scholarly journals A Novel Layered System to Prevent High-Energy, Ionizing Radioactive Photon Transmissions and Control Particle Behavior with the Utilization of Monte Carlo Transport Modeling via SPENVIS-based Modular Implementation

2018 ◽  
Vol 14 (1) ◽  
pp. 5352-5362
Author(s):  
Daniel Noon
Keyword(s):  
Gamma Ray ◽  
Human Life ◽  
European Space Agency ◽  
High Energy ◽  
Radiation Shielding ◽  
Layered System ◽  
Current Standard ◽  
Particle Detection ◽  
Photon Momentum ◽  
Space Agency

Today, mass nuclear weapons and reactor plants are becoming more prominent. However, current methods of radiation shielding are not viable due to heavy cost and ineffective means of weakening photon momentum. Therefore, it becomes necessary to design structures resistant to the behavior of radiation from exposing to human life. Specifically, 280 computational experiments were conducted in a SPENVIS environment utilizing Multi-Layered Shielding Simulation (MULASSIS) and Geant4 Radiation Analysis for Space (GRAS) on multiple shielding models. These thirteen models tested against nuclear, artificially-generated incident particles under single and multi-ray analyses with four angular photon distributions in comparison to SHEILDOSE, a current standard for cosmic radiation shielding developed by the European Space Agency. These designs using stainless steel, lead, slightly-radioactive bismuth, and lithium-hydride prevented over 99% of particle detection compared to SHIELDOSE, which conversely increased the neutron-energy dose by over 700%, and insufficiently reduced high-energy gamma ray penetration. Per kilogram, my model is 144 times cheaper and only a small fraction of the thickness of either SHIELDOSE or metal foams. Thus, the potential of enhanced nuclear plants, further space exploration, and an overall safer approach to utilizing or preventing exposure to atomic particles such as with multi-disaster protection buildings can become more readily available, thus saving millions of lives that are in impending danger.

scholarly journals THE ZADKO OBSERVATORY

2021 ◽  
Vol 53 ◽  
pp. 35-39
Author(s):  
J. A. Moore ◽  
B. Gendre ◽  
D. M. Coward ◽  
H. Crisp ◽  
A. Klotz
Keyword(s):  
Media Coverage ◽  
Gamma Ray ◽  
European Space Agency ◽  
Global Awareness ◽  
The Public ◽  
Technical Management ◽  
Space Agency ◽  
Nearby Stars ◽  
Near Earth Asteroids ◽  
Single Instrument

The 1.0 metre f/4 fast-slew Zadko Telescope was installed in June 2008 approximately seventy kilometres north of Perth at Yeal, in the Shire of Gingin, Western Australia. Since the Zadko Telescope has been in operation it has proven its worth by detecting numerous Gamma Ray Burst afterglows, two of these being the most distant 'optical transients' imaged by an Australian telescope. Other projects include a contract with the European Space Agency (ESA) to image potentially hazardous near Earth asteroids (2019), monitoring space weather on nearby stars (2019), and photometry of a transit of Saturn's moon Titan (2018). Another active Zadko Telescope project is tracking Geostationary satellites and attempting to use photometry to classify various space debris (defunct satellites). The Zadko Telescope's importance as a potential tool for education, training, and public outreach cannot be underestimated, as the global awareness of the importance of astronomy (and space science) as a context for teaching science continues to increase. An example of this was the national media coverage of its contribution to the discovery of colliding neutron stars in 2017, capturing the imagination of the public. In this proceeding, I will focus on the practical aspects of managing a robotic Observatory, focusing on the sustainability of the Observatory and the technical management involved in hosting different commercial projects. I will review the evolution of the Observatory, from its early, single instrument, state to its current multi-telescope and multi-instrument capabilities. I will finish by outlining the future of the Observatory and the site.

scholarly journals The e-ASTROGAM space mission: a major step forward for supernova physics

2017 ◽  
Vol 12 (S331) ◽  
pp. 351-356
Author(s):  
Vincent Tatischeff ◽  
Roland Diehl ◽  
Alessandro De Angelis
Keyword(s):  
Gamma Ray ◽  
European Space Agency ◽  
Space Mission ◽  
Medium Size ◽  
Major Step ◽  
Space Agency ◽  
Broad Energy Range ◽  
Order Of Magnitude ◽  
Energy Gamma ◽  
Broad Energy

Abstracte-ASTROGAM is a gamma-ray observatory operating in a broad energy range, 0.15 MeV – 3 GeV, recently proposed as the M5 Medium-size mission of the European Space Agency. It has the potential to revolutionize the astronomy of medium-energy gamma-rays by increasing the number of known sources in this domain by more than an order of magnitude and providing gamma-ray polarization information for many of these sources. In these proceedings, we discuss the expected capacity of the mission to study the physics of supernovae, both thermonuclear and core-collapse, as well as the origin of cosmic rays in SN shocks.

scholarly journals Impact of Modifier Oxides on Mechanical and Radiation Shielding Properties of B2O3-SrO-TeO2-RO Glasses (Where RO = TiO2, ZnO, BaO, and PbO)

2021 ◽  
Vol 11 (22) ◽  
pp. 10904
Author(s):  
M. I. Sayyed ◽  
M. Kh. Hamad ◽  
Mohammad Hasan Abu Mhareb ◽  
K. A. Naseer ◽  
K. A. Mahmoud ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Radiation Shielding ◽  
Transmission Factor ◽  
Attenuation Coefficients ◽  
Radiation Attenuation ◽  
Cross Linkage ◽  
Packed Structure ◽  
Shielding Properties ◽  
Hardness Values

The influence of modifier oxides (TiO2, ZnO, BaO, and PbO) on the mechanical and radiation shielding properties of boro-tellurate glasses is investigated. Samples with a composition of B2O3-SrO-TeO2-RO (RO represents the modifier oxides) were fabricated using the melt quench method, and their physical, mechanical, and radiation attenuation parameters were reported. For this aim, Monte Carlo simulation was employed to predict the radiation attenuation parameters, while the Makishima-Mackenzie model was adopted to determine the mechanical properties. The tightly packed structure with better cross-linkage density is possessed by the Ti-containing glass (SBT-Ti) system among the titled glass batch. The higher Poisson and micro-hardness values of the SBT-Ti glass indicate its structure’s reduced free volume and better compactness. For the glass with PbO, the linear and mass attenuation coefficients are highly increased compared to those glasses doped with TiO2, ZnO, and BaO. The thinner half-value layer was reported at 0.015 MeV, taking values 0.006, 0.005, 0.004, and 0.002 for samples with TiO2, ZnO, BaO, and PbO, respectively. SBT-Pb sample (with PbO) has a thinner HVL compared to other fabricated glass samples. The fabricated glasses’ thickness (Deq) equivalent to 1 cm of lead (Pb) was reported. The results demonstrated that Deq is high at low energy and equals 11.62, 8.81, 7.61, 4.56 cm for SBT-Ti, SBT-Zn, SBT-Ba, and SBT-Pb glass samples, respectively. According to the Deq results, the fabricated glasses have a shielding capacity between 30 and 43% compared to the pure Pb at gamma-ray energy of 1.5 MeV. At high energy (8 MeV), the transmission factor values for a thickness of 1 cm of the fabricated samples reach 88.68, 87.83, 85.95, and 83.11% for glasses SBT-Ti, SBT-Zn, SBT-Ba, and SBT-Pb, respectively.

scholarly journals Radiation GRMHD simulations of M87: Funnel properties and prospects for gap acceleration

2021 ◽  
Author(s):  
Philippe Z Yao ◽  
Jason Dexter ◽  
Alexander Y Chen ◽  
Benjamin R Ryan ◽  
George N Wong
Keyword(s):  
Black Hole ◽  
Radiation Field ◽  
Gamma Ray ◽  
Theoretical Models ◽  
High Energy ◽  
Point Sources ◽  
Photon Momentum ◽  
Very High Energy ◽  
Order Of Magnitude ◽  
General Relativistic

Abstract We use the public code ebhlight to carry out 3D radiative general relativistic magnetohydrodynamics (GRMHD) simulations of accretion on to the supermassive black hole in M87. The simulations self-consistently evolve a frequency-dependent Monte Carlo description of the radiation field produced by the accretion flow. We explore two limits of accumulated magnetic flux at the black hole (SANE and MAD), each coupled to several sub-grid prescriptions for electron heating that are motivated by models of turbulence and magnetic reconnection. We present convergence studies for the radiation field and study its properties. We find that the near-horizon photon energy density is an order of magnitude higher than is predicted by simple isotropic estimates from the observed luminosity. The radially dependent photon momentum distribution is anisotropic and can be modeled by a set of point-sources near the equatorial plane. We draw properties of the radiation and magnetic field from the simulation and feed them into an analytic model of gap acceleration to estimate the very high energy (VHE) gamma-ray luminosity from the magnetized jet funnel, assuming that a gap is able to form. We find luminosities of $\rm \sim 10^{41} \, erg \, s^{-1}$ for MAD models and $\rm \sim 2\times 10^{40} \, erg \, s^{-1}$ for SANE models, which are comparable to measurements of M87’s VHE flares. The time-dependence seen in our calculations is insufficient to explain the flaring behaviour. Our results provide a step towards bridging theoretical models of near-horizon properties seen in black hole images with the VHE activity of M87.

scholarly journals Detection capabilities of the Athena X-IFU for the warm-hot intergalactic medium using gamma-ray burst X-ray afterglows

2020 ◽  
Vol 642 ◽  
pp. A24
Author(s):  
Sarah Walsh ◽  
Sheila McBreen ◽  
Antonio Martin-Carrillo ◽  
Thomas Dauser ◽  
Nastasha Wijers ◽  
...  
Keyword(s):  
Large Scale ◽  
Intergalactic Medium ◽  
Gamma Ray ◽  
Statistical Significance ◽  
European Space Agency ◽  
Gamma Ray Burst ◽  
X Ray ◽  
Baryonic Density ◽  
Space Agency ◽  
High Statistical Significance

At low redshifts, the observed baryonic density falls far short of the total number of baryons predicted. Cosmological simulations suggest that these baryons reside in filamentary gas structures, known as the warm-hot intergalactic medium (WHIM). As a result of the high temperatures of these filaments, the matter is highly ionised such that it absorbs and emits far-UV and soft X-ray photons. Athena, the proposed European Space Agency X-ray observatory, aims to detect the “missing” baryons in the WHIM up to redshifts of z = 1 through absorption in active galactic nuclei and gamma-ray burst (GRB) afterglow spectra, allowing for the study of the evolution of these large-scale structures of the Universe. This work simulates WHIM filaments in the spectra of GRB X-ray afterglows with Athena using the SImulation of X-ray TElescopes framework. We investigate the feasibility of their detection with the X-IFU instrument, through O VII (E = 573 eV) and O VIII (E = 674 eV) absorption features, for a range of equivalent widths imprinted onto GRB afterglow spectra of observed starting fluxes ranging between 10−12 and 10−10 erg cm−2 s−1, in the 0.3−10 keV energy band. The analyses of X-IFU spectra by blind line search show that Athena will be able to detect O VII−O VIII absorption pairs with EWO VII > 0.13 eV and EWO VIII > 0.09 eV for afterglows with F > 2 × 10−11 erg cm−2 s−1. This allows for the detection of ≈ 45−137 O VII−O VIII absorbers during the four-year mission lifetime. The work shows that to obtain an O VII−O VIII detection of high statistical significance, the local hydrogen column density should be limited at NH < 8 × 1020 cm−2.

scholarly journals Investigation on radiation shielding parameters of ordinary, heavy and super heavy concretes

2014 ◽  
Vol 29 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Vishwaanath Singh ◽  
Nagappa Badiger
Keyword(s):  
Cross Sections ◽  
Gamma Ray ◽  
Weight Fraction ◽  
High Energy ◽  
Radiation Shielding ◽  
Normal Operation ◽  
Attenuation Coefficients ◽  
Effective Removal ◽  
Energy Gamma ◽  
Shielding Design

Shielding of a reactor is required for protection of people and environment during normal operation and accidental situations. In the present paper we investigated the shielding parameters viz. mass attenuation coefficients, linear attenuation coefficients, tenth-value layer, effective atomic numbers, kerma relative to air and exposure buildup factors for gamma-ray for ordinary, heavy, and super heavy concretes. Macroscopic effective removal cross-sections for fast neutron had also been calculated. Ordinary concrete is economically suitable for mixture high energy gamma-ray and neutron as it has large weight fraction of low-Z as compared with super heavy concretes to slow down the neutron. Super heavy concretes are superior shielding for both reactor operation and accident situations. The study is useful for optimizing for shielding design and radiation protection in the reactors.

Global Trend of Glacier Melting or Growing and its Impact on Heavy Storms

2016 ◽  
Vol 8 (01) ◽  
pp. 43-55
Author(s):  
Bharat Raj Singh ◽  
Onkar Singh
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Human Life ◽  
European Space Agency ◽  
Ice Sheet ◽  
Good News ◽  
Laser Altimeter ◽  
Space Agency ◽  
Ipcc Report ◽  
The Antarctic

Scientists calculate how much the ice sheet is growing or shrinking from the changes in surface height that are measured by the satellite altimeters. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean, the surface height changes and the ice-sheet mass grows or shrinks. But it might only take a few decades for Antarctica’s growth to reverse, according to Zwally. If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they’ve been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years and it is questionable whether there will be enough snowfall increase to offset these losses. The study analyzed changes in the surface height of the Antarctic ice sheet measured by radar altimeters on two European Space Agency European Remote Sensing (ERS) satellites, spanning from 1992 to 2001, and by the laser altimeter on NASA’s Ice, Cloud, and land Elevation Satellite (ICESat) from 2003 to 2008. The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away. But, this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for. On other hand, globally every country is facing heavy storm, disastrous rain fall and variance in Climate Change, causing greater loss in production of food grain, disruption of smooth living and development and enhancement of hazardous deceases on account of Global Warming and Climatic Changes. This paper focuses on the current issues and its remedial efforts to be made essentially to curb these issues and save human life and beautiful creatures on the globe.

scholarly journals Progress Toward a Space-Based Gravitational Wave Observatory

2015 ◽  
Vol 11 (A29B) ◽  
pp. 357-362
Author(s):  
Jeffrey C. Livas ◽  
Robin T. Stebbins
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Gamma Ray ◽  
European Space Agency ◽  
Gravity Gradient ◽  
Electromagnetic Spectrum ◽  
Space Agency ◽  
Pulsar Timing ◽  
The Universe ◽  
Gamma Ray Telescopes

AbstractThe discovery of binary pulsar PSR 1913+16 by Hulse & Taylor in 1974 established the existence of gravitational waves, for which the 1983 Nobel Prize was awarded. However, the measurement of astrophysical parameters from gravitational waves will open an entirely new spectrum for discovery and understanding of the Universe, not simply a new window in the electromagnetic spectrum like gamma ray telescopes in the 1970s. Two types of ground-based detectors, Advanced LIGO/Virgo and Pulsar Timing Arrays, are expected to directly detect gravitational waves in their respective frequency bands before the end of the decade. However, many of the most exciting sources are in the band from 0.1–100 mHz, accessible only from space due to seismic and gravity gradient noise on Earth. The European Space Agency (ESA) has chosen the 'Gravitational Universe' as the science theme for its L3 Cosmic Visions opportunity, planned for launch in 2034. NASA is planning to participate as a junior partner. Here we summarize progress toward realizing a gravitational wave observatory in space.

scholarly journals Study of Galactic Cosmic-Ray Flux Modulation by Interplanetary Plasma Structures for the Evaluation of Space Instrument Performance and Space Weather Science Investigations

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 749 ◽  
Author(s):  
Catia Grimani ◽  
Daniele Telloni ◽  
Simone Benella ◽  
Andrea Cesarini ◽  
Michele Fabi ◽  
...  
Keyword(s):  
Large Scale ◽  
European Space Agency ◽  
Cosmic Ray ◽  
High Energy ◽  
Interplanetary Coronal Mass Ejections ◽  
Particle Detectors ◽  
Space Agency ◽  
Interplanetary Plasma ◽  
Galactic Cosmic Ray ◽  
Science Investigations

The role of high-energy particles in limiting the performance of on-board instruments was studied for the European Space Agency (ESA) Laser Interferometer Space Antenna (LISA) Pathfinder (LPF) and ESA/National Astronautics and Space Administration Solar Orbiter missions. Particle detectors (PD) placed on board the LPF spacecraft allowed for testing the reliability of pre-launch predictions of galactic cosmic-ray (GCR) energy spectra and for studying the modulation of proton and helium overall flux above 70 MeV n − 1 on a day-by-day basis. GCR flux variations up to approximately 15% in less than a month were observed with LPF orbiting around the Lagrange point L1 between 2016 and 2017. These variations appeared barely detected or undetected in neutron monitors. In this work the LPF data and contemporaneous observations carried out with the magnetic spectrometer AMS-02 experiment are considered to show the effects of GCR flux short-term variations with respect to monthly averaged measurements. Moreover, it is shown that subsequent large-scale interplanetary structures cause a continuous modulation of GCR fluxes. As a result, small Forbush decreases cannot be considered good proxies for the transit of interplanetary coronal mass ejections and for geomagnetic storm forecasting.

scholarly journals Transient astronomy with the Gaia satellite

2013 ◽  
Vol 371 (1992) ◽  
pp. 20120239 ◽  
Author(s):  
Simon T. Hodgkin ◽  
Łukasz Wyrzykowski ◽  
Nadejda Blagorodnova ◽  
Sergey Koposov
Keyword(s):  
Early Detection ◽  
Gamma Ray ◽  
European Space Agency ◽  
Space Mission ◽  
Gamma Ray Burst ◽  
Space Agency ◽  
Large Numbers ◽  
Optical Wavelengths

Gaia is a cornerstone European Space Agency astrometry space mission and a successor to the Hipparcos mission. Gaia will observe the whole sky for 5 years, providing a serendipitous opportunity for the discovery of large numbers of transient and anomalous events, e.g. supernovae, novae and microlensing events, gamma-ray burst afterglows, fallback supernovae, as well as theoretical or unexpected phenomena. In this paper, we discuss our preparations to use Gaia to search for transients at optical wavelengths, and briefly describe the early detection, classification and prompt publication of anomalous sources.

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