Krypton sources

Separation of krypton and xenon from spent fuel rods should afford a source of xenon, technical usage of which is continuously growing (84). As of this writing, however, reprocessing of spent fuel rods is a pohtical problem (see Nuclearreactors). Xenon from fission has a larger fraction of the heavier isotopes than xenon from the atmosphere and this may affect its usefulness in some appHcations. 

Values extracted and in some cases rounded off from those cited in Rabinovich (ed.), Theimophysical Propeities of Neon, Ai gon, Krypton and Xenon, Standards Press, Moscow, 1976. m = melting point c = critical point. The notation 6.654.-4 signifies 6.654 X 10 . This source contains values for the compressed state up to 1000 bar, etc. This book was published in English translation by Hemisphere, New York 1988 (604 pp.). 

A beta attenuation sampler uses a 30-mCi Krypton-85 source (with energy of 0.74 MeV) and detector to determinate the attenuation caused by deposited aerosols on a moving filter. lb improve the stability over time, a refiertticc reading is period-icallv made of a foil with attenuation similar to that of the Alter and collected aerosol. 

A large number of nonlasing plasma lines emitted from the discharge plasma tube often interfere in the recorded Raman spectra. Loader (40) listed tables of plasma lines when using the argon ion and argon/krypton ion lasers as Raman sources. 

Our experimental techniques have been described extensively in earlier papers (2, 13). The gamma ray irradiations were carried out in a 50,000-curie source located at the bottom of a pool. The photoionization experiments were carried out by krypton and argon resonance lamps of high purity. The krypton resonance lamp was provided with a CaF2 window which transmits only the 1236 A. (10 e.v.) line while the radiation from the argon resonance lamp passed through a thin ( 0.3 mm.) LiF window. In the latter case, the resonance lines at 1067 and 1048 A. are transmitted. The intensity of 1048-A. line was about 75% of that of the 1067-A. line. The number of ions produced in both the radiolysis and photoionization experiments was determined by measuring the saturation current across two electrodes. In the radiolysis, the outer wall of a cylindrical stainless steel reaction vessel served as a cathode while a centrally located rod was used as anode. The photoionization apparatus was provided with two parallel plate nickel electrodes which were located at equal distances from the window of the resonance lamp. 

There is little evidence for 1 1 compounds between elements in this group under normal conditions. The diatomic van der Waals molecules, CaMg, SrMg and SrCa, however, have been synthesized by codepositing the atoms from separate sources with argon or krypton into solid matrices at 12 K. These low-T species are identified from their laser-induced fluorescence spectra. The ground-state spectroscopic data for these alkaline-earth dimers form a sensible series between the parent molecules Mg2, Caj and Sr2. ... 

For 2PA or ESA spectral measurements, it is necessary to use tunable laser sources where optical parametric oscillators/amplifiers (OPOs/OPAs) are extensively used for nonlinear optical measurements. An alternative approach, which overcomes the need of expensive and misalignment prone OPO/OPA sources, is the use of an intense femtosecond white-light continuum (WLC) for Z-scan measurements [71,72]. Balu et al. have developed the WLC Z-scan technique by generating a strong WLC in krypton gas, allowing for a rapid characterization of the nonlinear absorption and refraction spectra in the range of 400-800 nm [72]. 

The use of irradiation or electron bombardment offers an alternative approach to molecular dissociation to the use of elevated temperatures, and offers a number of practical advantages. Intensive sources of radiation in the visible and near-visible are produced by flash photolysis, in which a bank of electrical capacitors is discharged through an inert gas such as krypton to produce up to 105 joule for a period of about 10 4 s, or by the use of high power laser beams (Eastham, 1986 (loc.cit.)). A more sustainable source of radiation is obtained from electrical discharge devices usually incorporating... 

Kroll process, 13 84-85 15 337 17 140 in titanium manufacture, 24 851-853 Kroll zirconium reduction process, 26 631 KRW gasifier, 6 797-798, 828 Krypton (Kr), 17 344 commercial, 17 368t complex salts of, 17 333-334 doubly ionized, 14 685 hydroquinone clathrate of, 14 183 in light sources, 17 371-372 from nuclear power plants, 17 362 physical properties of, 17 350 Krypton-85, 17 375, 376 Krypton compounds, 17 333-334 Krypton derivatives, 17 334 Krypton difluoride, 17 333, 336 uses for, 17 336... 

Krypton is expensive to produce, which limits its use as an inert gas. It is used in a mixture with argon to fill incandescent light bulbs, fluorescent lamps, lasers, and high-speed photography lamps. Radioactive Kr-85 is used as a source of radiation to measure the thickness of industrial materials. It is also used to test for leakage of scientific instruments. 

Krypton also may be recovered from spent fuel rods of nuclear power plants. It is produced, along with xenon, in fission of uranium and plutonium. This process, however, is not a major source of krypton, and the recovered gas also contains radioactive Kr-85 isotope. 

Moureu and his collaborators, unfortunately, were never able to find any source of neon, argon, krypton, and xenon that would be easier to exploit than the atmosphere. M. Georges Claude however succeeded in tapping this difficult but limitless source of the rare gases and developed from it a wonderful new field of illumination (81, 83). 

---