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HBD Update Itzhak Tserruya

DC Upgrades meeting HBD, BNL, July 13, 2005

• PrototypesFull scale HBDReadout boardFEM

• Final detectorHBD DesignGEM design and pilot production Preamp redesign?Test Facility Gas system

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Full scale prototype

The full scale prototype passed all tests:

1. Gas tightness test – the detector holds ~4 ppm of water, 2 of them are from the gas system.

2. A triple GEM detector has been installed and tested inside the prototype in CF4 with Fe55 source.

Ready to fly to US …

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B.Yu

• 68 channels laid out to match FS prototype• Board thickness 5 FR4 layers ( .004” each ) 2 Cu layers ( 5 m each )

• Pulser distributed to 16/14/24/14 chs for testing• Design layout completed• Material ordered by WI from DITRON• Board will be made in Instrumentation shop after material arrives

Readout Board for Full Scale Prototype

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FEM prototype

• Was supposed to be ready in May

•Clock fan-out chip from CIPRESS was discontinued.

• Revision of layout with new clock chip was done

•Layout should go out next week

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HBD final design: global dimensions

Z= 656.4 mm

Clearance +/- 3 mm

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HBD final design: changes wrt prototype

Several changes are being made in the design of the final HBD wrt the prototype. The

changes are made:

• to reduce the z envelop of the detector

• in response of lessons learned from the prototype

The main changes are:

• a single 100 micron window instead of a 2x50 micron window

• thinner covers, ½” honeycomb instead of ¾” in the prototype gain 2 x 6 mm in the

z envelop

• a thin FR4 frame all around the covers prevents deformation of the covers at the

places of the screws.

• head of the screws immersed inside the frame gain 2 x 4 mm in the z envelop the z envelop is now 656.4 mm (down by 23.6 mm from the original value of

680 mm)

• more symmetrical shape, closer to two half cylinders

• 6 mm clearance between the two halves of the detector

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HBD assembled

2x21 HV connectors serving 2x3 detector modules

Gas out

Entrance window:Removable or glued?

FR4 frame all around the spacer

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HBD exploded view

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GEMs for final HBD• GEM design completed. • Pilot production (12 GEMs and 15 frames)

ordered from CERN and delivered.• Stretching and gluing devices ready.• 3 GEMs glued on frames, installed inside new

stainless steel test vessel.• Tests with CF4 underway.

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• Found new, small header and connector which could replace presently proposed ones Present header : 0.57 g Small header : 0.052 g 10 Cu pins on present PA : 0.13 g connector : 0.087 g

• Re-layout to place components on both sides could reduce board size by ~ factor 2 one extra layer of FR4 + small amount of Cu, but possibly go .006” .004” each layer so that final board thickness stays ~ same

• All components stay the same except one chip which would need to be changed to prevent possible oscillation

• Could possibly reduce X0 from: Preamp: 0.95% ~ 0.6% Header: 0.6% ~ 0.06% Total: 1.55% 0.66% (1.46% detector + gas)• Need to assess impact on schedule

Possible Redesign of PreampsSamtec Connector & Header

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HBD Gas System StatusStainless steel line from gas pad to mixing house is done.Currently working on lines in mixing house and lines from mixing house to assembly area.Working on finalizing parts list:

Dwyer parts 99% chosen. Order being filled out. Flow controller—500 l/hr (~8.5 lpm) National Instrument deviceSolenoid Valves Peter Paul electronics

Price doubled to ~1.8k for kalrez / viton sealsO2 and H20 AnalyzersStill working on other parts.

Prices higher by going to full metal for parts where we can.

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CF4 transmission measurements

We ordered one cylinder of CF4 from Spectra Gases Company, the same company used at BNL

We measured the transmission in CF4 over 23 cm in the “old, expensive” and in the “new, cheap”

The gas from Spectra Gases looks at least as good as the old one used during the R&D at Weizmann

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HBD test facility at SUNY

• MRI grant approved but still waiting for final signatures

• Very good progress in defining the specifications for the glove box. H2O < 10pmm, Particle Level < 100/m3 , Dehumidification Column with HEPA filtration, Monitoring Instruments H2O, O2, Pressure Pressure Range +- 10milbar, N2, leakage 0.05%vol/h, N2 Flow +250 l/Hr N2 From Liquid N2, with Backup Cylinders Automatically engaged Overpressure Vent, 4 Swagelock Fittings on each end to control gas Flow According to work.

Size Interior, Length 3m Min, Width 1.2 MAX, Height 1.4 Min Approx. Vol. 4.7m3

• Very good progress in setting up the CsI evaporation facility with “Big Mac”

CsI Cathode Production in BigMac

Thomas K Hemmick

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Big Mac Provides Large Volume (8’ diameter, 6’ tall) High Vacuum (few 10-7 torr) Lots of Feedthroughs

Lots of blank “do-it-yourself” ports

Mechanical Motions: 2 tables covering 320o in One tower (up/down & rotate)

Several Large ports 12” Inside Diameter

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Advantages of Big Mac Speeds up evaporation process by allowing

many GEMs inside at once. Large enough volume for QE measurement

inside vacuum after deposition. PHENIX needs 24 good GEMs

We’ll assume 4 sets of 6 GEMs plus 1 spare set. Possibility to remove via large port (airlock)

Good: No air exposure. Bad complexity = Bad vacuum = poor Q.E.

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CsI evaporation and QE Measurement:

A UV light in a slit pattern shines through segmented grid. Each grid segment (or each GEM segment) has current read

independently (y coordinate) The position of the carousel sets the x coordinate.

Arrange 6 GEMs in ARC facing down. Rotates via Big Mac Tables. Evaporate one-by-one (two?) Working on a scheme to remove all six with minimum

exposure to air. QE measurement (relative in situ, absolute with small

samples):

Expected to be ready for a full dry test beginning of September

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Summary

• Progress in all fronts

• Delays in almost all fronts. Most of them can be recuperated by

increased efficiency in the production procedures

• Serious delay in electronics