Simulating the stopping dynamics of highly charged ions in an ultra-cold, strongly coupled plasma

We introduce a method for stopping highly charged ions (HCIs) in a laser-cooled one-component plasma (OCP) of ²⁴Mg⁺ ions and present results on stopping times derived from realistic molecular dynamics simulations of the complete stopping process. This stopping scheme can provide ultra-cold highly charged ions for future in-trap precision mass measurements. The choice of an ultra-cold ion plasma as a stopping medium is governed by the almost negligible charge exchange of the HCI with the laser-cooled ions and the very low temperatures which can be reached. In our analysis we focus on the stability and fast recooling of the plasma – two features essential for the experimental realization of this stopping scheme.      

Metallreiche Gadoliniumhydridhalogenide

Metal-rich Gadolinium Hydride Halides Preparation, structures, and thermal behaviour of gadolinium hydride halides GdXH_n (X = Cl, Br, I; 0.7 < n < 0.9) are described. The preparation is done by heating Gd, GdH₂, and GdX₃ in sealed Ta ampoules to 900°C and 950°C. The arrangement of the heavy atoms corresponds to the 3 slab (X? Gd? Gd? X) structures of ZrCl and ZrBr. Besides these, a new stacking variant containing only 2 slabs in the identity period (2s-GdBrH_0·69 and 2s-GdIH_0·80; nomenclature of niobium dichalcogenides) is found.     

Quality criteria for the isotope dilution method with HRGC/MS

The isotope dilution method is characterized by the use of appropiately labelled standard compounds in conjunction with mass spectrometry coupled to chromatographic systems. Although the isotope dilution method seems to be a simple procedure, some quality criteria for sample preparation, measurement and quantification have to be considered. Furthermore, archiving and documentation of analysis data as well as the use of reference materials to validate the analysis method are important with regard to European standard regulations for quality assurance. In view of this background and the increasing application tendency to environmental problems, essential quality critera for the isotope dilution method are presented and discussed, with special respect to sample extraction, separation performance and sensitivity. Also the quantification procedures are summarized.     

Nebenreaktionen der Chloraminherstellung

Subreactions in the Chloramine Preparation. In the preparation of chloramine from solutions of ammonia and sodium hypochlorite there is considerable overchlorination, resulting in the formation and subsequent decomposition of dichloramine. Nitrogen, chloride ion, and hypochlorite ion are formed in the decomposition of dichloramine; in the presence of certain organic compounds the products of chlorination via radicals are observed. Chloramine is obtained in over 90% yield by neutralizing the alkali formed in the reaction of ammonia with hypochlorite. Etheral solutions of dichloramine are prepared from chloramine solutions by treatment with phosphate buffer.     

Spectraluntersuchungen über die Energie der Einwirkung von Brom auf aromatische Kohlenwasserstoffe

Ohne Zusammenfassung