M. S. Vladimirov

Heavy-particle energy loss simulation using the Geant4 toolkit

Currently, the Geant4 is a standard tool for simulating experiments in high-energy physics. In this paper, we describe an improvement of the ionization model for hadrons, ions, and classical magnetic monopole, implemented in Geant4. Simulation results are discussed; their accuracy is analyzed depending on chosen parameters, and compared with experimental data.

Prospects of the Study of Geological Structures by Muon Radiography Based on Emulsion Track Detectors

For the first time in Russia, researchers of the Lebedev Physical Institute and Skobeltsyn Institute of Nuclear Physics perform test experiments for studying the internal structure of large natural and industrial objects by the muon radiography method using the emulsion technique. The used technique is based on the high penetrability of cosmic muons and implies the detection of the attenuation of their flux passed through the object under study using nuclear photoemulsions with a uniquely high spatial resolution. The results of the first test experiment are presented, which confirm the promising application of the method when using emulsion track detectors and their subsequent hi-tech automated processing.

Detecting galactic cosmic ray transuranium nuclei in olivine crystals from meteorites

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.

Calibration measurements of the characteristics of tracks from superheavy nuclei in olivine crystals from meteorites

To identify the charge of detected cosmic ray nuclei, it is necessary that the dynamic and geometric parameters of tracks (the etching rate of a nuclear track, as well as the length and the diameter of the track channel) be determined with a high accuracy. Results of the experimental investigations of tracks produced in olivine crystals from the Marjalahti pallasite by accelerated Xe and U nuclei are presented. These investigations were performed as part of the Olimpiya project. It is shown that the etching rate and the fully etched track length are independent of the track orientation relative to the crystallographic symmetry axes of each olivine crystal under investigation.

Using muon radiography to study the structure of massive objects

The Lebedev Physical Institute of the Russian Academy of Sciences and the Skobeltsyn Institute of Nuclear Physics of Moscow State University conduct experiments using nuclear photoemulsion to study the internal structure of large objects via muon radiography. Analysis of an experiment in a mine in Obninsk belonging to the Geophysical Service of the Russian Academy of Sciences is of particular interest. Calculated and experimental data are presented.

Charge spectrum of superheavy nuclei of galactic cosmic rays obtained in the OLIMPIA experiment

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.

System for processing emulsion data of the OPERA experiment using the PAVICOM facility and prospects of its application to scan objects by muon radiography methods

The last data on the search results for neutrino oscillations in the OPERA experiment and the completed modernization of the PAVICOM facility (Lebedev Physical Institute) for automatic processing of nuclear emulsions of this experiment are presented. A new test application is developed for the PAVICOM to perform all stages of image processing. The application is tested using a GTX570 video card. The processing time for one frame is significantly reduced, which made it possible tomore than tenfold speed up processing. This is of crucial importance not only for prompt acquisition of statistically significant data of the OPERA experiment, but also for planned works on muon radiography.

Technique for determining the charge of cosmic ray nuclei by tracks in olivine crystals from meteorites

A technique for identifying the charge of cosmic ray nuclei, based on measurements of the length and average etch rate of tracks chemically etched in olivine crystals from the Marjalahti pallasite is described.

Simulation of Passage of Gallactic Cosmic Ray Nuclei in Meteorite-Pallasite Substance

The results are presented of model calculation of the interaction and yield of galactic-cosmic-ray superheavy-element nuclear fragmentation products from the 50 < Z < 92 range of their charges as they pass through a certain meteorite-pallasite substance thickness.

Study of the charge distribution of galactic cosmic rays and search for superheavy nuclei traces in olivine crystals from meteorites

The search for and identification of energetic nuclei of superheavy elements of cosmic rays in olivine crystals frommeteorites, currently performedwithin the Olympia project [1], are based on measurements of dynamic and geometrical parameters of tracks, i.e., chemically etchable regions of the traces of slowing down of these nuclei before their stop, using the fully automated PAVIKOM measuring system [2].