Development of ultrasensitive analytical techniques for the MAJORANA experiment

Dr. Galindo-Uribarri

Physics Division, Oak Ridge National Laboratory

Department of Physics and Astronomy

Department of Earth and Planetary Sciences

University of Tennessee

Tuesday, October 15, 2013

3:30 p.m., Room 104, Physics Building

Refreshments

3:15 p.m., Room 104

ABSTRACT: The Majorana experiment is a search for neutrinoless double-beta-decay, using HPGe detectors made from enriched 76Ge. This hypothesized, very rare process would demonstrate that the fundamental symmetry of lepton number is not conserved, and that the neutrino is its own antiparticle. The experiment requires unprecedented low backgrounds, obtained through ultra-clean copper that has been electroformed underground. The uranium and thorium levels in this copper are below the detection limits of existing assay techniques, but are one of the dominant sources of background in the experiment.

Our research involves using the highest operating voltage electrostatic accelerator in the world, the 25-MV Tandem from ORNL, as a prototype facility to aid in the development of new AMS methods [1,2]. These techniques will broaden the range of radionuclides that can be detected at ultra-low levels. The 25 MV Tandem at ORNL offers major advantages compared to lower voltage machines in the detection and characterization of many AMS isotopes. This ultra‐high sensitivity opens opportunities for applications in a variety of areas. I will describe the recent research activities at Oak Ridge National Laboratory with 26Al, 36Cl and the development of ultrasensitive assay of materials for underground physics experiments.