1112.1376 (D. S. Akerib et al.)

Radio-assay of Titanium samples for the LUX Experiment    [PDF]

D. S. Akerib, X. Bai, S. Bedikian, E. Bernard, A. Bernstein, A. Bradley, S. B. Cahn, M. C. Carmona-Benitez, D. Carr, J. J. Chapman, Y-D. Chan, K. Clark, T. Classen, T. Coffey, S. Dazeley, L. deViveiros, M. Dragowsky, E. Druszkiewicz, C. H. Faham, S. Fiorucci, R. J. Gaitskell, K. R. Gibson, C. Hall, M. Hanhardt, B. Holbrook, M. Ihm, R. G. Jacobsen, L. Kastens, K. Kazkaz, R. Lander, N. Larsen, C. Lee, D. Leonard, K. Lesko, A. Lyashenko, D. C. Malling, R. Mannino, D. McKinsey, D. Mei, J. Mock, M. Morii, H. Nelson, J. A. Nikkel, M. Pangilinan, P. D. Parker, P. Phelps, T. Shutt, W. Skulski, P. Sorensen, J. Spaans, T. Stiegler, R. Svoboda, A. Smith, M. Sweany, M. Szydagis, J. Thomson, M. Tripathi, J. R. Verbus, N. Walsh, R. Webb, J. T. White, M. Wlasenko, F. L. H. Wolfs, M. Woods, S. Uvarov, C. Zhang

We report on the screening of samples of titanium metal for their
radio-purity. The screening process described in this work led to the selection
of materials used in the construction of the cryostats for the Large
Underground Xenon (LUX) dark matter experiment. Our measurements establish
titanium as a highly desirable material for low background experiments
searching for rare events. The sample with the lowest total long-lived activity
was measured to contain <0.25 mBq/kg of U-238, <0.2 mBq/kg of Th-232, and <1.2
mBq/kg of K-40. Measurements of several samples also indicated the presence of
short-lived (84 day half life) Sc-46, likely produced cosmogenically via muon
initiated (n,p) reactions.

View original: http://arxiv.org/abs/1112.1376