HE CALORIMETER DETECTOR UPGRADE R

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HE CALORIMETER DETECTOR UPGRADE RD

• Y. Onel
• for
• University of Iowa
• Fairfield University
• Fermilab
• University of Mississippi

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Outline

• Introduction
• Results from Quartz Plate Calorimeter Prototype
  I
• Geant4 Simulations, and Test Beam Results
• New direction for the QPCAL-II
• Light enhancement options
• Test Beam Results from P-Terphenyl (PTP), ZnO
  deposited plates
• PTP-RTV test results
• New materials o-PT, m-PT, EJ-289
• Fiber-less readout options
• PIN Diode, APD, SiPMT, MPPC readouts.

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The Problem and the Solution

• As a solution to the radiation damage problem in
  SuperLHC conditions, quartz plates are proposed
  as a substitute for the scintillators at the
  Hadronic Endcap (HE) calorimeter.
• Quartz plates will not be affected by high
  radiation. But the number of generated cerenkov
  photons are at the level of 1 of the
  scintillators.
• Rad-hard quartz
• Quartz in the form of fiber are
• irradiated in Argonne IPNS for 313 hours.
• The fibers were tested for optical degradation
• before and after 17.6 Mrad of neutron and
• 73.5 Mrad of gamma radiation.
• Polymicro manufactured a special
• radiation hard anti solarization quartz plate.

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QPCAL-I Design and Construction

• RD results and the initial model shaped the
  prototype. The CMS NOTE 2007/019
• summarizing the RD studies is published.
• The manuscript is submitted to IEEE TNS.
• The final design
• 20cm x 20cm, 20 layers, 70 mm iron,
• 5 mm thick quartz grooved.
• It is portable for tests at CERN, Fermilab,
• and Iowa.
• The signal is read by Hamamatsu R7525 PMTs.
• The fibers are 1mm diameter Saint Gobain
• wavelength shifting fibers. They absorb photons
• down to 280 nm, and emit 435 nm.
• The fibers go 20 cm out of the quartz.

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QPCAL-I Plate Frames
Fibers

• The quartz plates are put into an aluminum
  frame.
• All quartz plates with fibers are wrapped with
• Tyvek and black tape.
• Then they are put into a frame, and
• wrapped again to make them light-tight.

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QPCAL-I Design Details

• Alternating PMT positions allow the plates to be
  tested with less iron between them. For the
  electron beam we set the absorber thickness to 2
  cm.
• 1 cm iron plates are purchased for use at CERN
  for electron beams.
• We put absorbers and plates on a rail for
  flexible positioning.

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QPCAL-I Design Details

• During the RD studies, we developed our own DAQ
  with NIM, CAMAC and LabView. But it is not fast
  enough for the 30 channels of the prototype. New
  DAQ is built with VME units.
• We built 3 Ten Channel Amplifiers
• Gain 30 dB (32 times)
• Rise Time lt 2 nsec
• Fall Time lt 2 nsec
• Noise Figure 3 dB ( 10uV)
• Bandwidth 500 MHz
• Input SWR 21 (0 200 MHz)
• Output SWR lt 21 (0 500 MHz)
• Maximum Output 2 volt peak
• Isolation gt 80 dB (0 500 MHz) between any two
  channels

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QPCAL-I Geant4 Simulation Model
We modeled the prototype with Geant4. The
simulation efforts keep developing. We simulate
the test beams and possible design changes.
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QPCAL-I Geant4 Simulations
Geant4 simulations of 100 GeV electron shower
profile and signal distribution on PMT
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QPCAL-I Geant4 Simulations
Geant4 simulations of 150 GeV pion shower
profile and signal distribution on PMT
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CERN Test Beam QPCAL-I

• - Movable table was used for the setup. It
  allowed
• us to do surface scan at 100 GeV electron and
• 80 GeV pion beams.
• - We got electron beam at 20, 50, 80, 100 GeV.
• Pion beam at 20, 50, 80, 100, 150, 200, 300,
• and 350 GeV.

• At CERN we used 2 cm thickness of iron absorber
  for the electron beam.
• 7 cm of absorber is used for Pion beam

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QPCAL-I Electron Response
Electron Response Profiles for Quartz.
Preliminary
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QPCAL-I Surface Uniformity
Preliminary
QPCAL I is designed to have superior surface
response uniformity. Beam size and leaking
shower creates non-uniformities.
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QPCAL-I Pion Response
QPCAL-1 has very good hadronic resolution, for
comparison purposes we include ZDC signal For
the same energy.
50 GeV Pion
Preliminary
QPCAL-1
300 GeV Pion
ZDC-HADRONIC Response for 300 GeV Pion
O.Grachov et al.
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QPCAL-I Response Linearity
Hadronic Response Linearity
Preliminary
Elecromagnetic Response Linearity
Preliminary
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QPCAL-I Energy Resolutions
Hadronic Resolution
Preliminary
Electromagnetic Resolution
Preliminary
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New Directions

• QPCAL-I analysis, and simulations are about to
  finish, we are preparing the CMS NOTE. QPCAL-1
  also has 10 scintillator plates on every other
  layers, this hybrid structure can improve the
  detector capabilities even more. We have not
  shown any scintillator result on this talk.
• QPCAL-1 proved that quartz plate cerenkov
  calorimeter is a very good candidate to replace
  HE calorimeter during SLHC era. Now, we are
  focused on eliminating WLS fibers and Hamamatsu
  PMTs from the design, this will be done by
• Increase the light yield with radiation hard
  scintillating/WLS materials PTP, PTP and RTV615
  mix, o-TP, m-TP, and ZnO. RTV 615 which is a 2
  component UV clear silastic-type epoxy.
• Readout will be done directly from the plate via
  APD, SiPMT, PIN DIODE, and MPPC.
• During the previous RD studies we have tested
  PTP for radiation hardness. During the
  preliminary tests we observed up to 40 light
  improvement with ZnO and PTP.

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LIGHT ENHANCEMENT w P-Terphenyl
Earlier studies showed that pTp crystalline
powder added to the top of a quartz plate could
enhance the light output by scintillation
mechanism. A linear response was measured up to
about 5g pTp/100cm2 in to a bialkali PMT. pTp
was known to be radiation resistant, so we are
optimistic it can used to enhance light output.

• pTp powder on 1/4" quartz plate.
• Sr-90 Measurements take directly in to a bialkali
  PMT.
• Linearity with pTp thickness seems okay.
• 1.5g/100cm2 corresponds to a 6/2 x3 gain

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pTp/RTV COOKIE STUDIES
RTV 615 silastic has good transmission in the
UV and radiation resistant - M.Atac. pTp can be
mixed to high densities gt5mg / 100cm2. Blue WLS
fibers embedded in the RTV can collect the light
efficiently. 10cm x 10cm x 2mm RTVpTp Cookie
with 1.5g, 3.0g, per 100cm2 are being studied.
10cm x 10cm x 2mm RTVpTp Cookie with 1.5g/100cm2
pTp.
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PTP RTV Tests

• 3.0 g/ 100cm2 cookie prepared in vacuum chamber

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PTP RTV Tests

• Fiber light collection efficiency low in single
  particle tests. Sr-90, Cosmics.
• Typical 1-photon peak observed with Sr-90
  source.

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• Surface scan of 1.5g and 3.0g 10cmx10cmx2mm
  silastic panell.
• Some uniformity problems under study.
• Significant gain in light yield between 1.5g pTp
  and 3.0g pTp.

3.0 pTp
1.5 pTp
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PTP RTV Tests
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PTP RTV Tests
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Quartz Plates with ZnO and PTP

• At Fermilab Lab7, we have covered 3 quartz plates
  with PTP by evaporation.
• We also cover 2 quartz plates with ZnO (3 Ga
  doped), by RF sputtering. 0.3 micron and 1.5
  micron.

Fermilab Lab7, thin film sputtering system and
guns.
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CERN Test Beam Aug 2007
We have opportunity to test our ZnO and PTP
covered plates, as well as APD readout option at
Cern test beam this August.
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MIPs from ZnO,PTP,plain quartz50 GeV Pion beam,
(50k events each run)
Mips from plain quartz plate.
Mips from PTP evaporated quartz plate.
Mips from 0.3 micron thick ZnO (3 Ga) sputtered
quartz plate.
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PTP and ZnO improvement

• We have measured the mips from ZnO, PTP, and
  plain quartz plates.
• Same PMT and 50 GeV Pions are used. 50k events
  for each run.
• ZnO and PTP covered plates increase the
  probability of creating mipp drastically.
• Multi photoelectron events increase considerably
  as well.

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2 APD READOUT OPTION
We have tested ECAL APDs as a readout option. 2
APD connected to plain quartz Plate yields
almost 4 times less light than fiberPMT
combination. We can solve this problem with
PTP/ZnO, and using few more APDs.
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NEW READOUT OPTIONS
We have 5 Hamamatsu S8141 APDs (CMS ECAL
APDs) ready to be used. The circuits have been
build at Iowa. These APDs are known to be
radiation hard. (NIMA 504, 44-47 (2003) We have
also purchased 2 other type of Hamamatsu APDs
S5343, and S8664-10K
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NEW READOUT OPTIONS

• We have purchased 2 types of PIN-Diodes
  Hamamatsu S5973 and S5973-02.
• They are gettng ready to be tested this summer.
• We are also trying to acquire SiPMTs.
• Compared to the others, the SiPMTs have
• lower noise level.
• For all of these readout options we designed
  different
• amplifier approaches
• 50 Ohm amplifier.
• Transimpedance amplifier.
• Charge amplifier.

50 Ohm Amplifier circuit design.
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NEW READOUT OPTIONS
The speed of the readout is essential. The pulse
width of the optical pulses from the
scintillator limits the selection of photodiode
or APD used. A bandwidth of 175 MHz is
equivalent to a rise and fall time of 1.75 nsec.

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Hamamasu MPPCs

• We have also purchased 2 silicon photodiodes
  from Hamamatsu.
• These units have 250ps time resolution
  (extremely fast), and 2.8x105 gain.
• They can read from 270nm to 900nm.
• These units are being prepared to be tested at
  Halloween Fermilab Test Beam

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EJ-298 waveshifting paint

• These paints consist of a polyvinyltoluene (PVT)
  binder and fluorescent dopants dissolved in a
  xylene solvent.
• EJ-298-A excitation range 320nm 370nm  
• EJ-298-B excitation range 300nm 370nm  
• EJ-298-C excitation range 270nm 370nm
• The paints may be applied to clean glass plates
  by brushing or by a draw-bar technique to produce
  a clear film.
• Well test EJ-298-C for light production and
  radiation hardness.

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Iowa Evaporation Chamber

• This summer we have made our old evaporation
  system work in Iowa, Lab7 fees are too expensive,
  well evaporate PTP, o-TP, and m-TP on quartz
  plates with different thicknesses.
• These plates will be tested at Fermilab Oct07.
• Afterwards they will be irradiated at Argonne for
  25MRad, and retested to see radiation hardness of
  these materials.

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CONCLUSION

• We have so fa done extensive RD studies on
  efficient cerenkov light collection from
• quartz plates using WLS fibers. These efforts
  have been summarized in CMS Note 2007/019
• and manuscript is submitted to IEEE TNS.
• The QPCAL-I prototype has been tested at CERN,
  and shows very good potential as a
• Hadronic, and Electromagnetic calorimeter. The
  detailed analysis report is almost ready to be
• submitted as a CMS Note.
• Now, we are focused on eliminating the WLS fibers
  and current PMTs from the design,
• and implementing light enhancement tools, as well
  as on plate readout. August 2007 Cern
• Test Beam yield very encouraging results on light
  enhancement by using PTP and ZnO
• deposited plates.
• Fiber-less readout options are investigated. PIN
  diodes, APDs, MPPCs, and SiPMTs are
• going to be evaluated as readout devices on
  Halloween 2007 Fermilab Testbeam.
• The QPCAL-II is going to be built in light of
  these studies.

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Backup Slides
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PPP-1 Resolution Plots