Radiation environment in the interplanetary space and Mars orbit during the declining phase of 24th solar cycle and transition to 25th cycle according measurements aboard ExoMars TGO

2021 ◽  
Author(s):  
Jordanka Semkova ◽  
Keyword(s):  
Solar Cycle ◽  
Interplanetary Space ◽  
Basic Research ◽  
Radiation Environment ◽  
Neutron Detectors ◽  
Dose Rates ◽  
24Th Cycle ◽  
National Science ◽  
Academy Of Sciences ◽  
National Science Fund

<p>Radiation environment in the interplanetary space and Mars orbit during the declining phase of 24th solar cycle and transition to 25th cycle according measurements aboard ExoMars TGO</p><p>Jordanka Semkova1, Rositza Koleva1, Victor Benghin3, Krasimir Krastev1, Tsvetan Dachev1, Yuri Matviichuk1, Borislav Tomov1, Stephan Maltchev1, Plamen Dimitrov1, Nikolay Bankov1, Igor Mitrofanov2, Alexey Malakhov2, Dmitry Golovin2, Maxim Mokrousov2, Anton Sanin2, Maxim Litvak2, Maya Djachkova2, Sergey Nikiforov2, Denis Lisov2, Artem Anikin2, Vyacheslav Shurshakov<sup>3</sup>, Sergey Drobyshev<sup>3</sup></p><p> </p><p><sup>1</sup>Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria, [email protected]</p><p><sup>2</sup>Space Research Institute, Russian Academy of Sciences, Moscow, Russia, [email protected]</p><p><sup>3</sup>State Scientific Center of Russian Federation, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia, [email protected]</p><p> </p><p>The dosimetric telescope Liulin-MO for measuring the radiation environment is a module of the Fine Resolution Epithermal Neutron Detector (FREND) onboard the ExoMars TGO.</p><p>Here we present results from measurements of the charged particle fluxes, dose rates and estimation of radiation quality factors and dose equivalent rates at ExoMars TGO science orbit (circular orbit with 400 km altitude, 74<sup>0 </sup>inclination, 2 hours orbit period), provided by Liulin-MO from May 01, 2018 to January 10, 2021.</p><p>The obtained data show that: an increase of the dose rates and fluxes is observed from May 2018 to February 2020 which corresponds to the increase of galactic cosmic rays (GCR) intensity during the declining of the solar activity in 24th solar cycle; From March to August 2020 the measured radiation values are practically equal, corresponding to the minimum of 24th cycle and transition to 25th cycle. The highest values of the dose rate (15.5/16.2 µGy h-1 at two perpendicular directions) and particle flux (3.24/3.33 cm-2s-1 at two perpendicular directions) are registered in this period; Since September 2020 a decrease of the dose rates and fluxes is observed, corresponding to the decrease of GCR intensity during the inclination phase of the 25th cycle.</p><p>The cosmic ray fluxes and doses measured in Mars orbit are recalculated into values meaningful for the deep interplanetary space at about 1.5 AU. The flux in the free space is at least 3.68 cm-2s-1 and the dose rate is 18.9 µGy h-1 in August 2020. The results demonstrate that the radiation conditions in the interplanetary space worsen in the minimum of the solar activity in 24th cycle compared to the previous solar minimum.</p><p>Liulin-MO charged particles measurements are compared for completeness to similar measurements performed by FREND neutron detectors: the instrument’s 3He neutron detectors are also a source of charged particles flux signal that can be used for correlation.</p><p>The results are of importance for benchmarking of the space radiation environment models and for assessment of the radiation risk to future manned missions to Mars.</p><p>Acknowledgements</p><p>The work in Bulgaria is supported by Project No 129 (KP-06 Russia 24) for bilateral projects of the National Science Fund of Bulgaria and Russian Foundation for Basic Research. The work in Russia is supported by Grant 19-52-18009 for bilateral projects of the National Science Fund of Bulgaria and Russian Foundation for Basic Research.</p>

Secular geomagnetic field variations in Bulgarian lands during Classical Age and Late Antiquity – new archaeomagnetic data

2021 ◽  
Author(s):  
Maria Kostadinova-Avramova ◽  
Petar Dimitrov ◽  
Andrei Kosterov ◽  
Mary Kovacheva
Keyword(s):  
Material Culture ◽  
Late Antiquity ◽  
Basic Research ◽  
Reference Points ◽  
Archaeological Sites ◽  
Historical Sources ◽  
National Science ◽  
Basic Research Grant ◽  
National Science Fund ◽  
Research Grant

<p>Numerous historical sources and archaeological monuments attest the age of Antiquity in Bulgaria – from both the early Roman period (I – III c.) and Late Antiquity (IV – VI c.). Owing to systematic archaeological excavations, lasting more than 100 years, plenty of information has been accumulated concerning not only all aspects and manifestations of its material culture, but also their evolution and chronology.  This in turn allows for interdisciplinary fields such as archaeomagnetism to progress.</p><p>There are many archaeomagnetically studied archaeological structures from the Antiquity. The results included in the Bulgarian database form 74 reference points. However, only 20 of them are full-vector determinations because 70 % of the investigated materials are bricks. Hence, the secular variation of declination is poorly constrained within the considered period. Moreover, the reuse of bricks in the constructions occurred quite often (especially in the Late Antiquity) providing for possible errors in archaeological dating. In addition, stronger effects of magnetic anisotropy and cooling rate are usually expected for bricks than for hearths, domestic ovens, production kilns or burnt dwelling remains (there are no results from pottery in the Bulgarian dataset) and both factors are not evaluated for most of the older results. All this can explain the contradictions observed between some of the experimental results juxtaposed over the absolute time scale. In an attempt to clarify these contradictions 13 baked clay structures from eight archaeological sites were archaeomagnetically studied producing seven new directional and eight new intensity data. The samples collected possess variable magnetic properties suggesting differences in clay sources and/or firing conditions. Magnetically soft minerals prevail in seven structures but in the remaining six, abundant HCSLT phase is detected. The success rate of archaeointensity determination experiments vary from 49 to 100 %. It appears that samples containing HCSLT phase always produces good araeointensity results unlike those with the dominant presence of soft carriers.</p><p>The new reference points are compared with the present compilation of Bulgarian archaeomagnetic dataset and with the data from the neighboring countries.</p><p> </p><p>This study is supported by the grant KP-06-Russia-10 from the Bulgarian National Science Fund and Russian Foundation of the Basic Research grant 19-55-18006.</p>

scholarly journals The 2011 National Science Foundation Political Science Awards

2012 ◽  
Vol 45 (01) ◽  
pp. 124-126
Keyword(s):  
Political Science ◽  
National Science Foundation ◽  
Research Training ◽  
Basic Research ◽  
Science Research ◽  
Fiscal Year ◽  
The Political ◽  
Science Program ◽  
Political Processes ◽  
National Science

The Political Science Program at the National Science Foundation (NSF) announces it awards for basic research support and dissertation improvement grants for fiscal year 2011. The Program funded 25 new projects and 44 doctoral dissertation improvement proposals. The Political Science Program spent $5,234,470 on these research, training and workshop projects and $483,822 on dissertation training grants for political science students. The program holds two grant competitions annually —Regular Research, August and January 15; Dissertation Improvement, September 16 and January 15— and constitutes a major source of political science research funding as part of fulfilling NSF's mission to encourage theoretically focused empirical investigations aimed at improving the explanation of fundamental social and political processes and structures.

scholarly journals Solar cycle changes of large-scale solar wind structure

2009 ◽  
Vol 5 (S264) ◽  
pp. 356-358 ◽  
Author(s):  
P. K. Manoharan
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Large Scale ◽  
Interplanetary Space ◽  
The Sun ◽  
Wind Structure ◽  
Level Of Activity ◽  
Solar Wind Structure ◽  
Current Minimum ◽  
Inner Heliosphere

AbstractIn this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985–2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of the solar cycle and it reduces to ~70%, near the minimum phase. However, in the current minimum of solar activity, the level of turbulence has gradually decreased, starting from the year 2005, to the present level of ~30%. These results suggest that the source of solar wind changes globally, with the important implication that the supply of mass and energy from the Sun to the interplanetary space has significantly reduced in the present low level of activity.

scholarly journals Funding system reform for excellence in science: an interview with Jinghai Li, President of NSFC

2019 ◽  
Vol 6 (1) ◽  
pp. 177-181 ◽  
Author(s):  
Zhonghe Zhou ◽  
Weijie Zhao
Keyword(s):  
Natural Science ◽  
Strong Support ◽  
Basic Research ◽  
Funding Agency ◽  
System Reform ◽  
Funding System ◽  
Reform Plan ◽  
Funding Programs ◽  
Excellence In Science ◽  
Academy Of Sciences

Abstract The National Natural Science Foundation of China (NSFC) is the major funding agency for China's basic research in natural science. The total budget for NSFC was 26.7 billion Yuan (RMB) in 2017, accounting for 27% of China's total investment in basic research. In the past decades, continuous increases in the National Natural Science Fund and other funding programs provided strong support for the rapid growth in China's science and technology (S&T). In the second half of 2018, NSFC unveiled a deep reform plan that aims to build a fair, efficient and standardized new funding system that meets the demands of excellence in science in the twenty-first century in 5–10 years. Why did NSFC propose this reform? What are the major tasks of this reform? And how would NSFC implement this reform? All-in-all, this reform would not only have profound effect on S&T in China but also matters the world for the global collaborative efforts for the science. Recently, National Science Review had an exclusive interview with Jinghai Li, President of NSFC and Academician of the Chinese Academy of Sciences, to learn his views and perspectives of the future of NSFC.

Solar Cycle Electron Radiation Environment at GNSS Like Altitude

2006 ◽  
Author(s):  
A. Sicard-Piet ◽  
S. Bourdarie ◽  
D. Boscher ◽  
R. Friedel ◽  
T. Cayton
Keyword(s):  
Solar Cycle ◽  
Radiation Environment ◽  
Electron Radiation
Sign in / Sign up

Export Citation Format

Share Document