TY - JOUR AU - PTOLEMY Collaboration (Betti, M. G. et al AU - de Salas, P. F. AU - Gariazzo, S. AU - Pastor, S. PY - 2019 DA - 2019// TI - A design for an electromagnetic filter for precision energy measurements at the tritium endpoint T2 - Prog. Part. Nucl. Phys. JO - Progress in Particle and Nuclear Physics SP - 120 EP - 131 VL - 106 PB - Elsevier Science Bv KW - PTOLEMY KW - Relic neutrino KW - Cosmic Neutrino Background KW - CNB KW - Neutrino mass KW - Transverse drift filter AB - 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 x 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 oscillates in an electrostatic harmonic trap as the electron drifts along the length of the filter. An analysis of the phase-space volume conservation validates the expected behavior of the filter from the adiabatic invariance of the orbital magnetic moment and energy conservation following Liouville's theorem for Hamiltonian systems. (C) 2019 Elsevier B.V. All rights reserved. SN - 0146-6410 UR - https://arxiv.org/abs/1810.06703 UR - https://doi.org/10.1016/j.ppnp.2019.02.004 DO - 10.1016/j.ppnp.2019.02.004 LA - English N1 - WOS:000464490900003 ID - PTOLEMYCollaborationBetti_etal2019 ER -