Straw tubes for forward tracking at the NLC

O.K. Baker, K. McFarlane, V. Vassilikopolus

Hampton University

Arlington, TX Jan 9-11, 2003

Hampton University . . .

• More than 12 years of experience in design, construction, and operation of wire chambers for experiments (JLAB, ATLAS).

• Planar

• straw tube

• Resources exist for taking on major projects• NSF-funded Physics Frontiers Center

• proximity to Jefferson Lab

• quality students and staff (PhD program at HU)

Hampton University

ATLAS at the LHC

Hampton collaborating on the barrel TRT construction

Transition Radiation Tracker: straw tubes

• Straws are:– 4 mm diameter– ~1.2 meters in length– carbon fiber reinforced– wire supports inserted– processed for stringent

LHC requirements– 30 W wire– Xe:CO2:CF4 gas (100

/ns drift velocity)

Transition Radiation Tracker: straw tubes

• Designed to handle:– 1034 cm-2 s-1 luminosity

– 14 MHz per straw

– reliable operation for a decade

– operate in 2T field

HU facilities: A TRT Barrel Module

Module beingSet up for test

Type-2 module (520 ‘straws’)

Simulated EventsAs they will ‘look’

after computer reconstruction

Hampton construction tasks

• A collaboration with Duke and Indiana on ATLAS barrel TRT

• Hampton:– Procure some TRT components– Process components (~64k ‘straws,’ matching

numbers of other parts)– ‘String’ a fraction of the modules (about 17%)

and complete mechanical construction (new)– Test all modules for uniformity of gain– Provide Module Gain Mapper for CERN

HU Production Facility

Clean Room (Class 10,000) ~ 1200 sq ft.Sensor production and module stringing

Hampton U Module Test Stand

HU: Module gain test

• Uniformity of gas gain is test of quality of module– Low gain areas will result in loss of tracking

and TR efficiency– High gain areas may break down– Window is not large: 8-10%

• Every wire must have its gain measured mapped at intervals along its entire length

Production at Hampton Straw Production

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CERN Plan

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Hampton Plan

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CERN StrawProduction

Required rate of production doubled

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Gain map at Hampton

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Straw number (1-520)

Z position Gain variation, 0 to 10%

Students

Wire chamber design and construction at Hampton

R&D at Hampton

Carbon-loaded Kapton straw tube wire chamberprovides z-coordinate readout (in addition to x).

z

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y

NIM A332, 469 (‘93); NIM A348, 307 (‘94)

Hampton Staff

O.K. Baker

K.W. McFarlane

V. Vassilakopoulos

Alan Fry (PE)

Chuck Long (ST)

Carolyn Griffin

Jackie Hodges

P. Wilkins

Aida Kelly

Base Production

Hampton University: straw tubes for forward tracking

• Propose to use straw tube wire chambers for forward tracking in the NLC spectrometer.

• Possibility to get bunch timing information.

• Robust, proven technology.

• HU track record in large projects.

• Resources (base) for taking on this project.