Production of helium

Fig. 5. Production of helium-group gases in a classical air-separation plant.

Fajans K, Gohring O (1913) Uber die komplexe Natur des UrX. Naturwissenschaften 1 339 Ramsay W, Soddy F (1903) Experiments in radioactivity and the production of helium from radium. Proc R Soc London 72 204-207... 

Ramsay, William, and Frederick Soddy. 1903. Experiments in Radio-Activity, and the Production of Helium from Radium. Nature (August 13, 1903) 354.—55. 

Sir WILLIAM RAMSAY and FREDERICK SODDY "Experiments in Radioactivity and the Production of Helium from Radium," Proceedings of the Royal Society of London, vol. Ixxii. (1903), pp. 204 et seq. 

The binary spectra of hydrogen-helium mixtures, Fig. 3.12, differ from the spectra of pure hydrogen, Fig. 3.10, especially by the translational line (familiar from the spectra of rare gas mixtures) whose intensity increases strongly with increasing temperature. Moreover, the rotational line intensities when normalized by the product of helium and hydrogen... 

For chemical reactions there is a convenient and natural way to specify the noise properties of the injection mechanism, which has already been used in some examples. One supposes that the molecules X are produced from a compound B, which is present in large amount and slowly decays into X. The production is then practically constant and the reverse reaction negligible, just as the production of helium by uranium may be regarded as constant. In other words, one describes the open system as a limiting case of a closed system that is not in equilibrium. The role of B is reduced to that of a reservoir. 

The status of WR abundance analyses through IAU Symposium 99 was very well summarized by Willis (1982) see also Linda J. Smith and Willis (1982,1983). Since then, additional information on the He/H ratios has been provided by Conti, Leep, and Perry (1983), while substantial progress on modeling the He spectra has been contributed by Hamann and Schmutz (1987 and references therein) and by Hillier (1987a, b). The WC stars are special, as the only well-defined class of massive stars showing us the products of helium burning. Currently, improved determinations of their C/He ratios are being made by Lindsey F. Smith and Hummer (1987) from near infrared spectra, and by Torres (1987) optically. 

Finally Jean Perrin presented an extensive (97 pages) Rapport sur les Preuves de la R6alit6 Moleculaire in which he summarized his famous experiments on the Brownian motion of emulsion droplets suspended in a liquid and discussed the fluctuations, the determination of the elementary charge, the a decay of some radioactive nuclei, and the corresponding production of helium. The last section of the paper contains a comparison of the values of Avogadro s number deduced by completely different methods. The very satisfactory agreement between all these values provides the proof of molecular reality announced in the title of the paper.11... 

Preparations of ionium are used as standards of a-ray activity when a more active standard than urano-uranic oxide is necessary. The production of helium from ionium has been obser ed. Uranium Xj may be used as an indicator for ionium when estimating the latter in terms of the equilibrium quantity contained in uranium minerals. ... 

Deuterium ( H), when heated to sufficiently high temperature, undergoes a nuclear fusion reaction that results in the production of helium. The reaction proceeds rapidly at a temperature, T, at which the average kinetic energy of the deuterium atoms is 8 X 10 J. (At this temperature, deuterium molecules dissociate completely into deuterium atoms.)... 

When hydrogen and helium are completely exhausted, heavier elements will burn at successively higher temperatures. Since the most abundant products of helium burning are 12C and 160, important reactions include ... 

The inert gases have a number of uses, and many of these depend upon the very fact that they are inert. The first commercial production of helium caught the British by surprise when a German Zeppelin was hit by incendiary bullets but did not catch fire. The Zeppelin, of course, had been filled with helium instead of highly flammable hydrogen. 

There is still usually plenty of hydrogen left in a star when helium fusion starts in the core. If the products of helium fusion mix with the outer layers of the star it is possible for other elements to be formed. The CNO cycle is an important fusion pathway (Fig. 1.2), which primarily effects the conversion of H to Ele. However, the cycle can be broken, resulting in the formation of heavier elements for example, by the fusion reaction shown in Eqn 1.5. 

The principal products of helium burning are thus 0 and C. That these are the third and fourfti most abundant isotopes in the Solar System (after H and He) shows that helium burning is a significant player in the formation of the elements. Other key products of helium burning are 0 and Ne produced fi om left over from hydrogen burning ... 

After helium is exhausted, the core of a star is composed mostly of carbon and oxygen, the principal products of helium burning. The star contracts again and the temperature and density rise. Carbon burning commences when the... 

Bauer CA (1947) Production of helium in meteorites by cosmic radiation. Phys Rev 72 354-355 Baur H (1980) Numerical simulation and practical testing of an ion source with rotational symmetry for gas mass spectrometers. PhD dissertation, ETH-Ziirich Nr 6596, 94 p (in German)... 

We use the following notation X rate of production of helium by the radium itself,... 

Fleischmann and Pons were actually the first to observe the production of helium-4 in the Pd/D system [4]. However, due to the extensive criticism of their 1989 announcement, they did not want ... to open another front for attacks on their work, and so their measurements of helium-4 were never officially reported. The first reported experiments correlating the calorimetric excess enthalpy and helium-4 production were conducted by Miles in 1990 at the Naval Weapons Center (now NAWCWD) in China Lake, California, and the helium measurements were performed under the supervision of Bush at the University of Texas [6-8]. The presence of helium-4 was observed in eight out of nine effluent gas samples collected during the presence of excess heat [7,8]. No helium-4 was observed for six out of the six samples of effluent gas for a Pd/H20 control study. Measurements were also conducted for heUum-3 in these studies, but none was detected [6]. In summary, for all experiments conducted by Miles at NAWCWD, 12 out of 12 produced no excess helium-4 when no excess heat was measured, and 18 out of 21 experiments gave a correlation between the measurements of excess heat and helium-4 [8, 18]. Three of the experiments that produced hehum-4 were conducted under double-blind rules [8, 18]. An exact statistical treatment for all experiments shows that the probability is only one in 750 000 that the China Lake set of heat and helium-4 measurements could be this well correlated due to random experimental errors [18]. Furthermore, the rate of helium-4 production was always in the appropriate range of 10 to 10 atoms per second per watt of excess power for D -I- D or other likely nuclear reactions [8,18]. 

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