High-resolution, three-step resonance ionization mass spectrometry of gadolinium.

High-resolution resonance ionization mass spectrometry has been used to measure triple-resonance autoionization (AI) spectra of gadolinium. Al resonances as narrow as 10 MHz have been observed and isotope shifts and hyperfine structure have been measured in selected AI states. The strongest AI state observed at 49663.576 cm-1 with a photoionization cross section of >3.6×10[sup -15] cm[sup 2] was found to have an overall detection efficiency of >3×10[sup -5], allowing application to a number of ultratrace determination problems. Analytical measurements with a diode-laser-based system have been successfully performed on bio-medical tissue samples. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]