He-like argon

On the other hand, the dependence of the laser contrast on the mean ion energy is shown in Fig. 12.6b. The mean ion energy increases slightly with the laser contrast. These results demonstrate that hot electrons produced by high-contrast pulses (smaller prepulses) shift the ion balance towards more highly charged states, which enhances both the X-ray yield of the He-like argon ion and the hydrodynamic/Coulombic pressure. 

Fig. 12.8. a The pulse duration dependence of the Heai line shape for a fixed laser energy of 49 mJ. Open circles, triangles, and squares represent experimental data for pulse durations of 30, 500, and 1000 fs, respectively. The solid, dotted, and dashed lines represent Doppler profiles obtained by fitting the central part of the line to the experimental data, b The pulse duration dependence of the kinetic energies of He-like argon ions calculated from the Doppler shift... 

The spectra are dominated by triplet and singlet transitions in He-like ions and associated satellite transitions in the Li- and Be-like system. The spectrum of He-like argon and iron ions is shown in Fig. 8.2. 

Fig. 8.2. (a) Spectrum of He-like argon obtained on tokamak TEXTOR open points - experimental spectrum, dashed line - theoretical fit. Spectrum was recorded at 3.7-4.7 s, Te = 1.1-1.2 keV. (b) Spectrum of He-like iron from the tokamak Tore Supra open points - experimental spectrum, dashed line - theoretical fit. Spectrum was recorded at time 4.0-6.0 s, Te = 2.0-2.2keV... 

TABLE 11.1 Example of experimental determination of He-like argon transition energies in eV pi]... 

The evaluation of the full MSC and VTX correction in combination with electron correlation (beyond second order) is prohibitive in any gauge for computational reason. Fortunately, however, one can conclude from the second-order results that these contributions should be relatively small in the Coulomb gauge and be well approximated by the zero-potential part. This gives the result shown in Table 3 for He-like argon (Z = 18). It is obvious from the results in the table that no sensible results can be deduced by using this approximation in the Feynman gauge. 

Helium is the second most abundant element in the universe (76% H, 23% He) as a result of its synthesis from hydrogen (p. 9) but, being too light to be retained by the earth s gravitational field, all primordial helium has been lost and terrestrial helium, like argon, is the result of radioactive decay ( He from a-decay of heavier elements, " °Ar from electron capture by... 

Strutt was the fourth Baron Rayleigh, son of John William Strutt, the third Baron Rayleigh, with whom Ramsay had collaborated on the discovery of argon. He, like Thomson, ran independent experiments that undermined Ramsay, Collie, and Patterson s results ... 

Fig. 8.3. (a) Radial profiles of argon density in TEXTOR point line H-like, dashed line He-like solid line Li-like ions. Emissivity profiles of the different argon stages presented in (b) point line H-like, dashed line He-like, solid line Li-like ions... 

Ar/ Ar in the least contaminated Samoan xenoliths varies from 4,000 to 12,000, with the highest values found in samples with the highest He/ He values. There is little evidence for atmosphere-like argon in the source of Samoan lavas, with values likely to be in excess of 5,000 (Poreda and Farley, 1992). These data, combined with i29xe and Xe anomalies 6% greater than the atmospheric value, contradict the idea that... 

He/" °Ar ratios (where " °Ar represents radiogenic " °Ar added to air-like argon to... 

FIGURE 11.12 He-like and Li-like argon spectrum using quartz (loT) crystal. HF power injected P = 400 W. Argon partial pressure pAr = 5 x 10 mbar, total pressure ptot = 5 x 10 mbar. This spectrum has been obtained with an integration time of 2 h. The focal position of this spectrum was in correspondence to the ls2p Pn — Is Sq peak, near channel 310. 

It is likely that the lead and sulfur atoms in most of the lead sulfarsenites and related minerals have the tercovalent argonic structures Pb—- and S y+, as in galena. Nowacki (1969) has published a valuable summary of results of structural studies of the so-called sulfosalt minerals, in relation to a system of classification of the structures that he has developed. Many structures of sulfide minerals have been determined by him and his coworkers. 

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