Recent Advances In The Physics Of Collective Excitations In The Paul Trap Simulator Experiment

The Paul Trap Simulator Experiment (PTSX) is a compact laboratory linear Paul trap that simulates the transverse dynamics of a charged-particle bunch coasting through a magnetic alternating-gradient (AG) transport system. The transverse dynamics of particles in the AG system in the beam’s frame-of-reference and those of particles in PTSX are described by the same sets of equations, including all nonlinear space-charge effects. Initial exper-imental results are presented in which the collective transverse symmetric mode (m = 0) and quadrupole mode (m = 2) have been observed in pure-barium-ion plasmas in PTSX, with an initial depressed-tune ν/ν0 ∼ 0.9, with the intent of identifying collective modes whose signature will serve as a robust diagnostic for key properties of the beam, such as line density and transverse emittance. The results of particle-in-cell simulations performed with the WARP code are compared to the experimental data