Tools for a precise tritium to helium-3 mass comparison

Abstract

The total mass of the three neutrino flavors v _e, v_μ, and v_τ is constrained by neutrino oscillation and tritium β-spectrum observations. The KATRIN β-spectrometer has an anticipated sensitivity of m(v_e) ∼ 0.2 eV, and independent ³H³He mass difference measurements with 20 meV/c² accuracy can provide an important check on systematic uncertainties. The Penning trap mass spectrometer techniques presented here were developed to measure the ratio of these particular masses at the equivalent 10⁻¹¹ precision level. They include an external ion source and beam-line to create helium and tritium ions and transport single ions to two Penning traps 4 cm apart. Electronics developed for this double Penning trap arrangement uses a single differential amplifier and extremely stable solid-state ring-electrode voltage source to measure the cyclotron frequency ratio of the two species in a stable magnetic field. The potential of several new methods to reduce measurement time and improve precision in mass measurements and other Penning trap experiments is explored.