Strong drive compression of a gas-cooled positron plasma

The use of rotating electric fields to control plasmas has found numerous applications in the manipulation and storage of antimatter. When used in strong magnetic fields plasma heating caused by the applied field is mitigated by cyclotron cooling, leading to an efficient broadband mode of compression known as the strong drive regime. We have found that it is possible to access the strong drive regime in a low field trap where cyclotron cooling is negligible and a gas is used for cooling, and we have been able to compress positron plasmas to more than 10% of the Brillouin density limit.