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A list of all the posts and pages found on the site. For you robots out there is an XML version available for digesting as well.
Pages
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Posts
Buffon’s needle problem: manim visualization
Published:
Syntax highlighting and execution of PHITS input files for Sublime Text editor
Published:
Managed to do syntax highlighting of PHITS input files for one of my favorite text editors Sublime.
Movement of a charged particle in electromagnetic field
Published:
This visualization was done as an illustrative material for lecture on the “Physics and Technology of Accelerators” at Dubna State University. Coded with VPython and powered by GlowScript.
FitsGeo: Python 3 package for PHITS geometry development and visualization
Published:
The idea of FitsGeo development came to me after some time of work with PHITS. PHITS is a Monte Carlo (MC) transport code similar to MCNP and certainly has some advantages comparing to other codes such as FLUKA. However, one main disadvantage related to convenience of use is visualization of geometry of input files. By that I mean that you don’t have a full control on your geometry while preparing your input file as it does Flair, which is advanced UI for FLUKA.
publications
Particle accelerator-based simulation of the radiation environment on board spacecraft for manned interplanetary missions
Published in Radiation Measurements (2017)
List of authors: G. N. Timoshenko, A. R. Krylov, M. Paraipan, I. S. Gordeev
Abstract: The high-energy accelerator-based simulation of both Galactic Cosmic Rays (GCR) and secondary radiation, to which astronauts will be exposed within a spacecraft in deep space, is a very relevant task for the purposes of space radiobiology. In this work, a method of simulating continuous proton, neutron, and π±-meson spectra within the habitable module of a spacecraft is described. The methods are based on a linear combination of the energy spectra of particles emitted at various angles from three different targets bombarded by a high-energy proton beam. The consecutive irradiation of targets makes it possible to create in a certain volume near the beam a summary field that is similar in characteristics to the nucleon field inside the habitable module exposed to GCR averaged over solar activity.
Calculating the Linear Energy Transfer Distribution in Radiobiological Experiments on the U400M Cyclotron
Published in Physics of Particles and Nuclei Letters (2020)
List of authors: G. N. Timoshenko, I. S. Gordeev
Abstract: Radiobiological experiments with the irradiation of various biological samples by nuclei from boron to neon with a primary energy of 30-50 MeV/nucleon are performed on the U400M cyclotron of the Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research. The linear energy transfer (LET) of the nuclei in samples is calculated using the code Lise++. For reducing the energy of nuclei and increasing their LET, aluminum filters with different thickness are placed before samples. The presence of filters and other absorbers before a sample results in the production of secondary charged particles whose LET may strongly differ from the LET of primary nuclei of the beam. This also affects the accuracy of calculating the absorbed dose. For this reason, detailed calculations of particle fields in samples are performed using the Monte Carlo code for radiation transport in matter PHITS 3.20 for several variants of sample irradiation with thick absorbers before samples. The calculated LET distributions are analyzed and compared with the calculations using the code Lise++.
Estimation of the Astronaut's Doses inside the Spacecraft Habitable Module in Deep Space
Published in Physics of Particles and Nuclei (2020)
List of authors: G. N. Timoshenko, I. S. Gordeev
Abstract: The estimation of the dose rates of astronauts inside the spacecraft habitable module with dimensions ∅6 m and length 12 m with an aluminum shell thickness of 15 g/cm$^2$ at the minimum and maximum of solar activity during flights in deep space has been presented. The estimation was based on the FLUKA calculations of the spectral characteristics of all components of the internal radiation field in the module from protons, deuterons, 3He, and nuclei with $2 \leq Z \leq 28$ of Galactic Cosmic Radiation. To estimate the dose, the fluence-to-effective dose equivalent conversion coefficients for the male astronauts (cohort of never smoking males aged 30-60 years) have been used.
FitsGeo – Python package for PHITS geometry development and visualization
Published in arXiv (2020)
List of authors: Ivan Gordeev
Abstract: An easy way to define and visualize geometry for PHITS input files introduced. Suggested FitsGeo Python package helps to define surfaces as Python objects and manipulate them conveniently. VPython assists to view defined geometry interactively which boosts geometry development and helps with complicated cases. Every class that sets the surface object has methods with some extra properties. As well as geometry generation for PHITS input, additional modules developed for material and cell definition. Any user with a very basic knowledge of Python can define the geometry in a convenient way and use it in further research related to particle transport.
Forecasting Radiation Environment around the NICA Booster
Published in Physics of Particles and Nuclei Letters (2020)
List of authors: G. N. Timoshenko, I. S. Gordeev
Abstract: The results of using the FLUKA package to calculate the radiation environment around building no. 1 of the Laboratory of High Energy Physics, which contains the ion injection systems, booster, and Nuclotron of the NICA complex in operation for the collider and for experiments with fixed targets, are presented. The calculation has been performed for the mode of 197Au ion acceleration to an energy of 578 MeV/n The main dose-forming component of the radiation field around the building is neutrons of a wide energy range. Detailed models of an ion acceleration ring and the geometry of shields and building details are used in the calculation. The calculation results indicate that the adopted design decisions with the given rates of ion losses will ensure compliance with radiation-protection norms during the operation of the NICA booster.
Simulation of radiation field inside interplanetary spacecraft
Published in Journal of Astrophysics and Astronomy (2020)
List of authors: G. N. Timoshenko, I. S. Gordeev
Abstract: A simulation of the radiation field inside a habitable module (a diameter of 6 m and length of 12 m) of a spacecraft generated by isotropic Galactic Cosmic Radiation (GCR) in deep interplanetary space is carried out for minimum and maximum solar activity using the FLUKA code. Protons, alpha-particles, deuterons, $^{\mathrm {3}}$He, and nuclei with ${Z} > 2$ are considered as primary GCR irradiating the spacecraft isotropically. The following particles are included in FLUKA radiation transport through the module shell ($15\hbox {g/cm}^{\mathrm {2}}$ of Al): protons, neutrons, $\gamma$-rays, electrons, $\pi^{\mathrm{\pm }}$-mesons, $\mu^{\mathrm {\pm }}$-mesons d, t, and nuclei from He to Ni. The inner particle spectra are needed to assess the astronaut’s radiation risk in a long-term interplanetary mission.
A new type of ground-based simulator of radiation field inside a spacecraft in deep space
Published in Life Sciences in Space Research (2021)
List of authors: I. S. Gordeev, G. N. Timoshenko
Abstract: The problem of full-scale ground-based modeling of cosmic radiation on heavy-ion accelerators for space radiobiology is very urgent. A new type of space radiation simulator at the $^{56}$Fe ion beam with energy 1 GeV/n is proposed. The simulator uses rotating converters consisting of segmented targets with varying thicknesses. When a flat uniform field of primary $^{56}$Fe ions is used, this design ensures the uniformity of the fields of all secondary particles behind the targets. The proposed setup with four replaceable converters makes it possible to simulate not only the distribution of linear energy transfers of cosmic radiation but also reproduce continuous energy spectra of all charged fragments of the projectile ion from protons to Co. The results of simulation of the internal radiation field inside the habitable module of a spacecraft with a shell of 15 g/cm$^2$ Al, generated by particles of galactic cosmic rays in the solar activity range from 0 to 190 Wolf numbers, are presented.
Computation of linear energy transfer of space radiation in biological tissue analog
Published in Planetary and Space Science (2021)
List of authors: G. N. Timoshenko, I. S. Gordeev
Abstract: Charged particle linear energy transfer (LET) distributions of the inner radiation field within an interplanetary spacecraft caused by Galactic Cosmic Radiation (GCR) are a good criterion of adequacy for accelerator-based GCR simulation. This paper presents the results of calculating the LET spectra inside the habitable module of the spacecraft (15g/cm$^2$ of Al shell) at the minimum and maximum of solar activity and comparing the calculations with the data obtained by the RAD dosimeter on the flight path to Mars in 2012. It is shown that the shape of the LET spectra weakly depends on the variation of solar activity over a wide range.
Reference Radiation Field for GCR Chronic Exposure Simulation
Published in Physics of Particles and Nuclei Letters (2021)
List of authors: G. N. Timoshenko, I. S. Gordeev
Abstract: A very urgent problem for space radiobiology is to model a chronic GCR exposure concerning simulations with animal models of human risks. However, it was impossible to realize similar irradiation in ground-based conditions until today because the use of heavy-ion accelerators for a long time for this purpose is not realistic. The booster of the Nuclotron--one of the heavy-ion accelerators of the NICA complex of Joint Institute for Nuclear Research--provides this unique possibility. The booster accelerates ions $^{197}$Au to 578 MeV/n with a charge state of 31+. Before injection of the booster beam to the main heavy-ion accelerator “Nuclotron”, the booster ions are fully stripped (to charge state 79+) by a thin copper foil. The efficiency of stripping is about 90%. The beam of remaining 10% of ions with no-target charge states will be directed to the trap. A small part of this beam can be used to generate the stable reference radiation field with parameters similar to the space radiation for chronic exposure of biological samples. This operation mode will continue 22 hours every day for eight months in the year at the NICA collider work with $^{197}$Au ions. The variant of such the field is discussed in the article.
Prediction of Radiation Environment around NICA Complex
Published in Physics of Particles and Nuclei Letters (2022)
List of authors: A. V. Butenko, I. S. Gordeev, A. D. Kovalenko, M. Paraipan, E. M. Syresin, G. N. Timoshenko
Abstract: The most important condition for starting work at the NICA accelerator complex, which is a powerful source of ionizing radiation, is to obtain a sanitary-epidemiological conclusion with the justification of a sanitary-protection zone around the facility. The size and configuration of the sanitary-protective zone around the NICA complex are determined by the mode of operation and the loss of particles in its various elements. Based on the calculations of the radiation situation performed earlier, the boundaries of the sanitary-protective zones have been defined for the heavy ions collision mode of the collider operation and for the additional mode in which high-energy protons interact in the collider.