CEX beam test at piE1 Satoshi Mihara

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CEX beam test at piE1Satoshi Mihara
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Elementary process
M?/2
? - (essentially) at rest captured on protons ?
- p ? ?0 n ? - p ? n ? ?0 ? ? ?
Eg55 MeV ? ? ?
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Angular selection
p-p?p0n p0(28MeV/c) ? g g 54.9 MeV lt E(g) lt
82.9 MeV

• Requiring qgt170o
• FWHM 1.3 MeV
• Requiring q gt 175o
• FWHM 0.3 MeV

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Overview of the beam test
22/Sep
29/Sep
6/Oct
13/Oct
20/Oct
27/Oct
3/Nov
10/Nov
17/Nov
24/Nov
1/Dec
8/Dec
pumping

• 25/Sep Detector was moved to the area. evacuation
• 27/Sep- Beam tuning
• 29/Sep pre-cooling
• 2/Oct-5/Oct Liquefaction
• 5/Oct-29/Oct Purification(gas phase)
• 5/Oct- Electronics setup
• 15/Oct p0 detected
• 24/Oct empty target run
• 1/Dec PMT amplifier study
• 6/Dec Recovery
• 7/Dec Cold xenon gas data for PMT calibration

Cooling/liquefaction
Beam tuning
p0 detected
purification
DAQ 7weeks
Recovery
Cold xenon gas data
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pE1 beam line

• Beam line
• Magic momentum (110MeV/c)
• FSH52, 4mm carbon degrader (110?107MeV/c) in
  ASY51
• 26mm carbon degrader in front of the target
• S1 counter (40x40x5mm3) to define the beam
• Area layout
• The Electronics barrack placed in the area with
  concrete shielding around it.
• All controls and monitors done in the barrack.
• Liquid nitrogen supplied from a dewar located in
  the area.

ASY51
Proton beam
Target
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Setup
Carbon degrader
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Hydrogen Target
g

• Thanks to Dr. J. Zmeskal.
• Liquid H2 cooled with a GM-refrigerator
• Temperature control
• Target cell
• 0.5mm t Al
• 40mm d x 100 L
• 125cc liquid hydrogen
• Kapton foil
• p entrance
• g exit

p
g
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NaI detector
Crystal Array

• For tagging g at the opposite side of LP
• 8x8 NaI crystals
• 40.6x6.3x6.3cm3
• Located 110cm from the target
• Signal processor and Trigger Box (QUAD module) to
  provide trigger signal

Trigger module
HV
Differentiator, Attenuator and base line
stabilizer
Output stage
Differential input stage
ADC
Attenuator
Trigger Box
x10
x10
Base Line Stabilizer
TDC
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Timing Counter

• 2 layers of
• 5cm x 5cm x 1cm BC404
• Hamamatsu R5505 at both ends
• 3mm t Pb plate
• 40 efficiency for 83MeV g
• Time resolution can be estimated internally.

5cm x 5cm x 1cm t BC404
R5505
S1
NaI
LP
100mm f Lead collimator
g
g
TC
tLP - tTC
TC
Viewed from the target
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Xenon Large Prototypeoperating condition

• Xenon extracted from the chamber is purified by
  passing through the getter.
• Purified xenon is returned to the chamber and
  liquefied again.
• Circulation speed 5-6cc/minute

• Gain/QE calibration
• LED and a as usual
• Absorption length after 2 weeks purification
• labs gt 140cm (90 C.L.)
• (central value 2.7m)

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Data Acquisition

• Hardware setup
• ADC 3 ranges for front-face PMTs
• TDC for all PMTs
• PMT amplifier (x10)
• BINP
• Lecce
• Software
• Online MIDAS
• Slow control (MSCBLabView)
• Refrigerator control, Temp., Pressure Monitor
• Data set
• Collimators in front of LP and NaI (gg back to
  back)
• Timing Counter (PbScintillator) in front of NaI

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Trigger

• back-to-back gg data
• NaI sum signal of the central 4 crystals
• LP sum signal of
• 8 PMTs on the front face 4 PMTs on the back
  face
• gg data with opening angle lt 180o
• NaI QUAD module
• Very low threshold trigger for LP
• One or two hit(s) in any one of 8 clusters
• a, LED, cosmic-ray, pedestal triggers for
  calibration

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Beam Condition
target

• p(p-)107MeV/c
• Almost maximum separation (8nsec) of arrival time
  to the target between p and m, and between p and
  e.
• Beam intensity
• Up to 2.6 MHz _at_ 1800mA
• Electron contamination in the beam
• Negligible in triggered events

sx12mm
sy12mm
8nsec
m
e
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p0 signal example
LP 55 MeV g NaI 83 MeV g
NaI ADC
LP 83 MeV g NaI 55 MeV g
LP ADC
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Background Condition

• Beam on/off
• PMT output for a events changes, reduced to 70
  of normal values
• Not due to bleeder current because we can see the
  effect even with lower PMT gain.
• Background events
• most probably caused by beam-related neutrons,
• Energy deposit up to 9-10MeV
• Corresponding to 1.5x106 pe/sec cause this
  deterioration.

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• CEX beam test
• NaI analysis ? Toshiyuki
• Xenon Large Prototype Analysis ? Ryu, Fabrizio,
  and
• Stability monitor ?
• PMT studies ? Yasuko and Alessandro
• TERAS beam test
• TERAS analysis Update ? Kenji
• Final Detector
• Cryostat ? Fabrizio R.
• Refrigerator ? Tom
• Liquid phase purification ? Satoshi