LAUSR

The formation of antihydrogen atoms from antiprotons injected into a positron plasma is simulated, focussing on the fraction that fulfil the conditions necessary for confinement of anti-atoms in a magneticminimum trap. Trapping fractions of around 10 are found under conditions similar to those used in recent experiments, and in reasonable accordwith their results.We have studied the behaviour of the trapped fraction at various positron plasma densities and temperatures and found that collisional effects play a beneficial role via a redistribution of the antihydrogenmagneticmoment, allowing enhancements of the yield of low-field seeking states that are amenable to trapping.