Laser-pumped helium magnetometer

摘要

A magnetometer comprises a transparent spherical photocell (1) filled with natural helium 4He. A laser (2) of the LNA (lanthanum- neodymium aluminate) type excites the photocell. An oscillator (3) generates a soft discharge inside the photocell (1). The electronic magnetic resonance frequency of helium atoms in the excited metastable state is determined on the basis of the light (FT) transmitted by the photocell, under excitation by a radio electric field, and the magnetic induction is thereby found.