A high-temperature laser ion source for trace analysis and other applications

We report here on the development of a high-temperature laser ion source useful for trace analysis and other applications. It consists of a high temperature ionization chamber, three tunable dye lasers pumped by copper vapor lasers for stepwise resonant ionization and a Mattauch-Herzog mass spectrometer for the analysis of photo-ions. The principle of the laser ion source and its theoretical efficiency are discussed, where the efficiency of a laser ion source is the ratio of photo-ions extracted out to the number of atoms introduced into the cavity. Experimentally, an efficiency of 2×10^–3 has been achieved for technetium. The scheme of gated detection is described which is used for suppressing isobaric background of molybdenum. The possible improvements are briefly mentioned for achieving isotopic analysis of 10⁸ atoms of ^97,98Tc in the presence of 10¹⁵ atoms of molybdenum, as separated chemically from molybdenum ore. Such an analysis of technetium isotopes produced in molybdenite ore by a (v,e^–) reaction, is expected to yield information about the solar neutrino flux.Permanent address: Bhabha Atomic Research Centre, Bombay 400085, India