KEK test beam KEKPS T585

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KEK test beam- KEK-PS T585 -

• M. Yoshida
• MICE CM _at_Osaka
• 2006/3/1

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Contents

• Introduction to KEK-PS T585
• Review of problems, focused on the tracker system

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Tracker prototype test in KEKKEK-PS T585

• Prototype SciFi tracker was tested to check basic
  performance in 1 Tesla solenoid magnet.
• KEK-PS T585 was performed in Sept. Oct. 2005 by
  world-wide collaboration.
• More than 20 people joined.

KEK-PS p2 beamline
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4-Station Tracker Prototype
Old waveguide 400cm
External waveguide 400cm
VLPC 2 cassette 2048 ch
internal waveguide 120cm
BEAM
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TOF hodoscope

• 2.5inch finemesh PMT (R6504S)
• Light guide
• Scintillater

55 hodoscope (2cm thick 2cm thick)
PMT A
53 cm
TOF 6?10
40 cm
PMT A
PMT B
PMT B
2005.9.26
TOF 1 ?5
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Experimental Setup
TOF hodoscope
ACC
8.5m
T1
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DATA Set

• VLPC LED calibration
• Beam survey
• High momentum beam
• 3 GeV/c
• p-
• Solenoid OFF
• check alignment, light yield, noise and so on.
• Low momentum beam
• 0.25, 0.325, 0.4 GeV/c
• m-, p-, e-
• Solenoid ON
• Rotation
• 3 deg. / 6 deg.

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Integration

• Tracker did not fit into the solenoid bore and
  TOF hodoscope plane
• mis-communication on design work
• Extracted waveguides from the opposite side
  (smaller bore)
• caused tracker located off-center, and slightly
  poor uniformity of magnetic field
• Tracker frame has dwell pins made of iron.
• Left them on the frame. It was estimated to be
  safe in 1T

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VLPC cryostat

• High room temperature seemed to spoil the
  performance of air-cooled compressor of cyocooler
• Added spot-cooler
• Moisture on lid due to high humidity
• Temperature setting of heater on lid changed to
  be as higher as possible
• Too high magnetic field for vacuum pump attached
  on cryostat
• Moved pumps 2-meter away from the cryostat

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VLPC readout

• The readout system with AVNET, Clock Gen. and AFE
  is too complicated for non-AFE-experts.
• We spent 4 days to set timing for LED and beam
  trigger
• We needed to scan trigger timing fed to AFE using
  beam particles.
• Tuning procedure should be well documented for
  non-experts.

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VLPC gain calibration

• Gain is estimated using LED data
• One VLPC cassette shows excellent performance,
  the other has too low gain to see photon peaks
• Assumed gain of 8 ADC-counts / p.e.

AFE board 107 MCM 1 Channel 1
8 cnts/p.e.
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Fiber mapping

• We have no logs to show the connections between
  the 4th station and waveguides.
• Constructed yellow-room besides experimental
  area, and opened the tracker cylinder to check
  the connection by eyes.
• There still remained confusion on mapping
• Investigate by using straight tracks of high
  momentum beam

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Light yield

• Light yields in 4th station (Station D) is much
  less than expectation.
• Investigation will be reported
• Have to feedback to mass-production.

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Summary

• In KEK test-beam, we obtained much experience on
  construction and operation of the tracker, to be
  feedback to full tracker production.
• Integration
• Cryostat
• Readout
• Calibration
• Mapping
• Analyses in details using beam data will be
  reported in subsequent talks.