Coulomb expansion of deuterated methane clusters irradiated by an ultrashort intense laser pulse

The simulations of three-dimensional particle dynamics show that when irradiated by an ultrashort intense laser pulse, the deuterated methane cluster expands and the majority of deuterons overrun the more slowly expanding carbon ions, resulting in the creation of two separated subelusters. The enhanced deuteron kinetic energy and a narrow peak around the energy maximum in the deuteron energy distribution make a considerable contribution to the efficiency of nuclear fusion compared with the ease of homonuelear deuterium clusters. With the intense laser irradiation, the nuclear fusion yield increases with the increase of the cluster size, so that deuterated heteronuelear clusters with larger sizes are required to achieve a greater neutron yield.     

Features of the total disintegration events of heavyemulsion targets caused by 4.5A GeV/c16O

Total disintegration events produced by 4.5\,A GeV/c $^{16}$O--AgBr interactions are analysed to investigate the characteristics of secondary charged particles produced in such collisions. The multiplicity distributions of grey, black, and relativistic charged particles can be well represented by Gaussian distribution. The average multiplicity of grey particles is found to increase with the mass of projectile increasing, while that of black particles is found to decrease with the mass of projectile increasing. This result is in good agreement with the prediction of fireball model. Finally, the linear dependence between grey and black particles is observed, but there is no distinct dependence between the production of relativistic charged particles and the target excitation.     

Biaxial nematics: symmetries,order domains and field-induced phase transitions †

We studied the symmetry and spatial uniformity of the orientational order of the biaxial nematic phase in the light of recent experimental observations of phase biaxiality in thermotropic bent-core and calamitic-tetramer nematics. Evidence is presented supporting monoclinic symmetry, instead of the usually assumed orthorhombic symmetry. The use of deuterium nuclear magnetic resonance to differentiate between the possible symmetries is described. The spatial aspects of biaxial order are presented in the context of the cluster model, wherein macroscopic biaxiality can result from the field-induced alignment of biaxial and possibly polar domains. The implications of different symmetries on the alignment of biaxial nematics and on the measurements of biaxial order are discussed in conjunction with the microdomain structure of the biaxial phase.     

Beiträge zur Mikrobestimmung von Kohlenstoff-14 und Tritium

Die Verwendung Con¹⁴C und Tritium zur Lösung kinetischer und analylischer Probleme erfordert zuverlässige Analysenmethoden. Es wird iiber die Herstellimg von Meβgasen durch Naβcerbrennung mil Chromsäure-Jodsäure-Gemischen, Trockenverbrennung in Gegenwart Con Katalysatoren wie Kupferoxid, Kobaltoxid und Zersetzungsprodukte des Silberpermanganats und durch Umsetziingentm geschlossenen Rohr berichtet. Die Aktivitätsniessungen erfolgten auf cerschiedene IVeise. Hier werden besonders die Ergebnisse diskutiert, die durch Ionisationskammermessungen erzielt wurden. Schlieβlich werden einfache Apparaturen zur routinemäβigen Durchfiihrung von Mikroanalysen beschrieben.     

Modified Preparation of 99mTe-Iron Hydroxide Macroaggregate (99mTe-Fe-(OH)2MA)

A modified method for preparing ^99mTc-FHMA for pulmonary studies is elabrated. It includes a new antioxidant sodium metabisulphite. The optimum conditions for the reparation are given. A simple and rapid procedure with a yield more than 98% is described which eliminates a further purification step.     

10 Jahre Ständige Kommission des RGW für die friedliche Anwendung der Atomenergie

0. Einleitwng

1. Reaktorwissenschaft und -technik und Kernenergetik

2. Kerntechnischer Gerätebau

3. Produktion von Isotopenerzeugnissen

4. Strahlenschulz und Schutztechnik

5. Isotopenanwendung

6. Strahlentechnik

7. Zur weiteren Tätigkeit der Ständigen Kommission Atomenergie des RGW     

Reaktion von Pyridin-2-Carbonsäure Mit Tetrabutylammonium-Tetrachloro-Nitridotechnetat(VI) Sowie Tetrabutylammonium-Tetrachlorooxotechnetat (V)

Abstract

The reaction of 2-pyridine carboxylic acid (Hpic) with (n-Bu₄N)[TcNCl₄] and (n-Bu₄N)[TcOCl₄] in ethanol and methanol, respectively, yields the dinuclear μ-oxo complex [(pic)₂NTc-O-TcN(pic)(Hpic)Cl] and the monomeric complex [TcO(pic)₂Cl].

Visible and infrared spectroscopy, ESR, ¹H-NMR and ⁹⁹Tc-NMR have been used to characterize the new compounds. The most important field of application for the new compounds synthesized is radiodiagnostics.     

Precise Radiometry: Some Recent Aspects of Fruitful Interaction with Atomic Physics

Modern radiometric analytics demands a complex consideration of nuclear and electron shell processes, if more pretentious aims are envisaged. As an example the small variation of decay rates of radionuclides presents possibilities for information on chemical situations of decaying atoms. In principle this phenomenon is well known since many years, but now the situation is such that, e.g. in ^99mTc internal conversion, a full agreement of the difficult experiments and the respective theory was established. The secondary emission of X-rays as a consequence of high excitation of electron shells in combination with nuclear transitions supplies another example for a methodical progress of radiometry. Investigations on ⁵¹Cr as an electron capture nuclide have shown that chemically induced variations of the K_α to K_β X-ray intensity ratio is at least qualitatively understood.