Development of a 3He magnetometer for use at cryogenic temperatures in the magnetic field range B > 0.1 Tesla

• Applicant: Professor Dr. Martin Fertl
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 542505174

We want to develop compact, reliable and easy-to-handle magnetometers based on thermally polarized 3He for use at cryogenic temperatures in the magnetic field range B > 0.1 T. Our measures and targeted goals: • Systematic studies and investigations to optimize the SNR ratio in the temperature range from 4K to 300K with the aim to reach a relative accuracy in magnetic field measurement of < 10^-8 for B > 0.1 T. • Dedicated and controlled reduction of the T1 time by addition of paramagnetic substances like O2 or porous silica gel loaded with Gd3+. • Quantitative understanding of the temperature dependence of T1. • Absolute field measurements: Use of fused silica sample holders of V < 0.5 cm^3 with high symmetry (spherical) as well as susceptibility matched materials for, e.g., support structures as well as Cu/Al zerosusceptibility wire

• DFG Programme: New Instrumentation for Research
• Co-Investigators: Dr. Peter Blümler; Professor Dr. Werner Heil