Vic Gehman Central


Friends, colleagues, family. Lend me your eyeballs... Greetings all. As you might have heard from me, I've set up this web site.  This is my attempt to maintain a reasonable web presence now that UW has terminated my web space on their servers. In the next few days, I hope to add things like my photo album to this site. Stay tuned for updates on all things well... Me.


My research includes searches neutrino mass using neutrinoless double-beta decay and for the direct laboratory detection of dark matter.  Specifically, this has entailed work on the MAJORANA neutrinoless double-beta decay experiment, and the CLEAN/DEAP dark matter search.


MAJORANA is a planned experiment looking for neutrinoless double-beta decay in 76Ge.  I worked on MAJORANA for my doctoral thesis, and have continued to do so as a postdoc and now as a grown up staff scientist.  For my doctoral work, I focused on understanding and reducing systematic uncertainties, particularly those involving pulse shape analysis.  MAJORANA is gearing up to build a demonstration experiment to show that we can reach the background goals necessary to reach the physically interesting half-lives for this reaction.

Currently, I am focusing on understanding the capabilities of the point-contact germanium detectors to be deployed in the demonstrator, as well as how best to do so.  I am also involved in several of the R&D test stands around the collaboration used to investigate different backgrounds and detector designs.


CLEAN/DEAP is a direct dark matter search using liquid argon and liquid neon as a detection medium.  We will use digital pulse shape analysis to distinguish between different types of backgrounds for the experiment.  CLEAN/DEAP is currently building a pair of demonstration experiments.  MiniCLEAN 360 will have an active mass of around 100 kg, and be capable of using both liquid argon and liquid neon.  DEAP/CLEAN 3600 will have a mass of 1000 kg, but will only use liquid argon.

My involvement in this experiment has revolved around testing and characterizing photomultiplier tubes (PMT) at cryogenic temperatures, and understanding the fluorescence efficiency of wavelength-shifting films used in the experiment.  These films shift the VUV scintillation light from liquid argon and neon to visible light capable of being observed by the PMTs.  I am also working on some phenomenological work on interpreting any future detections of dark matter.
Victor M. Gehman,
Jan 12, 2013, 10:21 AM
Victor M. Gehman,
Aug 16, 2008, 2:35 PM