Resonance Ionization Mass Spectrometry and Its Application in Nuclear Technology

Resonance ionization mass spectrometry is a new mass spectrometry technology formed by the combination of resonance ionization technology and mass spectrometry technology, which has the characteristics of element selectivity and high sensitivity, and can effectively overcome the problem of isobaric interference faced by commercial mass spectrometer. In order to meet the application requirement of ultra-trace nuclide analysis and measurement under complex matrix interference, a laser resonance ionization mass spectrometer based on magnetic-electric double focusing mass analyzer was developed in the laboratory. A forward Nier-Johnson double focusing structure, which was consisted of a cylindrical electrostatic analyzer and a sector magnetic mass analyzer was adopted for the mass analyzer. Firstly, the structure and theoretical parameters of the mass analyzer were introduced. Secondly, the results of theoretical simulation and experimental test were given. It showed that the instrument had achieved bidirectional focusing of direction and energy, and had small higher order aberration. The horizontal magnification and mass dispersion of the instrument were 0.78 and 500 mm, respectively. When the width of the source slit was 0.25 mm and the width of the detector entrance slit was 0.65 mm, the mass resolution (10% valley) reached about 580, which was close to the theoretical limit of mass resolution. Finally, the analysis and measurement work carried out by the laboratory on the instrument was introduced, and some applications of the device in ultra-trace radionuclide measurement under strong isotope interference were shown.