Low Background Counting Facilities at Lawrence Berkeley National Laboratory Open to the Public & Open for Business Kevin Lesko S-1 Workshop Low Background Counting 1
Scope of Low Background Counting at LBL • Direct g-ray Counting of Materials • g-ray Counting of neutron-activated Materials Na. I and HPGe detectors • Surface Facility on LBL campus • Low Background, Well-shielded Facility ~180 m underground (water) at Oroville in Northern California Foothills Kevin Lesko S-1 Workshop Low Background Counting 2
Logistics • Sample size: ~ 2 kg to obtain highest sensitivity, smaller samples possible • Counting times: ~ 2 weeks for highest sensitivity, but generally activity dependent • Neutron activated samples require careful coordination in advance • Samples should, ideally, stack on/around detectors, some customizing is possible at LBL • Fed-ex works fine Kevin Lesko S-1 Workshop Low Background Counting 3
Facilities and Sensitivities • LBL (Building 72) Facility • Na. I and HPGe detectors • ≥ 1. 5 m low activity concrete • Used for initial screening, ~ ppb level U, Th, 1 ppm K, ~0. 05 p. Ci/Kg 60 Co Kevin Lesko S-1 Workshop Low Background Counting 4
• Oroville Facility • Housed in Powerhouse of the Oroville Dam ~ 180 mwe, low activity Pb and Cu shields, Radon flushed counting chambers. • HPGe detectors • Site of the UCSB-LBL 0 nbb experiment • ~ 50 to 100 ppt U, Th, 100 ppb K, 0. 005 p. Ci/Kg 60 Co Kevin Lesko S-1 Workshop Low Background Counting 5
Kevin Lesko S-1 Workshop Low Background Counting 6
Table of Low Background Counting Sensitivities at LBNL’s Two Facilities. Direct Counting Sensitivities Berkeley Site Oroville Site Uranium and Daughters 0. 5 ppb 50 ppt Thorium and Daughters 2. 0 ppb 200 ppt K 1. 0 ppm 100 ppb 60 Co 0. 04 p. Ci/Kg 0. 004 p. Ci/Kg • Sensitivities are currently limited by detector contamination. More depth is not essential. Kevin Lesko S-1 Workshop Low Background Counting 7
Survey of “Customers” • 25 years of experience and service to the Nuclear Physics, High Energy Physics, Non-accelerator Physics communities • “open” facility, and expandable to house additional detectors as demand warrants • UCSB-LBL 0 nbb experiment • Sudbury Neutrino Observatory: solar n • CDMS: Dark Matter • Kam. LAND: reactor n • Katrin: tritium beta decay • Majorana, CUORE: 0 nbb • Daya Bay: q 13 Kevin Lesko S-1 Workshop Low Background Counting 8
Contact Information • Staff: Kevin Lesko Al Smith Donna Hurley ktlesko@lbl. gov 510 -486 -7731 Kevin Lesko S-1 Workshop Low Background Counting 9
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