Physics Colloquium - Single-Electron Radio Broadcasts and the Future of Neutrino Mass Measurement

Event Date: 

Tuesday, October 13, 2015 - 4:00pm

Event Location: 

  • Broida 1640


Ben Monreal, UCSB



Present and future attempts to measure the neutrino mass rely on precise energy measurements of nuclear beta-decay electrons, particularly from tritium. After many generations of scaling up, traditional beta spectrometers are rapidly approaching their technological limits, while remaining over an order of magnitude away from the cosmologically-favored neutrino mass.

We developed a new form of energy spectroscopy, based on detection of single-electron cyclotron radiation---a type of radiation described, as an E&M exercise, in introductory textbooks but not actually detected until now. It turns out that our detector sees more than the simple blips we need for the beta-measurement---instead, we're able to track electrons' energy and velocity evolution over milliseconds. I'll show recent results from the prototype "Project 8" electron spectrometer, and our plan for turning it into a large tritium experiment with neutrino mass sensitivity.