K. Z. Mamatkulov

Charge topology of the coherent dissociation of relativistic

The charge topology of coherent-dissociation events is presented for 11С and 12N nuclei of energy 1.2 GeV per nucleon bombarding nuclear track emulsions. This topology is compared with respective data for 7Be, 8,10B, 9,10C, and 14N nuclei.

^{11}

The charge topology in the fragmentation of 10C nuclei in a track nuclear emulsion at an energy of 1.2 GeV per nucleon is studied. In the coherent dissociation of 10C nuclei, about 82% of events are associated with the channel 10C → 2α+ 2p. The angular distributions and correlations of product fragments are presented for this channel. It is found that among 10C → 2α+ 2p events, about 30% are associated with the process in which dissociation through the ground state of the unstable 9Beg.s. nucleus is followed by 8Beg.s. + p decays.

C and

A nuclear track emulsion was exposed to a mixed beam of relativistic 12N, 10C, and 7Be nuclei having a momentum of 2 GeV/c per nucleon. The beam was formed upon charge exchange processes involving 12C primary nuclei and their fragmentation. An analysis indicates that 10C nuclei are dominant in the beam and that 12N nuclei are present in it. The charge topology of relativistic fragments in the coherent dissociation of these nuclei is presented.

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Application of the nuclear track emulsion technique (NTE) in radioactivity and nuclear fission studies is discussed. It is suggested to use a HSP-1000 automated microscope for searching for a collinear cluster tri-partition of heavy nuclei implanted in NTE. Calibrations of -particles and ion ranges in a novel NTE are carried out. Surface exposures of NTE samples to a 252 Cf source started. Planar events containing fragments and long-range -particles as well as fragment triples only are studied. NTE samples are calibrated by ions Kr and Xe of energy of 1.2 and 3 A MeV. c 2015 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the National Research Nuclear University MEPhI (Moscow Engineering Physics Institute).

N nuclei

Exposures of test samples of nuclear track emulsion were analyzed. Angular and energy correlations of products originating from the thermal-neutron-induced reaction nth +10 B → 7 Li + (γ)+ α were studied in nuclear track emulsions enriched in boron. Nuclear track emulsions were also irradiated with 86Kr+17 and 124Xe+26 ions of energy about 1.2 MeV per nucleon. Measurements of ranges of heavy ions in nuclear track emulsionsmade it possible to determine their energies on the basis of the SRIM model. The formation of high-multiplicity nuclear stars was observed upon irradiating nuclear track emulsions with ultrarelativistic muons. Kinematical features studied in this exposure of nuclear track emulsions for events of the muon-induced splitting of carbon nuclei to three alpha particles are indicative of the nucleardiffraction interaction mechanism.

Dissociation of

Dissociation of 1.2 A GeV 10 C nuclei in nuclear track emulsionis is studied. It is shown that most precise angular measurements provided by this technique play a crucial role in the restoration of the excitation spectrum of the 2α + 2p system. Strong contribution of the cascade process 10 C → 9 B → 8 Be identified.

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Activities performed in preparation for the search for ternary fission of heavy nuclei and the analysis of fragment angular correlations with nuclear track emulsion and an automated microscope are detailed. Surface irradiation of nuclear emulsion by a Cf source was initiated. Planar events containing nothing but fragment triples were found and studied.

C nuclei in a track nuclear emulsion at an energy of 1.2 GeV per nucleon

The results obtained by estimating the contribution of 8Be and 9B nuclei to the coherent dissociation of 10C, 10B, and 12C relativistic nuclei in nuclear track emulsions (“white” stars) are presented. The selection of white stars accompanied by 9B leads to a distinct peak appearing in the distribution of the excitation energy of 2α2p ensembles and having a maximum at 4.1 ± 0.3 MeV. A 8Be nucleus manifests itself in the coherent-dissociation reaction 10B → 2He + H with a probability of (25 ± 5)%, (14 ± 3)% of it being due to 9B decays. The ratio of the branching fractions of the 9B + n and 9Be + p mirror channels is estimated at 6 ± 1. An analysis of the relativistic dissociation of 12C nuclei in a nuclear track emulsion revealed nine 3α events corresponding to the Hoyle state.

Exposure of nuclear track emulsion to a mixed beam of relativistic 12N, 10C, and 7Be nuclei

Progress in the study of nuclear clustering in the relativistic 10B and 11C nuclei dissociation in nuclear track emulsion is presented. The contribution of the unbound 8Be and 9B nuclei to their structure is determined on the basis of measurements of the emission angles of relativistic He and H fragments.

Toward an Automated Analysis of Slow Ions in Nuclear Track Emulsion

Exposures of test samples of nuclear track emulsion were analyzed. The formation of high-multiplicity nuclear stars was observed upon irradiating nuclear track emulsions with ultrarelativistic muons. Kinematical features studied in this exposure of nuclear track emulsions for events of the muon-induced splitting of carbon nuclei to three α-particles are indicative of the nuclear-diffraction interaction mechanism.