Using electric fields to prevent mirror-trapped antiprotons in antihydrogen studies

The signature of trapped antihydrogen (H̄) atoms is the annihilation signal detected when the magnetic trap that confines the atoms is suddenly switched off. This signal would be difficult to distinguish from the annihilation signal of any trapped p̄ that is released when the magnetic trap is switched off. This work deduces the large cyclotron energy (>137 eV) required for magnetic trapping of p̄, considers the possibility that such p̄ are produced, and explores the effectiveness of an electric field applied to clear charged particles from the trapping volume before H̄ detection. No mechanisms are found that can give a p̄ such a large cyclotron energy and allow it to mimic an H̄ annihilation. The method used to release H̄ atoms from their magnetic trap without removing the magnetic field gradient that could possibly confine p̄ with a high cyclotron energy is also discussed.