Zero-deadtime processing in beta spectroscopy for measurement of the non-zero neutrino mass

Benjamin Laroque,C Doglioni,G.A Stewart,W Kamleh,D Kim,P Jackson,L Silvestris

doi:10.1051/epjconf/202024501014

Abstract

The Project 8 collaboration seeks to measure, or more tightly bound, the mass of the electron antineutrino by applying a novel spectroscopy technique to precisely measure the tritium beta-decay spectrum. The current system produces a single analog signal, which is digitized and processed in several stages before being saved to local disk storage. Online processing includes two stages, an FPGA connected to the analog to digital converter reduces the data down to the region of interest before shipping over the local network for further processing and storage. A normal CPU-based processing stage applies triggering logic to only save data at times when a signal is present, further reducing the total volume of data which needs to be written to disk or transferred for long-term storage. The next stage of the project will need to process many input channels and will integrate a necessary aggregation and combination step prior to applying the event search and triggering logic. We present the online processing system which has successfully been deployed for the current, singlechannel, phase. We also present the status and design for a many-channel platform.

Highlights

The Project 8 collaboration seeks to use precision measurement of the tritium beta-decay spectrum to either more tightly constrain or measure the effective mass of the electron-flavor antineutrino
In Cyclotron Radiation Emission Spectroscopy (CRES), a radioactive source is allowed to decay in a region with an ambient magnetic field, which causes any charged particles produced to produce cyclotron radiation
The frequency of the cyclotron radiation depends upon the magnitude of the magnetic field, and the particle’s charge-to-mass ratio, which for a relativistic particle is sensitive to its kinetic energy through the relativistic mass shift

Summary

Introduction

The Project 8 collaboration seeks to use precision measurement of the tritium beta-decay spectrum to either more tightly constrain or measure the effective mass of the electron-flavor antineutrino. In CRES, a radioactive source is allowed to decay in a region with an ambient magnetic field, which causes any charged particles produced to produce cyclotron radiation. A precise measurement of the frequency of cyclotron radiation can be combined with a particle’s known rest mass and independently measured magnetic field to determine the particle’s kinetic energy. The initial demonstrations of CRES have been conducted in a configuration where the entire source volume is contained within a waveguide, which acts as a very efficient signal collector, with characteristic dimensions determined by the frequency of the cyclotron radiation to be measured. The current plan is to instrument the source volume with a collection of antenna units Analog signals from these units will be amplified and digitized independently and combined in order to look for signals of interest

Online signal processing in the current phase

Plan for Phase III signal digitization and processing

Results and outlook