Oxygen Isotope Enrichment Research Articles

Laser photochemical enrichment of oxygen isotopes in methanol solution

Preferential reaction of 18O has been obtained by laser photolysis of room-temperature solutions of UO 2F 2 in methanol at 455 and 448 nm.

ArF laser enrichment of oxygen isotopes

Absorption by air in the optical cavity of an ArF discharge laser removes the 16O2 Schumann-Runge lines from the broad lasing output centered at 193 nm. Subsequent irradiation of an oxygen cell induces photochemistry of 17O and 18O, resulting in isotopically enriched ozone.

Argon matrix infrared spectra and vibrational analysis of the hydroperoxyl and deuteroperoxyl free radicals

Matrix reactions of H and D atoms from a microwave discharge source with oxygen molecules diluted in argon have produced significantly higher yields of HO2 and DO2 than the previous photolysis methods. Oxygen isotopic enrichment confirmed the previous vibrational assignments to HO2; significantly greater concentrations of DO2 allowed observation of the weak 0–0 mode at 1123 cm−1. Normal coordinate calculations using HO2 and DO2 oxygen isotopic frequencies gave excellent agreement with the observed data. The bonding in HO2 is suggested to be largely covalent, in contrast to the ionic species Li+O2−.

Oxygen isotope enrichment of sea water by evaporation

An evaporation mechanism proposed by Sverdrup is used as a model to interpret the changes in isotopic composition that occur during the evaporation of sea water. The relative humidity at the site of evaporation is shown to be an important factor in determining the net isotopic enrichment, especially at very high salinities. From these results it is proposed as a working hypothesis that brines originating by evaporation of sea water in a humid coastal environment will attain δO 18 values no higher than 6%..

Enrichment of Heavy Oxygen by Thermal Diffusion Method

Enrichment of heavy oxygen isotopes was carried out by use of thermal diffusion columns, using the normal oxygen gas as the raw material. The dimention of the unit separation column was as follows: inner diameter the wall was 10mm, outer diameter of the hot wire was 0.72mm and the effective length of the column was 295cm. The apparatus consisted of eleven columns, overall effective length being 17.7m. Each column was constructed carefully so as to keep the wire at the centre in the column using micalex spacers.It was found that the equilibrium separation factor of unit column was 7.5 and approached the theoretical value, probably due the improvement of geometrical condition between the cold wall and the hot wire. If the equilibrium is established, the concentration of heavy oxygen in the bottom reservoir would reach more than 90 atom %. The transport of the heavy oxygen amounted to 1.8cc(18O2)/day.