The Solar Energetic Particle Event of March 15 2013 - Characterization of the interplanetary medium conditions 

2021 ◽  
Author(s):  
Antonio Niemela ◽  
Nicolas Wijsen ◽  
Luciano Rodriguez ◽  
Jasmina Magdalenic ◽  
Stefaan Poedts
Keyword(s):  
Interplanetary Medium ◽  
Interplanetary Space ◽  
Solar Energetic Particle ◽  
Solar Energetic Particle Event ◽  
Coupled Models ◽  
Particle Radiation ◽  
X Ray ◽  
Particle Population ◽  
Long Duration

<p>On March 15, 2013, an Earth directed halo CME, associated with an SEP event, was observed. This study aims to characterize the interplanetary medium conditions in which the event propagated, in order to make the first steps towards the validation of the modeling of SEPs employing two recently coupled models, EUHFORIA (EUropean Heliosferic FORcasting Information Asset) and PARADISE (PArticle Radiation Asset Directed at Interplanetary Space Exploration).<br><br></p><p>The Sun in the days prior and after the event was very active, with several strong flares and coronal mass ejections during this period. The main event was associated with the long duration GOES M1.1 X-ray flare originating from the active region (AR) 11692, located at N11E12. Imagers aboard SOHO and STEREO spacecrafts observed the CME launch at 7:12 UT and the projected line of the sight speed was estimated to be about 1060 km/s. A rise in the $>$10 MeV GOES proton count was observed the following day, with flux exceeding the 1000 pfu threshold, and stayed above it for several days. Another strong CME was launched, within the following hours, towards the west but with a good magnetic connection to Earth's position, which could have accelerated even further the particle population seeded by the main event.</p><p><br>We model the solar wind and its transients CMEs with EUHFORIA, in order to obtain the realistic conditions of the ambient plasma through which the associated particles are propagating. Different spatial and temporal resolutions of the model will be explored to run the newly developed model for energetic protons PARADISE in an optimal environment and make a step towards better SEP predictions.</p>

scholarly journals Multi-scale characterization of glaucophane from Chiavolino (Biella, Italy): implications for international regulations on elongate mineral particles

2021 ◽  
Vol 33 (1) ◽  
pp. 77-112
Author(s):  
Ruggero Vigliaturo ◽  
Sabrina M. Elkassas ◽  
Giancarlo Della Ventura ◽  
Günther J. Redhammer ◽  
Francisco Ruiz-Zepeda ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Atomic Scale ◽  
Energy Dispersive ◽  
Mineral Particle ◽  
X Ray ◽  
Mineral Particles ◽  
Particle Population ◽  
Investigation Methods

Abstract. In this paper, we present the results of a multi-analytical characterization of a glaucophane sample collected in the Piedmont region of northwestern Italy. Investigation methods included optical microscopy, powder X-ray diffraction, Fourier-transform infrared spectroscopy, µ-Raman spectroscopy, Mössbauer spectroscopy, electron probe microanalysis, environmental scanning electron microscopy and energy-dispersive X-ray spectroscopy, and scanning/transmission electron microscopy combined with energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy. In addition to the crystal–chemical characterization of the sample from the mesoscale to the near-atomic scale, we have also conducted an extended study on the morphology and dimensions of the mineral particles. The main finding is that studying the same particle population at different magnifications yields different results for mineral habit, dimensions, and dimensional distributions. As glaucophane may occur as an elongate mineral particle (e.g., asbestiform glaucophane occurrences in California and Nevada), the observed discrepancies therefore need to be considered when assessing potential breathability of such particles, with implications for future regulations on elongate mineral particles. While the sample preparation and particle counting methods are not directly investigated in this work, our findings suggest that different magnifications should be used when characterizing an elongate mineral particle population, irrespective of whether or not it contains asbestiform material. These results further reveal the need for developing improved regulation for elongate mineral particles. We thus propose a simple methodology to merge the datasets collected at different magnifications to provide a more complete description and a better risk evaluation of the studied particle population.

scholarly journals The soft X-ray Neupert effect as a proxy for solar energetic particle injection

2020 ◽  
Vol 10 ◽  
pp. 64
Author(s):  
Ruhann Steyn ◽  
Du Toit Strauss ◽  
Frederic Effenberger ◽  
Daniel Pacheco
Keyword(s):  
Thermal Emission ◽  
Transport Model ◽  
Solar Energetic Particle ◽  
Particle Injection ◽  
New Approach ◽  
X Ray ◽  
Neupert Effect ◽  
Long Duration ◽  
Cast Model

The acceleration and injection of solar energetic particles (SEPs) near the Sun is one of the major unsolved problems in contemporary SEP transport modeling efforts. Here, we establish a new approach to the injection problem by utilizing a correlation between the soft X-ray thermal emission in solar flares, and their hard X-ray counterpart, the so-called Neupert effect, which is indicative of the presence of non-thermal particles. We show that the resulting injection function, in the initial phase of the flare, is similar to those inferred from inverting the transport problem based on in-situ observations. For few cases, we find early injections with no in-situ correspondence, that can be caused by particles accelerated before there is a magnetic connection between the source and the spacecraft. The method has limitations for long-duration injections, since it is not applicable to the decay phase of the flare where particle trapping might play a role. For a sample of SEP events in 1980, observed with the Helios-1 and IMP8 spacecraft, we show the results of a 2D SEP transport model based on this approach. We discuss that, with this method, a physics-based, real-time operational SEP now-cast model for the heliosphere is feasible.

Coronal Mass Ejections and the Rise Profiles of 0.3 MeV Electron Events

1994 ◽  
Vol 144 ◽  
pp. 479-482 ◽  
Author(s):  
S. W. Kahler ◽  
V. G. Stolpovskii ◽  
E. I. Daibog
Keyword(s):  
Short Duration ◽  
Coronal Mass Ejections ◽  
Interplanetary Space ◽  
Shock Acceleration ◽  
Relativistic Electrons ◽  
X Ray ◽  
Long Duration

AbstractThere is some evidence to suggest that relativistic electrons observed in interplanetary space may be produced in coronal shocks. If so, the rise phases of such events may be longer than those not arising in shocks. To test this possibility, we examined the rise profiles ofE< 0.3MeVelectron events observed on the Helios spacecraft. First we compared rise times of electron events associated with short-duration X-ray flares to events with long-duration X-ray flares. The latter events are more likely than the former to be associated with coronal shocks and coronal mass ejections (CMEs). For a smaller group of electron events we determined the rise times as a function of the speed of the CME observed with the NRL Solwind coronagraph to see whether higher shock speeds resulted in longer event rise times. The data show a weak indication that event rise times increase with CME presence and with CME speed, thus suggesting a role for shock acceleration.

scholarly journals Analysis of airborne metal containing particles with EDX/EDS detectors in electron microscopes

2011 ◽  
Vol 9 (2) ◽  
pp. 308-313 ◽  
Author(s):  
Przemysław Sielicki ◽  
Helena Janik ◽  
Agnieszka Guzman ◽  
Alan Reynolds ◽  
Jacek Namieśnik
Keyword(s):  
Particulate Matter ◽  
Electron Microscope ◽  
Major Element ◽  
X Ray ◽  
Minor Elements ◽  
Particle Population ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron

AbstractIn years 2006–2010 particulate matter analysis was undertaken for dust samples collected from Gdansk and London area in order to compare their morphology and composition. Part of those studies was devoted to analysis of particulate matter (PM) bearing metals. Characterization of the morphology and size of the particles collected onto the filters was performed using a scanning electron microscope (SEM) and transmission electron microscope (TEM). Both electron microscopes were equipped with energy dispersive X-ray spectrometers to identify the elemental composition of the particles. On analysis of the X-ray spectra acquired by both TEM and SEM, the particles were divided into 10 groups as follows: Al-rich, Ba-rich, C-rich, Ca-rich, Cl-rich, Fe-rich, Mg-rich, Na-rich, S-rich, Si-rich. Speciation of the particles based on the major element and accompanying minor elements yielded 34 particle types. However, some pairs of elements repeat, for instance: Na-Cl and Cl-Na, Al-S and S-Al, Si-Al and Al-Si, S-Ca and Ca-S. These are undoubtedly the same types of particles; variation in peak heights of the major and minor elements is normal in a mixed particle population.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Sign in / Sign up

Export Citation Format

Share Document