[en] For a given product concentration, choice of the cascade structure is presented. For the cascade, having the minimum number of columns for the desired production, the operation curves and other characteristics are calculated. (author)

[en] For minerals of metal pegmatite, the K, Ar content and the ⁴⁰Arsub(ex)/sup(36)Arsub(capt) ratio are measured. An apparent value of age reaches 10¹⁰ years. Based on Rb-Sr measurements, absolute time sequence of mineral crystallization, Δ t, is calculated. The plot sup(40)Arsub(ex)/sup(36)Arsub(capt) vs Δ t has been constructed from a typical form of which an assumption has been made on the existence of radioactive decay of two elements. A half-life period calculated for the first element, supposedly EcCs, is equal to 1 x 10⁶ years, and that for the second one, supposedly EcRa, is 7x10⁶ years. Application of these half-lives to treatment of literature data on the content of excess argon leads an analogous - up to 70x10⁶ years - succession of mineral crystallization. A conclusion is drawn on the radiogenic nature of excess argon

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[en] The construction of UHV metal-gas line is described. The instrumental set-up comprises the following units; (1) double vacuum crucible for Ar extraction, which is made of tantalum and can be heated by resistance oven to 1500 C; (2) ³⁸Ar isotope spike container with gas pipette for the isotope dilution technique; (3) two ovens - filled with CuO for oxidation of hydrogen and hydrocarbons and another filled with Ti shaving for cleaning all the reactive gases; (4) getter pump for final cleaning of argon and (5) 180 C-sector mass spectrometer for quantitative analysis of argon isotopes. (author). 11 refs, 8 refs

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[en] The ³⁵Cl(p, γ)³⁶Ar reaction was studied in the proton energy range E/subp/ = 2.36--2.42 MeV. Yield curves were obtained using NaI(Tl) and Ge(Li) detectors. The E/subx/ = 10854.2 +- 1.6 keV level, populated at the E/subp/ = 2414.4 +- 1.5 keV resonance, decays to the E/subx/ = 7711 and 8133 keV levels with branching ratios of (35 +- 15) % and (65 +- 15) %, respectively. From resonance strength and angular distribution measurements as well as from the comparison with the γ-decay scheme of the lowest T = 2 state of ³⁶Cl, the E/subx/ = 10854 keV level can be assigned definitely (J/sup pi/, T) = (0⁺, 2)

[en] Discussion is made on the origin of the atmosphere, the mass balance of rare gases, the isotopic abundance ratio of Ar, and the model of the evolution of the atmosphere. The relative abundance of rare gases in the atmosphere is much different from that of the sun. For example, ⁴⁰Ar is present in the air at the concentration of about 1%. This concentration is much higher than the solar abundance. This extraordinarily high concentration of Ar in the air is now attributed to the formation of ⁴⁰Ar by the decay of ⁴⁰K contained inside the earth. The isotopic abundance ratio of Ar, namely the abundance ratio of ⁴⁰Ar:³⁶Ar was estimated to have been about 10^-4, 4500 million years ago, whereas the ratio is now 99.6:0.337. This increase of the amount of ⁴⁰Ar is attributable to the decay of ⁴⁰K. The abundance of potassium in the earth is estimated to be about 130 ppm. The continuous degasification model cannot explain the change of the abundance of ⁴⁰Ar. On the other hand, the catastrophic degassification model well explains the change of ⁴⁰Ar in the atmosphere. (Fukutomi, T.)

[en] Complete text of publication follows. The exotic shapes of atomic nuclei has attracted much attention recently both from the experimental and from the theoretical sides. E.g. the superdeformed (SD) shape in N = Z nuclei were observed experimentally during the last decade. In particular the SD band of the ³⁶Ar nucleus was detected in 2000 [1]. Following the experimental observation a considerable theoretical effort has been concentrated on this band. In [2] e.g. the possible binary clusterizations of this state was studied systematically. Similar studies have been done also for the ground, and the hyperdeformed band. The latter one had been predicted from alphacluster model calculations [3]. The possible binary cluster-configurations are important not only for the better understanding of the structure of the shape isomers, but also from the viewpoint of predicting the favoured reaction channels to populate these states. This is the straightforward consequence of the close relation between the clusterization and reaction channels. (In fact, a cluster-configuration is defined by the reaction channel in which it can be observed.) One of the interesting conclusions of the work [2] was, that the hyperdeformed (HD) state of the ³⁶Ar nucleus could be populated in the ²⁴Mg+¹²C and ²⁰Ne+¹⁶O reactions. A recent analysis of the ²⁴Mg+¹²C elastic scattering [4] revealed the fact that the cross section can be described only by supposing resonances on top of the potential scattering. This very careful analysis incorporated phase-shift study, as well as Regge-pole and energy-dependent resonance calculations. The existence of five resonances have been proved, which have angular momenta 2, 4, 6, 7, 8. These states together with the resonances from the ²⁰Ne+¹⁶O reactions seem to establish a rotational band, as shown in the upper part of Fig. 1. Its moment of inertia is in a very good agreement with that of the HD shape predicted from alpha-cluster model [3]. The similarity of the (predicted and observed) moments of inertia, and the fact that the resonances were seen in exactly those reactions, which define the preferred cluster-configurations of the HD shape suggest that the recently observed band in Fig. 1. is a good candidate for the hyperdeformed shape isomer of the ³⁶Ar nucleus. For comparison also the ground and superdeformed bands are indicated in Fig. 1. Since a candidate for the HD state showed up, the exciting question arises if such a shape can be seen in shell-model calculation as well. In [5] we have carried out Nilssonmodel+ quasi-dynamical SU(3) calculation in order to find the answer. In this kind of study the shape isomers are obtained from the SU(3) symmetries, not from the minima of the potential energy surface. They are determined as the horizontal plateus of the stair-like functions, shown in Fig. 2. (In lighter nuclei, where detailed comparison could be made, the two method gave results in very good agreement with each other.) As it is seen in Fig. 2. in addition to the ground and superdeformed states the shell model predicts two candidates (a slightly triaxial, and a cylindrical one) for the hyperdeformed shape. The cylindrical state has exactly the same symmetry as that from the alpha-cluster model, and consequently the same moment of inertia, as well. To sum up: from cluster studies [2,3] we have predicted [2] the ²⁴Mg+¹²C and ²⁰Ne+¹⁶O channels to populate the HD state in the ³⁶Ar nucleus. Recently a highly-deformed rotational band has been observed [4] experimentally in these reactions. The moment of inertia is in complete agreement with the prediction. Furthermore, the same state has been found in Nilsson-model calculation [5]. Therefore, we conclude that it is a good candidate for the hyperdeformed band in the ³⁶Ar nucleus, as shown in Fig. 1. Thus it might very well be that the ³⁶Ar nucleus is the first N = Z nucleus in which the ground, superdeformed and hyperdeformed bands have been observed.