[en] A very efficient extraction of silver with tetrabutyl dithiopyrophosphate (TBDTPP) is followed by dramatic changes in the structure of the extractant molecule. The IR and NMR spectroscopic studies revealed that in the presence of Agsup(+) and NOsub(3)sup(-) ions the TBDTPP molecule rearranges first into a molecule containing a P-S-P bridge and one P=O group instead of P-O-P and P=S, respectively, and then into a molecule containing two P-S-C and two P=O groups at a P-O-P bridge. (author)

[en] General assumptions for project of target activation stand at AIC-144 cyclotron are presented. The project predicts production of ⁶⁷Ga, ¹¹¹In, ²⁰¹Tl, ¹³⁹Ce, ⁸⁸Y, ¹²³I and ²¹¹At isotopes using various target backings. Directions concerning target cooling and beam parameters are also described

[en] In the Laboratory of Chemistry and Radiochemistry, research on chemistry of the transactinide elements 104(Rf), 105(Db) and 106(Sg) in model systems with their homologs (Zr, Hf, Nb, Ta, Mo, and W) was continued, and studies on ion-exchange and extraction behaviour of Tc, Re and Os as homologs of Bh(107) and Hs(108) were started. Basing on the law of periodicity, conditions for separation of superheavy elements Rf, Sg, and Bh were adjusted. A particularly important achievement was participation of our group in the third experiment in the world on aqueous chemistry of Sg, performed in the summer 1998 in GSI Darmstadt. The Environmental Radioactivity Laboratory, was continuing non-stop records of the ground-level atmospheric radioactivity. Besides, Pu content was determined in two-years collection of rainwater samples. An air monitoring station was recently equipped with a prototype γ-spectrometric scintillation system which, modem-coupled with the central server, will be tested in the Laboratory. For ultra-low-background measurements a muonic chamber was designed and made, and new spectrometer's background was recorded in various shielding configurations. Research on α-active and γ-active environmental contaminants in Antarctic samples, supplied by the Institute of Botany of the Jagiellonian University, resulted in an M.Sc. thesis defended in June 1998. Other cooperations of the Laboratory in 1998 have been the following: a) determination of ⁹⁰Sr and ¹³⁷Cs in wild animals bones (Institute of Nuclear Techniques, Technical University, Budapest, Hungary and Medical Academy, Bialystok, Poland); b) PIXE determinations of trace elements in ASS-500 air filters (Department 2 of the Institute) and mineralogical studies of collected dusts (Institute of Geological Sciences, Jagiellonian University and the Institute of Geography, Pedagogical University, Cracow); c) a-spectrometric determination of radium isotopes in river waters and bottom sediments (Institute of Geography, UJ) and use of Pu and Cs contaminations as tracers to follow-up natural processes in peat bog (University of Agriculture, Cracow); d) preparation of α-spectrometric sources by electrodeposition (other groups of the Department) and determination of ²⁴¹Pu in α-spectrometric Pu sources (Silesian University, Katowice, Poland); e) comparative measurements of γ-background dose rate, using the PMS station, TL detectors and Gamma-Tracer probe (Health Physics Section of the Institute). In recognition of his expertise in radioecology, Dr Mietelski has been admitted as a Regular Member of the U.I.R. (Union Internationale de Radioecologie). Mrs Jasinska, Mr Kozak and Dr Mietelski received the Prize of the President of the City of Cracow for ''Organising and conducting continuous radiological monitoring of the air in Cracow and for the researches at the radioactive contamination of the environment''. The project on construction of the internal target assembly for isotope production was continued in the Laboratory of Physical Chemistry, in cooperation with the Cyclotron Section and Division of Mechanical Constructions of the Institute, and with the JINR, Dubna. In the meantime, in pilot experiments on the internal beam of the AIC-144 cyclotron, small activities of ¹¹C PET tracer were obtained from proton irradiated B₂0₃ targets. A joint project with the Silesian Medical Academy, on applications of ³²P sources pure (β^- emitter) in intravascular brachytherapy (IVBT), was started. Chemical and ionic methods of preparation of ³²P sources and their TL dosimetry were tested in cooperation with the Laboratory of the Ion Implanter and with the Health Physics Section of the Institute. Measurements of the activity of selenoenzymes in the context of human thyroid health or disease were continued in cooperation with the Medical College of the Jagiellonian University, and with the Rowett Research Institute, Aberdeen, Scotland

[en] The aim of this work was to check whether the stable cesium content in forest litter affects the value of radiocesium from litter-to-mushroom transfer factor Tf or not. Total cesium in litter, measured by AAS, varied from 0.1-2.7 micrograms/g. These data, combined with earlier results for mushrooms, showed no simple correlation for Tf. More complex relationships provided very high correlation coefficients, but their validity needs further investigation. (author)

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[en] Method of target cooling optimizing for isotope production is described. The target cooling system is a part of isotope production stand at AIC-144 cyclotron

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[en] The AIC-144 isochronous cyclotron has been constructed and put into operation in the Institute of Nuclear Physics. The first experiment, in which ¹¹C was produced in the ¹¹B(p,n)¹¹C reaction, took place on 18.12.1998. In further experiments, more radioactive isotopes were obtained in the following nuclear reactions; ¹¹B(p,n)¹¹C, ^natNi(p,xn)^56,57Co, ^natRb(p,xn)^83,85Sr, ^natRu(p,xn)'9^9-102Rh, ^natCd(p,xn)¹¹¹In, ^natTa(p,xn)^178,181W. Targets of natural isotopic abundance were bombarded with the internal proton beam at energies varying from 10 to 30 MeV. Projectile energy was selected by placing targets at the appropriate acceleration radius. The applied beam currents never exceeded 5 μA. The boron targets were prepared from molten B₂O₃ or as ionically implanted material. The rubidium was used in the form of powdered RbCl compressed on a metallic support, and other targets were pure metals. All targets were fixed in an aluminium frame attached to the water-cooled copper head of the probe, which in principle serves to beam current monitoring and will be replaced soon by a remotely-controlled dedicated target assembly. The qualitative and quantitative analysis of activation products was performed by gamma spectrometry. Irradiation products were separated from targets or not, depending on further application. Obtaining of ²¹¹At and other isotopes is planned for the future. (author)

No abstract available