Modeling the FTICR-MS signal of a $^7$Be ion plasma using a 2D PIC code

Beryllium-7 ($^7$Be) only decays by electron capture into lithium-7 ($^7$Li) with a half life of 53 days. As a result, its decay rate depends on the electron density around its nucleus. We desire to study the effect of ionization on its decay rate. We will do this by trapping a $^7$Be ion plasma in a Malmberg-Penning Trap and measuring its and $^7$Li's concentration as a function of time by using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). We use this ratio as a function of time to directly measure the decay rate of the confined ion plasma rather than using gamma detection. We have modeled these signals in a 2-dimensional electrostatic particle-in-cell (PIC) code. The two spectrum peaks merge at high densities and at low densities they can be resolved. The merged peak linearly shifts with the relative abundances of the species. We have also modeled $^7$BeH$^+$ and $^7$Li$^+$ at high densities. These two spectrum peaks shift with the relative abundances of the two species. The progress of this investigation will be presented.