Magnetic monopole detectors based on He(2(3)S).

Abstract

Magnetic monopole detectors based on the premise that these particles can create the triplet metastable state in helium, He(${2}^{3}$S), exclusively and without ionization are believed to be feasible. In one of these, He(${2}^{3}$S) is detected in an ionization chamber array using both pure helium and a mixture of He+${\mathrm{N}}_{2}$ in which Penning ionization occurs. In the second version, resonance ionization spectroscopy is used to selectively ionize He(${2}^{3}$S). In both cases, monopoles with velocities greater than ${10}^{\mathrm{\ensuremath{-}}4}$c can be searched for with both large and reliable detectors.