sPHENIX Event Plane Detector discussion

[Ron Belmont <belmonrj AT gmail.com>]

Hi All,

Here are the minutes from today’s meeting.  I made a short-ish executive summary and below that reproduce everything I had time to type during the meeting.  The key action items are following up on various orders - Jamie is going to make a detailed summary of that and share it with key people tonight.

Regards,

Ron

** executive summary **

We have a general consensus that there is likely a need to hold off on installing the sEPD sectors until after a few weeks of beam.  We want to avoid installing and uninstalling the sectors too many times, and the tracking system and the MBD will likely need a lot of access during the first few weeks.

The support structure is needed for other essential systems like VESDA.  There’s an alternate structure that can be made if needed, but getting in touch with ASTRO to make sure it gets completed is a high priority.  Alternately, it may be possible to build the support structure elsewhere.  Russ will share the drawings with Jamie who will check if it can be built by the shop at CU.  The go or no go date for the support structure is the first week of April (3–9).  Further follow up on this, like designating a point person for contact, to take place.

The SiPM boards are being built by CEM.  We need a first article ASAP.  This could be one board or four.  Contacting CEM to make sure these boards get built ASAP is a high priority.  The SiPMs needed for the boards are at Lehigh.  Rosi can hand deliver the SiPMs to CEM if necessary.  Further follow up on this, like designating a point person for contact, to take place.

The order for Meritec cables has been placed.  Following up with Meritec to ensure the cables are delivered is a high priority.  Further follow up on this, like designating a point person for contact, to take place.

** sEPD support structure **

need to support VESDA - have alternate design if needed, but better to have sEPD supports

ASTRO - machine shop company that's building the sEPD support - Russ offered to take communication info and hound them

Kin on Friday - a go or no go date - latest milestones from Maria - first week in April (3-9) - if support from ASTRO not ready then need to use other strut

want to avoid taking sEPD in and out a bunch of times - might be better to wait until tracking is commissioned before installing - same could be true for MBD as well (since MBD access is mostly blocked by presence of sEPD)

what is time scale - how long does it take to mount the active sectors? are the cables already in? a day or two days? exclusive access?

first time install - 6 hours for both sides

scintillator gets mounted to strongback ahead of time (doesn't need to be done in situ)

strongback goes up quickly

fiber connectors quick as long as fiber routing is set, which it is (Dan Cacace)

once we're in - the MBD won't be readily accessible - once we're there they can't touch stuff 

there is potentially a scenario in which you don't want to install the sEPD sectors

want to run the optical fibers in advance 

fiber bundle connectors from detector to box

meritec cables on order - need to check with them

get everything cabled but then wait for a couple of weeks into beam time before installing

Russ - have some components (strongback) to construct that might not be ready anyway - made some simplification to design - those still have to be machined - can be made by any machinist but too big to be made at Lehigh - can possibly be made at Colorado shop - need drawings to show to Colorado shop - Stony Brook also an option

drawings are finished, Russ is communicating with Rich to get status of drawings

do not need to additional support for cracked sectors (maybe add some additional glue)

all racks are there - sEPD rack may not be populated - not sure if enough crates (but definitely have enough ADC boards)

** SiPM boards **

ordered from CEM - need to follow up with them, but the boards are very simple

SiPMs are already at Lehigh, need to send to CEM

more made than needed

need four right away, Rosi can hand-deliver SiPMs

John can get Eric to deal with CEM

another possibility - get Eric to bug the meritec people

** from last week **

cosmics tests not so informative since we don't have the gains 

if we knew we were getting the boards in, say, two weeks, we would wait 

would be good to get a first article to make sure that the SiPMs aren't placed incorrectly - first article could be the four we need initially 

beginnings of actual electronics box

scrounging around for most parts

access for electronics box? outside on the side - needs water cooling, provisions for that - box needs to be constructed and tested (e.g. in high bay) before installing in situ (location on detector is not so convenient)

odd side 11, 12, 13, 15 tested over weekend, 17 being tested now

2 days per sector 

total of 9 sectors done, 21 remaining

5 odd and even both done

4 sectors odd only

now that EMCal isn't there - can put the counters closer together (20 cm instead of 70 cm, ~4 times the rate)

another 40-50 days of someone going over there multiple times a day - but if we had the SiPM boards that reduced by 2, and it could be reduced further if you can test more than one sector at a time - keep running tests like this but hope for more electronics soon... 

ASTRO, Meritec, CEM... high priorities, issues with companies being delayed and not communicating, need to bug them ASAP

do we need a point person (permanently at BNL for next 4 months) sitting at regular engineering meetings

putting things in later - should be propagated into a real schedule? - which schedule is "real" is not so clear

Dan C is working on box, but that box is very similar to EMCal box - the design is completed, details/drawings need to be completed

suggestion to have shared directory for various drawings - Russ will setup and Indico page

approximately infinite CAD labor available to us currently - should take advantage of it as much as possible

all fiber bundles assembled, need to put ends on for mating to SiPM boards

** material scan **

theta definition from geant

theta values for acceptance shown on slide 2 but not on later slides (Ejiro will update plots later)

Ejiro will redo study when more stuff (support structures, services, etc) added to simulations

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Ron Belmont (he/him/his)
RHIC/AGS Users' Executive Committee
Assistant Professor, Department of Physics & Astronomy
University of North Carolina at Greensboro
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On Jan 16, 2023, at 11:51 AM, Ron Belmont <belmonrj AT gmail.com> wrote:

Hi All,

Given the urgent need to meet to discuss the electronics and other issues, please reply letting us all know availability.  So far we’ve heard from John H and Dennis that they’re available tomorrow (Tues Jan 17) at 4pm so it’s shaping up to be a good time.  I’ve gone ahead and made an agenda page for tomorrow at 4pm EST - it can be changed if we settle on a different time but we need to decide that ASAP.

https://indico.bnl.gov/event/18099/ 

https://lehigh.zoom.us/j/99703618048?pwd=djFkNWNCSGk4dHlQRTdObkYwMXhKUT09 

Regards,

Ron

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Ron Belmont (he/him/his)
RHIC/AGS Users' Executive Committee
Assistant Professor, Department of Physics & Astronomy
University of North Carolina at Greensboro
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On Jan 15, 2023, at 3:15 PM, Jamie Nagle <jamie.nagle AT colorado.edu> wrote:

Hello Ron and sEPD list,

We really need to have a meeting in person this next week.     

Can I propose we just move the meeting back a day to Tuesday at 4 pm ET?    Alternative suggested times welcome.

Sincerely,

Jamie

||------------------------------------------------------------------------------------------
|| James L. Nagle   
|| Professor of Physics, University of Colorado Boulder

|| EMAIL:   jamie.nagle AT colorado.edu
|| SKYPE:  jamie-nagle        
|| WEB:      http://spot.colorado.edu/~naglej 
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On Sun, Jan 15, 2023 at 12:54 PM Ron Belmont <belmonrj AT gmail.com> wrote:

Hi All,

Since tomorrow is a federal holiday, there will be no sEPD meeting this week.  It would be good to follow up via emails to the list, especially about the issues discussed at last week’s meeting, like the status of the electronics and the path forward for further cosmics testing.

Regards,

Ron

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Ron Belmont (he/him/his)
RHIC/AGS Users' Executive Committee
Assistant Professor, Department of Physics & Astronomy
University of North Carolina at Greensboro
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