Star-fst-l mailing list

[Xu Sun <sunxuhit AT gmail.com>]

Hi Gerard,

Jeff changed the prescale for fscDY and fcsEM2 and it reduced the FST dead time to 44% now.

Best,

Xu

On Mon, Dec 20, 2021 at 10:19 PM Visser, Gerard <gvisser AT indiana.edu> wrote:

It looks like someone has done this in fact.

Certainly I don't have any objections to this plan. FST is still 44% dead and is limiting the data taken w/ other detectors therefore, but maybe it is OK for tonight.

It still may probably be the case that FSC triggers (several) maybe hotter than expected, I don't know.

     Gerard

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From: Aschenauer Elke-Caroline
Sent: Monday, December 20, 2021 10:15 PM
To: Visser, Gerard
Cc: Aschenauer Elke-Caroline; Landgraf Jeff; Xu Sun; Ogawa Akio; Ljubicic,Ante; Star-fst L
Subject: Re: [Star-fst-l] FST deadtime and raw events in the data stream

Gerard,

we have many FCS triggers, why not taking out the DY trigger for thsi night until we understand what is wrong with it, this will not hurt anything.

On Dec 20, 2021, at 22:12, Visser, Gerard <gvisser AT indiana.edu> wrote:

Don't want to add too much noise here but yes for tonight FST will be saturating at a low rate, 1450 Hz is plausible. Is there something that can be done to keep it in for commissioning but keep its rate down? Sorry for that situation.

Less important than fixing what seems wrong w/ FCS trigger, which could maybe just need a full clean restart (I don't know) or maybe has a setup issue.

These are the first runs since the detector was closed and seeing much higher effective hit rates I guess in consequence.

     Gerard

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From: Aschenauer Elke-Caroline
Sent: Monday, December 20, 2021 10:05 PM
To: Landgraf Jeff
Cc: Aschenauer Elke-Caroline; Visser, Gerard; Xu Sun; Ogawa Akio; Ljubicic,Ante; Star-fst L
Subject: Re: [Star-fst-l] FST deadtime and raw events in the data stream

Jeff, what is the energy threshold for the fcsDY, 20kHz for a DY trigger is not correct, it should have a very small rate, but it seems to me something is not correct or the requirements are not set right

Cheers elke

On Dec 20, 2021, at 22:03, Landgraf, Jeffery M. <jml AT bnl.gov> wrote:

I think FST just saturates at 1450hz.   If you try to shove more data through (fcsDY at 20khz) then the deadtime goes up but nothing else changes.  (well, fscDY starves out all other triggers.)

-Jeff