Study of light neutron-excess systems using radioactive beams and ACCULINNA-2 array of neutron detectors / Structural changes in the amorphous Al85Ni5Fe7La3 alloy under xenon ion irradiation

Seminars

Flerov Laboratory of Nuclear Reactions

Joint Laboratory Seminar

Date and time: Friday, 21 February 2025, at 11:00 AM

Venue: FLNR Conference Hall, Flerov Laboratory of Nuclear Reactions

  1. Seminar topic: “Study of light neutron-excess systems using radioactive beams and ACCULINNA-2 array of neutron detectors”

    Speaker: Alexander Knyazev

    Abstract:

    The present-day ACCULINNA-2 fragment separator and modernized MC-400 heavy ion accelerator open up new possibilities for studying the structure of light isotopes such as 5-7H, 7-10He, and others. Intermediate energies of secondary beams (~20–35 MeV/nucleon) and cryogenic targets of helium and hydrogen isotopes including tritium allow efficient use of charge exchange, stripping and nucleon pickup reactions for studying these exotic nuclei. 7H — nuclei undergoing four-neutron decay is one of the isotopes of interest for study. The uncertainty of measuring this isotope states can be reduced using the invariant and combined mass methods. Such an approach makes additional demands for neutron registration. It’s necessary to combine high efficiency of neutron registration with the low uncertainty of time measurement, low cross-current between modules and the ability to identify particles. To meet all these demands a modular time-of-flight neutron spectrometer based on BC-404 scintillator is being developed currently at FLNR.

    The current status of the spectrometer development is presented to the audience attention.

    (In connection with the election for the position of researcher)

  2. Seminar topic: “Structural changes in the amorphous Al85Ni5Fe7La3 alloy under xenon ion irradiation”

    Speaker: Vera Semina

    Abstract:

    The structure and thermal stability of the amorphous Al85Ni5Fe7La3 alloy in the initial rapidly quenched state and after 167 MeV xenon ion irradiation in 1012…2×1014 ion/cm2 fluence range were studied using methods of X-ray structural analysis, transmission microscopy and differential scanning calorimetry. It was found that under the experimental conditions the amorphous structure is stable up to ≈2×1013 ion/cm2 fluence. It was shown that irradiation results in a change in a short-range order in the amorphous matrix, the sequence of the separation of crystalline phases on heating and increases the temperature of crystallization beginning.

    (In connection with the election for the position of researcher)