Production of Forward RPC Gaps CMS Forward RPC EDR (10/10/2002 – 11/10/2002) Seong Jong Hong KODEL, Korea University

Contents CMS Forward RPC Gaps Mechanics of Forward RPC Gaps Gap Assembly Procedure / Quality Insurance Factory Overview Factory Layout HV/Ground Electrodes Production PET Coating Facility Gap Assembly Facility Gap Test Capacity of Gap production Cost Estimation Production and Delivery Summary

CMS Forward RPC Gaps RE1/1 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE1/2 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE1/3 36 (10 。 Detector) × 2 (L, R) × 3 = 216 Spare (10%) 65 RE1 total uncut gaps, 475 cut gaps RE2/1 18 (20 。 Detector) × 2 (L, R) × 3 = 108 RE2/2 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE2/3 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE3/1 18 (20 。 Detector) × 2 (L, R) × 2 = 72 RE3/2 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE3/3 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE4/1 18 (20 。 Detector) × 2 (L, R) × 2 = 72 RE4/2 36 (10 。 Detector) × 2 (L, R) × 3 = 216 RE4/3 36 (10 。 Detector) × 2 (L, R) × 3 = 216 Spare (10%) = 220 Total uncut gaps, 1611 cut gaps

Mechanics of Forward RPC Gaps RE 1/1 3-D

Vertical Cross Section Edge Spacer Coin Spacer

Gas ConnectionGas Pipe

Gap Assembly Procedure Quality Insurance Bakelite electrode preparation ProcedureQuality Insurance Cut bakelite into right sizeBakelite surface inspection Bakelite resistivity measurement Check the size of bakelite Silk-ink coating on the bakeliteResistivity measurement every batch Protective PET coating over the silk-ink coating

Edge spacer preparation Coin spacer preparation ProcedureQuality Insurance Molding by external venderThickness and width check Thickness : 2.0 ± 0.02 mm Surface scratching with sand paperThickness and width check Thickness : 2.0 ± 0.02 mm ProcedureQuality Insurance Machining by external venderThickness and diameter check Thickness : 2.0 ± 0.02 mm Scratching with sanding machineThickness and diameter check Thickness : 2.0 ± 0.02 mm

Gas inlet/outlet preparation ProcedureQuality Insurance Molding by external venderThickness and hole dimension check Thickness : 2.0 ± 0.02 mm Gap assembly ProcedureQuality Insurance Gluing and assemblyEpoxy lifetime check : 6 months in the refrigerator Amount of glue : guaranteed by the glue dispenser Assemble in the clean room (Class : particles/ft 3 ). Pressurizing device monitoring during curing (14 hours) Pressure : guaranteed by the water height

Factory Overview Located at Ilsan near the Kimpo airport. Two buildings. Each building : 180 m 2. The first building has - Bakelite storage area - Bakelite cutting facility - HV/Ground electrode production facility - Mylar coating facility The second building consists of - Gap assembly facility area (class : particles/ft 3 ) - Chamber assembly tables - Gap and chamber storage area - Chamber testing room Clean shoes inside the factory Clean gap assembly : class : particles/ft 3 Controlled temperature (20 ± 5 Celsius) and humidity (40 ± 10%) - Bakelite, gap and chamber storage area All the other area inside factory : temperature (20 ± 5 Celsius)

Factory Layout

Bakelite Cutting Facility - Cut bakelite weekly - Can cut up to 10 sheets

HV/Ground Electrodes Production Uniformity of resistivity - RE2/1 uncut gap - within 10% - Cell size : 5×5 cm 2

PET Coating Facility Protection of HV and ground electrodes and electrical insulation of HV and ground electrodes. - 2 sheets of 250  m on HV side - 1 sheet of 250  m on ground side The PET coating facility consists of - Free roll conveyor set to guide the bakelite to the laminating set. - Laminating set - Belt conveyor set to guide the mylar coated bakelite from the laminating set The laminating set consists of - PET unwinding roller - Hot melt heater - Nozzle for applying adhesive to bakelite - Knife for keeping adhesive thickness uniformly - Rubber coated roller and steel roller to press the PET film on the bakelite

- Current problem : Weak adhesive strength - Operating temperature of of hot melt glue : ~ 80° C - When hot melt applied to the bakelite, temperature of hot melt drops quickly - We will heat the bakelite with infrared lamp

Gap Assembly Facility The gap assembly facility consists of seven epoxy curing frames, an optical table for gap assembly, a lifting device and a pressurizing device Each epoxy curing frame - consists of an optical table and a gap-pressing device - can cure 1 uncut gaps or 2 cut gaps Gap assembly optical table - designed to produce various sizes of gaps using jigs - attached to the moving frame riding on rail Lifting device moves each assembled gap on the optical table to individual epoxy curing frame Pressurizing device - provides uniform pressure to the assembled gaps during epoxy curing - consists of an air vessel made of special rubber, and air supply equipment which provides air for the air vessel and maintains constant air pressure in the air vessel

Air inlet Pressure Frame Optical table Gap Jig Optical table Pressing device

Spacer grinder Gap storage area

Gap Test TestCriteria Gas leakageLess than 5 hPa leakage for 10 minutes under –20 hPa Epoxy strengthNo loss of coin spacer under +20 hPa for 5 minutes Current Uncut gap : below 1  A Cut gap : below 2  A Gap test facilities are being designed now

Capacity of Gap Production Work hour : 8 hours/day Working days : 250 days/year - Part preparation : 100 days/year - Gap assembly : 150 days/year Gap production capacity (with 6 storages) - The gap assembly facility has 7 storages - 3 uncut gaps/day × 150 days/year = 450 uncut gaps/year - 6 cut gaps/day × 150 days/year = 900 cut gaps/year Total number of gaps for CMS forward RPC uncut gaps, 1610 cut gaps

Cost Estimation SectionGapsAngle (Degree) Unit Price (CHF) Total Number Total Price (CHF) RE1/ ,000 RE1/2,33101, ,000 Subtotal204,000 RE2/ ,000 RE3,4/ ,000 RE2,3,4/2,33101, ,000 Subtotal560,000 Total764,000 Bakelite cost not included

Production and Delivery Year Month RE 1/1 (80) RE 1/2 (80) Delivery RE 1/3 (80) Delivery RE N/1 (120) RE N/2 (240) Delivery RE N/3 (240) Delivery RE 1/2, RE 1/3 : Delivery to China RE N/2, RE N/3 : Delivery to Pakistan Production capability 9 RPCs/Week, 36 RPCs/Month Schedule

Packing Custom-made box - consists of 4 shelves - 10 sets of gaps on each shelf 1 set : 1 uncut gap, 2 cut gaps Individual packing of 10 sets Shock watch To China : 4 boxes To Pakistan : 12 boxes

Summary Most of the gap production facilities are tested and satisfactory PET coating facility is being tested Facilities for quality insurance and gap test are being designed Funding for RE 1 station has been secured and production schedule has been confirmed by funding agency Funding for other stations has been committed by funding agency, but has no detailed plan