V. A. Ditlov

Institute for Theoretical and Experimental Physics · Laboratory of Quantum Fields and Interactions Physics

This work is a further development of our method, published in 2018, for computer analysis of micrographs taken from a plastic detector CR-39, etched after irradiation with a beam of ¹²C ions of energy 216 MeV/amu in the radiobiological research chamber of the ITEP-TWAC accelerator-storage complex. The aim of this work is to study geometric and opt...

During the decay (μ+ → e+) at the end of the muon tracks in nuclear photoemulsion, in addition to the tracks of positrons, electron tracks were observed. The distributions of electrons over residual ranges and over energies were found. Both distributions were fitted with Gaussian functions and it was shown that each of them consists of two peaks. T...

The energy spectra of fast (10¹−10² keV) electrons accompanying π⁺ → μ⁺ decays of positively charged pions (π⁺) stopped in a nuclear emulsion are obtained. These spectra are compared with the analogous spectra obtained earlier for electrons accompanying the decay μ⁺ → е⁺. The comparison in question confirms qualitatively the hypothesis that, in eit...

The numbers of detected ions and the beam density dispersions at different depths of plate locations that also cover the Bragg peak region were determined by automatically searching for etched micropores in photographs of surfaces of CR-39 plastic plates exposed to ¹²C ions with an energy of 216 MeV/amu in a chamber for radiobiological investigatio...

It is shown that during the stopping and decaying of positively charged muon (μ⁺) in a nuclear emulsion, there arises with a probability of about 10⁻² electron with energies between 10 and 180 keV. The energy spectrum and angular distribution of these electrons are measured. A hypothesis on the possible mechanism behind the appearance of electrons...

Interaction of high energy heavy ions with nuclear emulsion simulated using MCNPX 2.7 and its associated Monte Carlo codes. The simulations were performed for interactions of 4.1 AGeV/c Ne-22 ions with nuclear emulsion event by event via batch files written for this purpose. It is shown that MCNPX correctly simulates the spallation as well as "comp...

Aspects of BURSTS and Spallation reactions induced by high-energy heavy ions in thick targets (>10 cm thick) will be investigated: BURSTS are reviewed from a historical and phenomenological point-of-view. Details of interactions in nuclear emulsions will be compared for irradiations of 72 GeV 22Ne-ions from Dubna with irradiations of 72 GeV 40Ar-io...

Interaction of high energy heavy ions with nuclear emulsion simulated using MCNPX 2.7 and its associated Monte Carlo codes. The simulations were performed for interactions of 4.1 AGeV/c ²²Ne ions with nuclear emulsion event by event via batch files written for this purpose. It is shown that MCNPX correctly simulates the spallation as well as “compl...

Methods of automatic computer analyses of images have large impotence in numerous physical problems with different kinds of radiations, which use such solid-state detectors as nuclear photographic emulsions, plastics and others. We described a method of expanding boundaries of dark areas for such computer analyses of micro-pictures. We demonstrated...

Thick target irradiated with relativistic heavy ions go either via SPALLATION (not completely, however fairly well inderstood - no implicit dangers) or via BURSTS ( completel not at all understood, their neglectance in high-intensity irradiations of U-targets MAY lead to unexpted target instabilities - with the simultaneous release of trasuranium n...

This work is devoted to the analysis of possibilities of nuclear emulsions for Dark Matter search, particles of which can produce slow recoil-nuclei. Tracks of such recoil-nuclei in developed nuclear emulsion consist from several emulsion grains. The analysis was carried out with Monte-Carlo calculations made on the basis of the Track Theory and th...

The possibility of neutrinoless double beta decay is studied in the photoemulsion experiment with Mo-100 isotope. The results of measurements of positron-nucleus collisions for the purpose of estimating the background events simulating 2β-decay in the nuclear photoemulsion region adjoining molybdenum conglomerates are presented.

The measurement of positron--nucleus collisions was used to estimate the possibility of suppressing background events that simulate $\beta\beta$ decay in the emulsion region adjacent to molybdenum conglomerates. The range of the escape of two relativistic particles from the interaction was found to be $ = (0.60\pm 0.03) ~\mu$m, which approximately...

Track theory describes only mechanisms of formation of three-dimensional distributions of local responses around track axis. Radiation effects include very large set of diverse physical phenomena caused by different kinds of radiations into various materials. Relations between track theory and radiation effects are discussed. Both minimal size of u...

In the present work the dependence of the bulk etch rate of CR-39 solid state nuclear track detectors (SSNTD) on the concentration C and the temperature T of the NaOH etching solution has been studied. The superposition and interaction of physical and chemical processes happening during the etching phase is tried to approximate by an Arrhenius-like...

Studies using thick targets irradiated with heavy ions having total energies Etotal above 10GeV reveal some new features when solid-state-nuclear-track detectors (SSNTDs), nuclear chemistry, neutron counting techniques and emulsion investigations are used. Some of these results constitute unresolved problems which the authors are unable to interpre...

The formalism of the many-hit model (MHM) [Fromm, M., Awad, E.M., Ditlov, V.A., 2004. Many-hit model calculation for track etch rate in CR-39 SSNTD using confocal microscope data. Nucl. Instr. Phys. Res. B 26, 565–575; Ditlov, V.A., Awad, E.M., Fromm, M., Hermsdorf, D., 2005. The Bragg-peak studies in CR-39 SSNTD on the basis of many-hit model for...

Interactions of relativistic heavy ions with total energies above 30 GeV in thick Cu and Pb targets (≥ 2 cm) have been studied with various techniques. Radiochemical irradiation experiments using thick Cu targets, both in a compact form or as diluted “2π-Cu targets” have been carried out with several relativistic heavy ions, such as 44 GeV 12C (JIN...

This work is a study of new aspects in relativistic nucleus–nucleus interactions using the nuclear emulsion technique and it is aimed at development of a method of search of these interactions. Layers of nuclear photographic emulsion type-BR2 with sizes were irradiated with 72 GeV 22Ne beam parallel to emulsion surface. The scanning length was 110...

Etching rates along tracks of protons and lithium ions with energies in the Bragg peak region were explored. The energy losses in this region, especially for protons of low energies, are of particular interest from the physical as well as biological points of view. The microscopic track etch rate, VT, is studied using the many-hit model in its firs...

Any detector is composed of an enormous number of sensitive microscopic volumes (SMV) mainly in the state “NO” (Katz 1970. Unified Track Theory. In: Seventh International Colloquium on Corpuscular Photography and Visual Solid Detectors. Barcelona, pp. 1–29.). Irradiation evokes some spatial distribution of SMV in the state “Yes”. It can be describe...

The mean number ⌨N b〉 of particles evaporated in the interaction of 22Ne, 32S, and 56Fe nuclei with photoemulsion nuclei was measured as a function of the number of alpha particles emitted within the fragmentation cone. It is found that ⌨N b〉 decreases with increasing number of the alpha particles and increases with increasing number of projectile...

The present work studied an important part of ion tracks: the Bragg peak region. Information about the microscopic nature of ion-energy dissipation based on zero-approximation in frame of the many-hit model of the track structure theory was studied. The detector response, Vt, was calculated in terms of Poisson’s distribution as a function of the io...

A method for the identification of relativistic ions with low atomic numbers in nuclear emulsion was proposed for measurements with a semi-automatic microscope-computer system. In this method we used a simultaneous consideration of both blob and gap distributions over their sizes and a comparison of these distributions with Monte Carlo simulation o...

The problems of identification of slow nucleus with small atomic numbers in photographic emulsion are discussed. We proposed to measure the distance between track edge and track axis and to search the atomic numbers by minimizing the square differences between the theoretical and experimental values of these distances.

An optical model of a two-phase xenon chamber for direct calculation of light fluxes has been built up. A calculation method of photo multiplier tubes response at charged particle interacting in chamber was deduced. A method of D reconstruction of event coordinates was built and studied with use of this model.

The current status of a development project focused on constructing a novel two-phase xenon detector to search for Dark Matter is given. The response to neutrons in terms of ionisation and scintillation has been observed. Decay times of the scintillation due to nuclear recoils have been measured.

This work is devoted to the 20th Anniversary of the international “Nuclear Tracks in Solids” conferences. Several principal stages of track theory evolution have been analyzed.

Registration of fast electron flux in solid state detector was studied. We considered spatial distributions over detector volume of three values - probability of local responses, dissipated energy and number of moving electrons. We made a definition of a registration efficiency for dissipated energy dose and for electron flux. They were calculated...

Here we have made an attempt to describe etching along and perpendicular to the ion track axis with the many-hit response model. From experiments where sheets of Makrofol KG film were exposed to Au and Xe ions it was found that Vt/Vb depends on restricted energy loss (REL). Then, for the many-hit model the registration parameters of the detectors w...

We try to predict the sight of neutrino interaction inside nuclear emulsion after long exposure. It is very important because regression decreases the grain density on charge particle tracks.

We built up a simple mathematical apparatus in order to study particularities of behavior of etch processing in the very close distances from track axis and we studied the influence of different types of spatial damage distributions on the track parameters and etching kinetic.

In the present paper we consider the experiment on heavy nuclei identification by the method of grain counting in photographic emulsions exposed on board a spacecraft as early as 1974. Since we carried out the experiment, the theory of nuclear track detection has undergone a considerable evolution, and in the present paper based on this experiment...

The thermodynamic aspects of connection between inside physical states of detector sensitive microregion, visialization process and local response are pointed out. The general mathematical expressions for probabilities of local responses are given. Two private cases of its application are analysed.

For the track detectors, we consider registering action of δ-electron currents, which we deduced from the single electron action. As a result we have a general equation for a spatial distribution of responded hits sensitive regions with arbitrary geometrical shape. This equation gives us a triterion for the case when exists adquancy between spatial...

The purpose of this paper is to research the possibilities of a new method of application for the determination of nuclear charges using nuclear emulsions with essentially low silver halide concentration. Such emulsions allow the counting of grains in heavy nuclei tracks, unlike ordinary highly sensitive nuclear emulsions, which were used for photo...

The multiple scattering of β-electrons in nuclear photographic emulsion of β-spectrometer is considered. A numerical calculation method was developed on the basis of many-hit model of emulsion response in frame of the theory of multiple scattering of electrons. The dependences of spectra sensitivity, of ratio signal-noise and other parameters on β-...