Scaling behaviour of the ground-state antihydrogen yield from CTMC simulation as a function of positron density and temperature

Antihydrogen production has reached such a level that precision spectroscopic measurements of its properties are within reach. In particular, the ground-state level population is of central interest for experiments aiming at antihydrogen spectroscopy. The positron density and temperature dependence of the ground-state yield is a result of the interplay between recombination, collisional, and radiative processes. Considering the fact that antihydrogen atoms with the principal quantum number n=15 or lower quickly cascade down to the ground state within 1ms, the number of such states are adopted as a measure of useful antihydrogen atoms. It has been found that the scaling behaviour of the useful antihydrogen yield is different depending on the positron density and positron temperature.