1 SLEEVE Discussion Ianos Schmid – U.Iowa Lucien Cremaldi - U.Miss David R Winn – Fairfield And help from many 30 Oct 2010 Agun, Winn

2 Summary Tyvek, Teflon reflectors – Large body HEP experience. reflectivities >95% ~ HEM But resistive, semi-specular, high resistivity. CMS operational tests simple Tyvek and Teflon sleeve mockups: signal >93% of HEM signal, and low background from the sleeve itself (<10% of previous sleeve). See Taylan Yetkin talks. All other data using sources and HV show that the 2 materials (or variants) good as a HEM replacement.

3 Sleeve Drawing – I.Schmidt GOAL: Reduce Sleeve Length to ~6 mm And Reduce internal Telescoping length To minimum OK!

4 Sleeves in IPHI 3, IETA 29 IETA 29S IETA 29L TEFLON TYVEK Light guide tube Mirror “Telescopic” Sleeve made of 3M radiant mirror film (“HEM”). Non conductive. In HF+ IPHI 3 all mirrors were replaced with standard “German Mylar”. HEM sleeves were installed everywhere except IETA 29S and IETA 29L which have Teflon and Tyvec sleeves respectively.

5 Sleeves Ianos Schmid - Iowa A). Round Tyvek sleeve (For PMT’s presently used in HF) – kapton tape. B). Tyvek in adhesive lined polyolefin shrink tubing shaped by shrinking over mandrel. (concept worked well but adhesive glows under UV). C). White polyolefin shrink tubing. ABC

6 6 Baseline A: Tyveks 30 Oct 2010DRW -Tyvek: spun-bonded cyclic polyolefin (alkenes) –100% high density polyethylene – HDPE; n~1.5(!). Sheet formed by spinning continuous plexifilaments (0.5-5 µm), bonding w/ heat+pressure. Used extensively in HEP for collecting light from Scintillator or Cerenkov calorimeters/Counters. Rugged; Rad-Hard -Present Baseline: Types 1025D (or 1055D; corona-processed). Known Raddam – gamma known to be OK for HF region: <25% elongation capable 50 MRad;

7 Baseline B: Teflons 7 PTFE(Polytetrafluoroethylene) Semi-crystalline = white n= only material a Gekko cannot stick to. Tested: commercial teflons in sheets and films. GORE DRP Diffuse Reflector Material expanded/foamed (ePTFE) The foaming process gives good reflective properties (nanostructure/filaments). flexible. Costly.

8 Candidates TYVEK 1025 D(**)TYVEK inkjet sheet TYVEK 1073 DTYVEK inkjet banner TYVEK 1085 DTYVEK TY31 TYVEK 1056 DTYVEK cc sleeve TYVEK 1443 RGORE DRP -- 3 mm TYVEK 1079GORE DRP mm(**) TYVEK Vivia% Cotton paper Polyethelene (HDPE) (*)Teflon (*) 11 different types of Tyvek, two thickness of GORE DRP, polyethelene, and teflon. (*, **) presently being prepared in *Iowa or ** Fairfield machine shops

9 Radiation Backgrounds Alpha Source: - No Scintillation Background Tyvek, Teflon Am 241 Beta Source (Mississippi): – Teflon: ~no background, normal or grazing incidence? – Tyvek – 1-2 pe. Max Background Cerenkov? – Gore, VM2000 are out! Encouraging CMS in-situ DATA! - See Taylan Yetkin’s Talk – Preliminary: Teflon, Tyvek both ok! Neutron response F(n,x), C(n,x): not tested yet 18 F 9 + n  18 O 8 + p + 7 MeV  ! Activation not tested

10 Beta exposure Lucien Cremaldi & students/Ole Miss Tyvek VM200 & Teflon Gore Variants not good without modification. Eliminate. We need: a) R7600: Proper dQE/d and HV b) Sleeve geometry c) Higher energy  source d) Grazing incidence (0 o -10 o ) Compare HEM, teflon & tyvek: ???

11 Teflon vs Tyvek: Comments Teflon: slightly more UV-Vis reflective, less rad-hard, Fluorine evolutes?, F(n,  /  /T/..); F( , n/e/..), corona islands (10 18  -cm).. Slightly less Cerenkov than Tyvek But Gore Reflector seem to scintillate or more Cerenkov. Thickness a problem. $$$ Comments Tyvek: possible >Cerenkov?; less specular in base-type than Teflon?; but Bullet- proof! Bottom Line: Down Select Tyvek???

12 Sleeve Background Tasks: Ru 106 source – more energetic – Redo beta tests, but with…. Real sleeve prototypes: round HFPMT, square or round R7600, both teflon and tyvek – and Brillion(tyvek) and Gore(teflon) materials. R7600. Re-Measure tickets as function of angle 90 o -1 0 Neutron response F(n,x), C(n,x) Test Beam: Feb FNAL M – Need time x task and team members

13 Plans T> 10/01/11 Raddam/n signals: Co60, n in next 3-4 months - See Ugur Akgun talks. Beam Tests: – a) direct compare teflon, tyvek, HEM sleeves on light through guide from fiber bundle/q-calo, with R7600. – b) muon sleeve scan 0-90 o Forming into sleeves: exact procedures & shapes – Study glues (ex: accelerator magnet epoxies) or tapes (mylar, kapton, w/ or w/o adhesives) – for no Scintillation!

14 Sleeve Summary Two Good Candidate Sleeve Materials & Designs – Low to negligible ionizing background generation – Adaptable to square if necessary – Preserves Signal (at worst 93%). – HV-safe for HFPMT at 6mm. R7600 in test next 3 months. Point Designs for Sleeves progressing on time. – Decision as per loaded schedule. Fasteners/adhesives still to decide. Raddam, n-signal, and Activation Plans next 3 mo. Preliminary planning for manufacture and install