First meeting of the User Committee of the IBR-2 reactor

The first meeting of the User Committee of the IBR-2 neutron source was organized at FLNP on 24 of February and took place via videoconference. The User Committee of the IBR-2 neutron source has recently been established to increase the user activity related to the interactions with the FLNP, giving support to both specific and general user questions, and with the aim to provide a discussion forum for the benefit of the users. The IBR-2 User Committee proposes new strategic ideas and procedures to the FLNP Directorate with the ultimate goal to improve the quality and efficiency of the organizational issues related to the user operation at the IBR-2.

Delegates from Poland, Bulgaria, Hungary, Armenia and Spain have taken part on this first meeting of the User Committee and the FLNP directorate. The agenda of this meeting included the introduction of the User committee members and of the FLNP directorate, followed by a discussion on further steps of the development of the IBR-2 instruments & infrastructure, ways to improve users’ satisfaction and to a general success of neutron science at IBR-2. During this first meeting, some questions concerning organization of the neutron scattering experiments, as well as future plans and ideas were discussed in detail. From now on meeting of the User Committee will be organized on regular basis.

DNP Seminar, February 17 (Wednesday), 2021, 11:00, online

"The acceleration effect in quantum mechanics"

Zakharov M.A.

The report is devoted to the development of ideas about the Acceleration Effect as a general physical effect formulated in the recent work of A. I. Frank. It is devoted to the presentation of the results of a numerical study of the manifestation of the acceleration effect in the interaction of a particle with various accelerating quantum objects.

A wave packet with parameters characteristic of ultracold neutrons was considered as a particle. Various planar potential structures were used as quantum objects, namely: potential step, potential barrier, potential well, double potential step, interference filter, two-layer structure.

The problems were studied by numerically solving the nonstationary Schrödinger equation by splitting the evolution operator. The spectra of the resulting state after the interaction of the packet with the object were obtained.

The results demonstrate a pronounced presence of the acceleration effect in all studied problems. In the case of resonant structures, the acceleration effect is proportional to the lifetime of the state inside the object (which can be many times longer than the time of flight of a particle). The results obtained confirm the hypothesis that the acceleration effect is a consequence not so much of the passage of a particle through an accelerated refractive sample, as the existence of a nonzero interaction time in quantum mechanics.

Scientific and Technical Council Meeting of FLNP Spectrometers’ Complex Department February 19, 2020 (Friday) at 11:00, online

Meeting agenda:

Discussion of works submitted for the 2021 FLNP Competition in the section «Applied and Scientific-methodical research»

1. Application of the method of neutron resonance analysis for the investigation of archaeological objects. Sedyshev P. V., Simbirtseva N. V., Yergashov A. M., Mazhen S. T., Dmitriev A. Yu., Shvetsov V. N.
2. High Temperature Superconducting Magnet System with a high-pressure chamber for the DN‑12 diffractometer at the IBR-2 facility operated in magnetic field up to 5 T and a temperature range of 4.5 - 300 K. Chernikov, S. Kulikov, O. Culicov, Buzdavin A.
3. Development and construction of an experimental station for neutron radiography and tomography at the WWR-K research reactor (Almaty, Republic of Kazakhstan). V. Lukin, D. P. Kozlenko, S. E. Kichanov, K. M. Nazarov, B. Muhametuly, E. A. Kenzhin, , A. A. Shaimerdenov, E. Bazarbaev, B. N. Savenko
4. Experimental data analysis methods in correlation RTOF diffractometry at long-pulse neutron source. Bokuchava
5. Research of radiation hardness of magnetic field’ sensors of TOKAMAKs. Bulavin, E. Shabalin, A. Verkhogliadov, E. Kulagin, S. Kulikov
6. A data acquisition and synchronization system. Ahmadov G., Berikov D., Kopatch Yu., Nuruyev S., Telezhnikov S.
7. Method of reducing the level of power oscillation in pulsed reactor «Neptune». Shabalin E.P., Hassan A.A., Rzyanin M.V., Podlesnyy M.М.

DNP Seminar, February 10 (Wednesday), 2021, 11:00, online

"Digitizers "DSR" (Digital Signal Recorder) and their application for nuclear physics research"

Yu.N. Kopatch, S.V. Alpatov

A waveform digitizer is an electronic data acquisition device that digitizes analog signals using fast analog-to-digital converters (ADCs) at a specified clock frequency and stores the resulting digitized data to disk or memory for subsequent processing.

The use of digitizers in modern experiments as the main component of a data acquisition system in many cases allows significant gains in compactness and cost, and also provides more opportunities for the data analysis.

The report discusses the characteristics and features of the DSR-2, DSR-32, DSR-8/16, and DSR-128 digitizers with a high-speed USB3 interface, developed at FLNP JINR.

DNP Seminar, January 27 (Wednesday), 11:00, online

"Investigation of rare fission mode processes using silicon pixel detectors Timepix"

Ahmadov G. S., Holik M., Kopatch Y. N., Berikov D. et al.

Rare fission modes (ternary and quaternary fission), in which light charged particles are emitted, are the subject of intensive experimental and theoretical studies, since these studies can be attributed to one of the main sources of information on the mechanism of nuclear fission. To study these processes, an experimental setup was assembled (figure), consisting of three semiconductor telescopes ∆E-E and a silicon detector. Thin detectors with an area of 10 × 10 mm² and a thickness of 15 and 140 μm were used to measure ∆E, and Timepix silicon pixel detectors with an area of 14 × 14 mm² and a thickness of 300 and 600 μm were used to measure E. A special synchronization bus has been developed and integrated into the FITPix COMBO. It can be used as a Timepix (including receiving pulses from the back side) or as a simple spectrometric device - Spectrig (when connected to an external detector such as an ∆E detector). The synchronization bus has also been designed to handle trigger and busy signals to effectively filter out unpaired events when performing coincidence measurements. Test measurements were carried out with a ²²⁶Ra alpha and ²⁵²Cf spontaneous fission source and the results of these measurements are presented.