Plasma diagnostics at electron cyclotron resonance ion sources by injection of laser ablated fluxes of metal atoms

Short pulses of neutral particles generated by laser ablation of metal targ ets have been injected into the Frankfurt 14 GHz electron cyclotron resonan ce (ECR) ion source. Rise/fall times of pulses of highly charged ions of Cd and Mg were registered as a function of microwave power and gas pressure. From a comparison of the measured data to numerical simulations, values of the electron density and the temperature in the ECR plasma were estimated t o be about 0.75x10(12) cm(-3) and a few keV. The effective electron tempera ture increases with increasing microwave power and decreases with increasin g gas pressure. The electron density is only a weak function of the microwa ve power, but increases significantly with the gas pressure. In the Ar/O-2 gas-mixing mode of operation, an improved confinement of lowly charged ions was observed. (C) 2001 American Institute of Physics.