Ion-Ion Interaction Induced Nondispersive Dynamics in an Electrostatic Ion Beam Trap.

We demonstrate both experimentally and using a numerical simulation that, under special conditions, the repulsive Coulomb interaction helps to suppress the emittance growth of an rf-driven bunch of ions in an electrostatic ion beam trap. The underlying mechanisms can be explained by the synchronization of ion motion when nonlinear interactions are present. The surprising effect can help in improving the phase space manipulation of ions and the beam control in storage rings and accelerators and may be applied to other systems with many-body interactions in a periodic potential.

Simultaneous electrostatic trapping of merged cation & anion beams.

Simultaneous trapping of merged cation and anion beams in the hybrid electrostatic ion beam trap (HEIBT) opens new opportunities for the study of the interactions of isolated atomic molecular or cluster ions with oppositely charged ionic species. Application of the trapped merged beams requires a detailed understanding of the trapping dynamics and the effect of the Coulombic attractive and repulsive forces between the ions on their motion in the trap. The simultaneous trapping regime is explored experimentally for SF anion and SF cation beams and compared to realistic ion trajectory simulations.

Time-dependent dynamics of radio-frequency-bunched ions in an electrostatic ion beam trap.

The dynamics of ions in an electrostatic ion beam trap in the presence of an external time-dependent field is studied with a recently developed particle-in-cell simulation technique. The simulation technique, capable of accounting for space-charge effects, has reproduced all the experimental results on the bunch dynamics in the radio frequency mode. With simulation, the motion of ions is visualized in phase space and it is shown that the ion-ion interaction strongly affects the distribution of ions in phase space in the presence of an rf driving voltage.

Thermometry of stored molecular ion beams.

The radiative cooling of a stored, initially rotationally hot OH[Formula: see text] ion beam is probed by photodetachment using an electrostatic ion beam trap combined with an in-trap velocity map imaging spectrometer, providing direct measurement of the time-dependent rotational population. The rotational temperatures are estimated from photodetached electron spectra as a function of time using a Boltzmann distribution model and further verified by a rate law model using known Einstein coefficients. We demonstrate that during the entire cooling time, the rotational population can be well described by a Boltzmann distribution.

Particle-in-cell techniques for the study of space charge effects in an electrostatic ion beam trap.

We developed a simulation technique to study the effect of space charge interaction between trapped ions in the electrostatic ion beam trap (EIBT). The importance of space charge is demonstrated in both the dispersive and the self-bunching regime of the ion trap. The simulation results provide an estimate for the space charge effect on the trapping efficiency.