Development, characterization, and first application of a resonant laser secondary neutral mass spectrometry setup for the research of plutonium in the context of long-term nuclear waste storage

Abstract

Plutonium is a major contributor to the radiotoxicity in a long-term nuclear waste repository; therefore, many studies have focused on interactions of plutonium with the technical, geotechnical, and geological barriers of a possible nuclear waste storage site. In order to gain new insights into the sorption on surfaces and diffusion of actinides through these complex heterogeneous materials, a highly sensitive method with spatial resolution is required. Resonant laser secondary neutral mass spectrometry (Laser-SNMS) uses the spatial resolution available in time-of-flight secondary ion mass spectrometry (TOF-SIMS) in combination with the high selectivity, sensitivity, and low background noise of resonance ionization mass spectrometry (RIMS) and is, therefore, a promising method for the study and analysis of the geochemical behavior of plutonium in long-term nuclear waste storage. The authors present an approach with a combined setup consisting of a commercial TOF-SIMS instrument and a Ti:sapphire (Ti:Sa) laser system, as well as its optimization, characterization, and improvements compared to the original proof of concept by Erdmann et al. (2009). As a first application, the spatial distributions of plutonium and other elements on the surface of a pyrite particle and a cement thin section were measured by Laser-SNMS and TOF-SIMS, respectively. These results exemplify the potential of these techniques for the surface analysis of heterogeneous materials in the context of nuclear safety research.

New horizons in microparticle forensics: Actinide imaging and detection of 238 Pu and 242m Am in hot particles

“…Combining RI with SIMS is called resonant laser secondary neutral mass spectrometry (rL-SNMS), a technique also used for investigation of nuclear materials ( 32 ), in the field of cosmochemistry ( 33 ) and with low spatial resolution for plutonium imaging on clay ( 34 ). The sputter process produces initially formed ions and neutral atoms.…”

Doppler splitting and expansion dynamics of laser-produced plasma plume under a high vacuum ambience

“…5 Schönenbach et al developed a resonant laser secondary neutral mass spectrometer for plutonium isotope analysis. 6 Isselhardt et al developed a correction model for laser-induced bias based on the measurement of the 235 U/ 238 U ratio. 7 A high useful yield, the number of atoms detected per atom consumed, is considered for ultra-trace analysis (e.g.…”

New Developments in the Production and Research of Actinide Elements

“…Some trace analysis techniques rely on laser resonance ionization or light absorption and therefore also require a thorough knowledge of atomic structure. For resonance ionization spectroscopy (RIS) of actinides, the development of efficient excitation and ionization schemes is ongoing [97][98][99][100], and recent reports attest to advances in the use of spatially resolved secondary neutral mass spectrometry combined with RIS on sample atoms [96,101,102].…”