A Discussion on the physics of the solar atmosphere - High resolution x-ray spectra of the Sun

1976 ◽  
Vol 281 (1304) ◽  
pp. 375-382 ◽  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Solar Atmosphere ◽  
High Spatial Resolution ◽  
Coronal Plasma ◽  
Temperature Sensitive ◽  
The Sun ◽  
Multiplet Structure ◽  
X Ray ◽  
Areas Of Interest

The last few years have seen great advances in the instrumentation used to obtain X-ray spectra of the Sun. These new observations reveal a wealth of multiplet structure containing many lines which allow us to understand more of the nature of the coronal plasma. Three areas of interest are examined. (1) The temperature sensitive satellite lines to helium —like resonance lines. (2) The strong lines of neon —like iron, Fexvii. (3) The combination of high spectral and high spatial resolution (Skylab) observations.

scholarly journals ZnWO4 Nanoparticle Scintillators for High Resolution X-ray Imaging

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1721
Author(s):  
Heon Yong Jeong ◽  
Hyung San Lim ◽  
Ju Hyuk Lee ◽  
Jun Heo ◽  
Hyun Nam Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
High Resolution ◽  
Tungsten Oxide ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
Average Size ◽  
And Tungsten

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO4) particles. The ZnWO4 particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.7 nm, and 2.127 μm; the zinc oxide and tungsten oxide were created using anodization. The spatial resolutions of high-resolution X-ray images, obtained from utilizing the fabricated particles, were determined: particles with the average size of 176.4 nm produced the highest spatial resolution. The results demonstrate that high spatial resolution can be obtained from ZnWO4 nanoparticle scintillators that minimize optical diffusion by having a particle size that is smaller than the emission wavelength.

Low Voltage X-Ray Microanalysis of Bulk Bio-Organic Samples

1998 ◽  
Vol 4 (S2) ◽  
pp. 190-191
Author(s):  
Patrick Echlin
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Voltage ◽  
Biological Material ◽  
High Spatial Resolution ◽  
Low Voltage ◽  
Similar Type ◽  
The Other ◽  
X Ray

Although high resolution (2nm), low voltage (lkV), SEM of bio-organic materials can now be performed more or less routinely using instruments fitted with a field emission source, virtually no low voltage x-ray microanalysis has been carried out on this type of specimen. Boyes and Nockolds showed that quantitative microanalytical information could be obtained from polished inorganic samples at a spatial resolution of l00nm at 5kV and Johnson et al obtained similar type of data at a spatial resolution of 150nm at 3kV. High spatial resolution (l0nm) microanalysis can be achieved in frozen dried or chemically compromised sections of biological material examined at high voltage in the TEM but frozen hydrated chemically unfixed sections are damaged. The other approach is to use the SEM with frozen hydrated, chemically uncompromised samples, usually at about 10-15kV, in order to obtain sufficient signal from the elements of interest which typically lie in the range Na (Z=l 1) to Ca (Z=20).

High Spatial Resolution Soft X-Ray Microscopy and Microanalysis of Thick and Hydrated Materials

1998 ◽  
Vol 4 (S2) ◽  
pp. 352-353
Author(s):  
W. Meyer-Ilse ◽  
J. T. Brown ◽  
C. Magowan ◽  
J. Yeung ◽  
K. E. Kurtis ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Atmospheric Pressure ◽  
High Spatial Resolution ◽  
Ccd Camera ◽  
Optical Path ◽  
Zone Plate ◽  
Full Field ◽  
X Ray ◽  
Scientific Fields

The Center for X-ray Optics (CXRO) built and operates a high-resolution soft x-ray microscope (XM-1) at the Advanced Light Source in Berkeley. We report on the use of this instrument in a variety of scientific fields, including biology, civil engineering and environmental sciences.The microscope is a conventional (full field) x-ray microscope, which uses zone plate lenses to provide high resolution transmission images. The optical setup is similar to the Göttingen x-ray microscope, operated at the BESSY synchrotron radiation facility in Berlin, Germany. A condenser zone plate, fabricated by the Göttingen group, is illuminating the sample and an objective zone plate, fabricated by Erik Anderson (CXRO), is forming an enlarged image on an x-ray CCD camera. While the optical path of the microscope is in vacuum, the sample is at atmospheric pressure, flushed by helium. The spatial resolution of our microscope is 43 nm, measured as the distance from 10%-90% intensity in the image of a knife-edge.

scholarly journals SIMURIS: High-Resolution Solar Physics

1993 ◽  
Vol 141 ◽  
pp. 184-187
Author(s):  
Robert J. Rutten ◽  
Luc Damé
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
Solar Physics ◽  
Short Wave ◽  
Spatial Extent ◽  
The Sun ◽  
Space Telescopes ◽  
X Ray ◽  
Solar Telescopes

AbstractThe magnetic fields of the Sun provide the major incentive to do solar physics. The small spatial extent of the magnetically constrained structures and processes in the solar atmosphere provide the major incentive for high resolution solar telescopes. The visibility of the outer solar atmosphere in the ultraviolet and X-ray domains provide the major incentive for solar space telescopes. Cost provides the major incentive to use interferometric techniques. SIMURIS employs short-wave interferometry from space to measure solar structures and processes with high resolution.

A Large Area, High-Resolution a-Si:H Array for X-Ray Imaging

1994 ◽  
Vol 336 ◽  
Author(s):  
L.E. Antonuk ◽  
Y. El-Mohri ◽  
W. Huang ◽  
J. Siewerdsen ◽  
J. Yorkston ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Frame Rate ◽  
Large Area ◽  
X Ray ◽  
X Ray Imaging ◽  
Pixel Pitch ◽  
Resolution Requirements ◽  
Good Agreement

ABSTRACTThe development of a large area, high-resolution, a-Si:H x-ray imager is reported. The array has 1536×1920 pixels, a pixel pitch of 127μm, and an area of 19.5×24.4 cm2. Tne array is tailored to the high frame rate and high spatial resolution requirements of diagnostic x-ray imaging. The design of this array is presented and examples of x-ray images are illustrated. Initial Measurements of the sensor capacitance and pixel time constant properties are in good agreement with theoretical expectations. These results indicate that high-resolution arrays of this construction are capable of providing fluoroscopic images at rates of at least 30 frames per second.

scholarly journals High-Spatial-Resolution Bone Densitometry with Dual-Energy X-ray Absorptiometric Region-free Analysis

Radiology ◽  
2015 ◽  
Vol 275 (1) ◽  
pp. 310-310 ◽  
Author(s):  
Richard M. Morris ◽  
Lang Yang ◽  
Miguel A. Martín-Fernández ◽  
Jose M. Pozo ◽  
Alejandro F. Frangi ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Bone Densitometry ◽  
High Spatial Resolution ◽  
Dual Energy ◽  
X Ray

scholarly journals Deriving VIIRS High-Spatial Resolution Water Property Data over Coastal and Inland Waters Using Deep Convolutional Neural Network

2021 ◽  
Vol 13 (10) ◽  
pp. 1944
Author(s):  
Xiaoming Liu ◽  
Menghua Wang
Keyword(s):  
Neural Network ◽  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Ocean Color ◽  
Super Resolution ◽  
Inland Waters ◽  
Coastal Oceans ◽  
Chl A ◽  
Color Data

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite has been a reliable source of ocean color data products, including five moderate (M) bands and one imagery (I) band normalized water-leaving radiance spectra nLw(λ). The spatial resolutions of the M-band and I-band nLw(λ) are 750 m and 375 m, respectively. With the technique of convolutional neural network (CNN), the M-band nLw(λ) imagery can be super-resolved from 750 m to 375 m spatial resolution by leveraging the high spatial resolution features of I1-band nLw(λ) data. However, it is also important to enhance the spatial resolution of VIIRS-derived chlorophyll-a (Chl-a) concentration and the water diffuse attenuation coefficient at the wavelength of 490 nm (Kd(490)), as well as other biological and biogeochemical products. In this study, we describe our effort to derive high-resolution Kd(490) and Chl-a data based on super-resolved nLw(λ) images at the VIIRS five M-bands. To improve the network performance over extremely turbid coastal oceans and inland waters, the networks are retrained with a training dataset including ocean color data from the Bohai Sea, Baltic Sea, and La Plata River Estuary, covering water types from clear open oceans to moderately turbid and highly turbid waters. The evaluation results show that the super-resolved Kd(490) image is much sharper than the original one, and has more detailed fine spatial structures. A similar enhancement of finer structures is also found in the super-resolved Chl-a images. Chl-a filaments are much sharper and thinner in the super-resolved image, and some of the very fine spatial features that are not shown in the original images appear in the super-resolved Chl-a imageries. The networks are also applied to four other coastal and inland water regions. The results show that super-resolution occurs mainly on pixels of Chl-a and Kd(490) features, especially on the feature edges and locations with a large spatial gradient. The biases between the original M-band images and super-resolved high-resolution images are small for both Chl-a and Kd(490) in moderately to extremely turbid coastal oceans and inland waters, indicating that the super-resolution process does not change the mean values of the original images.

APD-based x-ray imaging telescope using Fresnel zone plates for extremely high spatial resolution

2005 ◽  
Author(s):  
Michael R. Squillante ◽  
Richard A. Myers ◽  
Mitchell Woodring ◽  
James F. Christian ◽  
Frank Robertson ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Fresnel Zone ◽  
Fresnel Zone Plates ◽  
X Ray ◽  
Zone Plates ◽  
X Ray Imaging ◽  
Imaging Telescope
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