Resonance Ionization Mass Spectrometry (RIMS): Fundamentals and Applications Including Secondary Neutral Mass Spectrometry

High-useful yield and new autoionizing state of resonantly ionized tungsten

“…As a general rule of thumb, laser irradiance more than three times the saturation irradiance (corresponding to ∼95% of the maximum signal) results in little extra signal while increasing non-resonant backgrounds in complex sample matrices, which ultimately increases measurement uncertainty. 21…”

“…The relative enrichment of odd isotopes in RIMS analyses is a phenomenon known as the “odd-even” effect. 21,24,25 Owing to hyperfine splitting, odd isotopes have more paths to ionization than even isotopes and ionize at a faster rate. This can favor the ionization of odd isotopes relative to even isotopes even in nominally saturated transitions, since atoms in the wings of the laser power distribution will not experience saturation irradiance.…”

“…Details on RIMS, the LION instrument, and data evaluation have been previously published. 18–21 For all analyses, an IonOptika liquid metal ion gun with a 15 keV Ga + ion beam focused to ∼1 μm and oriented at an incident angle of 60° from the surface normal was used to sputter material with either a 10 or 20 μm square raster. After the primary ion pulse, secondary ions were ejected from the system by applying a 5000 V pulse to the sample.…”

Transuranium isotopes at ISAC/TRIUMF

“…Resonance ionization spectroscopy (RIS) pioneered by Hurst and Letokhov [7] was soon adapted for applications in mass spectrometry [8] and rare ion beam production at ISOL (Isotope Separation OnLine) facilities [9] like ISAC. Increased ionization efficiency and high element selectivity due to element-specific, multi-step resonant laser excitation of atoms are the main advantages.…”

Multi-Element Isotopic Analysis of Hot Particles from Chornobyl

“…Resonant laser ionization adds the necessary selectivity, targeting the electronic structure of a given element to step-wise excite it beyond the ionization potential [25][26][27]. The technique removes the need for chemical preparation, which allows for multiple analyses to take place on the same sample.…”