PHENIX Safety Review

Overview of the PHENIX Hadron Blind Detector

Craig Woody BNL

September 15, 2005

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Topics

Detector Gas system High voltage system Low voltage system, FEMs, cables Grounding Installation of detector near beam pipe Operation inside magnetic field

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HBD Detector

• Uses deep UV transmitting gas (CF4) with no gas window to detect Cherenkov light from low momentum electrons

• 50 cm of CF4 radiator

• GEM detectors with CsI photocathodes to detect Cherenkov light

Proximity focused Cherenkov detector

1.4 g CsI total (for entire detector)

CsI layer(top GEM)

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HBD Prototype in Lab in Physics

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Total detector volume ~ 626 l

(313 l each side)

Flow rate ~ 60 l/hr ( ~ 150 l/hr purge)

HBD Gas System

Pure CF4

Single pass system for Run 6

Extensive gas monitoring to maintain

O2 and H2O levels to a few ppm

R.Pisani

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Gas Monitoring

McPherson 234/302 VUV spectrometer - uses pure argon as reference gas (no vacuum) - completely enclosed 30 W D2 lamp

• H20• O2

• VUV transmission

Gas monitoring near detector (under stairs by labyrinth) D.Lynch

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High Voltage System

CAEN SY2527

A1732

• Commercial CAEN system (SY2527 + A1732 modules) located on top bridge above Central Magnet

• Maximum HV for detector < 4 KV

• Maximum HV for A1732 is 6 KV, but can be limited to 4 KV

• 48 HV cables from bridge to 24 voltage divider boxes located near detector (~ 10 m)

• 168 short (~ 1m) HV cables from divider boxes to detector

• Will use lab standard RG-59 (A-30304)All connectors SHV

(maximum rating 5 KVDC)

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LV Distribution

S.Boose

Entire System47 A @ + 6.5 V32 A @ - 7.0 V

× 2 for safety

Per cable (x 24)1.9 A @ + 6.5 V1.3 A @ - 7.0 V

Individual boards also fused

Fuses

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LV Power Cables

S.Boose

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Signal Cables

Total length 10 m

Individually shielded pairs

Grouped in bundles of 16 pairs

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Grounding System

HV Supply

LV Supply

FEM

PreampBoard

GEMDetector

HVDistribution

Box

+6.5 V-7.0 V

MVD Rack

return

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Operation in Magnetic Field

No magnetic components inside

detector

Will operate with inner and outer coils in opposite polarity

producing very low magnetic field in the

region of the detector

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Backup Slides

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HBD Gas System Current Status

• Run6 simplified system

• Single pass

• Limited data logging

• PC software in 2006

• Recirculation in 2006

R.Pisani

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HBD System Parameters

R.Pisani

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HBD Full Gas System Schematic

R.Pisani

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FEM Organization

• Crate Base system• 4 crates in a rack• 6UX 160mm IEEE 1101.10 Standard Crate

mechanics – VME 64X etc.• Custom Backplane• All clock cables are 2mm Hard Metric cables • Signal cable/test pulse are 2mm Hard Metric cables• There are also Ethernet, Optical and power cables

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Updated HBD FEM Diagram

Clock Master

Clock fanout ADCOptical

out

Backplane

Crate

GTM/Ethernet

New Daughter card + DCM

Test pulse

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+4 V BUSBAR- 4V Analog - 4V Analog

Ground BUSBAR

+5.5V Digital

Ground BUSBAR

AMP 25A Power Connector

BackPlane

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FUSE

ADC Board Clock Master

Optical TransmitterClock Fanout

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S- S+ G S+ S-

Signal arrangement

Use 2MM Hard Metric cable to move signals between preamp/FEM

2mm HM connector has 5 pins per row and 2mm spacing between pins and rows

There are two types of cable configuration:

*100 ohms parallel shielded cable

50 ohms coaxial cable

Our choice is

This gives us signal density 2mm x 10mm for every 2 signals.Same type of cables will be used for L1 trigger data.

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Signal Cable

• Meritec Custom 2mm Cable Assembly, 1X5 to 1X5 with 8 stack and 16 lines 700319-01, using polyester expando sleeving, 394” in length

–

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B.Yu

• Prototype - 68 channels• Final board - 96 channels• Power + 6.5 V, -7.0 V ( ± 5V after regulators)• Preamps : 165 mW each ( 16 W/board)

Readout Boards

Voltage regulators

Fuses