Combined proton-neutron therapy can be the best opportunity for neutron radiation therapy due to highly conformal proton irradiation and high relative biological effectiveness of neutrons. The study compares 4 schemes of sequential in vitro exposure of Chinese hamster fibrosarcoma cells B14-150 to 14.5 MeV neutrons and a scanning beam of protons. Treatment efficiency increased with increasing the contribution of the neutron component to the total dose from 30 to 40% and the delivery of the neutron dose as the first fraction in the two-fraction proton-neutron exposure.

As is known, rare-earth metals (REMs) are promising magnetocaloric materials. The magnitude of the magnetocaloric effect (MCE) of REMs significantly depends on their purity. This paper presents results of studies of the magnetic and magnetocaloric properties of sublimed dysprosium, prepared in the course of the present study, with an emphasis on its impurity and structure perfection. The comprehensive analysis of the chemical composition of sublimed dysprosium, which was performed for the first time by atom probe tomography, showed that the metal corresponds to high-purity rare-earth metals (3N+). The MCE effect was studied using direct measurements of the adiabatic temperature change (ΔTad) in pulsed (up to 50 T) and steady (up to 14 T) magnetic fields. The studies of the MCE of polycrystalline sublimed Dy by direct method showed that the high ΔTad value for sublimed Dy are comparable with that for magnetic fields of 5 T. The vacuum sublimation, which is more economical and technologically advanced in contrast to single crystal growing, can be used to create magnetocaloric REM-based materials with high MCE values.

A Penning ion source for a miniature linear accelerator is investigated. A discharge current dependence on the anode voltage for several pressure values is calculated. The estimates are based partly on simplified theoretical models, partly on experimental data obtained on previous work. The ion current component is selected from the obtained dependences and the ion current component value, extracted from the ion source, is estimated. The extracted current dependences and the ion extraction efficiency coefficient value on the voltage at the anode at different source output aperture diameters are calculated.

We present in this paper the experimental results of magnetothermal properties in Dy films and their comparison with the theoretical modeling of the same data. We consider the temperature interval between 80 and 200K, where Dy is ferromagnetic in low-temperature regions and helimagnetic for high temperatures. Our findings show that due to different phases in the considered temperature interval, the Dy induces thermal hysteresis in specific applied fields. We found that the ferromagnetic phase is favored in the heating process, and in the cooling process, the helimagnetic phase is favored.

Modern radiotherapy, employing traditional linear accelerators, has nearly reached its apex in terms of efficacy in treating oncological diseases. The challenge before researchers in the field of implementing cutting-edge technologies pertains to the utilization of fundamentally different therapeutic approaches, one of which is remote neutron therapy. Its salient advantages include an increased relative biological effectiveness of radiation, while the complexities of implementing specific technological solutions encompass forming a beam of the required geometry and spectral characteristics. The article delineates the key milestones in the development of the usage of fast neutron beams for remote radiotherapy, a general description of the neutron therapy complex and its primary structural components is also presented. These are currently being developed as an innovative, mass-producible medical project.

A Penning ion source for a miniature linear accelerator is investigated. A discharge current dependence on the anode voltage for several pressure values is calculated. The estimates are based partly on simplified theoretical models, partly on experimental data obtained on previous work. The ion current component is selected from the obtained dependences and the ion current component value, extracted from the ion source, is estimated. The extracted current dependences and the ion extraction efficiency coefficient value on the voltage at the anode at different source output aperture diameters are calculated.

The review is devoted to theoretical–experimental studies of the magnetothermal properties of several classes of magnetic materials: heavy rare earth metals and a family of binary and three-component alloys based on iron and rhodium. The results of calculations of properties from first principles, the self-consistent (mean) field model, empirical and ad hoc models, and numerical simulation methods are presented and analyzed. As well, numerous experimental data are presented: direct determination of the magnetocaloric effect (MCE), measurement of magnetic characteristics (field and temperature dependences of magnetization and magnetic susceptibility), measurement of temperature dependences of heat capacity, differential calorimetry, Hall magnetometry, EXAFS spectroscopy, scanning and transmission electron microscopy.

The role of size effects in the formation of the magnetic structure of Dy and Ho thin films in absence of epitaxial strain is studied in this work. It was found that, for Dy in the temperature range between the Néel temperature and the Curie temperature of bulk Dy and, for Ho, in the temperature range between the Néel temperature and the temperature of phase transition into the conic phase, the temperature dependences of the period of magnetic helicoid in the bulk and film metals are similar. The character of the transition into the ferromagnetic phase in the Dy films changes at lower temperatures, and the transition into the commensurable conic phase in the Ho films is suppressed. This is explained exclusively by the influence of dimensional effects.

Summary The article describes a new AINK-PL pulsed neutron gamma-spectrometric logging equipment for determining the elemental composition of rocks, a method for obtaining elements, and provides examples of comparing the results with core data

Tagged neutrons are used to perform an experimental investigation of the inelastic scattering of 14.1 MeV neutrons on 23Na and 35Cl nuclei as part of the TANGRA project at the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research. The energies and yields of γ quanta for transitions observed in the experiment are measured, and the γ angular distribution coefficients for the highest intensity γ transitions are obtained. The experimental data are compared to others in the literature.

The TALYS 1.9 program is used to calculate cross sections of processes that occur during the scattering of fast neutrons on 48 Ti, 52 Cr, and 56 Fe isotopes. Results from model calculations are compared to data obtained in the TANGRA project using tagged neutrons from the yields of γ-quanta for Ti, Cr, and Fe isotopes, and the results from earlier experiments. Analysis of the model description’s sensitivity to the choice of the direct reaction mechanism shows the most informative characteristic from this viewpoint is the differential cross section of inelastic scattering.

An Erratum to this paper has been published: https://doi.org/10.1134/S0031918X21880013

Abstract—The present work surveys literature data related to the study of iron–rhodium-based (Fe–Rh) alloys. The crystal, magnetic, and electronic properties of the FeRh alloy and FeRh-based materials in the form of both bulk, thin-film, and nano-structured objects are considered. Peculiarities of the first-order antiferromagnet–ferromagnet transition are analyzed, and various explanations of its nature are discussed. Different approaches to the preparation of the iron–rhodium-based alloys are reported; an analysis of the effect of heat treatment conditions on the properties of the material and their reproducibility in measuring the magnetocaloric properties is performed. Causes for the record values of the magnetocaloric effect (MCE) observed for the material are shown, and prospects of the application of this alloy in magnetic refrigeration technology, medicine, electronics, and magnetic data recording technology are discussed.

Nowadays, one of the most important global goals in medicine is to find ways to control cancer. Magnetic fluid hyperthermia is a promising method for cancer treatment due to its localized influence and low damage to healthy tissue. Ferrite nanoparticles are widely used in this cancer modality because of their low Curie temperature, biocompatibility, and production simplicity. In this work, (Mn(1−x)Znx)Fe2O4 sol was obtained by hydrothermal synthesis from chlorides of zinc, manganese, and iron (III) at 180 °C for x = 0.1 and x = 0.2. The results of dynamic light scattering analysis have shown that the average hydrodynamic diameter of nanoparticles in the sol is about 70 nm. According to scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), the powdered nanoparticles are spherical with a high degree of crystallinity. X-ray powder diffraction analysis (XRD) has confirmed single-phase formation in samples. The magnetic properties measured have indicated that the nanoparticles have reached temperatures close to the range required for deactivation of cancer cells under the influence of a variable magnetic field.

SPECTROSCOPY. M. L. Litvak1, Y.N. Barmakov2, S.G. Belichenko2, E.P. Bogolubov2, A.S. Kozyrev1, I.G. Mitrofanov1, A.V. Nosov1, A.S. Perkhov1, A.V. Samoshin2, A.B. Sanin1, S.E. Sholeninov2, V.N. Shvetsov3, D.I. Yurkov2, A. O. Zontikov3, V.I. Zverev2, 1Space Research Institute, Moscow, Russia, 117997, litvak@mx.iki.rssi.ru, 2Federal State Unitary Enterprise «All-Russia Research Institute of Automatics» (VNIIA), Moscow, Russia, 3Joint Institute for Nuclear Research, Dubna, Russia.