sPHENIX TPC PRIORITIES – 9/2/2020

Based on discussions from the earlier TPC status meeting, listed below are short-term status and action items. Even with COVID delays, TPC looks to not be the limiting factor for sPHENIX assembly. Go through this FORWARD next time (9/9).ACTION: Put action items on things!Especially important ACTIONs: Photo-tour of lab work as available, update of roller rings, update of tubes.Next time, on Wednesday, 9/9 at 9:30AM.Connor's updated weight calc (see 6/03/2020) is conservatively 2250 lbs.

1. GEMS: (Klaus) GEM schedule drives overall schedule. Production awaiting templates, should be ready in next ~ days, expect first articles of R1, R2, and R3 by end August, to confirm holes are in the right spots, everything fits, etc. (existing prototypes have HV leads too short to use in final assembly)The particular module/layer GEM delivery plan is finalized. We have paid to get an additional tech, now 3 techs, starting in January, so all will be delivered by March 2021. If this schedule changes, updated Glenn.

We have components for tests at SBU: Gluing jigs with pins, frames with resistor openings, etc.. ACTION: first article from CERN is in clean room awaiting inspection todaySOW needs Jim and Russ's signature, then Klaus will transmit to CERN (after gem inspection) Tom prompted and will reprompt appropriate folks to source technician funds from proper account #.

2. PAD PLANE: (SBU) First R3s arrived. Aiwu inspected (see slides from 6/24/2020). ~1 hour per board for detailed inspection, all look good. Small defect near the vias is an issue with our design, but consultation with experts is that these will not impact perfromance. R2 routing complete, got quote. For final boards, we will have an electrical test (populate with full FEE + DAM set, with GEM above the pad, apply a voltage pulse, take data) along with microscopic inspection, but that will take a little while.Assembly house was not happy with Tom's documentation of turnkey steps. Ordered R2 stand-alone and will pursue assembly later with RCE. First article R2s will be on hand today or tomorrow (three pieces).ACTION: Ross will send updated FEE saturation numbers to Jin as needed to finish R1 design.

3. TPC ASSEMBLY CART: (John Cozzolino) Review took place on July 14. Drawing and parts list (tubing cut to size) in hand at machine shop, including step file.

SBU/James made metal order with Tom's sign-off. Schedule for production still pending Machine shop staffing. John provided step file as well. Central pipe will be lathed at BNL, as will pocket and a few other parts, and moved to SBU afterward. The assembly drawings are mostly complete, but need a few more details, limited by designer availability. Rev A done: Current trucking details shown below (expect open trailer or soft-top, since we don't want to forklift. SBU will build a plywood house around it, to protect against catastrophic flying objects). Lifting points detailed, lifting beam included in design (rough concept at this point). Expect we can find one on-hand that is adjustable for our purposes. Want to get signatures on this soon. Rev B has added a pocket to hold the pipe, similar to what will be used on the wall in the hall. Designing lifting points and integration into installation setup (pilots and extensions). Three points - two at shoulders, one at nose piece. There are two lifts: 1) lift the cart onto/off the truck, 2) lift the tube. Finishing this is high priority. Need within ~2 months of return to lab. Revised rollers to carry the revised TPC weight. During lift, we will see ~2 Gs. Dan found upgrade: same-size rollers rated to 550lbs each. These seem to be the only substitute that fit our needs. Vendor did not give a test report, but reiterated that they will meet the design load. Will change tube to steel per discussion: Need a spec for the correct ID of the balls. Could use slotted shim to tighten to fit without removing balls. (John investigated the existing balls with spring washers - no viable option was found)Will probably need to hold another review in August(?) with finished drawings etc.'Tandemloc' has 'AT14' adjustable 8klbs spreader bar, would be suitable. Comes certified and with load tests results -- BNL probably happy with that -- and it could do all the lifts. BNL should purchase for simplicity of reviewing safety.Discussed on 8/17 locally between Chris and John. Pipe now stainless steel -- weight when fully loaded now ~5k lbs. See old drawing (left) compared to new drawing (right).Changed design and weight not a problem for routing out of SBU basement.Carter found two certified lifting beams at BNL that would meet our needs (15 ton capacity compared to 3 ton need)

Should purchase tube (OD 10") as soon as possible. Will need cart ready once GEM modules begin to arrive. Likely November. Probably need to purchase by BNL for October in order to machine.

John and Chris are working on review findings (https://indico.bnl.gov/event/8906/attachments/29240/46085/tpctransport_fdr_report_20200714-1.pdf).:1) ball transfers. no spring-loaded ones fit. Moved to steel pipes (stainless for cart, for rust prevention) 2) doing more FE on joints3) installation pipe will be matched to cart, with thicker wall.4) rigging plan is ongoing (reminder this is a critical lift). eyebolts added and being studied with

FEA.5) verify capacities (casters are fine, and jacks upgraded). Doing FE at 2g for the balloons.6)Add features so the restraining strap doesn't rely on friction alone to prevent rotation. Connor is working on that.

ACTION: John and Chris (Connor should have a look too) will finish addressing findings from review John will make a short excel document with Recommendation, proposed response, and status. (present on Sept 9)Connor and John will meet to discuss proper ID of the ball ring and correct tolerance on pipes. John will send Connor the part/name of the ball casters.Connor will update ball caster drawing with new part, washer, shim, diam. etc --> rev B.John will talk with Chris Runion(?) to get TPC tube drawing.

4. Installation Procedure: (John C. and Connor) Installation Slides on 8/19/20 indico page show how pipe could be installed and supported. BP can be pushed back to make room, installation pipe can be broken and spliced to fit in front of muID wall. During installation, can support pipe from ends without additional crane (but still prefer having the crane) without exceeding fatigue level. Considering universal fixture to support 10" pipe steel pipe (needn't be stainless). Lift via kinematic mounts. Many other details. Added details of how to install the installation pipe (can use old roller rings that aren't sufficient for TPC installation. Discussed the pipe installation last week. Likely install pipe from the north (via tapped holes), then TPC from the south.ACTION:Connor will design crane fixture to follow TPC from behind. On hold while focusing on LV cabling. Next week will start drawings and semi-formal insertion procedure.Connor is still waiting for an access to take a look at the South MuID wall.

5. COOLING BLOCKS: (Dan) Model is more or less done. Ordered prototype cooling blocks arrived at the lab (see slide 6/10/20) . Might use softer alloy?-- not arced like the real one. Enough plates and wedges for module 2. Still on site at BNL. Not comfortable finalizing design before modeling/mock-up (board is fixed and sent for production now). Will probably build a separate platform for Chilldyne rack(s? ~90k$ per). Dan thinks West is best choice. Vendor says system slightly below loop.Rob has tested the cooling loops (see 7/30/2020 slides) with copper manifolds. These match the

simulation results, with about half the backpressure that was expected. Flow higher in the narrower lines than expected. Looks very good. Concerned about nylobraid to copper pipe connections, considering adding custom barbs (see slides) instead of hose clamps. If hoses are more than 60 thou, they will definitely obstruct the cards.Working on cooling block prototype. Maybe with dummy plates+heat load while waiting to get new FEEs -- test all 6 cards in block later. When we know what we want to purchase, should get started on purchase. (Rob)Up to high radiation, don't expect strong change in wattage of chips on the FEE. Cooling block design loose and somewhat tricky to 'install' in test. Held gap pad in place with a small screwdriver during wedge insertion. Wedge engages ~1/4" before full insertion, jams up some and tries to move the cooling plate, but looks like it works with this pad. May need to modify. Most design changes can/should wait until thermal tests. Screws should be locked in.Reviewed on 8/25. Sounds positive, but awaiting findings.Do we want a gluing fixture? Tom points out they may deform if hand-glued roughly. Dan agrees.Have learned as much as we can with heaters on plates. (see slides 8/12) Instrumentation is stuffing a few boards for a test stand, will use mock-up to cool that stand in the fixture.Went through various hose options (thinner walls have to be more rigid, so not ideal)ACTION: Rob and Carter will test some different hose clamps as a more airtight connection, and look for thinner nylobraid options. Will send fitting options to Dan.Dan will show some gap pad options (different thermal cond. and hardness).

6. HV CARD DESIGN: (SBU) Design in hand, but modifications may still be needed. Simple layout, just need to match retention and other geometrical constraints. R3 card will be mirrored.ACTION: None until April 2021.

7. HV CARD RETENTION: (Dan) Now that the GEM HV pigtail locations have been finalized, we need to design a suitable bracket to hold the HV cards in place. Bracket will be indepenent from cooling blocks. Will proceed once other services are complete.

8. TPC SERVICES: (Also Frank) Routing, support points, and strain relieving locations (where required) for :a) water cooling lines (Dan) design now waiting on Rob's bench tests. Clocking so there are spokes at 45 degrees helps with flow balancing. Design requires careful assembly, but easier than some of PHENIX gas system. Will use Nylabraid for jumps in quadrants (no conducting, and can see exactly where a leak occurs). Calc is the pressure drop is well within what the system can tolerate. Cooling system, including FEEs and blocks, is about 500 lbs per wheel. Prefer to have these symmetric wrt vertical.Cooling block testing would ideally have FEEs, but for now mocking up with heaters on metal cooling plate + gap pads. Nothing caught fire. Thermal camera was not able to image the plate well (reflections). Working on that. Reviewed 8/25. Will likely recommend making a full-sector prototype.ACTION: wait for Rob's bench tests. See cooling block section. Revisit with review comments when available.

b) gas feeds (Rob) gas analyzer etc are known already, more orders placed (not full system yet). 8 openings available per side, but want some of those for temperature sensors. Want at least 6 for gas, but could maybe use T connectors to slip in sensors in parallel. Parts are straightforward. Gas flows at 16 lpm from N to S (probably. for shortness of return line) CM has a large gap at IR and OR, so plenty of flow past it. Emergency vent on return line (outside of detector) 45% of EV of gas system now purchased. Tubing is flexible, so route gas tubing LAST. Use black tubing for light-tightness (though UV performance is probably the same). Reviewed 8/25.ACTION: Dan will confirm no space crunch for instrumentation. Revisit with review comments. Follow up with Rob to order parts when possible.c) high and low voltage cables including Hall probes and radiation monitors. (John C and Connor). Takao's 5/13 talk has extensive voltage and amperage calculations. Prefer to maintain quadrant symmetry for all additional sensors as well. Expect to put on the 1/4-20 mounts, since no other space available. Cable (6 SHV pass-through wires (3 OFC, 3 IFC) on N and S, expect to use one voltage on each) and connector specs now in hand. Infra. HV card is on the left as seen from outside the gas, looking toward z=0.CM HV provided on 60 kV cable, will already be attached and coiled when TPC is delivered. No patching of that -- will route directly to PS. Expect 1 spare cable on north and on south for routing to the IFC and OFC end rings inside the TPC. Regarding specific wire choices, want to maximize flexibility. The finer the better. Considering using multi-strand HV, would save space over initial quote( have used these before with no issues). Want to make drain wire available, but not connect to anything initially. Probably want to bundle one FEE card, but not any larger bundle than that, in order to avoid messy fan-out. Klaus has started discussing order with vendor. Although we could let a vendor add connectors, we will probably want to do custom cut to fit in the lab to accommodate small details we're not including in the drawings. We do need to have them install the cord-grips on the cables. Connor showed strain relief concept (See slides from 8/19/2020).Plausible to run spares in cable tray, but do in-place repair/replace/piggy-back for last routing along TPC if a cable fails there.ACTION: Connor will continue work on HV/LV cable routing and patch panel replacement (or delegate). Connor (?) will assemble a short technical document, send to Glenn,Takao about cable cross sectional area and weight per unit length.Ivan and Connor will create shopping list of TPC cables and connectors that are known already (cables from racks to patch panel), run it by Frank Toldo. Connor will get samples of the wire mesh grip and cables in order to test it.

9. PATCH PANELS FROM OVERHEAD SERVICE PODS: (Connor, Ivan, Takao) Connor showed the revised patch panel design (slides, 07/30/2020), and has since proposed strain relief at the iHCAL end ring, with interconnects only occuring where they transition to the WW cables rather than a full panel (slides, 08/19/2020), which is cheaper and has less opportunity for noise on the lines by removing the additional interconnect at a patch panel. Routing clears the NPT ports and takes advantage of the transition from sheath to individual cables.

Racks: Two racks for LV distribution for each side (2 north, 2 south), which fits into rack power budget. Laying out area for main plug-ins around the azimuth (external to wagon wheel) of the TPC from the upper facility service trays. Where the cables transition needs discussion with Peter H (knows what other services are in the area). How to connect 12 gauge cable to 18 gauge connector? Gas and cooling at 3 and 9 o'clock, LV in 4 strain-relief panels. Routing is one sector per spoke:

cross section of power cables is the largest routing challenge (fibers are significantly less total xs). Strip individual cables out of bundle at the point where they bend away from the spoke (bundled cables can't bend, individual cables would need sheath if run along trays). After the bend they can be heatshrinked as needed to keep them bundled properly (attach ad-hoc, to laser bench struts etc). At the end of the spoke we will move to inline connectors, which will gang together cabling to four cards. We will need to tie these down so they don't impart forces to the fanned-out cables. The ganged cables then route to the strain relief panels.For EIC interest, routing the DC LV along the cooling blocks and existing WW shadows so they don't add to radiation thickness in the remaining open areas. Connor and Ivan spoke with Lori Stiegler, Eugene Santiago, and Alex[is] Tulio from ESH. Removing outer sheath from cabling is okay at the final turns. Must meet other safety standards if more than 20 cables are bundled (as near strain-relief panels).CM SHV cables are routed without breaks. GEM SHV (PRQ8) cables. May need to avoid patch panel in order to maintain rating.ACTION: Connor will talk to Dan to verify temperature and connector spec suitable for environment. Will talk to Joel and Peter about the cable bundle spec.Connor will add connectors to models, and to include connector bend radius etc. Finish putting cabling over existing cards and manifolds. slides ~next week.Frank Toldo has (probably) purchased cord grips, can test ~next week.Connor will verify larger cable with Ivan

10. LASER BENCHES: (Connor, Dan) (See Connor's slides 06/03). Baseline is two rotating mirrors inside rotating 'egg' for steering, 4 modules for symmetry with the TPC Presumably sealed with small glue seam inside aluminum tube, linking light guide to tube. Optics table design same width as laser, with kinematic mounts tunable remotely for beam positioning. INtend to have preliminary review on Aug 24Compact beam optics from QLI (needs ~10cm) can be mounted directly to cages along long

straight section of beem steering dogleg. (2 dof on first mirror for position, 2 on second for angle, or a Risley mirror?) Optical layout has changed slightly since we purchased parts for Kristina (as of 7/15). We will eventually need to use the updated parts.Dan showed 3D-printed parts to test mechanical stops.Rigid frames hold the ~12lb benches, but needs to be more rigid (see Dan's slides, 7/15/2020). Dan added additional supports to raise resonance above 90Hz. (see Aug 7 laser meeting slides)Want to design for beam monitoring via active aperture (diodes on PCB), followed by a QLI beam intensity monitor. System must be aligned on the bench, then made mechanically tight and single-unit, so that aperture doesn't misalign with the egg. Want that passing through the apertures means we hit the egg primary mirror.Can't remove motor housings for egg, but still looks like it will fit in the current volumeWant ~alignment hole in CM so we can see appearance of laser on far side of CM.QLI says: Attenuator design may be larger than in the drawing because we need a non-magnetic motor. Can maybe move the attenuator and beam energy monitor downstream in the optical lattice if need be, though Dan says it's not practical. We still need to determine how to cool this (35-50W, ~few liters/minute). Forced air is our choice, but need to know flow rate from QLI, where ports for purging etc are.

Kristina has the parts (see slides 7/30/2020). The smaller motor has some pins.Dan has had some trouble pinning down the motor vendor to get a non-magnetic version. We need to press them on schedule. QLI needs drawings for the motor, if it exists. Especially need to know the dimensions. Dan got cost and timeline from DTI for R&D of non-magnetic version: 8-12 weeks, ~45k$ total, ~30k$ for R&D. ~15k$ for devices themselves. (details are posted to 8/26/2020 indico page) Need to bench test these and confirm they're the right choice -- bump tests! Tom proposes 100% spares, for backup and the ability to modify design.Reviewed Aug 25.Kristina has some of the Bump Test parts. Klaus has put the Raspberry Pi in the lab for Kristina.ACTION: Kristina needs to modify the parts for a few pieces to match to the printer capabilities.will

modify and print 3D Bump Test .stl files.Think about where to do the optics and motors (Kristina) work (Evaporator room S-103?)Bob will track down wattage (35W?) and flow (10cfm?) for cooling and send Rob an email. Rob will show a slide on how to achieve this in the next 1-2 weeks.

11. DIFFUSE LASERS: (Bob, Ross, Nikhil) Numerical aperture of rounded-tip fiber provides a good match to our needs. Samples of CM stripes and surface show the high contrast between the two materials. Prototype taken apart, thinking about how to bring in the fiber, but unable to complete that due to lab shutdown. Simulation of hand-sculpted tip (illumination from Bob's bench test) produces factor of ~4 between bright and dim areas. Adding diffuser on top of this reduces that to 2:1, two diffusers makes it 1.5:1.

We were looking at using multiple-(Thorlabs) diffuser cassette to replace the sculpted tip (Molex), but note that these will not be hand-sanded, but rather precision machined to our profile. Dan showed several other (engineered?) diffusers from Edmonton that have very promising angular profiles with significantly higher transmission than the thorlabs quoted value. Could still buy more lasers to get headroom. Identified rack for laser (1W2) including laser power supplies and diffuse laser sources. Need to check what we need for intensity to get the MIP signal, but should be readily achievable. Calc'd as 1 uJ per pulse per port (12 per cap). Diffuse laser is 67 uJ, though there will be losses at coupling. Still need to design fixture that holds the fiber. Best design will be a question of what's more expensive.This work is in P6, but without this level of detail on breakdown (can put it in on project replanning, based on info from Bob and Dan -- parts procurements, design timeline, design and procurement reviews ). We could consider multiple fibers feeding a single diffuser. Need to finish light calculations so we can finalize the CM mask.Bob is talking to the splitter/mirror vendor, we have an idea from Dan on how to condense the ***ACTION: Ross will contact Klaus with a proposed timeline.

12. Central Membrane: (SBU) All have been manufactured in terms of support brackets. Materials (5mm parts) for alignment/assembly jig is in the SBU shop, which is running a few small jobs interleaved with 3D printer tending for PPE. They've billed for it, so presumably ready for pickup. Evaporator has AC power now, and has been pumped down. Dynamic range of stripe widths needed for current fiber design probably not achievable, but there's room to optimize (see above). Vanderbilt is open and waiting for us.Petals are ENiG finish. We intend to evaporate chromium, followed by aluminum. Need to order the evaporation material, and need liners for the evaporator pocket (crucible liners).Aditya successfully defended his thesis. Have a replacement for his presence.Nikhil has supplied a drawing, prefers 41" Lyra ring.ACTION: (Ross) Nikhil will flesh out the drawing with position of the source, height, and other

dimensions. Ross will nudge/follow up.

13. Assembly Issues: Spring energized seals have been checked. One outer seal was too long, remaining 3 are fine. Pulling without stretching, has about 0.75" extra circumference compared to wagon wheel (as measured, for both). Won't slow us down, because we can put it on the second wagon wheel. Vendor took back the out-of-spec one; the replacement has arrived. We will handle this one extremely carefully (they say we stretched the original, though we find that unlikely).Received samples of module O-rings. 1% shorter than actual run seems to provide a good fit. Designed for hardness of 90. Looked at durometer-75 viton instead (50 is not available). Tom firmly believes Viton is the best material choice, but they will test in any case, and make sure the test seals satisfy. Aiwu and Prakhar have been developing plan on how to layout the cleanroom for assembly. HEPA filters installed on WW support frame. First striped circuit card likely installed on IFC today(9/3/2020).The three HV IFC holes through the WW have been confirmed by Connor to be 'top dead center' in sector (not spoke) clocking. The OFC has a slight split around 'top dead center'.ACTION: Tom will check O-rings on Thurs and confirm they're suitable/soft enough. Aiwu will order the durometer-75 Viton O-rings, after a look.Aiwu, Prakhar, and John C. will flesh out assembly procedure. Present next week?What is the target value for the IR of the roller balls? John will give tolerances to Tom and Connor for short email exchange to finalize.