Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4....

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Cosmic Ray Test of GEM- Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005

Transcript of Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4....

Page 1: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

Cosmic Ray Test of Cosmic Ray Test of GEM-MPI/TPC in Magnetic FieldGEM-MPI/TPC in Magnetic Field

Hiroshima UniversityKuroiwa

CDC Group

Mar. 4. 2005

Page 2: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

MPGD-Readout TPCMPGD-Readout TPC TPC

– MWPC (Multi Wire Proportional Chamber) readout Two-track separation capability > 1cm

– MPGD (Micro Pattern Gas Detector) readout GEM , MicroMEGAS

Performance test of GEM-TPC by cosmic ray

Requirement

Spatial resolution

σx < 150μmσz < 1mm

Two-track sep.

Δ2hit < 2mm

Page 3: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

GEM as the Readout MPGDGEM as the Readout MPGD Almost no E×B effects ⇒ good spatial

resolution Fast and spatially narrow induced signals ⇒ good two-track separation No wire ⇒ thin sector boundaries Suppression of positive ion feedback

Page 4: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

GEM-MPI/TPCGEM-MPI/TPC MPI/TPC

– Field cage : Maximum drift length = 27cm– Pad plane : 10cm×10cm– Gas : TDR (Ar : CH4 : CO2 = 93 : 5 : 2)– Readout : MWPC ⇒ GEM

Page 5: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

GEM-MPI/TPCGEM-MPI/TPC GEM

– 10cm×10cm– Cu electrodes 5μm thick– Bi-conical holes due to chemical etching (CERN)– 3 GEM plane– VGEM : 320V

Page 6: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

GEM-MPI/TPCGEM-MPI/TPC Pad

– Pad plane : 12×64 pads cover 10cm×10cm– Pad size : 2mm×6mm (0.3mm gap)– Readout channels : 7 pad rows×12 pads

6mm

2mm

0.3mm0.3mm

Page 7: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

Experimental SetupExperimental Setup Setup

– Trigger : scintillation counter×3 , 10×27cm– E-field : 300V/cm– B-field : 1T– VGEM : 320V

– Gas : TDR

Page 8: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

ResultResult X resolution (Row 1)

nominal residual (σn.r.) from track without self info

Row 1 has the worst tracking error in all rowsgeometric meanσ = sqrt(σn.r.・ σfull) σfull : from track with self info

Page 9: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

ResultResult X resolution (Row 6)

nominal residual tracking error is small in the middle row

geometric mean σ shows almost same behavior as the row 1

Effect of large-pad size

Page 10: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

Pad SizePad Size

Change the pad width

Pad width : 2mm Pad width : 1mmproduced by the end of March

Beam test at KEK-PS in April and June

Page 11: Cosmic Ray Test of GEM- MPI/TPC in Magnetic Field Hiroshima University Kuroiwa CDC Group Mar. 4. 2005.

Summary and PlanSummary and Plan Summary

– Geometric mean of row 1 and row 6 show almost same behavior.

– Effect of large-pad size

Plan– 1mm pad– Cosmic ray test– Beam test at KEK-PS in April and June

GEM , MicroMEGAS