HE CALORIMETER DETECTOR UPGRADE R&D STATUS

E. A. Albayrak, HCAL Meeting, Fermilab, Nov. 2006

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HE CALORIMETER DETECTOR UPGRADE R&D STATUS

E. A. Albayrak

forThe University Of Iowa

Fairfield University

The University of Mississippi


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Outline

• The Problem, and proposed solution• Summary of the previous results

– Cerenkov light collection, uniformity, efficiency– Radiation hard quartz plates– Light enhancement option: P-Terphenyl (PTP)

• The recent R&D update- Quartz type, plate size, fiber geometry, wrapping material issues are settled. New

focus is to increase the light production, and solving fiber radiation problem. - We continue to Geant4 simulations on Quartz Plates. - In February 2006, Fermilab Test Beam: The tests of the new fiber geometry, PTP

light enhancement tests. - In May 2006, PTP radiation damage studies at IUCF (Indiana University

Cyclotron Facility). - Summer 2006 wrapping material reflectivity tests .- September 2006, Fermilab Test Beam: Zinc-Oxide, PTP, and Anthracene are

tested .


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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 solarization quartz plate.


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Pre2006 Conclusion

• Polymicro special production of “solarization quartz” is radiation hard.• Using different fiber geometries, making the quartz thicker (5-6mm), and smaller

(10cm x 10cm) increased our light collection up to 25% of the HE scintillator plate. For more light we should increase the amount of fiber in plate.

• We used plastic WLS fiber with 0.6mm diameter. We haven’t tried a radiation hard WLS fiber. With a bigger diameter we can increase the light collection.

• The initial simulations showed that light collection uniformity with respect to fiber geometry varies drastically. We should find more uniform fiber distribution.

• Tyvek is the best option to wrap the plates. It is easy to work, very good UV reflective material. Mylar disintegrates when it is in contact for a long time.

• PTP raddam tests are promising. If we can dope the plates or wrappers with PTP, we can increase the light collection. The bench tests verifies clear light production increase with PTP.

• The quartz capillaries and liquid WLS have been tested for Numerical Aperture and attenuation. The results are promising, need improvement on liquid filling techniques, quartz endplugs, and UV transparency.


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The “NEW” Geometry


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Quartz Plate Simulations

O-shape wls

Y-shape wls

S-shape wls

Bar-shape wls

We will run uniformity simulations and tests on the Bar geometry.


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February 2006 Test Beam

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Measurements

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• The bar geometry collected up to 50%-75% of the light original HE plate.• For 66 GeV beam, the cerenkov light collection efficiency drops w.r.t. scintillators.


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February 2006 Fermilab Test Beam Results with PTP

• Two GE quartz plates counter was tested with and without PTP.• The PTP was loaded on to the Tyvek wrapper.• 20% increase in light yield was observed.• We attribute this to the test beam pmt (R1398) It collected light in the visible range. • UV enhanced pmts will be used in the CERNTest beam 2006. Higher concentrations of PTP will be applied.

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0 0.01 0.02 0.03 0.04 0.05

Pterphenyl Coatings on 1/4" Quartz Plate

Np

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May 2006 PTP Raddam Tests

• PTP irradiated at Indiana University Cyclotron Facility, in May '06

• We reached 10 Mrad level with 200 MeV protons.

• Samples diluted in Toluene and subjected to C14 source. Counting rates measured vs concentration.


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LSC count of pure and radiated PT at low concentrations with C14 source

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concentration / saturation (%)

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purePTradPT

10 MRad 200 MeV protons

• Little damage observed when compared to unirradiated sample.

May 2006 PTP Raddam Tests


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Flourecence Spectrum of Pure and Radiated p-terphenyl280nm Excitation Wavelength

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wavelength (nm)

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radPT - Molecular damaged

PT Benzene RingEmission

purePT

Pterphenol Tests

• Fluorecence analysis performed. • Molecular damage observed shifting light from UV to visible!• Chemical Analysis of damage under investigation.• More Neutron, Proton irradiations

Pterphenol Tests


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Zinc Oxide Plate

Zinc Oxide Readout with Fibers

3 mm thick 6” x 6” Quartz Plate, coated with 9 micron of ZnO which is expected to yield about 300-400 photons

The WLS fibers placed on the upstream side, and the ZnO film is on the downstream side of the quartz plate, to reduce Cerenkov light captured in the WLS fibers

Sept 06, Fermilab Test Beam


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Zinc Oxide


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Anthracene and pTerphenyl films

• Formed from a melt squeezed between pieces of glass

• The thickness of the glasses 1” x 3” x 1/16 inch. • The films are estimated to be ~100 microns thick. • They are readout by 2 WLS • Fibers are placed upstream. • The anthracene has a higher response, estimated to

be about 2-3 pe, vs 1-2 pe for the pTP.


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Anthracene


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pTP


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Reflection studies

Measurement of the reflective properties of different samples of Mylar, HEM,

Tyvek and Aluminum foil. • Each sample was mounted on a ring and

placed at the end of a light guide. • A PMT was mounted at the other end of

the PMT to measure light reflected back up the light guide.

• An optical fiber carried light into the light guide and bounce it off the reflective surface back to the PMT.

• Levels were measured and compared for each substance.

• A PMT was mounted behind the reflective sample to collect any light that may pass through the sample.

• A 337nm Nitrogen LASER was used .


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Reflection studies

Name Thickness (in) Comment: Al 0.0010 Opaque to room light; Shiny and Dull side

HEM 0.0019 Transparent to room light; shiny (white) and dull (dark side)

M1 0.0011 Opaque to room light; shiny (white) and dull (dark) side

M2 0.0010 Transparent to room light; shiny (white) and dull (dark) side

M3 0.0009 Opaque to room light; shiny (white) and dull (dark) side

M4 0.0010 Transparent to room light; shiny (white) and dull (dark) side

T1 0.0138 Opaque to room light; black on one side;

T2 0.0041 Translucent; Shiny and dull side


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Reflection studies

Reflection Test

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m1_s m1_d m2_s m2_d m3_s m3_d m4_s m4_d HEM_s HEM_d al_s al_d t1_s t1_d t2_s t2_d

Material

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arg

e (

pC

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The Future Plans

• The “generation 1” Quartz Plate Calorimeter prototype is being build with the “NEW” fiber geometry, based on the information we collected during these R&D studies.

• We have focused on light collection technique. We started from 1% photon production ratio with respect to the original HE scintillators. At the latest design we increased the cerenkov signal from a quartz plate to almost 75% of the original HE scintillator. We will run uniformity simulations and tests at different wavelengths.

• The parallel studies performed by Missisippi and Fairfield has increased the options we can use on future generations of the Quartz Plate Calorimeter Prototypes.

• PTP can be used to increase the light 20% more, contingent to the radiation hardness tests.

• We have not addressed to the radiation hardness of the wavelength shifting fiber, yet. The preliminary plan is to carry the cerenkov photons with quartz fibers and shift it before the light detector (PMT or HPD) via liquid wavelength shifter.

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HE CALORIMETER DETECTOR UPGRADE R&D STATUS