Heidelberg 2015 – wissenschaftliches Programm
UP 7.2: Hauptvortrag
Donnerstag, 26. März 2015, 11:30–12:00, C/gHS
Atom counting system to measure trace krypton contamination in ultra-pure xenon — •Andre Loose, Tanya Zelevinsky, and Elena Aprile — Columbia University, 550 W 120th Street, New York, NY 10027, USA
The Atom Trap Trace Analysis (ATTA) Project at Columbia University is an experiment designed to measure the abundance of Kr in a Xe sample to the parts per trillion (ppt) level. Setting an upper limit on the amount of Kr-85 present in natural Xe is critical for knowing the sensitivity of dark matter searches based on LXe as target and detector medium. In particular, the ATTA will be an essential assaying tool for the XENON program. We completed the full ATTA setup and it's characterization for metastable Ar-40* in Ar and Kr-84* in Xe. The abundance of Kr-85 will then be inferred using previously measured relative isotopic abundances. We designed and tested custom pipettes to avoid air contamination of samples during the transport from the XENON1T detector to our ATTA setup. We verified the system calibration by comparing ATTA and rare gas spectrometer measurements for the same sample, and conducted first ATTA measurements of ultra-pure Xe.