Speaker
Description
Direct measurements of the tritium β-decay spectrum near its endpoint provide one of the most sensitive probes of the absolute neutrino mass. After the KATRIN collaboration published the world-leading upper limit of $m_\nu$ = 0.45$\,$eV (90% C.L.), a new R&D phase is ongoing to develop an experiment with an improved sensitivity on $m_\nu$ of at least one order of magnitude. Sensitivity studies have shown that the transition from molecular tritium T$_2$ to atomic tritium T is an essential technology development.
We present graphene as a candidate sensor to detect atomic tritium beams. T$_2$ Chemically, passes over the carbon lattice without interacting, whereas T selectively chemisorbs to form sp³-bonds. These atoms act as dopants, measurably altering the band structure and electrical resistivity of graphene. This principle allows for in-situ sheet resistance observations, which tracks real-time measurements for an atomic beam system. The studies present here, are conducted with nonradioactive hydrogen.
We report in-situ sheet resistance measurements and ex-situ Raman spectroscopy of graphene hydrogenation. Furthermore, we present the latest progress in the implementation of a backgate for our graphene samples, which allows for modulation of the Fermi level, thus enabling an additional dimension in phase space for characterization.