The results of an experiment devoted to studying archeological objects in the territory of the Holy Trinity Danilov Monastery in the town of Pereslavl-Zalessky, Yroslavl region, and performed by the muon radiography method are presented. The experiment in question is described, and the first results of the data analysis, which demonstrate the sensitivity of the chosen method to the task at hand, are presented.

A new additional aspect of the analysis of the data of the OLYMPIA experiment on the search for nuclei of heavy cosmic ray components in olivine crystals from stony—iron meteorites is presented. Two groups of crystals with different charge spectra of recorded nuclei are detected. Possible causes of this phenomenon and its effect on the final spectrum are discussed.

Solid-state track detectors made of glass have been used for detecting fission fragments since the 1960s [1–3]. These detectors are efficient for recording, they are relatively insensitive to light and background beta and gamma radiations, and they have a low own background. The passage of a multicharged ion in a glass creates a hidden image in the form of residual defects along the track of the ion with a width of ~10 nm. This hidden image can be detected by chemical etching. In an optical microscope, the etched track is observed as a well of a conical shape with a vertex coinciding with the trajectory of the particle, and with a diameter on the glass surface of the order of 5 to 10 μm. Compared to other solid-state detectors of multicharged ions (micas, plastics), glasses have a number of advantages, especially the lack of layering, which prevents the restoration of the full length of the track. We need to note the spectrometric property of glasses, namely, the proportionality of the linear size of the etched defect to the charge of the particle slowing in the detector to a stop. This property allows establishing a relationship between the particle charge and the geometric parameters of the track. In this study we used phosphate glasses as materials for detectors of charged particles. In these glasses, the main glass-forming component is phosphorus pentoxide P2O5. In particular, phosphates were successfully used in 1969 at the LNR JINR in an experiment to search for element 105 by spontaneous fission [4]. Previously we demonstrated a successful implementation of the automated processing of the detected tracks [5]. The aim of this study is to develop an offline method for an automated search for rare events of the decay of superheavy nuclei in order to record multicharged ions and determine their characteristics.

The results of the search for tracks of heavy and superheavy nuclei of galactic cosmic rays in the charge range Z = 26 − 129, identified in olivine crystals from Maryalahti and Eagle Station meteorites are presented. The database including characteristics of 21743 tracks, obtained in the OLIMPIA experiment, is currently the largest one within the charge range under study. It includes three tracks of superheavy nuclei with charge 119 −6 +10 and a minimum lifetime estimated as several tens of years, which can be considered as a direct experimental validation of the existence of natural superheavy nuclei from the “stability island”.

This work was performed within the OLYMPIA experiment on the study of tracks of heavy and superheavy cosmic ray nuclei in olivine crystals from Marjalahti and Eagle Station pallasites. Depth distributions of the track formation rate for heavy cosmic ray nuclei in olivine crystals from pallasites of different pre-atmospheric sizes were obtained. The dependences obtained were used to analyze the data on the track density in olivine crystals from the Marjalahti pallasite. In three crystals, the track distribution with a high density gradient was detected, which indicates a complicated radiation history of the meteorite.

Cosmic ray muonography is a novel technique for imaging of the internal structures of large natural and industrial objects. It exploits the capability of high energy muons from cosmic rays to penetrate large thicknesses of large subjects to be studied, in order to obtain a density map. It uses muon flux attenuation and absorption in materials of investigated objects. Nuclear emulsions are tracking detectors well suited to be employed in muonography for investigations of inner structure of large objects up to kilometers size, since emulsions have firstly an excellent angular resolution, they are compact and robust, do not require power supply. The muonography methods are applied to study one of UNESCO world heritage objects, the unusual building in the Naryn-Kala citadel hidden underground. The use of nuclear emulsions as probing radiation detectors provides for a uniquely high resolution capacity of recording instrumentation combined with the potential of modern image analysis methods giving 3D reconstruction of the internal structures of the investigated object.

The method of using natural track detectors, i.e., meteorite olivine crystals, is developed and improved applied to the problem of searching for superheavy nuclei in nature, in galactic cosmic rays (GCR). The new technique implements the sequence of etching, grinding, and track identification operations using the automated PAVICOM facility. The data on the track length and etching rate in combination with the results of calibration on heavy nucleus accelerators allowed the development of a technique for determining the GCR nucleus charge with an accuracy of ±2. On this basis, a significant set of experimental data on superheavy nuclei of natural origin was obtained (21743GCRheavy nucleiwith Z >20, including three nucleiwith a charge of 119 −6 +10 ). The minimum lifetime T min of the last-mentioned is within 50 years< T min < 100 years, which exceeds the lifetime of transfermium nuclei synthesized on accelerators by many orders of magnitude. The long-lived superheavy nuclei detected in the GCR spectrum can belong to the “stability island”.

Results of nuclear physics research made using track detectors are briefly reviewed. Advantages and prospects of the track detection technique in particle physics, neutrino physics, astrophysics and other fields are discussed on the example of the results of the search for direct origination of tau neutrino in a muon neutrino beam within the framework of the international experiment OPERA (Oscillation Project with Emulsion-tRacking Apparatus) and works on search for superheavy nuclei in nature on base of their tracks in meteoritic olivine crystals. The spectra of superheavy elements in galactic cosmic rays are presented. Prospects of using the track detection technique in fundamental and applied research are reported.

This paper focuses on the basic principles of the muon radiography method, reviews the major muon radiography experiments, and presents the first results in Russia obtained by the authors using this method based on emulsion track detectors.

The aim of the OLIMPIYA experiment is to search for and identify traces of heavy and superheavy nuclei of galactic cosmic rays (GCR) in olivine crystals from stony-iron meteorites serving as nuclear track detectors. The method is based on layer-by-layer grinding and etching of particle tracks in these crystals. Unlike the techniques of other authors, this annealing-free method uses two parameters: the etching rate along the track (V-etch) and the total track length (L), to identify charge Z of a projectile. A series of irradiations with different swift heavy ions at the accelerator facilities of GSI (Darmstadt) and IMP (Lanzhou) were performed in order to determine and calibrate the dependence of projectile charge on Vetch and L. To date, one of the most essential results of the experiment is the obtained charge spectrum of GCR nuclei within the range of Z > 40, based on about 11.6 thousand processed tracks. As the result of data processing, 384 nuclei with charges Z >= 75 have been identified, including 10 nuclei identified as actinides (90 < Z < 103). Three tracks were identified to be produced by nuclei with charges 113 < Z < 129. Such nuclei may be part of the Island of Stability of transfermium elements.

An original method of studying chemically etched tracks of heavy nuclei in olivine from pallasite meteorites was used to obtain a charge distribution of approximately 9000 nuclei with charges above 55 in galactic cosmic rays. Three superheavy nuclei with the charges in the range of 105<Z<130 were detected. Regression analysis enabled to amend the charge of one of these nuclei up to the value 119(-6)(+10) with the probability of 95%. Such nuclei have to form islands of stability of superheavy elements; their occurrence in nature supports the validity of theoretical predictions and justifies efforts for their synthesis under the Earth conditions.

In this paper, we present the last results of the OLIMPIA experiment on the search for and study of traces of heavy and superheavy element nuclei of galactic cosmic rays in olivine crystals from meteorites. The charge spectrum of cosmic rays in the region of heavy nuclei is obtained, three superheavy nuclei of natural origin with charges in the range 105 < Z < 130 and lifetimes longer than 3000 years, being a part of the so-called “stability island”, are identified.

Results of the experimental research, performed within the framework of the OLIMPIYA project on investigation of the relict galactic cosmic ray nucleus tracks in olivine crystals from the Marjalahti and the Eagle Station meteorites, are presented. Up to now, there were processed 170 crystals, and about 6000 tracks with nuclear charge Z > 55 were registered. About 45 tracks are identified as nuclei with charge of 88 < Z < 92. Charges of three nuclei, associated with super long tracks, exceed Z = 92. In the first approximation the charge value of two of these nuclei lies in the range of 105 < Z < 130. The charge of one of them is estimated as Z = 119 +/- 6. We believe that confirm the hypothesis of the existence of "stability islands" for natural trans-Fermi nuclei.

Results from the experimental search for and identification of tracks from the superheavy and transuranium nuclei of galactic cosmic rays in pallacite olivine crystals, conducted as part of project OLIMPIA [1], are presented. To date, 170 crystals from Marjalahti and Eagle Station pallacites have been processed and 6800 tracks corresponding to nuclei with charges Z > 55 have been found; 45 of these are from nuclei with charges of 88 < Z < 92 and three super-long ones were produced by nuclei with Z > 105. The charge of one of these nuclei is estimated in the first approximation as Z = 119(+10,−6). Our data confirm the hypothesis of islands of stability for natural trans-Fermi nuclei.