摘要:

Laser resonance ionization mass spectrometry has been investigated as a method for the determination of trace amounts of actinides and technetium. A high sensitivity and selectivity have been achieved by three-step photoionization of the elements in the atomic state followed by time-of-flight measurement for mass analysis. The system for photoionization consists of three dye lasers which are pumped simultaneously by a copper vapour laser of 30 W average power at a pulse repetition rate of 6.5 kHz. The time-of-flight spectrometer has a mass resolution better than 2500. By ionization via autoionization states and by saturation in each excitation step a detection limit of less than 108atoms of actinides or of technetium in the sample can be reached.

ISSN:0021-1915    

DOI:10.1080/10256018808623954

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

In the last years the autoradiography has been developed to a quantitative method of radioactivity measurement. Operating techniques of quantitative autoradiography are demonstrated using special standard objects. Influences of irradiation quality, of backscattering in sample and detector materials and of sensitivity and fading of the detectors are considered. Further on questions of quantitative evaluation of autoradiograms are dealt with, and measuring errors are discussed. At last some practical uses of quantitative autoradiography are demonstrated by means of the estimation of activity distribution in radioactive foil samples.

ISSN:0021-1915    

DOI:10.1080/10256018808623955

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

With regard to the planned starting of the new microtron in the GDR first investigations on raw materials for the gasconcrete production have been done to clear up the possibilities of photon activation analysis (PAA). Irradiations have been partly carried out on linear accelerators with a self-developed moveable activation equipment. PAA-results of qualitative and quantitative elemental analysis are described. The detection of chlorine is important for studying the oversalting processes in buildings.

ISSN:0021-1915    

DOI:10.1080/10256018808623956

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An automatic laboratory is described, which can analyse the reprocessing input of U and Pu by isotope dilution mass-spectrometry. A robot prepares the sample for the separations of U and Pu from fission products by an automat. Alpha- and mass-spectrometers analyse the samples and record the data automatically. The evaluation is done on-line by a central computer. Performance of the installation is described.

ISSN:0021-1915    

DOI:10.1080/10256018808623957

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

We analyzed six profiles of the copper shale from the Basin of Sangerhausen (GDR) (determination of 52 chemical elements) to understand the vertical and lateral distribution of the elements (52 determinations) and the role of “Bote Faule” in the process of mineralization was studied. Using instrumental neutron activation analysis the concentration of 27 chemical elements were determined. On basis of the calculated correlation coefficients for element pairs their binding types could be estimated and some peculiarities of the distribution of elements were established. Results of isotope geochemical investigations of the carbonate fraction support the supply of oxidic waters across the “Bote Faule” from the ingression of the Zechstein sea to late diagenesis of copper shale.

ISSN:0021-1915    

DOI:10.1080/10256018808623958

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256018808623959

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Some rare earth elements (REE) are important secondary components of the Ca-titanate-mineral perowskite concentrate. For the valuation of an analytical separation method of the REE from the mineral (HF – H2SO4pressurising, fluoride, hydroxide, and oxalate precipitalions) nuclear reactor activated mineral samples were used. By high resolution gamma spectrometry the141Ce content of the filtrates and of the final product (REE concentrate) was measured. The proportions of element concentrations of mineral concentrates to REE concentrates were evaluated by means of NAA with a252Cf source for La, Ce, Pr, Nd, Eu, and Na, and by measurement of natural γ-radiation for Th and Ra.

ISSN:0021-1915    

DOI:10.1080/10256018808623960

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Some analytical procedures for the determination of tritium, strontium-90 and iodine-129 in liquid radioactive wastes from nuclear power plants of the type WWER-440 are described. Liquid scintillation counters (3H), beta-counters applying an Al-absorber (90Sr) and neutron activation analysis (129I) applying a suitable separation process are used. The results are discussed with respect to the waste management manufactured in future and the deposition of radioactive wastes coming from the nuclear power station “Kozloduj”.

ISSN:0021-1915    

DOI:10.1080/10256018808623961

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The present paper assesses the feasibility of the determination of several elements (mainly with a small nuclear charge) in complex metallic matrices by a combination of individual autoradiographic techniques. The ways of preventing various techniques from interfering with each other have also been considered. A new analytical procedure that minimize such interference has been proposed: the autoradiography of the radionuclides introduced into the samples via various physico-chemical methods; the activation autoradiography of charged particles; neutron-induced autoradiography; the track autoradiography of the instant products of nuclear reactions; and α-radioactivity-induced track autoragdioraphy. The paper cites examples of multielement autoradiographic investigations of iron, zirconium- and niobium-based alloys conducted on corrosion-tested samples.

ISSN:0021-1915    

DOI:10.1080/10256018808623962

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Compared are some of the properties of the solid state track detectors (SSTD) on the basis of nitrogen-free cellulose derivatives (cellulose acetate, triacetate and acetobutyrate), cellulose nitrate (LR-115, CN-85) and a CR-39 track detector. The optimum composition of the cellulose acetobutyrate has been established which will ensure the best mechanical properties. A simple device has been used to measure the α detection effectiveness over the energy range from 0 to 1.2 MeV of the cellulose acetobutyrate detectors in an electric field or under UV radiation or after catalytic etching. The proton detection effectiveness of the CN-85 detector has been measured. Also presented are the track autoradiograms of the distribution of B, Li, N and3He in silicon, silicon carbide and steel.

ISSN:0021-1915    

DOI:10.1080/10256018808623963

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor