Erice: INTERNATIONAL SCHOOL OF NUCLEAR PHYSICS, 47th COURSE

Scaling Cyclotron Radiation Emission Spectroscopy(CRES) to large volumes in the Project 8 neutrino mass experiment

Abstract

Project 8 is a next-generation experiment aiming to perform a direct measurement of the neutrino mass using the endpoint region of the tritium beta-decay spectrum, with a final target sensitivity of 40 meV. To achieve this goal, Project 8 employs Cyclotron Radiation Emission Spectroscopy (CRES), a technique in which the kinetic energy of beta-decay electrons is reconstructed from the frequency of their cyclotron radiation. After successful proof-of-principle demonstrations of CRES for tritium end point measurements, the next challenge is to scale the technique to much larger source volumes while improving upon the precision of the measured signal.

A promising way to achieve this goal is to use a cylindrical resonant cavity, in which the cyclotron radiation from magnetically trapped electrons is enhanced on-resonance. The Low Frequency Apparatus(LFA) is the bridge between proof-of-principle cavity CRES tests and the future neutrino-mass experiment. It will establish resonant, mode-filtered cavities as cubic-meter CRES detectors compatible with atomic-tritium operations and yield a competitive neutrino-mass upper limit.

In this talk, I will discuss the challenges of scaling CRES to large volumes, focusing on recent progress in multi-mode cavity design.