 

Hi Gerard,

Now the question becomes, could we run the PPB at 37~40 degrees?

If so, we could apply a tighter cut for that module and see if we could get reasonable hits.

Best,

Xu