Isotope-selective Microscale Imaging of Radioactive Cs without Isobaric Interferences Using Sputtered Neutral Mass Spectrometry with Two-step Resonant Ionization Employing Newly-developed Ti:Sapphire Lasers

Abstract

The characterization of radionuclides in Fukushima is important to determine their origins and current state in the environment. Radionuclides exist as fine particles and are mixed with other constituents. A measurement method with both micro-imaging capability and highly selective element detection is necessary to analyze these particles. We developed such an imaging technique using a time-of-flight secondary ion mass spectrometry and wavelength-tunable Ti:Sapphire lasers for the resonance ionization of target elements without mass interference. This is called resonant laser ionization sputtered neutral mass spectrometry. The instrument has a high lateral resolution and a higher ionization selectivity using two-step resonance excitation of Cs with two lasers at different wavelengths. Optimization of the wavelength for resonance ionization using a Cs compound was performed, and a real environmental particle containing radioactive Cs was analyzed. Isotope images of three kinds of Cs were successfully obtained without interfere from Ba isotopes for the first time.

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

“…nuclear forensics and isotopic imaging with a high spatial resolution of a sample surface). 8,9 However, Goreinger et al investigated the matrix effects and reported a useful yield of only 0.09% for U obtained from even the U metal, and the ejecta was dominated by UO and UO 2 . 10 Moreover, the U atom signals drop due to the chemisorption of both oxygen atoms and molecules in both ejecta and background gas and the population distribution in low-lying electronic states.…”

Zirconium analysis in microscopic spent nuclear fuel samples by resonance ionization mass spectrometry

“…While not commercially available, several RIMS facilities are now in operation worldwide with applications ranging from cosmochemistry to nuclear fuel analysis. [15][16][17][18] Today, Ti:Sapphire lasers are commonly used in modern RIMS facilities due to their wide tuning range and reliability.…”

Design optimization of microfluidic-based solvent extraction systems for radionuclides detection

“…they involve time consuming chemical operations (> hours), they require large sample volumes (> milliliter), and they produce secondary wastes (mL to L) and radiation toxicities. To overcome the disadvantages, novel methods such as laser resonance ionization and capillary electrophoresis have also been applied to the analysis of decommissioning wastes [3,4]. They realize highly sensitive detection for trace amounts of target elements, but are unsatisfactory due to the long-time measurement, limitation of sample properties (fluorescent reagent, pH range, aqueous solution, etc), requirement of large/expensive instruments, and bulk-scale pretreatment of samples using extraction, acidic eluents, and adsorbent resin.…”