[Dsg-rich] [EXTERNAL] RICH electronics
Marco Mirazita
Marco.Mirazita at lnf.infn.it
Tue Sep 24 04:18:53 EDT 2019
Hi all,
let me make a couple of remarks.
1) The temperature limits were set to ensure a safe operation of the
whole system, which, as Ben said, includes not just the FPGA, but
cables, MAROC, external temperature close to TOF, etc. I don't want to
change these limits unless strictly necessary and only if with no risk
for the detectors.
However, we know that the current running conditions are mostly driven
by one FPGA which is producing more heat (its temperature is about 2 or
3 degrees higher than the neighbors) and by chance it is also in the
hottest spot of the panel.
2) The cooling system was originally designed to be able to feed two
RICH modules with one compressor, in case of failure of the other one.
We are now far from this situation. We run one RICH with 900 slm with a
maximum of 1200 slm per compressor. But we never attempted a real
optimization of the air flow. For example, the lower line is flowing
less air than the upper one, while I would expect the opposite.
For these reasons, I think there could be room to optimize the running
conditions and get closer to the original design.
But let me stress again that this optimization must ensure to stay
within the safety limits.
Best regards,
Marco
Il 2019-09-24 04:12 Amrit Yegneswaran ha scritto:
> given ben's last sentence
>
> (highlighted; i guess "it" in the sentence refers to "the
> temperature" as does "that".
> from which we have it = that => i = hat or i =tha, aah the pronouns
> they are precious!)
>
> anyway i'm now very confused about the planned test and the intent
> thereof?
>
> are we thinking reducing the airflow from ~950 slm will reduce the
> temperature below 65c?
> pardon my obtuseness.
>
> so what mods are you conjuring up tyler?
>
> -------------------------
>
> FROM: Benjamin Raydo <braydo at jlab.org>
> SENT: Monday, September 23, 2019 5:33 PM
> TO: Tyler Lemon <tlemon at jlab.org>; Amrit Yegneswaran <yeg at jlab.org>;
> Marco Mirazita <Marco.Mirazita at lnf.infn.it>
> CC: dsg-rich <dsg-rich at jlab.org>
> SUBJECT: Re: [Dsg-rich] [EXTERNAL] RICH electronics
>
> Hi Tyler,
>
> Matteo is correct about the temperature limit of 85C to respect the
> FPGA timing constraints, but we also have fiber cables running close
> to those parts that are rated for 80C (I'd expect some deformation
> possible if we go above this for a long period).
>
> Can we set a safe limit of 75C for any reported FPGA temperature for
> your tests (short term limit: <1hr)? If your tests need to run in such
> a way that you want a higher limit, let us discuss again if you don't
> mind. For long term it would be great to keep it as low as possible
> and for the moment I believe we've been running with the hottest FPGA
> temp to be around 65C so don't want to see that increase significantly
> if there are any changes to the cooling.
>
> Hope that helps.
>
> Thanks,
> Ben
>
> -------------------------
>
> FROM: Tyler Lemon <tlemon at jlab.org>
> SENT: Monday, September 23, 2019 4:59 PM
> TO: Amrit Yegneswaran <yeg at jlab.org>; Marco Mirazita
> <Marco.Mirazita at lnf.infn.it>; Benjamin Raydo <braydo at jlab.org>
> CC: dsg-rich <dsg-rich at jlab.org>
> SUBJECT: Re: [Dsg-rich] [EXTERNAL] RICH electronics
>
> Hi Ben,
>
> In October, we're planning on doing some testing to optimize RICH's
> cooling system and see what would needed to modify the system to cool
> two RICH sectors.
>
> With respect to the RICH readout electronics, FPGAs, and their
> timing, are there any temperature limits we should take into
> consideration when testing the cooling system?
>
> Thanks,
> Tyler
>
> -------------------------
>
> FROM: Amrit Yegneswaran <yeg at jlab.org>
> SENT: Monday, September 23, 2019 4:48 PM
> TO: Tyler Lemon <tlemon at jlab.org>; Marco Mirazita
> <Marco.Mirazita at lnf.infn.it>
> CC: dsg-rich <dsg-rich at jlab.org>
> SUBJECT: Re: [Dsg-rich] [EXTERNAL] RICH electronics
>
> tyler
> address fpga temp issue with ben.
> i believe 60c is right at the edge of timing issues, not sure.
> -------------------------
>
> FROM: Dsg-rich <dsg-rich-bounces at jlab.org> on behalf of Tyler Lemon
> <tlemon at jlab.org>
> SENT: Monday, September 23, 2019 3:11 PM
> TO: Marco Mirazita <Marco.Mirazita at lnf.infn.it>
> CC: dsg-rich <dsg-rich at jlab.org>
> SUBJECT: Re: [Dsg-rich] [EXTERNAL] RICH electronics
>
> Hi Marco,
>
> Looking back at EP temperatures during steady operations (I picked
> 3/10/2019 to 3/31/2019), Hardware Interlock RTDs were ~40 deg C and
> FPGA temperatures were ~60 deg C.
>
> Is there a temperature increase that would be considered acceptable?
> For example if the FPGA temperatures were ~70 deg C rather than ~60
> deg C?
>
> The first test should be determining what flow rate is actually
> needed to maintain EP temperatures in that acceptable range with all
> RICH electronics on.
>
> -Tyler
>
> -------------------------
>
> FROM: Marco Mirazita <Marco.Mirazita at lnf.infn.it>
> SENT: Monday, September 23, 2019 9:01 AM
> TO: Tyler Lemon <tlemon at jlab.org>
> CC: dsg-rich <dsg-rich at jlab.org>
> SUBJECT: Re: [Dsg-rich] [EXTERNAL] RICH electronics
>
> Hi Tyler,
> sorry, I had in mind that the replacement of the PT was scheduled for
>
> last Wednesday.
>
> The tests we have in mind to optimize the cooling system is basically
>
> what you said. But we still have to make a plan of the specific
> measurements we need. We will do this plan in the next weeks.
> Any suggestion from you and the DSG is welcome.
>
> Best regards,
> Marco
>
> Il 2019-09-20 20:46 Tyler Lemon ha scritto:
> > Hi Marco,
> >
> > The PT replacement has not been completed. It is scheduled for next
> > Wednesday September 25.
> >
> > As for the visit to optimize RICH running conditions, I will not be
> > at work for at least part of the week of October 21 to October 25,
> > however there should be other people from DSG that would be able to
> > help.
> >
> > What tests are being planned for the visit? Would it essentially be
> > varying the settings of the cooling system (flow rate, buffer tank
> > pressure, compressor output pressure) and seeing how the
> temperature
> > within RICH is affected?
> >
> > Best regards,
> > Tyler
> >
> > -------------------------
> >
> > FROM: Marco Mirazita <Marco.Mirazita at lnf.infn.it>
> > SENT: Friday, September 20, 2019 12:21 PM
> > TO: Tyler Lemon <tlemon at jlab.org>
> > CC: dsg-rich <dsg-rich at jlab.org>; Valery Kubarovsky <vpk at jlab.org>;
> > marco contalbrigo <mcontalb at fe.infn.it>
> > SUBJECT: Re: [EXTERNAL] RICH electronics
> >
> > Hi Tyler,
> > do you know if Bob has completed the replacement of the FT?
> > If so, the compressor could be restarted on Monday morning, once we
> > are
> > sure everything is working properly I can turn on the RICH
> > electronics
> > and keep it on for the night and then make the tests on Tuesday
> > morning.
> >
> > As you know, we didn't have much time to optimize the working point
> > of
> > the cooling system after the RICH installation, we simply choose
> > running
> > conditions that ensure a safe operation of the detector.
> > But these running conditions might be problematic with two RICH
> > modules
> > and definitely not sustainable in case of failure of one of the two
> > compressors.
> > Therefore, also in preparation of the upcoming CLAS12 data taking,
> > I'm
> > planning a visit to JLab for Dario and Sandro to try to optimize
> the
> > running conditions, and to be effective this work must be
> coordinated
> >
> > with you and the DSG.
> > The proposed dates are from October 21 to October 31. Is this plan
> ok
> >
> > for you?
> > Thank you,
> > Marco
> >
> > Il 2019-09-18 14:12 Tyler Lemon ha scritto:
> > > Hi Marco,
> > >
> > > Bob Miller has scheduled the replacement of the faulty pressure
> > > transducer (PT) on the air-cooling buffer tank for next
> Wednesday,
> > > September 25.
> > >
> > > Could the tests be scheduled to start Thursday September 26?
> > >
> > > Best regards,
> > > Tyler
> > >
> > > -------------------------
> > >
> > > FROM: Marco Mirazita <Marco.Mirazita at lnf.infn.it>
> > > SENT: Wednesday, September 18, 2019 4:08 AM
> > > TO: Tyler Lemon <tlemon at jlab.org>
> > > CC: dsg-rich <dsg-rich at jlab.org>; Valery Kubarovsky
> <vpk at jlab.org>;
> > > marco contalbrigo <mcontalb at fe.infn.it>
> > > SUBJECT: [EXTERNAL] RICH electronics
> > >
> > > Hi Tyler,
> > > the RICH electronics is off since quite a lot of time and in
> > > preparation
> > > of the upcoming CLAS12 running I would like to turn it on to
> verify
> > > that
> > > everything is still working and eventually to take new scaler
> > > calibration data.
> > > I could plan this work for the beginning of the next week.
> > > In preparation for that, we should coordinate to have all the
> > systems
> > >
> > > ready. Would you be available to start the compressor for the
> test?
> > > Thank you,
> > > Marco
> >
> > _______________________________________________
> > Dsg-rich mailing list
> > Dsg-rich at jlab.org
> > https://mailman.jlab.org/mailman/listinfo/dsg-rich [1]
>
>
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