Modelling the behavior of the positron plasma temperature in antihydrogen experimentation

Antihydrogen is now routinely produced at CERN by overlapping clouds of positrons and antiprotons. The mechanisms responsible for antihydrogen formation (radiative capture and the three-body reaction) are both dependent on the temperature of the positrons (T e ), though with a different weight. Here we present a simple model of the behavior of the positron temperature based on the main processes involved during antihydrogen synthesis, namely: antiproton–positron collisions, positron heating due to plasma expansion and cooling via the emission of synchrotron radiation. The time evolution of T e has been simulated by changing the relevant parameters of the mechanisms involved in order to highlight the importance of the different (competing) effects.