Mineral Oil Tests for the MiniBooNE Detector

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Mineral Oil Tests for the MiniBooNE Detector
Jennifer L. Raaf University of Cincinnati November
8, 2001

• Overview of MiniBooNE Experiment
• Detector
• Event Signatures
• Attenuation Tests
• Cincinnati Tester
• Alabama Tester
• Index of Refraction Measurements
• Fluorescence Test
• Other Oil Tests
• Summary

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The MiniBooNE Collaboration
I. Stancu University of Alabama, Tuscaloosa, AL
35487
S. Koutsoliotas Bucknell University, Lewisburg,
PA 17837
E. Church, G. J. VanDalen University of
California, Riverside, CA 92521
E. Hawker, R. A. Johnson, J. L. Raaf, N.
Suwonjandee University of Cincinnati, Cincinnati,
OH 45221
E. D. Zimmerman University of Colorado, Boulder,
CO 80309
L. Bugel, J. M. Conrad, J. Formaggio, J. M. Link,
J. Monroe, M. H. Shaevitz, M. Sorel, G. P.
Zeller Columbia University, Nevis Labs,
Irvington, NY 10533
D. Smith Embry Riddle Aeronautical University,
Prescott, AZ 86301
C. Bhat, S. J. Brice, B. C. Brown, B. T. Fleming,
R. Ford, F. G. Garcia, P. Kasper, T. Kobilarcik,
I. Kourbanis, A. Malensek, W. Marsh, P. Martin,
F. Mills, C. Moore, E. Prebys, A. Russell, P.
Spentzouris, R. Stefanski, T. Williams Fermi
National Accelerator Laboratory, Batavia, IL 60510
P. J. Nienaber College of the Holy Cross,
Worcester, MA 01610
D. C. Cox, A. Green, H.-O. Meyer, R.
Tayloe Indiana University, Bloomington, IN 47405
G. T. Garvey, W. C. Louis, G. B. Mills, V.
Sandberg, B. Sapp, R. Schirato, R. Van de Water,
D. H. White Los Alamos National Laboratory, Los
Alamos, NM 87545
R. Imlay, A. Malik, W. Metcalf, M. Sung, M. O.
Wascko Louisiana State University, Baton Rouge,
LA 70803
J. Cao, B. P. Roe University of Michigan, Ann
Arbor, MI 48109
A. O. Bazarko, P. D. Meyers, R. B. Patterson, F.
C. Shoemaker Princeton University, Princeton, NJ
08544
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The MiniBooNE Detector
Mini Booster Neutrino Experiment

• Two stage experiment currently under construction
  at Fermilab
• Designed to search for neutrino oscillations
• Oil Cerenkov detector
• 12 m diameter carbon steel sphere
• 250,000 gallons of mineral oil
• 1280 photomultiplier tubes (PMTs) detect
  scintillation
• and Cerenkov light

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MiniBooNE Event Signatures
Cerenkov light prompt and forming rings
Scintillation light late and
isotropically distributed
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Why Mineral Oil?

• No expensive filtration system needed as with
  water detectors
• Density provides more targets for neutrino
  interactions

Several important tests were performed to aid in
the decision of which oil to use

• Attenuation length
• Density
• Index of refraction and dispersion
• Fluorescence

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Cincinnati Attenuation Tester
Reference PMT
(EMI 9813)
Monochromator
Test PMT
(EMI 9813)
Oil sample
Deuterium light source

• Data taken are the ratio of
• Test range is 3000-5000 Å in steps of 10 Å
• 90 of the light travels through oil sample
• 10 light travels to reference PMT
• Setup provides relative attenuation length of
  different oils and shape of transmission curve

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Cincinnati Tester Results
Reproducibility of runs

• Ten oils tested
• very different
• shapes
• very different
• absorption
• features

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Alabama Attenuation Tester

• Attenuation length determined by
• measuring intensity of blue light
• as a function of path length in oil
• Goal measure attenuation lengths
• as large as 20 m with an error better
• than 2.5 m.
• Since this tester has only a
• 1 m path length, must measure
• light intensity with an accuracy
• of better than 1.

Blue LED 460 nm
Collimator Lens
Lexan Fluid Level Indicator
Stainless steel pipe
WALL
Valve
Beaker
XP2264B PMT
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Alabama Tester Results
Oil Sample Atten. Length (m) FIT Date tested
Telura 622 2.21 0.01 9/6
Superla 7 9.84 0.09 9/4
Witco 10.79 0.11 8/31
Duoprime 90-2 12.76 0.14 9/4
Duoprime 70 13.96 0.16 9/5
Duoprime 90-1 14.33 0.19 8/31
Marcol 10 14.52 0.18 9/12
Parol 80 HP-C 15.41 0.21 9/5
Marcol 9 23.65 0.46 9/5
Marcol 7 26.45 0.59 9/6
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Index of Refraction Measurements
Mercury line source

• Container rotated on table until
• minimum deflection observed
• Index of refraction measured
• for six lines of the mercury
• spectrum

Spectrometer table
Equilateral Plexiglas container

• Indices of refraction are fit to a one
  resonance model
• for dense media

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Density and Index of Refraction

• Density and index of refraction directly
• related

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Fluorescence Test

• Fluorescence tests performed on 3 cm3
• volume sample of oil to check for unusual
• features
• All oils tested were normal

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Other Oil Tests

• Two different scintillation tests in progress
• Needed to understand inherent
• scintillation properties of chosen oil
• May add organic scintillator to chosen
• oil at a later date
• Allows for controlled amount of
• scintillation light
• Ensures known value of scintillation
• timing for use in event reconstruction

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Summary

• Several factors played into the decision
• of an oil for the detector
• Attenuation length
• Index of refraction and density
• Fluorescence
• Need to understand other properties of
• the chosen oil
• Scintillation
• Important to understand the properties
• of the chosen mineral oil very well to
• aid in event reconstruction