LASER ION-SOURCE VIA DIRECT IONIZATION AT THE OUTLET OF A HELIUM JET

A laser ion source based on laser resonant ionization at the outlet of a helium jet was proposed for on-line isotope separator of the Heavy Ion Research Facility in Lanzhou, China a few years ago. An off-line t est setup was built at Tsinghua University, The initial experimental r esults of the setup indicate that carrying neutral Na monoatoms to the outlet of a helium jet and directly ionizing the Na atoms in the heli um jet beam by laser resonant ionization is very efficient. It provide s an effective method for producing element selected ions with high ef ficiency, low background, and short transporting time. It is applicabl e for the separation of various elements, and is particularly useful f or refractory elements. (C) 1997 American Institute of Physics.