The electron cyclotron resonance coupled to laser ion source for charge state enhancement experiment:: Production of high intensity ion beams by means of a hybrid ion source

The experiment concerning the ECLISSE method (ECR ion source coupled to a laser ion source for charge state enhancement) has been carried out by coupling a laser ion source (LIS) to the superconducting electron cyclotron resonance source (SERSE) electron cyclotron resonance (ECR) ion source with the goal to obtain intense beams of highly charged ions (cw or pulsed mode) from metal samples, especially from refractory elements. The coupling efficiency of the ion beam produced by the LIS with the ECR plasma was remarkable and the measured beam intensities were quite high. The maximum charge states, obtained with a good reproducibility, were 38(+) for Ta and 41(+) for Au. The highest current was obtained for 25(+) and 28(+) for Ta and Au ions, respectively, and it was in both cases of the order of some tens of microampere, i.e., higher than the current obtained from SERSE with other methods (i.e., evaporation and sputtering). The ion beam stability and reproducibility were both acceptable. The possibility to get a further enhancement of the available charge states was limited by charge exchange processes connected with the target ablation. The main features of the LNS facility based on a Nd:YAG (yag, yttrium aluminum garnet) laser (0.9 J/9 ns, laser power densities <5x10(10) W/cm(2)) and on the SERSE superconducting ECRIS working in single frequency mode (18 GHz) will be shown in the following. The analysis of the results and the way to get rid of the existing limits will be also presented and discussed. (C) 2004 American Institute of Physics.