Laser isotope separation of rare earth elements

Abstract

The experimental results on the laser isotope separation of the neodimium, samarium, europium, gadolinium, dysprosium, and erbium by the selective two-step photoionization are given. The rare earth elements have been chosen for the investigation because they constitute a good series of the very similar but different atoms that are heavy enough and allow experiments to be carried out that are representative enough. The experimental technique developed for the laser isotope separation experiments has been applied to measure the excitation energy transfer cross sections at the collisions in the gas of the same atoms ((153)Eu ? (151)Eu, sigma = 1.4 x 10(-13) cm(2)). The combination of the selective two-step photoionization and ion mass filtration allowed us to develop a very convenient technique for the precise measurement of hyperfine structure in the spectrum of odd isotopes. The examples of dysprosium and erbium are given. The technique is good for the rare and unstable isotopes as well. The ionization cross sections for the transition starting off the excited level have been estimated ( approximately 10(-17) cm(2)). For the example of gadolinium the possibility of creating neutral atomic vapor dense enough for laser isotope separation by the electron-beam evaporation technique has been demonstrated.

A physics‐based model for the ionization of samarium by the MOSC chemical releases in the upper atmosphere

“…The photo ionization wavelength threshold is given by where λ IP = 219.686 nm is the longest photon wavelength with enough energy to ionize atomic samarium assuming an ionization potential of I 1 = 45519.6 cm −1 (5.6437 eV). The photo ionization cross section is based on the work of Karlov et al []. The photo ionization rate (or time) from level λ α is determined from where the spectrum of the solar flux F Sun has been previously shown in Figure .…”

“…based on the work of Karlov et al [1978]. The photo ionization rate (or time) from level λ α is determined from…”

A Comprehensive Review of Selected Major Categories of Lithium Isotope Separation Techniques

“…The selective photoionization technique for isotope isolation of Nd, Sm, Eu, Gd, Dy, Er, Li, U, etc. was shown by Karlov et al [ 77 ] Resonance‐based diode laser ionization of lithium isotopes was reported by Olivares et al, [ 78 ] where the lithium isotopes were isolated using the ultranarrow‐width laser with tuning capability along with the fine structure levels at 2 p . A 47% increase in 6 Li concentration using a two‐step laser ionization via the time‐of‐flight (TOF) mass spectrophotometer was recorded by Saleem et al [ 79,80 ] Additional isotope selectivity for achieving greater isotope enrichment can be given by the TOF mass spectrophotometer.…”

Generation of deep ultraviolet narrow linewidth laser by mixing frequency Ti:sapphire laser at 5 kHz repetition rate

“…Coherent laser sources have wide applications in spectroscopy, lithography, and photochemical process [1][2][3]. In particular, such kind lasers with narrow linewidth and high power are more attractive in fine precision spectroscopy, optical pumping, and laser isotope separation [4][5][6]. Conventional dye lasers have been used as the primary sources in visible and near-IR range because of their excellent tunable ability, but the disadvantages such as poor beam quality, degradation with time, toxic chemicals, complex recycle system, and expensive cost restrict their further development.…”