Realistic simulation of the ion cyclotron resonance mass spectrometer using a distributed three-dimensional particle-in-cell code

This work describes an Internet accessible three-dimensional particle-in-cell simulation code, which is capable of near first principles modeling of complete experimental sequences in Fourier transform ion cyclotron resonance mass spectrometers. The graphical user interface is a Java client that communicates via a socket stream connection over the Internet to the computational engine, a server that executes the simulation and sends real-time particle data back to the client for display. As a first demonstration, this code is applied to the problem of the cyclotron motion of two very close mass to charge ratios at high ion density. The ion populations in these simulations range from 50,000 to 350,000 coulombically interacting particles confined in a cubic trap, which are followed for 100,000 time-steps. Image charge, coherent cyclotron positions, and snapshots of the ion population are recorded at selected time-steps. At each time-step in the simulation the potential (coulomb + image + trap) is found by the direct solution of Poisson's equation on a 64 x 64 x 64 computational grid. Cyclotron phase locking is demonstrated at high number density. Simulations at different magnetic fields confirm a B-2 dependence for the minimum number density required to lock cyclotron modes. (J Am Soc Mass Spectrom 1999, 10, 136-152) (C) 1999 American Society for Mass Spectrometry.