1. 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

2. 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 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 D. C. Cox, A. Green, H.-O. Meyer, R. Tayloe Indiana University, Bloomington, IN 47405 E. D. Zimmerman University of Colorado, Boulder, CO 80309 R. Imlay, A. Malik, W. Metcalf, M. Sung, M. O. Wascko Louisiana State University, Baton Rouge, LA 70803 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 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 P. J. Nienaber College of the Holy Cross, Worcester, MA 01610

3. J. L. Raaf, IEEE NSS Conference, November 8, 2001 3 The MiniBooNE Detector Two stage experiment currently under construction at Fermilab –Designed to search for neutrino oscillations Oil Čerenkov detector –12 m diameter carbon steel sphere –250,000 gallons of mineral oil –1280 photomultiplier tubes (PMTs) detect scintillation and Čerenkov light Mini Booster Neutrino Experiment

4. J. L. Raaf, IEEE NSS Conference, November 8, 2001 4 MiniBooNE Event Signatures Čerenkov light: prompt and forming rings Scintillation light: late and isotropically distributed

5. J. L. Raaf, IEEE NSS Conference, November 8, 2001 5 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

6. J. L. Raaf, IEEE NSS Conference, November 8, 2001 6 Monochromator Deuterium light source Reference PMT Test PMT Oil sample 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 Reference light at that wavelength Light transmitted through oilTest PMT Reference PMT = Cincinnati Attenuation Tester (EMI 9813)

7. J. L. Raaf, IEEE NSS Conference, November 8, 2001 7 Cincinnati Tester Results Reproducibility of runs Ten oils tested very different shapes very different absorption features

8. J. L. Raaf, IEEE NSS Conference, November 8, 2001 8 Alabama Attenuation Tester Blue LED 460 nm Collimator Lens Stainless steel pipe XP2264B PMT Beaker Valve Lexan Fluid Level Indicator 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%.

9. J. L. Raaf, IEEE NSS Conference, November 8, 2001 9 Alabama Tester Results Oil SampleAtten. Length (m) FITDate tested Telura 6222.21 ± 0.019/6 Superla 79.84 ± 0.099/4 Witco10.79 ± 0.118/31 Duoprime 90-212.76 ± 0.149/4 Duoprime 7013.96 ± 0.169/5 Duoprime 90-114.33 ± 0.198/31 Marcol 1014.52 ± 0.189/12 Parol 80 HP-C15.41 ± 0.219/5 Marcol 923.65 ± 0.469/5 Marcol 726.45 ± 0.599/6

10. J. L. Raaf, IEEE NSS Conference, November 8, 2001 10 Index of Refraction Measurements Mercury line source Spectrometer table Equilateral Plexiglas container Container rotated on table until minimum deflection observed Index of refraction measured for six lines of the mercury spectrum Indices of refraction are fit to a “one resonance” model for dense media

11. J. L. Raaf, IEEE NSS Conference, November 8, 2001 11 Density and Index of Refraction Density and index of refraction directly related

12. J. L. Raaf, IEEE NSS Conference, November 8, 2001 12 Fluorescence Test Fluorescence tests performed on 3 cm 3 volume sample of oil to check for unusual features All oils tested were “normal”

13. J. L. Raaf, IEEE NSS Conference, November 8, 2001 13 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

14. J. L. Raaf, IEEE NSS Conference, November 8, 2001 14 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