Laser Resonance Ionization Mass Spectrometry (LRIMS) is a powerful analytical tool that permits the detection of ultratrace elements and isotopes in biological systems. This performance is achieved by combining the elemental selectivity of laser resonance ionization with the mass selectivity of mass spectrometry. In order to make LRIMS's practical, a turn-key, all solid state tunable ultraviolet laser must be developed. Analysis indicates a modest, several millijoule laser tunable over the wavelength range 250 nm to 350 nm, and .3 cm(-l) bandwidth would be an ideal ionization source. The elemental vapor required prior to ionization may be effectively generated by a second, more energetic, long pulse (greater than l usec) laser. Candela Laser Corporation proposes the development of a laser source that addresses both needs. The proposed laser is based on the recently developed flashlamp pumped Titanium doped sapphire laser. Nonlinear optics steps are proposed to generate the ultraviolet radiation. The Phase I plan is first to identify the optimum choice of nonlinear optical materials and to demonstrate second and third harmonic generation. Coverage of the range of interest, required energy, and bandwidth will be demonstrated. Phase I will demonstrate a temporally programmed pulse output from the laser consisting of a long pulse, low peak power part that will produce the elemental vapor and short pulse, high peak power part for efficient frequency up conversion.
