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Cosmic Radiation

Richard L Hughson, Alexander Helm, Marco Durante
National space agencies and private corporations aim at an extended presence of humans in space in the medium to long term. Together with currently suboptimal technology, microgravity and cosmic rays raise health concerns about deep-space exploration missions. Both of these physical factors affect the cardiovascular system, whose gravity-dependence is pronounced. Heart and vascular function are, therefore, susceptible to substantial changes in weightlessness. The altered cardiovascular function in space causes physiological problems in the postflight period...
October 20, 2017: Nature Reviews. Cardiology
Suzanne Staggs, Lyman Page, Joanna Dunkley
Measurements of the anisotropies in the Cosmic Microwave Background (CMB) radiation have provided a wealth of information about the cosmological model that describes the contents and evolution of the universe. These data have led to a standard model described by just six parameters. In this review we focus on discoveries made in the past decade from satellite and ground-based experiments, and look ahead to those anticipated in the coming decade. We provide an introduction to the key CMB observables including temperature and polarization anisotropies, and describe recent progress towards understanding the initial conditions of structure formation, and establishing the properties of the contents of the universe including neutrinos...
October 20, 2017: Reports on Progress in Physics
I Ambrožová, M Davídková, K Pachnerová Brabcová, R V Tolochek, V A Shurshakov
Cosmic radiation consists of primary high-energy galactic and solar particles. When passing through spacecraft walls and astronauts' bodies, the spectrum becomes even more complex due to generating of secondary particles through fragmentation and nuclear interactions. Total radiation exposure is contributed by both these components. With an advantage, space research uses track etched detectors from the group of passive detectors visualizing the tracks of particles, in this case by etching. The detectors can discriminate between various components of cosmic radiation...
September 29, 2017: Radiation Protection Dosimetry
Tatsuhiko Sato, Aiko Nagamatsu, Haruka Ueno, Ryuho Kataoka, Shoko Miyake, Kazuo Takeda, Koji Niita
Estimation of cosmic-ray doses is of great importance not only in aircrew and astronaut dosimetry but also in evaluation of background radiation exposure to public. We therefore calculated the cosmic-ray doses on Earth, Moon and Mars as well as inside spacecraft, using Particle and Heavy Ion Transport code System PHITS. The same cosmic-ray models and dose conversion coefficients were employed in the calculation to properly compare between the simulation results for different environments. It is quantitatively confirmed that the thickness of physical shielding including the atmosphere and soil of the planets is the most important parameter to determine the cosmic-ray doses and their dominant contributors...
September 29, 2017: Radiation Protection Dosimetry
An-Lun Li, Wei-Fan Pan, Rong-Jiun Sheu
Galactic cosmic-ray-induced air showers constitute the largest source of radiation exposure for aircrew and passengers. To facilitate the evaluation of effective doses received by this population, a database containing dose rates of various radiation components in the atmosphere was established; the parameterization accounted for altitude, geomagnetic rigidity and solar modulation. Energy spectra of secondary cosmic rays and effective dose rates were calculated using the FLUKA Monte Carlo code. An auxiliary MATLAB program with a graphical user interface was developed to estimate the aviation route dose through interpolation and integration...
September 23, 2017: Radiation Protection Dosimetry
F Leontaris, A Clouvas, S Xanthos, A Maltezos, C Potiriadis, E Kiriakopoulos, J Guilhot
The Telemetric Early Warning System Network of the Greek Atomic Energy Commission consists mainly of a network of 24 Reuter-Stokes high-pressure ionization chambers (HPIC) for gamma dose rate measurements and covers all Greece. In the present work, the response of the Reuter-Stokes HPIC to terrestrial and cosmic radiation was evaluated in comparison with spectroscopic data obtained by in situ gamma spectrometry measurements with portable hyper pure Germanium detectors (HPGe), near the Reuter-Stokes detectors and time series analysis...
August 10, 2017: Radiation Protection Dosimetry
Martin Bulko, Karol Holý, Žofia Pohronská, Monika Mullerová, Radoslav Böhm, Ol'ga Holá
In this article, the effective dose to the population from natural sources of ionizing radiation in the vicinity of Mochovce nuclear power plant in Slovakia is presented. All major contributions to the effective dose were taken into account, including the contributions from gamma radiation of soil and rocks, cosmic radiation, and indoor and outdoor radon and thoron. On the basis of recent indoor radon measurements in Slovak cities and publicly available data about radon concentration in the soil air, a roughly linear relationship was found between these variables...
September 18, 2017: Radiation Protection Dosimetry
Matthew J Abplanalp, Brant M Jones, Ralf I Kaiser
Pure methane (CH4/CD4) ices were exposed to three ionizing radiation sources at 5.5 K under ultrahigh vacuum conditions to compare the complex hydrocarbon spectrum produced across several interstellar environments. These irradiation sources consisted of energetic electrons to simulate secondary electrons formed in the track of galactic cosmic rays (GCRs), Lyman α (10.2 eV; 121.6 nm) photons simulated the internal VUV field in a dense cloud, and broadband (112.7-169.8 nm; 11.0-7.3 eV) photons which mimic the interstellar ultra-violet field...
October 3, 2017: Physical Chemistry Chemical Physics: PCCP
Rutulkumar Patel, Hiroyuki Arakawa, Tomas Radivoyevic, Stanton L Gerson, Scott M Welford
Efforts to protect astronauts from harmful galactic cosmic radiation (GCR) require a better understanding of the effects of GCR on human health. In particular, little is known about the lasting effects of GCR on the central nervous system (CNS), which may lead to behavior performance deficits. Previous studies have shown that high-linear energy transfer (LET) radiation in rodents leads to short-term declines in a variety of behavior tests. However, the lasting impact of low-, medium- and high-LET radiation on behavior are not fully defined...
September 29, 2017: Radiation Research
Cody W Whoolery, Angela K Walker, Devon R Richardson, Melanie J Lucero, Ryan P Reynolds, David H Beddow, K Lyles Clark, Hung-Ying Shih, Junie A LeBlanc, Mara G Cole, Wellington Z Amaral, Shibani Mukherjee, Shichuan Zhang, Francisca Ahn, Sarah E Bulin, Nathan A DeCarolis, Phillip D Rivera, Benjamin P C Chen, Sanghee Yun, Amelia J Eisch
Astronauts traveling to Mars will be exposed to chronic low doses of galactic cosmic space radiation, which contains highly charged, high-energy (HZE) particles. (56)Fe-HZE-particle exposure decreases hippocampal dentate gyrus (DG) neurogenesis and disrupts hippocampal function in young adult rodents, raising the possibility of impaired astronaut cognition and risk of mission failure. However, far less is known about how exposure to other HZE particles, such as (28)Si, influences hippocampal neurogenesis and function...
September 25, 2017: Radiation Research
Daniel Wollschläger, Gaël Paul Hammer, Thomas Schafft, Steffen Dreger, Maria Blettner, Hajo Zeeb
Exposure to ionizing radiation of cosmic origin is an occupational risk factor in commercial aircrew. In a historic cohort of 26,774 German aircrew, radiation exposure was previously estimated only for cockpit crew using a job-exposure matrix (JEM). Here, a new method for retrospectively estimating cabin crew dose is developed. The German Federal Radiation Registry (SSR) documents individual monthly effective doses for all aircrew. SSR-provided doses on 12,941 aircrew from 2004 to 2015 were used to model cabin crew dose as a function of age, sex, job category, solar activity, and male pilots' dose; the mean annual effective dose was 2...
September 20, 2017: Journal of Exposure Science & Environmental Epidemiology
Pavel Bláha, Nataliya A Koshlan, Igor V Koshlan, Daria V Petrova, Yulia V Bogdanova, Raisa D Govorun, Viliam Múčka, Evgeny A Krasavin
Fundamental research on the harmful effects of ionizing radiation on living cells continues to be of great interest. Recently, priority has been given to the study of high-charge and high-energy (HZE) ions that comprise a substantial part of the galactic cosmic ray (GCR) spectra that would be encountered during long-term space flights. Moreover, predictions of the delayed genetic effects of high linear energy transfer (LET) exposure is becoming more important as heavy ion therapy use is increasing. This work focuses mainly on the basic research on the delayed effects of HZE ions on V79 Chinese hamster cells, with emphasis on the induction of HPRT mutations after prolonged expression times (ET)...
October 2017: Mutation Research
John W Norbury, Tony C Slaba, Nikolai Sobolevsky, Brandon Reddell
For the first time, the American (NASA) and Russian (ROSCOSMOS) space radiation transport codes, HZETRN and SHIELD respectively, are directly compared to each other. Calculations are presented for Galactic Cosmic Ray (GCR) minimum Hydrogen, Oxygen and Iron projectiles incident on a uniform Aluminum cylinder of varying thickness. Comparisons are made for the flux spectra of neutrons, light ions (Z≤ 2), heavy ions (Z> 2) and pions emitted from the back of the Aluminum cylinder. In order to provide more benchmark comparisons, some calculations with the GEANT and FLUKA transport codes are also shown...
August 2017: Life Sciences in Space Research
Daniel Matthiä, Thomas Berger
Galactic cosmic radiation and secondary particles produced in the interaction with the atmosphere lead to a complex radiation field on the Martian surface. A workshop ("1st Mars Space Radiation Modeling Workshop") organized by the MSL-RAD science team was held in June 2016 in Boulder with the goal to compare models capable to predict this radiation field with each other and measurements from the RAD instrument onboard the curiosity rover taken between November 15, 2015 and January 15, 2016. In this work the results of PLANETOCOSMICS/GEANT4 contributed to the workshop are presented...
August 2017: Life Sciences in Space Research
Wouter C de Wet, Lawrence W Townsend
In this work, the radiation environment on the Martian surface, as produced by galactic cosmic radiation incident on the atmosphere, is modeled using the Monte Carlo radiation transport code, High Energy Transport Code-Human Exploration and Development in Space (HETC-HEDS). This work is performed in participation of the 2016 Mars Space Radiation Modeling Workshop held in Boulder, CO, and is part of a larger collaborative effort to study the radiation environment on the surface of Mars. Calculated fluxes for neutrons, protons, deuterons, tritons, helions, alpha particles, and heavier ions up to Fe are compared with measurements taken by Radiation Assessment Detector (RAD) instrument aboard the Mars Science Laboratory over a period of 2 months...
August 2017: Life Sciences in Space Research
Hunter N Ratliff, Michael B R Smith, Lawrence Heilbronn
The paper presents results from MCNP6 simulations of galactic cosmic ray (GCR) propagation down through the Martian atmosphere to the surface and comparison with RAD measurements made there. This effort is part of a collaborative modeling workshop for space radiation hosted by Southwest Research Institute (SwRI). All modeling teams were tasked with simulating the galactic cosmic ray (GCR) spectrum through the Martian atmosphere and the Radiation Assessment Detector (RAD) on-board the Curiosity rover. The detector had two separate particle acceptance angles, 4π and 30 ° off zenith...
August 2017: Life Sciences in Space Research
John Flores-McLaughlin
Planetary bodies and spacecraft are predominantly exposed to isotropic radiation environments that are subject to transport and interaction in various material compositions and geometries. Specifically, the Martian surface radiation environment is composed of galactic cosmic radiation, secondary particles produced by their interaction with the Martian atmosphere, albedo particles from the Martian regolith and occasional solar particle events. Despite this complex physical environment with potentially significant locational and geometric dependencies, computational resources often limit radiation environment calculations to a one-dimensional or slab geometry specification...
August 2017: Life Sciences in Space Research
Bent Ehresmann, Cary J Zeitlin, Donald M Hassler, Daniel Matthiä, Jingnan Guo, Robert F Wimmer-Schweingruber, Jan K Appel, David E Brinza, Scot C R Rafkin, Stephan I Böttcher, Sönke Burmeister, Henning Lohf, Cesar Martin, Eckart Böhm, Günther Reitz
The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory (MSL) Curiosity rover has been measuring the radiation environment in Gale crater on Mars since August, 2012. These first in-situ measurements provide an important data set for assessing the radiation-associated health risks for future manned missions to Mars. Mainly, the radiation field on the Martian surface stems from Galactic Cosmic Rays (GCRs) and secondary particles created by the GCRs' interactions with the Martian atmosphere and soil...
August 2017: Life Sciences in Space Research
Tony C Slaba, Nicholas N Stoffle
The Mars Science Laboratory Radiation Assessment Detector (MSLRAD) is providing continuous measurements of dose, dose equivalent, and particle flux on the surface of Mars. These measurements have been highly useful in validating environmental and radiation transport models that will be heavily relied upon for future deep space missions. In this work, the HZETRN code is utilized to estimate radiation quantities of interest on the Martian surface. A description of the modeling approach used with HZETRN is given along with the various input models and parameters used to define the galactic cosmic ray (GCR) environment and Martian geometry...
August 2017: Life Sciences in Space Research
Daniel Matthiä, Donald M Hassler, Wouter de Wet, Bent Ehresmann, Ana Firan, John Flores-McLaughlin, Jingnan Guo, Lawrence H Heilbronn, Kerry Lee, Hunter Ratliff, Ryan R Rios, Tony C Slaba, Michael Smith, Nicholas N Stoffle, Lawrence W Townsend, Thomas Berger, Günther Reitz, Robert F Wimmer-Schweingruber, Cary Zeitlin
The radiation environment at the Martian surface is, apart from occasional solar energetic particle events, dominated by galactic cosmic radiation, secondary particles produced in their interaction with the Martian atmosphere and albedo particles from the Martian regolith. The highly energetic primary cosmic radiation consists mainly of fully ionized nuclei creating a complex radiation field at the Martian surface. This complex field, its formation and its potential health risk posed to astronauts on future manned missions to Mars can only be fully understood using a combination of measurements and model calculations...
August 2017: Life Sciences in Space Research
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