Publications by authors named "Aleksandr Makarov"

2 Publications

  • Page 1 of 1

Low-energy states, ground states, and variable frustrations of the finite-size dipolar Cairo lattices.

Phys Rev E 2021 Apr;103(4-1):042129

School of Natural Sciences, Far Eastern Federal University, Vladivostok, Russky Island, 10 Ajax Bay, 690922, Russian Federation.

To investigate the influence of geometric frustration on the properties of low-energy configurations of systems of ferromagnetic nanoislands located on the edges of the Cairo lattice, the model of interacting Ising-like magnetic dipoles is used. By the method of complete enumeration, the densities of states of the Cairo pentagonal lattices of a finite number of Ising-like point dipoles are calculated. The calculated ground and low-energy states for systems with a small number of dipoles can be used to solve the problem of searching for the ground states in a system with a relatively large number of dipoles. It is shown that the ground-state energy of the Cairo pentagonal lattices exhibits nonmonotonic behavior on one of the lattice parameters. The lattice parameters can be used to control the degree of geometric frustration. For the studied lattices of a finite number of Ising dipoles on the Cairo lattice in the ground-state configurations, a number of closed pentagons is observed, which are different from the obtained maximum closed pentagons. The magnetic order in the ground-state configurations obeys the ice rule and the quasi-ice rules.
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http://dx.doi.org/10.1103/PhysRevE.103.042129DOI Listing
April 2021

Neutron Source Based on Vacuum Insulated Tandem Accelerator and Lithium Target.

Biology (Basel) 2021 Apr 21;10(5). Epub 2021 Apr 21.

Faculty of Physics, Novosibirsk State University, 2 Pirogov Str., 630090 Novosibirsk, Russia.

A compact accelerator-based neutron source has been proposed and created at the Budker Institute of Nuclear Physics in Novosibirsk, Russia. An original design tandem accelerator is used to provide a proton beam. The proton beam energy can be varied within a range of 0.6-2.3 MeV, keeping a high-energy stability of 0.1%. The beam current can also be varied in a wide range (from 0.3 mA to 10 mA) with high current stability (0.4%). In the device, neutron flux is generated as a result of the Li(p,n)Be threshold reaction. A beam-shaping assembly is applied to convert this flux into a beam of epithermal neutrons with characteristics suitable for BNCT. A lot of scientific research has been carried out at the facility, including the study of blistering and its effect on the neutron yield. The BNCT technique is being tested in in vitro and in vivo studies, and the methods of dosimetry are being developed. It is planned to certify the neutron source next year and conduct clinical trials on it. The neutron source served as a prototype for a facility created for a clinic in Xiamen (China).
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http://dx.doi.org/10.3390/biology10050350DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8143170PMC
April 2021
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