A design for an electromagnetic filter for precision energy measurements at the tritium endpoint

Abstract

We present a detailed description of the electromagnetic filter for the PTOLEMY project to directly detect the Cosmic Neutrino Background (CNB). Starting with an initial estimate for the orbital magnetic moment, the higher-order drift process of E × B is configured to balance the gradient-B drift motion of the electron in such a way as to guide the trajectory into the standing voltage potential along the mid-plane of the filter. As a function of drift distance along the length of the filter, the filter zooms in with exponentially increasing precision on the transverse velocity component of the electron kinetic energy. This yields a linear dimension for the total filter length that is exceptionally compact compared to previous techniques for electromagnetic filtering. The parallel velocity component of the electron kinetic energy oscil-arXiv:1810.06703v1 [astro-ph.IM]

Deuterium Adsorption on Free-Standing Graphene

“…The exceptional mechanical properties of graphene accompanied by the obtained semiconducting response of graphane, can pave the way towards pioneering technologies for widespread highly-efficient applications in devices where semiconducting graphane can be combined and engineered with conducting graphene. Furthermore, the achieved D-graphene functionalisation in a safe process opens up new possibilities in view of the use of the heavier tritium isotope as the key element for a futuristic prototype neutrino detector [ 11 ].…”

“…Recently, graphane as constituted by tritium (T)—the -unstable isotope of hydrogen—covalently bonded to graphene, has been also suggested to represent an ideal candidate for the realisation of a new detector able to measure the endpoint of the tritium -electron spectrum. This prototypical T-graphene-based detector (the Ptolemy project [ 11 ]) has been designed to improve the electron neutrino mass measurement, thanks to its very high sensitivity. A scaled version of such a T-graphene-based detector would in principle be able to measure the cosmological neutrino background generated a few seconds after the big bang [ 12 ].…”

“…A scaled version of such a T-graphene-based detector would in principle be able to measure the cosmological neutrino background generated a few seconds after the big bang [ 12 ]. The stabilisation of T is a crucial condition for the detector, which could be achieved by T chemisorption on graphene [ 11 ]. Since T presents severe safety issues, fundamental tests on the adsorption can be carried out with lighter tritium isotopes—deuterium and hydrogen.…”

“…Furthermore, we show that deuterium causes quenching of the electronic spectral density below the Fermi level, confirming the semiconducting nature of graphane. The present results on D-NPG constitute a further step towards the elaboration of a strategy for perspective atomic T-graphane growth for new prototype detectors [ 11 ].…”

Relic neutrinos: local clustering and consequences for direct detection

“…The precise setup of PTOLEMY will be defined in the incoming years, tough many studies are in progress (see e.g. [12]).…”