LST Mechanical Design Review

Utility Routing, Cableways & Crate Locations

Peter KimOctober 21, 2003

October 21, 2003 P.Kim 2

OVERVIEW• SPACE ISSUES

– Where Do All the Cables Go?– Cable Routing inside the Sextant– Cable Routing Around the Detector– Cable Routing to Outside Shielding Wall

WITHOUT DISTURBING OTHER COMPONENTS

• Some RPC Infrastructure Remains– Top/Bottom Sextants installed in 2004, Side Sextants

in 2005 – Cylindrical RPC & ENDCAP RPC Operational after

2005

October 21, 2003 P.Kim 3

Current IFR/RPC System

• High Voltage– CAEN HV Supply in Elec. Hut outside the Shielding Wall– HV Distribution Boxes positioned around BABAR Detector– 8 kV HV Cables to RPC Modules behind the Corner Plates

• Gas System– Gas Manifold/Bubblers/Flowmeters in Racks above BABAR– Teflon/Polyflo Tubes feed RPC Modules behind the Corner

Plates

• Signal Readout– Preamps on RPC Modules – Twisted Pair Flat Ribbon Cable carries Signal to FEC in Racks

around BABAR Detector; Processed Signals go to DAQ via Optical Fibers

October 21, 2003 P.Kim 4

RPC HV Cable Routing

Gas Supply

HV Cables

Drawing from R. Principe

Shielding Wall

October 21, 2003 P.Kim 5

BABAR CABLE TRAYS

LST will use North Tray

TRAYS are Busy, but Space available for LST HV/Gas Lines

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RPC Gas Tubes

TEFLON Gas Supply Tubes TEFLON / POLYFLO Connections

Backward SideFront SideTEFLON

POLYFLO

October 21, 2003 P.Kim 7

A Sextant full of RPC

From R. Boyce’sTalk this Morning

October 21, 2003 P.Kim 8

LST High Voltage System• HV Distribution (Baseline Design)

– HV Supply located above Electronic Hut outside Shielding Wall– One HV Cable (10-wire or 20-wire Kerpen) for each LST Module– Total of 564 Cables (94 Cables in each Sextant)– No Distribution Boxes near BABAR: Long Cables (25-40 m) from HV Supply to LST Modules

• Cable Trays & Cableways– HV Cables need to be Separated from Other Supply Lines– New Cable Tray under the Shielding Wall– New Cableways to run HV Cables Around BABAR Detector

• Inside Each Sextant– Top/Bottom Sextants: Use Open Space Either Side of CENTER PLATE – Side Sextants: Use existing RPC Signal Cable Box in the Middle

October 21, 2003 P.Kim 9

High Voltage Supply

BABARDetector

Electronic Hut

RPC HV Supply

LST HV Supply

October 21, 2003 P.Kim 10

BABAR Viewed From South

Center Plate

Corner Plate

Side PlateRemoved

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Closeup View of Side Sextant

Side Plate Goes Back in Here

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Open Box

Signal Readout Cable Box(2” Wide, 5” Deep)

Signal Readout Cable Box(2” Wide, 5” Deep)

Space Available forLST HV/Gas Lines(6” Wide, 5” Deep)

October 21, 2003 P.Kim 13

High Voltage Cable

KERPEN 6 kV HV Cable

Zero Halogen, Frame Retardant Polymer Sheath

Diameter: 9.1 mm for 10-conductors 10.7 mm for 20-conductors

Minimum Bending Radius = 6 x Diameter Tinned copper, Flexible stranded Conductors (0.16 mm diameter)

October 21, 2003 P.Kim 14

LST Gas System• Gas Distribution

– Reuse Rack space on Top of BABAR, currently occupied by RPC Crates

– New Gas Manifolds, but Reuse RPC Bubblers/Flow meters– LST Gas is NON-FLAMMABLE

• Reuse RPC Teflon Tubes– Need to install 60 more lines (228 for RPC; 288 for LST)– RPC Tubes going to the Front Side need to be Rerouted (LST Gas Tubes go to Backward Side only)

• Polyflo Tubing– Teflon/Polyflo Connections – Two Bundles of 24 Polyflo Cables (Input/Output Lines) enter Sextants in the Middle

October 21, 2003 P.Kim 15

HV-GAS Supply for LST

October 21, 2003 P.Kim 16

LST Electronics Readout

• BASELINE DESIGN– Z-Strip Signal Read out from the Back Side 1152 Channels per Sextant– Phi Signal Read out from the Front Side 758 Channels per Sextant– AMPHENOL Twisted/Flat Readout Cable– Preamps on FEC, Not on the LST Module

– 7 Crates for Z Signals and 6 Crates for Phi Signals– Output Digital Signal to DAQ via Optical Fibers

• CRATE Features– VME Standard 6U High (26.5 cm); 55 cm Wide, 55 cm Deep– 7 Crates for Z Signals and 6 Crates for Phi Signals– All Input/Output Cables are Connected from the Front

October 21, 2003 P.Kim 17

Amphenol Readout Cable

MicroribbonTwitst/Flat Cable

17 Twisted Pairs Shielded & Jacketed

Diameter at Round Section: 0.75 cm

48 Phi Cables / Sextant 72 Z Cables / Sextant

Enough Room in Two 5 cm x 12 cm Cable Boxes / Sextant

October 21, 2003 P.Kim 18

Examples of Conduits for Phi Signal Readout

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Rack Locations

• Keep the Racks Close to LST Modules– Deterioration of Raw Signal over Distance– Higher Background Noise Pick Up over Distance

• Space Considerations– Allow Access to Other Parts of BABAR Detector, Endcap

Doors, Earthquake Braces, etc.– Cooling Fans / Air Circulation– Removal and Insertion of FEC Cards

October 21, 2003 P.Kim 20

Electronic Rack Locations on the Forward Side

Drawing fromR. Principe

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Electronic Rack Locations on the Backward Side

October 21, 2003 P.Kim 22

Space Check with Mockup Crates

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Installation Schedule

• Racks & Fixtures Design, Fabraication, and

Installation before July Shutdown

• New Cable Trays and Conduits installed while

RPCs are being removed

• GAS Tubes and HV Cables will be laid down One

Layer at a time, following LST module install schedule

October 21, 2003 P.Kim 24

SUMMARY

• NO SPACE PROBLEM EXPECTED UNDER BASELINE DESIGN

• LOTS OF WORK TO DO, BUT WILL BE ABLE TO MEET IFR INSTALL SCHEDULE FOR 2004/2005