R&D xenon resistance of plastics- specimens, properties looked for, sparkdown, EL probability of FC, prototype? show corner method of field reduction EL mesh pre-deflection (staples?, weights> preload? ground quartz/ito? bonded mesh R&D (many problems with fine wires), heatshrink band , nitinol? e-beam/?DB? welding of heads to flanges, PMT housings to head shell- show method slide titanium fasteners and methods nedox, hydraulic tensioners CF flanges for pressure- should we use helicoflex& O-ring? Flat face (div 1 appendix Y) calcs OK for div 2? CANS, R&D sapphire window sealing- parbak? kel-f oring, PEEK? , pressure capacity, thickness flare or VCR fittings, external pressure resistance, fittings, bends threaded fittings- magnaplate canadize? tiodize type 4? pretesting of sapphire windows- need a cycling pressure chamber flexure of sapphire - need to verify good optical contact heat conduction of PMT base- need wattage, do 1D calc write presentation talk to shops about ti fab. determine safety factors. Weibull statistics? need to test: pressure resistance,leakage,optical performance we'll need a pressure test vessel with a light source ( 172? LED?) it would be good to visually verify no optical separation under pressure (HP sight window? questions for helicoflex- what is e0 forHN requirements for backup on pressure (PEEK ring OK?) currently: designed clamp flange - fixed error with ASME calc- flangesnow 5cm thick, as expected, thinner than raised face designs hv cable - central feedthrough looks possible with semicon heatshrink grade down-needs testing- 95kV/6cm we could do 30 kv over 2cm length and check for sparkover, need to install in hp gas tube- we can do 150 psi without problem. thin rings (20) on buffer periphery look OK E/p=1.7 (nominal, with moderate enhacement) going to change sapphire window back to PEEK "thick gasket for compression" helicoflex should back to heis OK- will call them (thin washers shown too delicate, may pinch under helicoflex or O-ring jim perrrin- ppi-7-21-11 conversation will look up comparable case studies involving clean gas. vacuum OK for sniffing- used at low suction pressrues to prevent diphragm separation- heat transfer not an issue center diaphragm has channels and TFE coating- he will look for failure data of this diaphragm- ? how to tell its leaking? catalog numbers are in SCFM not actually CFM - he thinks- our pump is a 2000 series -2083 to giver 200 SLPM- 7.06 CFM PMT issues- 1750V max voltage, 1.5 kV nom BNC, multipins not good enough? PMT insulatable inside can w/thin heatshrink SHV triax would be great, if 4 to a flange (not likely) floating entire carrier plate (Cu) at Vc gives ~5C temp rise at edge. insulation is thin thermal conductive kapton film, with good overlap simplified gasket grooves- more likely pipe will work got some quotes for ti pipe 200$/ft in large qty's 350 for small Hi- We are looking for some electrical insulation for a special vacuum tube (photomultiplier). It is 3.05" in diameter and has a bulb shape, very much like a common light bulb. We want to insulate just the bulb section, not the stem. Your layflat PVC tubing,part number 158-175 seems appropriate, but maybe it is better to use part number 210. If you can provide some samples of each, in both thin and thick wall, that would be appreciated. We need only a foot or two to verify what works. Also, we are looking for a heatshrink product called stress control. It has a digh dielectric constnat and is semiconductive, do you carry it? thank you very much HV feedthrough ideas what we need is a straight rigid cable- this can be potted into a feedthrough how to make center conductor rigid? wick or pressure feed epoxy through. heat cure likely needed solder using a flash current put cable into tube, compress longitudinally then try to pull out conductor-insert rod no good way to use existing cable so, we make our own how to seal- LN chill cable then slide into tube (miniboone idea) using a tefzel rod rod desing compatible with essex 125kV cable#2196 (semicon od=4mm, ldhmwpe od=12.4mm) we want ground tube to slide over, but need "semicon" of cable how long can one gundrill plastic? feedthrough fabrication- 90 cm long tefzell (ETFE) is low modulus, high elongation to break (300%) high thermal expansion and high heat deflection temp, god diele. strength (1.8 kV/mil (.01") brobably 500V (1/8")- all good properties obtain tefzel custom molded tube 20mm OD x 4mm id x 2.5m long _ I have an rfq out fab center conductor- 4mm od x 1m + 10cm taper + 3mm od x 1m + some on end for threading fab bushing (interference fit) machine radius step in tefzel tube for bushing- will need trick lathe setup with follow rest heat tefzel to 200C insert 3mmm rod through ID and pull through using a plate w hole for rod only, cool pull assembly straight using extra center conductor and LN2 chill heat flange bushing and drop onto tefzel quickly- allow shrink fit to develop apply stress control heatshrink over exposed cable- both sides (bevel for trumpet) apply woven shield and heatshrink pvc over sc on vacuum side ground both ends of heatshrink on vacuum side and hipot to 120kV assemble -1.5kV tube over heatshrink and screw into bushing. Field Cage Ideas use copper stripes on ESR/TTX bond first to a Possible tasks for Sara- tracking plane design- need more input from pressure vessel- nozzles, drawings, supports, FEA analysis assist on energy plane design, gas system calcs? window rfqs 1. (5 ea.), UV grade Sapphire window (vendor to furnish transmission curve prior to pruchase) 8.38 +/- 0.03 cm. dia. x 0.50 +/- 0.005 cm. thk. C-axis normal to window. Bevel both edges 0.03 cm. x 45 deg. Superpolish and high temp. anneal after finishing for maximum strength (5 angstrom RMS min.) Commercial flatness (2 waves/in) ; parallelism within 5 arc-min, high precision scratch/dig 20/10 2. 100 ea., item 1 above 3. (5 ea.), Hereaeus Suprasil (grade 1,2,3 or Standard, whichever is cheapest) synthetic fused silica window 8.38 +/- 0.03 cm. dia. x 1.27 +/- 0.01 cm. thk. Bevel both edges 0.03 cm. x 45 deg. Commercial flatness (2 waves/in) ; parallelism wi,thin 5 arc-min, high precision scratch/dig 20/10 4. 100 ea., item 1 above Pressure Vessel before we can finalize we need to: clear g2 or g3 Ti as radioclean- late Sept. set overall length, need to : determine shield axial length determine fe board axial length components all pressure rated? decide if we want a central manifold for tracking plane protects against direct loss of EXe for feedthrough failure design gas relief we need two, one passive, one high speed actuatable both vent to 30 m^3 evacuated vacuum tank size vent pipe and burst disk (prelim- 100 mm sufficient) determine reaction force and "echo"; gussets or baffles needed? determine angled, straight, or none side HV nozzle option choose clamp, or bolts- EL stray mesh wire problem@LBL? clear inconel for radiopurity field cage, solid or porous (for vent and flow requirements) EL access, through flange or via ports procurement process: draw up and specify preliminary design (what we presently have) send out for quotes and fab times contract certifying firm to check specification (once revised) choose fab contractor based on prelim. design? vessel design presently is: grade 2 Ti, w/Inconel 718 bolts (72 each 20mm nom dia) bolt spacing to allow hydraulic tensioning 10mm wall thickness, heads and vessel (thinner possible with div 2) 50-60 mm flange thickness each torispheric head has one 100mm dia. central nozzle for cabling one additional nozzle for gas flow or venting or HV an internal flange for energy plane, or tracking plane sys mounting a structural lip for shear resistance and extra light-tightness main vessel has: one vertical 100 mm dia. nozzle on top for HV to cathode mesh (offset, no angle possible) one port on top for 30 kV feedthrough two or more DN40 ports for 30 kV feedthrough EL gap viewing and access (w/high pressure covers) two internal flanges for field cage mounting two O-ring grooves on each face (1 Helicoflex capable) a sniffer port cross drilled between each O-ring groove set- NPT port to exterior vessel fab options: TIG Welded- bolted flanges flanges machined from plate higher distortion- more stress relieving required rotary table inside welding tent-automated welding? E-beam welded (to greatest extent)- bolted flanges flanges ring rolled forgings- need to find experienced vendor some TIG welding needed for off-axis nozzles Clamp design? will greatly facilitate repeated opening- is LBL experience avoidable? highest radiopurity smallest OD 1.23m vs 1.3m (Inconel 718) flanges ring rolled forgings requires Ti forging for clamps (no plate) PMT cans Suprasil (13mm) or sapphire (4-5mm) costs are similar (sapphire $1000 ea, Suprasil $1200 ea) S1 efficiency UV sapphire may be ~30% transparent at 172 (4-5mm) n>1.9@175nm Suprasil ~80% (12.5mm) n=1.56 (@190nm) Krytox optical grease? (90%@25um, 175nm) TPB might be Gas system Cryopumping efficiency for Vac. tank sys. high trapping efficiency - in operation gas distribution inside emergency venting fast valve performance how to sense - response time required? reactions and possible damage to cryopanel or experiment? simulate (OpenWAM) Pressure Vessel This is a preliminary Specification of a pressure vessel for the purpose of obtaining a preliminary quote ( price and schedule). In addition, propsective vendors are encouraged to provide feedback on details of fabrication The final specification is expected to be released for RFQ approx. 2 months after this release. Description: The NEXT Collaboration requires a pressure vessel, to be used as the housing for a neutrino detector having the following general requirements: Size: 1.14m I.D. x 1.6m Inside Length, cylindrical, horizontal axis with torispheric heads Assembly Configuration: 3 parts, a main cylindrical vessel with flange connections on each end to the torispheric heads Material: vessel: Titanium ASME grade 2 ; all bolting: Inconel 718 Fluid: Gaseous Xenon, Argon, Neon, Nitrogen, with possibly small amounts of CF4, CH4, all gases at room temperature to 50C (possible corrosive, flammable or toxic media) Pressure Range: High Vacuum (1X10^-6 torr to 16.4 bara (15.4 barg) Low residual background radioactivity Internal detector components will be supported by flanges on the vessel, both exterior and interior. Vessel to be designed ,fabricated and tested in full accordance with ASME Pressure Vessel Code section VIII. The design will be according to the rules of ASME sec VIII division 2 to the greatest extent possible, and to the rules of section VIII division 1 and/or division 2, part 5 (design by analysis) where needed. Fabrication and inspection will be performed according to division 2, even for any sections designed to div. 1 rules. The pressure vessel is being designed by the Collaboration with regards to materials, thicknesses. There are two possible configurations: A bolted flange (flat faced) flanged Vendor is invited offer some details as to preferred fabrication details before final specification is issued. The two unique and noteworthy aspects of this vessel are the radiopurity requirement and, to a lesser extent, the need to mount internal components Our neutrino detector is highly sensitive to trace amounts of radioactive materials, most notably Uranium (U) and Thorium (Th) Most metals and alloys contain uranium and thorium in trace amounts, from several parts per billion (PPB) to hundreds of parts per million (PPM). Two notable exceptions are electrolytically pure copper and Commercially Pure (CP) Titanium Of these materials, CP Titanium grades 2 and (perhaps) 3 (ASME) provide the highest strength to radiopurity ratio. The lightweight of Titanium is also desirable. Thus we have chosen CP titanumium grade 2 as the material for the pressure vessel. We have one nominal pressure vessel design for which there are some possible feature options not yet excluded: Nominal vessel: Material: Ti grade 2- shells (8mm), flanges (5 cm) (including CF), and nozzles, primarily per ASME sec VIII div 2. OPTION- Ti grade 2H or 3, if available, and equally radiopure - pending b.g. tests Process: MIG or TIG welded - (no thoriated components of any kind- Q.C. very important) OPTION- E-beam under full vacuum (no friction stir) - may become requirement pending TIG b.g. tests Main Flanges: flat-faced, (O-ring or helicoflex seal), Inconel 718 bolted (Appendix Y)- plate stock OK OPTION- Clamp-type flanges (flat faced O-ring or helicoflex)- ring roll forged flanges; forged ti g2 clamps- Inconel 718 clamp bolts OPTION- Inconel x750 bolts - pending 718 b.g. tests Nozzle Flanges: CF, Ti grade 2 w/soft aluminum gaskets - need durability tests -grade 5 (high strength) not allowed in ASME OPTION- Ti grade 2H or 3 if avail. - needs testing OPTION- Ti grade 2, using single helicoflex seals OPTION- Ti grade 2 using VITON CF gaskets (PEEK? - needs testing) OPTION- Ti grade 2 non- CF double O-ring with pumpout port (on attached item) In talking with Dave, I agree with him that we should not have CF flanges welded to vessel, we do not know how durable thay are. If we damage them, we are stuck using a Viton gasket that Xe will permeate through. However, we have pressure rated CF hardware (feedthroughs, maybe windows) that we need to attach. So I propose we designe the vessel having all nozzles with flat faced flanges (no grooves). Then we attach adapter plates having: a double O-ring groove on one side a CF (or other) on the other side, a pumpout port on the side. Adapter flanges can be Ti grade 5 if not so hot, or even Ti grade 2; they would be replaceable. The main flanges would still have O-rings (Helicoflex compatible) and pumpout ports. One other change would be to preclude the use of plate for flanges; we could have leakage problems with unseen flaws in the plane of the plate Nozzle flanges would be required to be machined from bar stock, and the main flanges would be roll forged; see this video for process: http://www.youtube.com/watch?v=GDyWyDP3cvs&feature=related We then have one nominal pressure vessel design for which there are some possible feature options not yet excluded: Nominal vessel (9/13/11): Material: Ti grade 2- shells (8mm), flanges (5.5 cm) (including CF), and nozzles, primarily per ASME sec VIII div 2. OPTION- Ti grade 2H or 3, if available, and equally radiopure - pending b.g. tests new--> OPTION- use minimum thickness, gr. 2 (6.35mm), less material, but may need pad reinforcement on all nozzles (no e-beam) Process: MIG or TIG welded - (no thoriated components of any kind- Q.C. very important) OPTION- E-beam under full vacuum (no friction stir) - may become requirement pending TIG b.g. tests Main Flanges: flat-faced, with O-ring or helicoflex seal, Inconel 718 bolted - (div. 1, Appendix Y) roll forgings required (rolled and welded not as strong) OPTION- Clamp-type flanges (flat faced O-ring or helicoflex)- rolled and welded plate or ring roll forged flanges; forged ti g2 clamps- Inconel 718 clamp bolts OPTION- Inconel x750 bolts - pending 718 b.g. tests new--> OPTION- high strength grade 9 or new grade 38 flanges using H-seal metal gaskets (3% aluminum) Nozzle Flanges: CF, Ti grade 2 flat faced (no grooves), ASME design (not CF)- use double O-ring adapter plates as needed OPTION- Ti grade 2H or 3 if avail. - needs testing new--> OPTION- high strength grade 9 or new grade 38 flanges using H-seal metal gaskets (3% aluminum) Pressure Vessel remaining tasks and decisions: minimum thickness (6.35mm) or 7-8mm? - physics question primarily need to look at nozzles - do we need pad reinforcement? Supports need designing. Saddles should be welded on- ASME div 2 has design rules lift and rotate attachments for heads need designing- ASME rules internal flanges may need more design pressure relief vent pipe sizing (auxiliary nozzle on energy head) do we use a central manifold on tracking plane (CFs in vacuum, not Xe) do we want EL inspection ports? finalize diameter of EL cathode feedthrough - not much room pumpout holes in flanges need analysis (simple calcs? FEA?) internal weight needs folding into calcs (shear forces) heat transfer of tracking plane needs solution - 500 W CF flange compliance with ASME, we have mfr. rated CF components ? Tom Christie- Bostec Engineering, conversation 9/12/11, said the following: H seals much better for pressure: CF edges, because asymmetric, tend to roll over after repeated use H used up to 20ksi (140MPa) pressure more robust than CF- slight damage OK- no special handling!? CF not very ASME compliant- low pressure limits H-seal independent from flange design O-ring compatible - damaged knife edge not fatal concerned about grade 2 ti- we need to test- he will send samples to start Gasket hardnesses: cu- mid Knoop B hardness Ni - below knoop B Al - below Ni people do ofter reuse gaskets joints opened closed 40-50 times no damage metal O-rings have narrow pressure range My thoughts: grade 2 or 3 will be too soft for H-seals, but 9 or (new) grade 38 Ti are probably hard enough, however- main flanges are too large for proper alignment (.015" needed ) nozzle flanges are good candidate for this seal- less of a radiopurity issue, big nozzle flanges outside My feeling is that we should: stick with flat faced nozzle flanges, ASME compliant on PV, and use sniffable double O-ring adapter plates that can accomodate Helicoflex gaskets. Main vessel flanges stay double O-ring, Helicoflex compatible to do: send revised dwgs and model to Sara for spec. gas system review to Igor determine min operating pressure with 100 kg determine fill ratio identify electrical issues ask Vacom about hV under pressure study resistor heating in xenon, convection currents- temp rise ask H-seal about prices calcualte gas load from palstics calculate pressure cycling in purifier loop (OpenWAM; use engine) pumpworks: pmt system review requirements pressure can window tube, bend and straight sealing pressure isolation on suddenleak heat, delta T vacuum paint design options solder or push-on rigid (shim to fit) or bellows heat spreader flare or swageloks pre-cable tube sections? R&D obtain PMT(s) build prototype, use stainless pipe need a window test cell use same O-ring and kapton gasket for test design an build pressure test chamber to test: leakage under pressure ( Ar then Xe, Ne?) ? internal vacuum inside can set up CC gauge on backplate test temperature rise inside add thermistor to resistor board PMT performance? Review: add some question marks on first slide capacitor in base? how big? radipourity? Azriel- add in 2nd high pressure test ( to destruction) _DOE Tom- add long path length in cryo scavenging system Tom- hazard of plugging in cryo scavenge system Tom- add anti-rotation to back plate Tom- cryo folks use vacuum grade copper braid- tig weldable Tom- break hoop continuity fo rmore compliance Tom- check vacuum compatibility of thermal grease- will render parts unsolderable look at better pumping wiht larger cable conduits- now that Azriel to look at: voltage scheme cableing resistance Dear Igor- I looked through the sec/quote you received in 2010 from PPI/USA ("BUDGET2069QUOTE...) and the spec/quote you received in may 2011 from PPI/UK ( DS10 065..). I do not see any material difference in the two pumps other than the change from 100 to 200 SLPM, which I would think would add little to the pump cost. Both have SS heads and diaphragms. The plumbing diagram that came with the UK spec/quote shows an aftercooler, but I don't find this listed on the spec sheet. I would think its addition would be minimal cost. I do not see very many valves on the pump (water cooling, intake and outlet, bypass,vent, leak check) so asking for bellows sealed valves here should not add much cost. Some things that would be good to consider would be the aftercooler and discharge pulsation damper, neither are included in either spec/quote. So I have no idea why the price is so much higher on the UK quote. I am going to ask Jim Perrin to requote on a 15 bar 200SLPM pump tommorrow. I'm going to ask about their B model which goes to 2 cfm (we only want 0.5cfm@15bar) to see if it is cheaper. In my notes of a conversation I had with him in July, I find that he specified the 2083 ( he wrote that quote as well as the 2069 pump qote) as a 7.6 CFM displacement pump. This does not jive with my calculation that 200 SLPM @15 bar is 0.5CFM (it would be 0.75 CFM @ 10 bar). So perhaps he is mistakenly quoting a pump with 10x the capacity we want? herees' my calc: Notes on pumps: PPI has B model good for 2 cfm we are asking for 0.5 is the B cheaper why the 2083? Pump is sized for full flow through purifier do we want more vessel flow ( cooling? mixing?) we can use bypass for purifier flow PPI pump is a 15:1 compressor we can pump out reclamation volume with it- to 1 bar allows greater reclamation area and volume PPI stock head leakage scheme is: pressure based, not vacuum based, and: does not work if it leaks and pressure cannot build common to oil and gas leakage we will want a vacuum sniff for Xe but: need to guard against oil contamination questions for PPI change min pressure spec to 7 bara why does 7 SCFM require a 2000 series pump @10 bar (0.7 CFM) why not a B pump? is there a price difference? can you compute pulse pressure if we give you line size and length to vessel? can you give details of the pulse dampers? hermeticity, elastomer are these engineered for the comuted pulse pressure differential can you advise on seal and valve materials- we will be pulling vacuum for leak detection- low oil permeance required conversation with J. Perrin 9/23/11 cannot give answer on CFM vs SCFM discrepancy- will check and get back to me B series pumps not actively promoted- can supply existing sizes though 5% pulse pressure variation assumed- does not think they calculate- will check if they have tool pulse dampers are simply extra volumes, welded pipe- no active element inside ideas for plate flaw inspection NDT experts ATS- conversation friday ultrasound best for lamination type defects quote: $850/plate, includes both UT and X-ray for subsurface, dye penetrant and eddy current for surface helium leak check: raw square plate (1st check, before buying plate) bond (or use tacky vacuum tape) vacuum manifolds to all plate edges use internal spacers for vacuum load pull vac on one side and flow helium on others- repeat for transverse direction rough machined circular ring (2nd check, before finishing 1st machine op) bond (or tvt) plates to upper and lower surfaces,overlapping ID pull vac and flow helium on OD (bag and flood? or this is in addition to standard ASME req ultrasound or radiograph gas flow requirements: We are currently specifying a 200 SLPM pump because we have specified a 200 SLP hot getter hot getters are typically sized to deliver a single digit ppb level for 5N gas, once through (several ppm) they last 1 year at this rate- so one can calculate the total amount of contamination removed we find at LBNL that onece clean- we can reduce our flow rate a lot- consistent with cleaning up emitters Azriel suspects that one could simply pump on vessel to clean evertything up- James feels otherwise- that one should flow gas to clean up the former is a vacuum conductance problem and the latter is a mixing problem (assumed) these can be easily compared to see which is better if vacuum pumpis cleans up faster, then we can relax the pump flow spec. if the experiment can be run while still cleaning gas pressure vessel status- before we can issue a final user design specification there are several small issues: dimensions: height above floor, currently 72 cm -possible issues PMT's in EL viewports- we have room for 1" cubes with pressure tight covers (for possible EL spark diagnosis) maximum external pressure do we plan for upgrade to water or scintillator tank? if so, what is max hydrostatic head? 0.35 bar? presently with 8mm wall thick, vessel has 2 bar ext press. I recommend we stick with 1.5 barg external in specification applied loads attached component weights on nozzles- seismic loads emergency gas vent forces on nozzles- see press. relief below copper shield forces- static, seismic - no problem max seismic acccel = 1.1 m/s (no isolators) - is this final? main flanges bolts or clamps- radiopurity? radius? helicoflex or O-ring only helicoflex recommended force 220 N/mm for large flanges, but, can Helium seal at 30 N/mm ( smaller flanges only) flanges presently dual compatible, but it costs us: 2.5cm flange thickness (5.5 cm - vs 3.0 cm) 6.25cm extra radius- pushes shielding out 4x higher bolt mass (2x length, 2x cross-sec area) I recommend we drop the helicoflex (full 220N/mm) capability 120 12mm bolts instead of 72 22mm bolts hand tightenable, no hydraulic tensioners required may still be Helicoflex comaptible at 30 N/mm O-rings on vessel or heads? on vessel- sniff port on heads, movable- must break line on heads- grooves more susceptible to damage nozzle flanges CF is not ASME compliant- CF in grade 2 ti dicey (iffy) helicoflex on grade 2, dicey, but not so much as CF therefore: use adapter plate to ASME flat flanges o-ring- double (sniffable) compatible resurfaceable, if helicoflex damaged DN100 nozzle flanges outside shielding - we can use grade 9 or 38 ( high strength)- want to? attachments? lifting lugs on heads? turning trunnions on heads? lift lugs on vessel? pressure relief req. size for fire very small, 20 mm dia- 60 lbf (250N) reaction force - negligible size for fast vent- 100 mm dia. (1 min to reach 1 atm) >2000 lbf reaction - must be braced carefully size for regulator failure? probably not large given 1/2 "tubing I recommend keeping 100 mm dia; we can constrict if needed- may be useful vacuum tank(s) where to locate? (doesn't fit under detector) if 1 m dia. , we need 38m length remaining pv design analyses: supports and attachments lifting lugs on heads external pressure calc torispheric head nozzles pressure relief event pipe size requirements applied loads (combined loads) from: supports internal components dynamic loads seismic- internal components gas vent nozzle flanges grade 9 or 38 do you like the flat faced design? model additions: vac tank feedthroughs central manifold spring mounts fix HV feedthrough field cage panel edge connectors buffer region field cage fix copper tubing plumbing for gas VAT fast valve cartoons: gas system/pv diagram Hv feedthrough assembly field cage/lt assembly daz 3 SDZFREE-030-0365813-RRH-001-HBWGEWP meeting with James- cans- meshplanes- James- Suprasil plate available- very expensive acrylic plate maybe OK Dave- use curved acrylic coated with TPB having raised dots- press and fuse mesh into dots field cage- James- baseline design(shuman 10/5) outside convolutions may spark over solid insulator favored- drawings soon for Clement polyethylene (UHMW) ?casting?, with rings inside- drill for resistors -ground paint(or ?) on OD eliminates annulus gas gap decouples ESR/TTX panels from field cage 50 kV is easy- 95 kV? Derek- full length, no breaks at HV - James - OK with this will need internal HV feedthrough -STAR or baseline (CM) hv feedthrough James- baseline design basically OK semicon heatshrink over dielectric is a good idea had a grade down ring structure on cable for same thing pressure vessel James- Ti grade 1 ( 80 ksi? or 35ksi?) was used in LUX Ability Engineering did vessel- cost not much higher than for SS took 3 tries to get radiopure mtl- lot sold before tests came back- had to try again used helicoflex gasket- will see if drawings and calcs are available- done by Ability Derek- grade 1 OK for vessel- use of solid field cage insulator can reduce overall dimensions will make inquiry to Ability or LUX about helicoflecx details gas system, pump Dave- variable speed pump motor a good thing Pressure vessel quick calculation summary: assume 2cm annulus reserved for solid insulated field cage: Titanium, grade 1, no Copper liner, O-ring or low force helicoflex ID=1.10m wall thickness: 10mm (8.6 mm min) OD, flange: 1.21m flange thickness: 3.5cm (each) bolts: 120 M12-1.0mm x 10 cm lg. Inconel 718, torque to 50 N-m min. Stainless Steel, 304L, 5 cm copper liner,O-ring or low force helicoflex: ID=1.20m wall thickness: 10 mm (8.5 mm min) OD, flange: 1.39 m flange thickness: 3.0cm (each) bolts: 120 M14-1.0mm x 10 cm lg. Inconel 718, torque to 80 N-m min. Numbers not yet worked out for high force helicoflex, but I expect flange OD on order of 1.55m, with 24mm bolts, probably requiring hydraulic tensioners. High force helicoflex drives up flange thickness, OD and bolt diameter (main flanges). For grade 1 Ti, force may cause brinelling, not sure yet. However LUX used helicoflex on grade 1; I have an inquiry in to the mfr. and to James about details. O-ring leakage calc (enclosed, butyl, nitrile) indicates 2X10^-4 std cc /sec through each O-ring (@15bar) = ~ 1 kg loss Xe over 10 years- if we don't recover. I feel we could try a helicoflex at low force and if we get 1x 10^-6 std. cc/sec leak rate this is all we need. I have an inquiry in to Helicoflex about this. Kel-F (PCTFE) O-rings may well provide this, some data shows 1-2 orders of magnitude less permeation than butyl or nitrile. Helicoflex He leak rate is 1.5*10^-8 for 15 bar, more than we really need. For copper lined SS vessel, I think a starting point is to tile bars 1.4m long x ? wide inside barrel, and, for heads, expand the SiPM copper shield to eliminate the hole, and expand the copper carrier plate in the energy head. I will need to come up with a low profile pipe arangement for the conduits, which should not be too difficult. LUX questions: can you share all details? (we are not competitors) who's the engineer that contracted the vessel is there an UDS? an MDR? a set of as-built drawings? helicoflex details? is there a set of radiopurity measurements? who was Ti supplier? how long did it take to get material? SERVICING: energy head There are nominally 120 bolt holes 13mm dia, as clearance for the M12-1.0 bolts. A number of these will instead be threaded for M14-1.0 bolts for the purpose of attaching lifting and/or sliding fixtures for initial retraction off of vessel. Stresses at these larger dia. Holes are still within ASME allowables when pressurized. This avoids welding any type of lift eyes or lugs onto the heads. Once retracted by 1 m, (no rotation) windows can be serviced and replaced from the front side. Special wrenches can unscrew the screw-on rings. The PMT is not currently removable from this side, but maybe we can change this as an option. If access to the back side is needed, there are two possibilities: 1. rotate/table option remove HV cable remove PMT fts, un-pin remove octagon/HV receptacle open shielding attach floor rails remove most flange bolts attach trunnions (rotation pins) to flange via threaded flange bolt holes attach recievers (trunnion forks) to rails, adjust up to trunnions attach rotation control mechanism (worm and gear sector on trunnion?) remove remaining flange bolts translate head 1 m axially remove HV feedthrough remove elliptical outer shield remove trumpet shield attach temporary support, carrier plate to central manifold rotate head 90 deg. nozzle up 2. in place option- horizontla translation only (probably hard to work on) Servicing, field cage With the change to a solid insulated field cage ( from the panel/fc design by shuman) and reduction of vessel gap we have a stronger need for a double length beam system, either cantilevered or with supports on both ends of the open vessel. Here is a rough outline of topics to discuss for the pressure vessel and PMT enclosures, with estimated times for discussion PV Issues Design- 10 min mostly done, but- need to freeze internals- should schedule- steel not so critical to get done quickly (cost, better integration) I recommend finish User Design Spedc draft and RFQ ASAP- even if not final design steel or Ti (JINR claim for low background material) - still expensive- internal flanges for mounting- field cage may need to mount to copper bar (or spacer plate) mfr needs to weigh in on weld joint design - may need to move int. flanges a bit- thicken main flanges? copper bar weight- foot design - ASME methodology copper in head - is support sufficient? double O-rings on heads, sniff ports on vessel- no helicoflex no CF Radiopurity- 5 min sample material lots - put holds on it precision- 5 min highest stress relief needed- full solution annealing specified at various stages- leak tightness- vac test before acceptance vac check/ultrasound flange rings after rough cut vac check plate samples (same time as radiopurity tests) contracting- 5 min how do we choose mfr? certification firm? -put package out to bid? put package out to bid? do our own vendor search PMT Module Issues alternatives considered - 5 min hermetically sealed- DB or braze sapphire windows and feedthroughs- long R&D gas backfill- Xe contamination, poor circulation common enclosure- inability to isolate PMTs - SuperK2? individual enclosures, vacuum filled -5 min ti pipe, screwtop lids,O-ring seals, leakage, recovery vacuum, through conduits and central manifold -5 min breakdown? cooling sapphire thickness, support -5 min test pressure, statistics sealing, leakage PMT mounting -5 min PMT base and cool scheme -5 min R&D plan - 5 min Detector Integration- 15 min- General exposition of detector subsystems (sequence)- 3 min maybe separately as well, early? movie for JJ to play? Boundary freezing progression -discussion? will be set by PV fabrication Assembly/disassembly sequence of components - 5 min (sequence, movie?) integrate with shielding movement? WORKSHOP outline Pressure Vessel Requirements review Ti vs Steel/Cu Design Status Design Presentation Issues- sufficiency of design orientation pressure relief tracking cabling radiopurity precision required flange design leak tightness contracting other PMT Module Mechanical Issues Requirements review Alternatives considered Design presentation Issues window sizing base cooling and voltage window coating R&D plan Detector Integration- 15 min- General exposition of detector subsystems (sequence)- 3 min maybe separately as well, early? movie for JJ to play? Boundary freezing progression -discussion? will be set by PV fabrication Assembly/disassembly sequence of components - 5 min (sequence, movie?) integrate with shielding movement?