Production of Forward RPC Gaps

CMS Forward RPC EDR(10/10/2002 – 11/10/2002)

Seong Jong HongKODEL, 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 713 238 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 2416 805 uncut gaps, 1611 cut gaps

Mechanics of Forward RPC Gaps

RE 1/1 3-D

Vertical Cross Section

Edge Spacer Coin Spacer

Gas Connection Gas Pipe

Gap Assembly ProcedureQuality Insurance

Bakelite electrode preparation

Procedure Quality Insurance

Cut bakelite into right size Bakelite surface inspection

Bakelite resistivity measurement

Check the size of bakelite

Silk-ink coating on the bakelite Resistivity measurement every batch

Protective PET coating over the silk-ink coating

Edge spacer preparation

Coin spacer preparation

Procedure Quality Insurance

Molding by external vender Thickness and width check

Thickness : 2.0 ± 0.02 mm

Surface scratching with sand paper Thickness and width check

Thickness : 2.0 ± 0.02 mm

Procedure Quality Insurance

Machining by external vender Thickness and diameter check

Thickness : 2.0 ± 0.02 mm

Scratching with sanding machine Thickness and diameter check

Thickness : 2.0 ± 0.02 mm

Gas inlet/outlet preparation

Procedure Quality Insurance

Molding by external vender Thickness and hole dimension check

Thickness : 2.0 ± 0.02 mm

Gap assembly

Procedure Quality Insurance

Gluing and assembly Epoxy lifetime check : 6 months in the refrigerator

Amount of glue : guaranteed by the glue dispenser

Assemble in the clean room(Class : 104-105 particles/ft3 ).

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 m2.• 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 : 104-105 particles/ft3) - Chamber assembly tables - Gap and chamber storage area - Chamber testing room• Clean shoes inside the factory• Clean gap assembly : class : 104-105 particles/ft3

• 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 cm2

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 inletPressure

Frame

Optical table

Gap Jig

Optical table

Pressing device

Spacer grinder Gap storage area

Gap Test

Test Criteria

Gas leakage Less than 5 hPa leakage for 10 minutes under –20 hPa

Epoxy strength No 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

- 805 uncut gaps, 1610 cut gaps

Cost Estimation

Section Gaps Angle

(Degree)

Unit Price

(CHF)Total

NumberTotal Price

(CHF)

RE1/1 3 10 550 80 44,000

RE1/2,3 3 10 1,000 160 160,000

Subtotal 204,000

RE2/1 3 20 800 40 32,000

RE3,4/1 2 20 600 80 48,000

RE2,3,4/2,3 3 10 1,000 480 480,000

Subtotal 560,000

Total 764,000

Bakelite cost not included

Production and Delivery

Year 2 0 0 3 2 0 0 4 2 0 0 5

Month 1 2 3 4 5 6 7 8 910

11

12

1 2 3 4 5 6 7 8 910

11

12

1 2 3 4 5 6 7 8 910

11

12

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 ChinaRE 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