scholarly journals Jupiter's X-ray aurora during a mass injection and Io mass loading events observed by XMM-Newton, Hubble, and Hisaki

2021 ◽  
Author(s):  
Affelia Wibisono ◽  
Graziella Branduardi-Raymont ◽  
Will Dunn ◽  
Tomoki Kimura ◽  
Andrew Coates ◽  
...  
Keyword(s):  
Large Scale ◽  
Hubble Space Telescope ◽  
Giant Planet ◽  
High Energy ◽  
Mass Loading ◽  
Inner Magnetosphere ◽  
X Ray ◽  
Mass Injection ◽  
Field Lines ◽  
Auroral Emissions

<p>Voyager 1 detected the first extra-terrestrial UV auroral emissions when it explored the Jupiter system in 1979 while the planet’s X-ray aurora was discovered later that year by the Einstein Observatory. Electrons are accelerated into Jupiter’s atmosphere near the poles and excite native molecular and atomic hydrogen. These then release UV photons after returning to the ground state. The same population of precipitating electrons can also emit high energy (>2 keV) X-ray photons by bremsstrahlung to produce Jupiter’s hard X-ray aurora. At higher latitudes and within the oval of UV and hard X-ray emissions is where the more diffuse UV and low energy (<2 keV) soft X-ray aurorae are found.  Charge exchange processes between precipitating ions and neutrals in the gas giant planet’s atmosphere are responsible for the soft X-ray emissions.</p><p>Simultaneous observations of Jupiter’s UV and X-ray aurorae were carried out by the Hubble Space Telescope (HST), Hisaki satellite and XMM-Newton in September 2019 to support Juno’s 22<sup>nd</sup> perijove. Images of the northern far UV aurora by HST showed internally driven dawn storms and injection events occurring at least twice during the observation period. These features are thought to be caused by magnetic reconnection happening in the middle magnetosphere. This subsequently leads to the dipolarization of the field lines which injects hot magnetospheric plasma from the middle to the inner magnetosphere. Hisaki saw an impulsive brightening in the Io plasma torus on the day of the second event showing that there was indeed a large-scale injection that penetrated the central torus in the inner magnetosphere. At this time, the northern aurora brightened in both extreme UV and hard X-ray, which suggests that there was an increase in electron precipitation.  There was no response from the soft X-ray aurora, and no quasi-periodic pulsations, often observed in the auroral emissions, were detected during either of the events. X-ray spectral analysis reveals that the precipitating ions were iogenic. We conclude that we have witnessed two cases of mass injection in the Jovian inner magnetosphere due to Io mass loading events.</p>

Investigation of Residual Stress/Strain and Texture in a Large Dissimilar Metal Weld Using Synchrotron Radiation and Neutrons

2013 ◽  
Vol 772 ◽  
pp. 193-199 ◽  
Author(s):  
Carsten Ohms ◽  
Rene V. Martins
Keyword(s):  
Synchrotron Radiation ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Large Scale ◽  
High Energy ◽  
X Ray Diffraction ◽  
Butt Weld ◽  
X Ray ◽  
Component Size ◽  
Thin Slice

Bi-metallic piping welds are frequently used in light water nuclear reactors to connect ferritic steel pressure vessel nozzles to austenitic stainless steel primary cooling piping systems. An important aspect for the integrity of such welds is the presence of residual stresses. Measurement of these residual stresses presents a considerable challenge because of the component size and because of the material heterogeneity in the weld regions. The specimen investigated here was a thin slice cut from a full-scale bi-metallic piping weld mock-up. A similar mock-up had previously been investigated by neutron diffraction within a European research project called ADIMEW. However, at that time, due to the wall thickness of the pipe, stress and spatial resolution of the measurements were severely restricted. One aim of the present investigations by high energy synchrotron radiation and neutrons used on this thin slice was to determine whether such measurements would render a valid representation of the axial strains and stresses in the uncut large-scale structure. The advantage of the small specimen was, apart from the easier manipulation, the fact that measurement times facilitated a high density of measurements across large parts of the test piece in a reasonable time. Furthermore, the recording of complete diffraction patterns within the accessible diffraction angle range by synchrotron X-ray diffraction permitted mapping the texture variations. The strain and stress results obtained are presented and compared for the neutron and synchrotron X-ray diffraction measurements. A strong variation of the texture pole orientations is observed in the weld regions which could be attributed to individual weld torch passes. The effect of specimen rocking on the scatter of the diffraction data in the butt weld region is assessed during the neutron diffraction measurements.

scholarly journals Alternatives to the Existence of Large Cooling Flows

1990 ◽  
Vol 115 ◽  
pp. 232-239
Author(s):  
Wallace Tucker
Keyword(s):  
Surface Brightness ◽  
Large Scale ◽  
Theoretical Calculations ◽  
Central Peak ◽  
High Energy ◽  
Cooling Time ◽  
Radiative Cooling ◽  
Massive Black Hole ◽  
X Ray ◽  
Cooling Flows

AbstractArguments against the existence of large scale cooling flows in clusters of galaxies are presented. The evidence for cooling flows is all circumstantial, consisting of observations of cool gas or hot gas with a radiative cooling time less than the Hubble time, or a central peak in the x-ray surface brightness profile. There is no evidence for large quantities (several tens to several hundreds of solar masses per year) of matter actually flowing anywhere. On the contrary, several lines of evidence — stellar dynamics, observations of the amount of star formation, x-ray surface brightness observations, theoretical calculations of the growth of thermal instabilities, the amount of cold gas — suggest that cooling flows, if they exist, must be suppressed by one to two orders of magnitude from the values implied by simple estimates based on the radiative cooling time of the x-ray emitting gas. Two heat sources which might accomplish this — thermal conduction and relativistic particles, are considered and an alternative to the standard model for cooling flows is presented: an accretion flow with feedback wherein the accretion of gas into a massive black hole in the central galaxy generates high energy particles that heat the gas and act to limit the accretion.

scholarly journals Fast high-energy X-ray imaging for Severe Accidents experiments on the future PLINIUS-2 platform

2018 ◽  
Vol 170 ◽  
pp. 08003
Author(s):  
L. Berge ◽  
N. Estre ◽  
D. Tisseur ◽  
E. Payan ◽  
D. Eck ◽  
...  
Keyword(s):  
Large Scale ◽  
Spot Size ◽  
High Energy ◽  
Simulation Software ◽  
Small Scale ◽  
Noise Sources ◽  
X Ray ◽  
X Ray Imaging ◽  
The Future ◽  
Set Up

The future PLINIUS-2 platform of CEA Cadarache will be dedicated to the study of corium interactions in severe nuclear accidents, and will host innovative large-scale experiments. The Nuclear Measurement Laboratory of CEA Cadarache is in charge of real-time high-energy X-ray imaging set-ups, for the study of the corium-water and corium-sodium interaction, and of the corium stratification process. Imaging such large and high-density objects requires a 15 MeV linear electron accelerator coupled to a tungsten target creating a high-energy Bremsstrahlung X-ray flux, with corresponding dose rate about 100 Gy/min at 1 m. The signal is detected by phosphor screens coupled to high-framerate scientific CMOS cameras. The imaging set-up is established using an experimentally-validated home-made simulation software (MODHERATO). The code computes quantitative radiographic signals from the description of the source, object geometry and composition, detector, and geometrical configuration (magnification factor, etc.). It accounts for several noise sources (photonic and electronic noises, swank and readout noise), and for image blur due to the source spot-size and to the detector unsharpness. In a view to PLINIUS-2, the simulation has been improved to account for the scattered flux, which is expected to be significant. The paper presents the scattered flux calculation using the MCNP transport code, and its integration into the MODHERATO simulation. Then the validation of the improved simulation is presented, through confrontation to real measurement images taken on a small-scale equivalent set-up on the PLINIUS platform. Excellent agreement is achieved. This improved simulation is therefore being used to design the PLINIUS-2 imaging set-ups (source, detectors, cameras, etc.).

scholarly journals MOVES III. Simultaneous X-ray and ultraviolet observations unveiling the variable environment of the hot Jupiter HD 189733b

2020 ◽  
Vol 493 (1) ◽  
pp. 559-579 ◽  
Author(s):  
V Bourrier ◽  
P J Wheatley ◽  
A Lecavelier des Etangs ◽  
G King ◽  
T Louden ◽  
...  
Keyword(s):  
Stellar Wind ◽  
Hubble Space Telescope ◽  
Spectral Energy Distribution ◽  
Neutral Hydrogen ◽  
High Energy ◽  
Spectral Energy ◽  
Variable Environment ◽  
X Ray ◽  
Far Ultraviolet ◽  
In Transit

ABSTRACT In this third paper of the MOVES (Multiwavelength Observations of an eVaporating Exoplanet and its Star) programme, we combine Hubble Space Telescope far-ultraviolet (FUV) observations with XMM–Newton/Swift X-ray observations to measure the emission of HD 189733 in various FUV lines, and its soft X-ray spectrum. Based on these measurements we characterize the interstellar medium towards HD 189733 and derive semisynthetic XUV spectra of the star, which are used to study the evolution of its high-energy emission at five different epochs. Two flares from HD 189733 are observed, but we propose that the long-term variations in its spectral energy distribution have the most important consequences for the environment of HD 189733b. Reduced coronal and wind activity could favour the formation of a dense population of Si2+ atoms in a bow-shock ahead of the planet, responsible for pre- and in-transit absorption measured in the first two epochs. In-transit absorption signatures are detected in the Lyman α line in the second, third, and fifth epochs, which could arise from the extended planetary thermosphere and a tail of stellar wind protons neutralized via charge-exchange with the planetary exosphere. We propose that increases in the X-ray irradiation of the planet, and decreases in its EUV irradiation causing lower photoionization rates of neutral hydrogen, favour the detection of these signatures by sustaining larger densities of H0 atoms in the upper atmosphere and boosting charge-exchanges with the stellar wind. Deeper and broader absorption signatures in the last epoch suggest that the planet entered a different evaporation regime, providing clues as to the link between stellar activity and the structure of the planetary environment.

scholarly journals High-Energy X-Ray Compton Scattering Imaging of 18650-Type Lithium-Ion Battery Cell

2019 ◽  
Vol 4 (3) ◽  
pp. 66 ◽  
Author(s):  
Kosuke Suzuki ◽  
Ari-Pekka Honkanen ◽  
Naruki Tsuji ◽  
Kirsi Jalkanen ◽  
Jari Koskinen ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Lithium Ion Battery ◽  
Compton Scattering ◽  
Present Method ◽  
Large Scale ◽  
Lithium Ion ◽  
High Energy ◽  
The Other ◽  
Battery Cell ◽  
X Ray

High-energy synchrotron X-ray Compton scattering imaging was applied to a commercial 18650-type cell, which is a cylindrical lithium-ion battery in wide current use. By measuring the Compton scattering X-ray energy spectrum non-destructively, the lithiation state in both fresh and aged cells was obtained from two different regions of the cell, one near the outer casing and the other near the center of the cell. Our technique has the advantage that it can reveal the lithiation state with a micron-scale spatial resolution even in large cells. The present method enables us to monitor the operation of large-scale cells and can thus accelerate the development of advanced lithium-ion batteries.

Laser-plasma extreme ultraviolet and soft X-ray sources based on a double stream gas puff target: interaction of the radiation pulses with matter

2015 ◽  
Vol 23 (2) ◽  
Author(s):  
A. Bartnik
Keyword(s):  
Large Scale ◽  
Extreme Ultraviolet ◽  
High Energy ◽  
High Energy Density ◽  
Small Scale ◽  
X Ray ◽  
Target Interaction ◽  
University Of Technology ◽  
Photoionized Plasmas ◽  
Intense Radiation

AbstractIn this work a review of investigations concerning interaction of intense extreme ultraviolet (EUV) and soft X-ray (SXR) pulses with matter is presented. The investigations were performed using laser-produced plasma (LPP) EUV/SXR sources based on a double stream gas puff target. The sources are equipped with dedicated collectors allowing for efficient focusing of the EUV/SXR radiation pulses. Intense radiation in a wide spectral range, as well as a quasi-monochromatic radiation can be produced. In the paper different kinds of LPP EUV/SXR sources developed in the Institute of Optoelectronics, Military University of Technology are described.Radiation intensities delivered by the sources are sufficient for different kinds of interaction experiments including EUV/SXR induced ablation, surface treatment, EUV fluorescence or photoionized plasma creation. A brief review of the main results concerning this kind of experiments performed by author of the paper are presented. However, since the LPP sources cannot compete with large scale X-ray sources like synchrotrons, free electron lasers or high energy density plasma sources, it was indicated that some investigations not requiring extreme irradiation parameters can be performed using the small scale installations. Some results, especially concerning low temperature photoionized plasmas are very unique and could be hardly obtained using the large facilities.

scholarly journals Sources of X-rays from galaxies

2011 ◽  
Vol 7 (S284) ◽  
pp. 183-192
Author(s):  
Q. Daniel Wang
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Supernova Remnants ◽  
Large Scale ◽  
Formation Rate ◽  
Galactic Nuclei ◽  
High Energy ◽  
High Mass ◽  
X Rays ◽  
X Ray

AbstractGalactic X-ray emission is a manifestation of various high-energy phenomena and processes. The brightest X-ray sources are typically accretion-powered objects: active galactic nuclei and low- or high-mass X-ray binaries. Such objects with X-ray luminosities of ≳ 1037 ergs s−1 can now be detected individually in nearby galaxies. The contributions from fainter discrete sources (including cataclysmic variables, active binaries, young stellar objects, and supernova remnants) are well correlated with the star formation rate or stellar mass of galaxies. The study of discrete X-ray sources is essential to our understanding of stellar evolution, dynamics, and end-products as well as accretion physics. With the subtraction of the discrete source contributions, one can further map out truly diffuse X-ray emission, which can be used to trace the feedback from active galactic nuclei, as well as from stars, both young and old, in the form of stellar winds and supernovae. The X-ray emission efficiency, however, is only about 1% of the energy input rate of the stellar feedback alone. The bulk of the feedback energy is most likely gone with outflows into large-scale galactic halos. Much is yet to be investigated to comprehend the role of such outflows in regulating the ecosystem, hence the evolution of galaxies. Even the mechanism of the diffuse X-ray emission remains quite uncertain. A substantial fraction of the emission cannot arise directly from optically-thin thermal plasma, as commonly assumed, and most likely originates in its charge exchange with neutral gas. These uncertainties underscore our poor understanding of the feedback and its interplay with the galaxy evolution.

Defective MnO2 nanosheets based free-standing and high mass loading electrodes for high energy density aqueous zinc ion batteries

2021 ◽  
Author(s):  
Ping Shang ◽  
Yuanhao Liu ◽  
Yingying Mei ◽  
Lisha Wu ◽  
Yanfeng Dong
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
High Energy ◽  
Zinc Ion ◽  
Wearable Devices ◽  
High Energy Density ◽  
High Mass ◽  
Mass Loading ◽  
Free Standing ◽  
Mno2 Nanosheets

Aqueous zinc ion batteries (ZIBs) hold great promises for large-scale energy storage and wearable devices due to their low cost and high safety, but suffer from low capacity and energy...

Quantification of Large Scale Micro-X-Ray Fluorescence Elemental Images

2001 ◽  
Vol 55 (11) ◽  
pp. 1448-1454 ◽  
Author(s):  
Christopher G. Worley ◽  
George J. Havrilla ◽  
Paul S. Dunn
Keyword(s):  
Concentration Distribution ◽  
Large Scale ◽  
Surface Oxidation ◽  
Sample Surface ◽  
High Energy ◽  
Depleted Uranium ◽  
Established Method ◽  
X Ray ◽  
Elemental Concentrations ◽  
Relative Differences

Niobium is commonly alloyed with uranium to prevent surface oxidation, and determining how the niobium concentration is distributed throughout a sample is useful in explaining observed material properties. The niobium concentration distribution was determined across the surface of depleted uranium samples using micro-X-ray fluorescence (MXRF). To date, MXRF has been employed primarily as a qualitative tool for determining relative differences in elemental concentrations across a sample surface. Here, a process was developed to convert qualitative MXRF niobium distribution images from depleted uranium samples into images displaying concentration values. Thus, MXRF was utilized to determine elemental concentrations across a surface in a manner similar to that of the established method of electron microprobe X-ray analysis (EMPA). However, MXRF can provide such information from relatively large sample areas many cm2 in size that are too large to examine by the higher spatial resolution technique of EMPA. Although the sample surfaces were polished to the same degree as the standards, little or no sample preparation should be necessary for sample systems where a high energy analyte XRF line can be used for imaging.

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