[Halld-pid] Start Counter Meeting Minutes, April 17, 2014
Fernando J Barbosa
barbosa at jlab.org
Fri Apr 18 13:10:41 EDT 2014
Hi Tim,
Great!
Thanks and best regards,
Fernando
On 4/18/2014 12:43 PM, Timothy Whitlatch wrote:
> Hi Fernando,
>
> I believe the spacers will be fine. We can get them in many
> thicknesses. When the hub is ready, we will bring it to you along with
> the spacers and verify this assumption by attaching the ST1s. The Hub
> should be ready by the end of next week.
>
> Cheers,
>
> Tim Whitlatch
> Hall D Engineer
> Jefferson Lab
> 12050 Jefferson Ave ste 402
> Newport News, Va 23606
> 757-269-5087
>
> ------------------------------------------------------------------------
> *From: *"Fernando J Barbosa" <barbosa at jlab.org>
> *To: *halld-pid at jlab.org
> *Sent: *Friday, April 18, 2014 11:48:24 AM
> *Subject: *Re: [Halld-pid] Start Counter Meeting Minutes, April 17, 2014
>
> Hi Mark,
>
> Maybe I missed something but the spacers were always part of the design.
> The question, as I understood at the meeting, was whether the spacers
> provided enough precision and uniformity during attachment of the ST1s.
>
> Best regards,
> Fernando
>
>
> On 4/18/2014 11:42 AM, Mark Ito wrote:
> > Folks,
> >
> > Please find the minutes below and at
> >
> >
> https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_17,_2014#Minutes
> >
> > -- Mark
> > ___________________________________________________________________
> >
> > GlueX Start Counter Meeting, April 17, 2014
> > Minutes
> >
> > Present:
> > * FIU: Werner Boeglin, Eric Pooser
> > * JLab: Fernando Barbosa, Eugene Chudakov, Mark Ito (chair)
> >
> > Electronics
> >
> > Fernando gave us a report.
> >
> > All fabrication of ST-1, ST-2, and ST-3 boards is done. The signal
> > split for ADC and TDC is now done on ST-3, not on ST-2 as
> before. The
> > ST-3 testing is complete. The pre-testing (checking SiPM
> connections,
> > etc.) of the ST-1s is done and the 10 ST-2s are being tested
> now. That
> > should be done by tomorrow. After that the 30 channels on the ST-1s
> > will be tested with a laser in the dark box. Also a test will
> be done
> > to measure the electronic component of time resolution using
> the laser.
> > It has a 100 ps rise-time and negligible jitter. This will be
> done with
> > a complete chain from ST-1 to ST-2 to ST-3 to discriminator to
> TDC. A
> > diffuser is used so that all four SiPMs can be illuminated. A
> set of a
> > few amplitudes will be measured, and both ADC-bound and TDC-bound
> > signals will be looked at. All tests should be done by the end
> of the
> > month.
> >
> > On the mechanical side, there is a plan to do a test fit of the
> > electronics on the aluminum support ring once that becomes
> available.
> >
> > When the items have been shipped to FIU, Nick Sandoval will go
> down and
> > help to get the test set-up started. Fernando needs about one month
> > notice to arrange travel.
> >
> > We had a discussion on the scheme for making sure that the ST-1
> boards
> > do not short against the aluminum support ring. [Added in
> press: this
> > discussion assumed that there is no allowance for spacing
> washers in
> > the design. This turned out not to be the case; a 40 mil washer is
> > called out in the drawings. This rendered the discussion moot.]
> >
> > The group reminded Mark that we will not ship ADCs, TDCs, or
> > discriminators to FIU for testing the detector there. FIU will use
> > their existing read-out electronics. We will send an MPOD and all
> > cables that connect the ST-2s to the ST-3. We discussed how
> many signal
> > cables need to be shipped (those running from the ST-3). We
> decided to
> > defer a decision on that.
> >
> > We decided that we should do a test mechanical assembly at JLab
> before
> > shipping the support structure to FIU, including as much as is
> > practical: support ring to target support, ST-3 on installation
> cart,
> > cables from ST-2 to ST-3, etc. The exact plan needs to be
> worked out.
> >
> > Schedule
> >
> > Werner laid out a very rough schedule given what we know now.
> > 1. scintillators arrive at FIU: mid-May
> > 2. scintillator testing and detector assembly done: end of June
> > 3. Nick visit: early July
> > 4. testing done: end of July
> > 5. ship to JLab: mid-August
> >
> > Assembly Jig
> >
> > Eric presented the final design for the assembly jig. See his
> slides
> > ([18]PDF, [19]Powerpoint) for details. Eric plans to call Chuck
> Hutton
> > and discuss the design as well.
> >
> > Progress at McNeal
> >
> > [Added in press: Eric talked to Robert McNeal just after the
> meeting
> > and sent in this report.]
> >
> > All 50 paddles have been inspected and have passed the initial QA
> > check. Machining of the paddles has not yet commenced. They are
> waiting
> > for the machines to finish other jobs. However, production
> should begin
> > within a week.
> >
> > Robert quoted that the paddles will be shipped out to FIU, no later
> > than 05/02/2014 which is right at the 4 week lead time we were
> quoted.
> >
> > Eric provided Robert with the most up to date mechanical
> drawing of the
> > paddles. There were no substantial differences between the two
> drawings
> > and this update will have no negative consequences.
> >
> > Robert mentioned that they do quantify the final dimensions of the
> > paddles after they are machined. This is done both optically and by
> > machine. Standard operating procedure dictates that they will only
> > measure approximately 8 of the 50 paddles. He is willing to
> provide us
> > with this data. It is possible for them to inspect all 50
> paddles and
> > provide us with their associated measurements for a minor
> inspection
> > fee initially estimated at $200.00. Further discussions will be
> made
> > regarding whether we should purchase this inspection data.
> >
> > References
> >
> > 18.
> https://halldweb1.jlab.org/talks/2014-2Q/Finalized_Assembly_Jig.pdf
> > 19.
> https://halldweb1.jlab.org/talks/2014-2Q/Finalized_Assembly_Jig.pptx
> >
>
>
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