The underlying physics of the resonance ionization mass spectrometric technique in association with laser desorption measurements remains under-explored, and the application to isotopic measurements largely untested when compared with other approaches. When the technique was first implemented, lasers were expensive and balky to use, limiting the ultimate application of the method. Since that time, lasers have evolved significantly, resulting in lower cost, size, power, and increased ease of use, enabling measurements using laser desorption as the basis for the mass spectrometer. Because of these advances, secondary ionization approaches can approach 100% efficiency, enabling sub-parts per billion detection limits, and significantly increased measurement precision. This proposal expands the basic physical understanding of the underlying atomic processes, in addition to exploring methods that could enable real-time in-situ isotopic measurements of trace isotopic and elemental systems. Initial results show that the laser and mass spectrometer systems could be made portable for real-time field use, while maintaining sufficient precision and accuracy for enabling geo-chronology, geo-location, forensics, archeology, food tracking, and studying nuclear processes. The team will engage students in the geologic science, physics, and engineering of geo-chronology, resonance ionization, and mass spectrometry in order to support this effort.