Application of Neutron Activation Analysis for identification of cosmic matter on Earth

Neutron activation analysis (NAA) is an analytical method based on the measurement of characteristic radiation from radionuclides formed by neutron irradiation of the material of interest. The most suitable source of neutrons for NAA is a research reactor. The neutron activation analysis has been found to be extremely useful in the determination of trace and minor elements in geological and extraordinary samples. The method is non-destructive, giving many advantages, which are described. Measured abundances of the elements in meteorites, from major constituents down to those appearing only in trace amounts, provide information important for the theories of the origin and history of the Solar System

The Oslo Meteorite Research for Cosmogenic Radionuclides and The Interpretation of The Results

Nondestructive high-resolution gamma spectrometry techniques were used to measure cosmogenic radionuclides in 32.5g fragment of Oslo meteorite which the fall was not observed. Five radioisotopes with half-lives ranging from 278.1 days to 7.17´105 years have been detected. The signals observed for 26Al, 22Na, 54Mn, 57Co and 60Co were interpreted in terms of the meteoroid depth profiles and terrestrial age after the fall. The pre-atmospheric radius of the chondrite was estimated to be >100 cm. Concentrations of short-lived nuclides limits the fall date before December 2011

Laboratory Research on Hydraulic Losses on SHP Inlet Channel Trash Racks

There is currently a growing trend towards renewable energy sources, which are characterised by a guaranteed power supply and low failure rate. Hydropower plants (small or large) are an example of such a source. They supply a total of 16% of the world’s electricity. The advantages of a small hydropower plant include the relatively simple construction process and the lack of need for upstream water storage. SHPs are one of the most cost-effective and environmentally friendly energy technologies, which is why they are steadily increasing in popularity. One of the important components of SHPs are the trash racks in the inlet channels. Their main purpose is to catch debris and other elements carried downstream and to prevent these pollutants from reaching the turbine units. They can also protect migrating ichthyofauna such as larger fish. If trash racks are installed in the inlet channel, hydraulic losses are to be expected due to the reduction in the flow cross-section through the racks (bars) themselves and through the accumulation of debris and various types of trash on these racks. Energy losses on the trash racks affect the financial aspect of SHP investments. This paper presents the results of laboratory tests on trash racks for SHPs by taking into account the different shapes of the bars used, their number and spacing, and the angles of the trash racks to estimate the hydraulic losses on the trash racks. The measured values of hydraulic losses Δh on the trash racks varied according to the type of trash racks, the density of the bars in the cross-section, and the angle of the trash racks from the horizontal, reaching the highest values on the trash racks with angle bars (AB). They were almost eight times greater than those recorded on cylindrical-bar (CB) trash racks, although they involved different angles. It was shown that the discrepancy in the magnitude of losses on trash racks can be large, even for the same type of trash racks. It depends significantly on the design (shape and bar spacing) of the trash racks and the way the trash racks are installed. Depending on the inclination angle, the increase in energy losses reached 70% for angle bars, 60% for flat-bar trash racks, and almost 40% for cylindrical bars. The values of energy loss as well as the loss coefficient β varied non-linearly for the different bar types depending on the angle of inclination of the gratings, and the degree of this non-linearity depended on the type of bars and the blockage ratio of the section. The presented research results can be useful both during the design and the operation of an SHP

Formation of impact craters and their types

Craters form after meteoroid or asteroid impact son celestial bodies surface are created during three different periods: contact/compression, excavation and modification stage. Depending on its size the craters can be divided into three main types: simple, complex and multi-ring craters. The enormous energy released during the impact forms evident records in basis as shatter cones or breccias and affect the surrounding rock (visible only in micro scale) by shock metamorphism, which has no equivalent in the Earth’s geological processes

Surface prospection of soil samples composition of elements originate from “Meteoryt Morasko” reserve

The research was focused on strewnfield in “Meteorite Morasko” reserve. The main goal of the project was to find correlation between chemical composition of soil and concentration of cosmogenic material which was discovered in the region. After field prospection the sampling was made for three reference regions in the reserve. ICP-MS method was used to determine the elemental composition of soil samples. Investigation has been carried out to indicate the chemical components which iron meteorite matrix is built of like Fe, Ni and Co. Results of the study gave information about distribution and correlation of chemical components in the reserve

Search report of meteorites in Oslo

A piece of a meteorite that had crashed through the roof of a cottage house was find in the central Oslo quarter Rodelřkka at the beginning of March 2012. Some days later the second discovery in the melting snow of Ekebergsletta hilltop plateau triggered the hunting for meteorites in almost all sides of Oslo. The pieces of third meteorite broken by cars and spread out by snowplow was discovered on the asphalt road side by Maciek Burski, the member of Polish Meteoritical Society. Later on the missing fragments of the Maciek’s most east find was collected by Meteoritical Section members of Comet and Meteor Workshop (PKiM) with the help of local meteoritical authorities. The total mass of this unobserved fall is 6.22 kg in five pieces spread out in the eight km-long strewnfield with 200 g and 4.65 kg meteorites on the opposite ends. The Meteorite is not classified yet but unofficial information is “breccia H3-4”

Cosmogenic radionuclides in the Antonin meteorite

The Antonin meteorite fell on July 15, 2021 in Wielkopolska Voivodeship. Its fall was recorded by fireball camera network and the meteorite specimen was recovered soon after, during a dedicated search expedition. Main mass of Antonin was provided for scientific research relatively quickly after recovery, thanks to which the studies of cosmogenic radionuclide concentrations were carried out in the g spectrometry laboratory at the National Center for Nuclear Research in Otwock/Świerk. The analyses revealed concentration of 7Be and the traces of the cosmogenic radionuclides of 48V and 51Cr, whose half-lives are in the range of 15–28 days, clearly confirming the relationship of the specimen with the observed fireball. The relatively high concentrations of 58Co, 56Co, 46Sc, 57Co and 54Mn (half-lives of several months) also confirm the recent fall of the specimen. Additionally, collected radionuclide data allow to estimate pre-atmospheric size of the meteoroid. Distribution of 60Co and 26Al indicates a meteoroid chunk with a radius of 20–25 cm. The result of 26Al measurement suggests that the investigated meteorite fragment comes from a rather shallow depth of this meteoroid. In addition, the original mass of the meteoroid from which the Antonin meteorite originated was estimated to be less than 100 kg, most likely 70 kg

Measurements of radioactive gamma emitters in trinitities

Trynitite is a material in form of a glass created as a result of a nuclear explosion close to ground. The mechanism of its formation is similar to the formation of impact glasses and tektites, although the material usually contains trapped bubble voids, much more water and it is radioactive. High resolution non-destructive gamma spectrometry technique was used to measure rdionuclides in the chips of trinitities. The signals were detected for 137Cs, 152Eu, 226Ra, 241Am and 133Ba. The most extreme concentration was found for cesium 137Cs which the specific activity reached the level of 2317 mBq/g. Much lower values were obtained for 241Am – 722 mBq/g, 152Eu – 211 mBq/g, 226Ra – 451 mBq/g and 133Ba – 94 mBq/g

60Co measurement in steel cast

Radioactive cobalt isotope 60Co is produced in neutron activation process of stable isotope 59Co by neutron capture reaction 59Co(n,g)60Co, in solar wind charge exchange 60Ni(n,p)60Co or in spallation process 62Ni(n,p2n)60Co. These processes are responsible for isotope 60Co production either in nuclear reactor on Earth or beyond – in stars and in meteorites (induced by cosmic rays). In this work the results of 60Co measurements in metal sources by gamma spectrometry laboratory are presented. A metal reference radioactive standards made up of steel cast with discs shaped geometries and different diameters have been tested in gamma-ray spectrometry measurement system. The reference activity concentrations of 60Co were in the range of (0.291±0.010) Bq·g–1 to (1.544±0.030) Bq·g–1. The mean minimal detectable activities (MDA) obtained by series of the 6 to 18 hours lasting measurements of described above standards with HPGe detectors carried out in NCBJ OR POLATOM were in the range of 6.1 mBq·g–1 to 8.5 mBq·g–1. The results correspond to the values of 60Co activity concentration measured in the iron meteorites with young terrestrial ages