[22p-A404-11~17] 8.5 Plasma phenomena, emerging area of plasmas and their new applications

△ [22p-A404-15] Study on density and lifetime of helium metastable atoms for helium-4 optically pumped magnetometers

〇(M1)Soya Hidaka¹, Yosuke Ito¹, Keiichiro Urabe¹ (1.Kyoto Univ.)

Keywords:Magnetometer, Numeric calculation, Helium plasma

Optically pumped magnetometers with helium metastable atoms are expected to be sensors for biomagnetic-field measurements. In this study, we simulated the density and lifetime of the atoms to investigate conditions that the sensors become sufficiently sensitive to magnetic fields. Numerical calculations revealed that the density reached 1.5×10¹⁸ m^-3 at helium pressure of 10 kPa, and the lifetime without any contamination was found to be 567 μs.