A Ioffe Trap Magnet for the Project 8 Atom Trapping Demonstrator

The goal of the Project 8 experiment (B. Monreal and J. Formaggio, 2009) is to measure the absolute neutrino mass using tritium, which involves precisely measuring the energies of the beta-decay electrons in the high-energy tail of the spectrum (A. A. Esfahani et al. , 2017). The experimental installation of Project 8 Atom Trapping Demonstrator requires a magnet with rather unusual field properties. The magnet has to contain within the cold mass a large volume enclosed by a continuous, uninterrupted boundary higher than 2 T, whereas the field in a substantial volume inside this boundary has to be of the order of 10−4 T or less. A 1-T solenoid field provides the background field necessary fo…