2019, Kamanin, D. V., Alexandrov, A. A., Alexandrova, I. A., Goryainova, Z. I., Pyatkov, Y. V., Tomas, A. V., Пятков, Юрий Васильевич

© 2019, Eurasian Journal of Physics and Functional Materials. All Rights Reserved.Specific linear structures in the region of a big missing mass in the fission fragments mass correlation distributions were revealed due to effective cleaning of this region from the background linked with scattered fragments. One of the most pronounced structures looks like a rectangle bounded by the magic nuclei. The fission events aggregated in the rectangle show a very low total kinetic energy. We propose possible scenario of forming and decay of the multi-cluster pre-scission configuration decisive for the experimental findings.

2020, Kamanin, D. V., Alexandrov, A. A., Alexandrova, I. A., Goryainova, Z. I., Pyatkov, Y. V., Пятков, Юрий Васильевич

© 2020. All Rights Reserved.Specific mode of the collinear cluster tri-partition of the 252Cf nucleus is discussed. The structure manifests itself as a rhombic-spiral structure in the fission fragments correlation mass distribution.

2019, Kamanin, D. V., Pyatkov, Yu. V., Пятков, Юрий Васильевич

© Published under licence by IOP Publishing Ltd.A cluster is broadly understood to be an object which keeps its identity in a larger scale system. Manifestations of clustering can be revealed in very different size systems from exotic nuclei to galaxies. In our work we search for cluster effects in low energy fission of heavy nuclei. In the series of experiments carried out with the spectrometers based both on the gas filled (FOBOS spectrometer and its modifications) detectors and mosaics of solid-state detectors (setups at the beams of alpha-particles and deuterons, COMETA spectrometer) using the "missing mass" method and with the direct detection of three decay partners, we have discovered a new type of the ternary decay of heavy nuclei dubbed by us "collinear cluster tri-partition (CCT)". The most interesting aspects of both the original methodic used and the physics of the effect observed are discussed in the presented report.

2023, Kamanin, D. V., Pyatkov, Y. V., Solodov, A. N., Strekalovsky, A. O., Пятков, Юрий Васильевич

2020, Strekalovsky, A. O., Kamanin, D. V., Goryainova, Z. I., Zhuchko, V. E., Pyatkov, Y. V., Пятков, Юрий Васильевич

© 2020, Allerton Press, Inc.Abstract: A time-of-flight spectrometer was used to compare the masses of nuclear fission fragments before and after their passage through the carbon foil, event by event. For all the registered fragments, there was a significant loss of mass of the fragment, and the registered fragment-residue turned out to be a magic nucleus. For spontaneous fission of 252Cf nuclei, the effect was observed for both light and heavy mass peaks. This gives grounds to assume that the fragment of the conventional binary fission is born in the shape isomer state, which looks like a di-nuclear system consisting of a magical core and a light cluster.

2019, Strekalovsky, A. O., Kamanin, D. V., Alexandrov, A. A., Alexandrova, I. A., Pyatkov, Y. V., Пятков, Юрий Васильевич

© Published under licence by IOP Publishing Ltd.The manifestation of a new original effect appearing at crossing of the metal foils by fission fragments is reported. The effect takes place predominantly at front impacts. The obtained results suggest that a fragment from conventional binary fission is borne in shape-isomer state which looks like a di-nuclear system with magic core.

2021, Ososkov, G. A., Rudenko, M. O., Pyatkov, Y. V., Пятков, Юрий Васильевич

© 2021, Pleiades Publishing, Ltd.Abstract: This paper is devoted to the analysis of manifestations of clustering in rare multibody decays of heavy nuclei. A computer model of the fine structure was developed jointly with the physicists of FLNR JINR; it was found based on experiments with the transuranium element Californium. To test the hypothesis that the structure really exists and is not a noise artifact, it was proposed to use a deep convolution network as a binary classifier trained on a large sample of model and noise images. Preliminary results of using the developed neuroclassifier show the prospects for this approach.

2019, Strekalovsky, O. V., Kamanin, D. V., Strekalovsky, A. O., Pyatkov, Yu. V., Пятков, Юрий Васильевич

Copyright © 2019 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).The article describes the electronics for the two-arm time-of-flight fission fragment spectrometer COMETA-F. The time pick-off detector is comprised of a thin electron conversion foil, an electrostatic mirror, and two microchannel plates supplied by Baspik and mounted in a chevron configuration. The mosaics of Si PiN diodes is used to measure both energy and time-of-flight. The waveform of detected signals is digitized by V1742 modules, which sample signals through a DRS4[1] chip. The DRS4 chip is a switched capacitor array, which can sample the input signal at a frequency of 5 GHs. The start for registration is provided by a specially designed trigger module. The V945 discriminator thresholds are individually settable in a range from -1 mV to -255 mV via VME through an 8-bit DAC.

2019, Kamanin, D. V., Alexandrov, A. A., Alexandrova, I. A., Goryainova, Z. I., Pyatkov, Y. V., Tomas, A. V., Пятков, Юрий Васильевич

© Published under licence by IOP Publishing Ltd.In our previous publications we discussed possible physical scenario standing behind rectangular-like structures in the fission fragments mass-correlation distributions from 252Cf(sf). The rectangle is bounded by the known magic nuclei such as 68Ni, 84Se and others. The fission events aggregated in the rectangle show extremely low total kinetic energies. Previously only decay mode with two Ni clusters in the exit channel was discussed. A more complete analysis is presented which gives additional arguments in favour of true quaternary fission of 252Cf (sf).

2022, Pyatkov, Y. V., Kamanin, D. V., Solodov, A. N., Goryainova, Z. I., Korsten, R., Kuznetsova, E. A., Пятков, Юрий Васильевич