The behavior of electrons in the ALPHA apparatus is very sensitive to magnetic fields. Electrons move in circular orbits with a period that depends on the strength of the magnetic field. For strong magnetic fields the motion is fast, for small fields, the electrons move more slowly. ALPHA has developed a magnetic field sensing technique based on this principle. By precisely measuring the character of electron motion via a parameter called the “cyclotron resonance”, magnetic fields can be measured with very high precision. The resulting magnetometer will enable gravity experiments with antimatter.
- Electron cyclotron resonance (ECR) magnetometry with a plasma reservoir Physics of Plasmas 27, 032106 (2020)
- In situ electromagnetic field diagnostics with an electron plasma in a Penning–Malmberg trap New Journal of Physics, Volume 16, 2014