Kinetic isotope effect approximation that reduced masses are approximately equal to the masses of the hydrogen, deuterium, or tritium was used. In addition, the vibrational motion was assumed to be approximated by a harmonic oscillator, so that formula_19 (X = H, D, or T). The subscript ""s"" refers to these "semi-classical" kinetic isotope effects, which disregard quantum tunneling. Tunneling contributions must be treated separately as a correction factor. For isotope effects involving elements other than hydrogen, many of these simplifications are not valid, and the magnitude of the isotope effect may depend strongly on some or all of the neglected factors. Thus, kinetic
Atomic vapor laser isotope separation Atomic vapor laser isotope separation Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. As compared to gas centrifuges the AVLIS process provides high energy efficiency, high separation factors, and a low volume of radioactive waste. A similar technology, using molecules instead of atoms, is molecular laser isotope separation (MLIS). The absorption lines of and U differ slightly due to hyperfine structure; for example, the U absorption peak of 502.74 nanometers shifts to 502.73 nm in U. AVLIS uses tunable dye