TPC R&D in Canada Dean Karlen / University of Victoria & TRIUMF Canadian LC-TPC Group: Carleton...

TPC R&D in CanadaTPC R&D in CanadaDean Karlen / University of Victoria & TRIUMFDean Karlen / University of Victoria & TRIUMF

Canadian LC-TPC Group:Canadian LC-TPC Group: Carleton University:Carleton University: Robert Carnegie, Madhu Dixit, Hans Mes, Robert Carnegie, Madhu Dixit, Hans Mes, Kirsten Sachs Kirsten Sachs University of Montreal:University of Montreal: Jean-Pierre Martin Jean-Pierre Martin University of Victoria:University of Victoria: D.K., Paul Poffenberger, Gabe Rosenbaum D.K., Paul Poffenberger, Gabe Rosenbaum

2003 ALCPG Cornell Meeting: 13/7/032003 ALCPG Cornell Meeting: 13/7/03 TPC R&D in Canada / D. Karlen / UVic & TRIUMFTPC R&D in Canada / D. Karlen / UVic & TRIUMF 22

OutlineOutline

Focus of the Canadian LC-TPC R&D programFocus of the Canadian LC-TPC R&D program

Updates:Updates: On the eastern front: TPC1On the eastern front: TPC1

finalizing analysis of P10 and ArCO2 cosmic data from 2002finalizing analysis of P10 and ArCO2 cosmic data from 2002 investigation of resistive foil for induction signalsinvestigation of resistive foil for induction signals

On the western front: TPC2On the western front: TPC2 first results from cosmic data in magnetic field (June 2003)first results from cosmic data in magnetic field (June 2003) comparison with Monte Carlo simulationcomparison with Monte Carlo simulation

Plans...Plans...


Focus of Canadian TPC R&DFocus of Canadian TPC R&D

Investigate the design of the end plate for the Investigate the design of the end plate for the TPC to achieve its objectives:TPC to achieve its objectives: micropattern gas avalanche detectormicropattern gas avalanche detector modest size pads: ~2 mm modest size pads: ~2 mm ~6 mm pads ~6 mm pads ~100 micron resolution per pad row in the transverse ~100 micron resolution per pad row in the transverse

directiondirection good two particle separation powergood two particle separation power


Endplate designEndplate design

Significant effort to study the performance of Significant effort to study the performance of GEM devices with rectangular readout padsGEM devices with rectangular readout pads cosmics used to measure resolution propertiescosmics used to measure resolution properties

TPC 1AFall 2001

TPC 1BSummer 2002

TPC 2Summer 2003


Cosmic ray trackingCosmic ray tracking

The traditional approach:The traditional approach: examine data from eachexamine data from each

row separately: define a row separately: define a point along the trackpoint along the track





find best track that goesfind best track that goesthrough pointsthrough points





find best track that goesfind best track that goesthrough pointsthrough points

measure resolution by themeasure resolution by thescatter of the dots from thescatter of the dots from thetracktrack



Problem with the Problem with the traditional approach:traditional approach: information in one rowinformation in one row

is not sufficient to defineis not sufficient to definea point along the track:a point along the track: charge sharing depends oncharge sharing depends on

x coordinatex coordinate azimuthal angleazimuthal angle width of charge cloudwidth of charge cloud

dependence is non-lineardependence is non-linear linear centroid findinglinear centroid finding

degrades resolutiondegrades resolution



Our whole track approach:Our whole track approach: combine information fromcombine information from

all rows to determine theall rows to determine thetrack parameters:track parameters: x coordinatex coordinate azimuthal angleazimuthal angle width of charge cloudwidth of charge cloud

the concept of a point on the concept of a point on the track is non-existentthe track is non-existent

x resolution for a singlex resolution for a singlerow is measured byrow is measured byperforming two track fits performing two track fits



The sharing of charge byThe sharing of charge byneighbouring pads is a simple neighbouring pads is a simple enough concept to develop a enough concept to develop a first principles model forfirst principles model formaximum likelihood maximum likelihood

Benefits of the whole trackBenefits of the whole trackapproach:approach: no empirical parametersno empirical parameters

less calibrationless calibration

reasonable estimates forreasonable estimates forerror matrixerror matrix

better resolutionbetter resolution


News from the Eastern FrontNews from the Eastern Front

Finalizing analysis of data from TPC-1bFinalizing analysis of data from TPC-1b F analysis code developedF analysis code developed


Transverse resolutionTransverse resolution

100 100 m resolutionm resolutionachieved with 2 mmachieved with 2 mmpads… furtherpads… furtherimprovements expectedimprovements expected


Resistive anode studiesResistive anode studies

To spread signals over larger area, a resistive To spread signals over larger area, a resistive film can be used:film can be used:

Especially importantEspecially importantfor Micromegas…for Micromegas…


Resistive anode studiesResistive anode studies

Early results look promisingEarly results look promising


News from the Western FrontNews from the Western Front

Progress since Arlington:Progress since Arlington: New TPC (TPC2) commissioned in VictoriaNew TPC (TPC2) commissioned in Victoria Cross compiler for STAR electronics developed to Cross compiler for STAR electronics developed to

build more efficient DAQ systembuild more efficient DAQ system Cosmic tracking indicated field distortionsCosmic tracking indicated field distortions TPC redesign fixed the distortionsTPC redesign fixed the distortions TPC brought to TRIUMF for magnetic field testsTPC brought to TRIUMF for magnetic field tests Track fitter extended for curved tracksTrack fitter extended for curved tracks Begin using JAS3 for automated analysisBegin using JAS3 for automated analysis Analysis of the magnetic field runsAnalysis of the magnetic field runs

code is publicly available via anonymous CVS accesscode is publicly available via anonymous CVS access


Victoria groupVictoria group

Graduate student:Graduate student: Gabe RosenbaumGabe Rosenbaum

RA (part-time):RA (part-time): Paul PoffenbergerPaul Poffenberger

Summer students:Summer students: Camille Belanger-ChampagneCamille Belanger-Champagne Brie HoffmanBrie Hoffman

Technical support: (many)Technical support: (many) D.K.D.K.


TPC2 commissionedTPC2 commissioned

Constructed at Carleton University, operated at Constructed at Carleton University, operated at the University of Victoria with cosmic telescopethe University of Victoria with cosmic telescope


Data acquisitionData acquisition

Cross compiler built (Paul)Cross compiler built (Paul) can compile applications for STAR electronics on can compile applications for STAR electronics on

Linux, and load onto VxWorks platformLinux, and load onto VxWorks platform see see www.linearcollider.cawww.linearcollider.ca for information for information

New data acquisition program (Paul/Gabe)New data acquisition program (Paul/Gabe) data runs written to single filedata runs written to single file

contains header information for run/eventcontains header information for run/event

only channels connected to FEE cards writtenonly channels connected to FEE cards written ~10% deadtime loss for cosmics~10% deadtime loss for cosmics


Tracking with 6 STAR FEE cardsTracking with 6 STAR FEE cards


Tracking distortions foundTracking distortions found

Residual from track depends on track location:Residual from track depends on track location:

x coordinate (mm)

mea

n re

sidu

al f

or c

entr

e ro

w (

mm

)


TPC modificationTPC modification

End of drift volume had a wire mesh to terminate End of drift volume had a wire mesh to terminate cylindrical volume just in front of square GEMs: cylindrical volume just in front of square GEMs: source of field distortions?source of field distortions?

wire mesh

drift volume


TPC modificationTPC modification

New endpiece constructed:New endpiece constructed: 70 70 m wire strung with 2.5 mm spacingm wire strung with 2.5 mm spacing


Tracking distortions fixedTracking distortions fixed

With new end piece, problem is solvedWith new end piece, problem is solved

x coordinate (mm)

mea

n re

sidu

al f

or c

entr

e ro

w (

mm

)


Analysis codeAnalysis code

Track fitting now with curvatureTrack fitting now with curvature

data taken with no mesh:large field distortions!


Setup at TRIUMFSetup at TRIUMF


Example events at ~25 cm driftExample events at ~25 cm drift

0 Tesla 0.45 Tesla 0.9 Tesla

= 2.3 mm = 1.2 mm = 0.8 mm

Gas: P10


Diffusion measurementsDiffusion measurements

Transverse diffusion significantly reduced at Transverse diffusion significantly reduced at high B fieldshigh B fields

B = 0

B = 0.45 T

B = 0.9 T

3cm 30 cm

B (T)B (T) D D ((m/m/cm)cm)(Data)(Data)

D D ((m/m/cm)cm)(MC)(MC)

0.0. 498498 541541

0.450.45 221221 221221

0.90.9 134134 137137


Track resolutionTrack resolution

Fit track to all but one rowFit track to all but one row fix fix 00, 1/, 1/rr, and , and ,,

fit to one rowfit to one rowalonealone

compare compare xx00

from the two fitsfrom the two fits fit to Gaussianfit to Gaussian

3cm 30 cm

TDR spec.goal

B = 0

B = 0.45 T

B = 0.9 T


Resolution dependenciesResolution dependencies

No large dependencies No large dependencies on threshold or gainon threshold or gain

Track angle effect visibleTrack angle effect visible~ 2 primary

~ 1 primary

~ 5000

~ 2500

0 < < 0.05

0.05 < < 0.1


Comparison with MC simulationComparison with MC simulation

GoodGoodagreementagreement

MC truth info MC truth info confirms thatconfirms thatprocedure toprocedure tomeasure resolutionmeasure resolutionis sensibleis sensible


Induction signals visibleInduction signals visible

Pads next to those collecting electrons see Pads next to those collecting electrons see induced pulses (also seen in our x-ray test cell)induced pulses (also seen in our x-ray test cell)


Magnetic field distortionsMagnetic field distortions

Field not completely uniform within drift volume:Field not completely uniform within drift volume: cause ionization tracks to rotate in azimuthcause ionization tracks to rotate in azimuth


Magnetic field distortionsMagnetic field distortions

To check, use cosmic telescope to define a To check, use cosmic telescope to define a standard beamstandard beamof cosmicsof cosmics mean mean angle angle

changes inchanges inthe directionthe directionexpectedexpected


Plans for TPC2Plans for TPC2

With the successful TRIUMF magnet tests, we With the successful TRIUMF magnet tests, we will take the TPC to DESY for tests in their will take the TPC to DESY for tests in their superconducting magnet (up to 5 Tesla)superconducting magnet (up to 5 Tesla) starts next week!starts next week!

TPC R&D in Canada Dean Karlen / University of Victoria & TRIUMF Canadian LC-TPC Group: Carleton...

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