scholarly journals Detection and Imaging with Leak Microstructures

Instruments ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 15
Author(s):  
Mariano Lombardi ◽  
Gianfranco Prete ◽  
Giovanni Balbinot ◽  
Alice Ferretti ◽  
Giuseppe Galeazzi ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Silicon Detector ◽  
Alpha Particles ◽  
Preliminary Results ◽  
Single Electrons ◽  
Heated Filament

Results obtained with a new, very compact detector for imaging with a matrix of leak microstructures (LM) are reported. Spatial linearity and spatial resolution obtained by scanning and the detection of alpha particles with 100% efficiency, when compared with a silicon detector, are stressed. Preliminary results obtained in detecting single electrons emitted by the heated filament (Ec < 1 eV) at 1–3 mbar of propane are reported.

Digital imaging in radiology: preliminary results obtained with a high spatial resolution 2D silicon detector

1993 ◽  
Vol 40 (4) ◽  
pp. 987-991 ◽  
Author(s):  
B. Alfano ◽  
A. Bandettini ◽  
W. Bencivelli ◽  
E. Bertolucci ◽  
U. Bottigli ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Digital Imaging ◽  
High Spatial Resolution ◽  
Silicon Detector ◽  
Preliminary Results

A Preliminary Observation on AgGaSe2 as a Nuclear Radiation Detector

1982 ◽  
Vol 16 ◽  
Author(s):  
Eiji Sakai ◽  
Hiromichi Horinaka ◽  
Hajimu Sonomura ◽  
Takeshi Miyauchi
Keyword(s):  
Radiation Detector ◽  
Silicon Detector ◽  
Alpha Particles ◽  
Nuclear Radiation ◽  
Surface Barrier ◽  
Applied Bias Voltage ◽  
Nuclear Radiation Detector ◽  
Barrier Detector ◽  
Temperature Noise ◽  
Silicon Surface Barrier Detector

ABSTRACTAn about 108 ohm-cm AgGaSe2 crystal of 0.5 mm × 4 mm × 4 mm was polished and contacts were made by evaporating 130 μg/cm2 gold of 3 mm diameter on the two faces of the crystal. The detector was tested using 5.5 MeV alpha-particles at room temperature. Noise increased above an applied bias voltage of 80 V. For + 50 V applied on the electrode opposite to the particle incident electrode, i.e., for electron traversal mode, the preamplifier output pulses showed a risetime of 20 μs and an amplitude of about one-tenth of that obtained from a silicon surface-barrier detector whereas the silicon detector showed a risetime of 0.07 μs. For - 50 V applied on the same electrode, i.e., for hole traversal mode, no pulses were observed.

Use Of A Solid-State Detector for the Analysis of X-Rays Excited in Silicate Rocks by Alpha-Particle Bombardment

1971 ◽  
Vol 15 ◽  
pp. 388-406 ◽  
Author(s):  
Ernest J. Franzgrote
Keyword(s):  
Alpha Particle ◽  
Particle Bombardment ◽  
Pulse Height ◽  
Silicon Detector ◽  
Alpha Particles ◽  
X Rays ◽  
Solid State Detector ◽  
X Ray ◽  
Alpha Scattering ◽  
Silicate Rocks

The analysis of alpha-excited X-rays has been studied as a possible addition to the alpha-scattering technique used on the Surveyor spacecraft for the first in situ chemical analyses of the lunar surface.Targets of pure elements, simple compounds, and silicate rocks have been exposed to alpha particles and other radiation from a curium-214 source and the resulting X-ray spectra measured by means of a cooled lithium-drifted silicon detector and pulse-height analysis.Alpha-particle bombardment is a simple and efficient means of X-ray excitation for light elements. Useful spectra of silicate rocks may be obtained in a few minutes with a source activity of 50 millicuries, a detector area of 0.1 cm2 and a sample distance of 3 cm. An advantage over electron excitation is the higher characteristic response relative to the bremsstrahlung continuum. Peak-to- background ratios of greater than 100 to 1 have been obtained for elemental targets. Relative efficiencies of X-ray excitation by alpha particles and by X-rays from the curium source have been determined.Resolution of the detector system used is approximately 150 eV for the lighter elements. This is sufficient to resolve the Kα X-rays of the geochemically important elements, Na, Mg, Al, and Si in silicate rocks. Although these and lighter elements are analyzed as well or better by the alpha-scattering and alpha-proton technique, the X-ray mode enables results to be obtained more quickly.The study shows that the addition of an X-ray mode to the alpha-scattering analysis technique would result in a significant improvement in analytical capability for the heavier elements. In particular, important indicators of geochemical differentiation such as K and Ca (which are only marginally separated in an alpha-scattering and alpha-proton analysis) may be determined quantitatively by measuring the alpha-excited X-rays. An X-ray detector is under consideration as an addition to an alpha-scattering instrument now under development for possible use on a Mars-lander mission.

Underwater Gliders for Ocean Research

2004 ◽  
Vol 38 (2) ◽  
pp. 73-84 ◽  
Author(s):  
Daniel L. Rudnick ◽  
Russ E. Davis ◽  
Charles C. Eriksen ◽  
David M. Fratantoni ◽  
Mary Jane Perry
Keyword(s):  
Spatial Resolution ◽  
Autonomous Vehicles ◽  
Demonstration Project ◽  
Current Development ◽  
University Of Washington ◽  
Preliminary Results ◽  
Scripps Institution ◽  
Underwater Gliders ◽  
Wide Range ◽  
Recent Demonstration

Underwater gliders are autonomous vehicles that profile vertically by controlling buoyancy and move horizontally on wings. Gliders are reviewed, from their conception by Henry Stommel as an extension of autonomous profiling floats, through their development in three models, and including their first deployments singly and in numbers. The basics of glider function are discussed as implemented by University of Washington in Seaglider, Scripps Institution of Oceanography in Spray, and Webb Research in Slocum. Gliders sample in the archetypical modes of sections and of "virtual moorings." Preliminary results are presented from a recent demonstration project that used a network of gliders off Monterey. A wide range of sensors has already been deployed on gliders, with many under current development, and an even wider range of future possibilities. Glider networks appear to be one of the best approaches to achieving subsurface spatial resolution necessary for ocean research.

Application of ECOSTRESS multispectral LWIR images to assess topsoil properties: preliminary results on agricultural test sites in Central Italy

2020 ◽  
Author(s):  
Anvesh Rangisetty ◽  
Raffaele Casa ◽  
Victoria Ionca ◽  
Giovanni Laneve ◽  
Simone Pascucci ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Surface Temperature ◽  
Spatial Resolution ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Central Italy ◽  
Preliminary Results ◽  
Medium Resolution

&lt;p&gt;Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) is a thermal infrared sensor, developed by NASA-JPL, launched in June 2018. ECOSTRESS acquires five LWIR spectral channels between 8 and 12 &amp;#956;m, with 70 m of spatial resolution at different times of the day and night.&lt;/p&gt;&lt;p&gt;The availability of multispectral TIR bands allows the retrieval of Land Surface Temperature (LST) and Land Surface Emissivity (LSE) by using well known procedures, like Temperature and Emissivity Separation (TES). The availability of LSE images in the LWIR atmospheric window at a medium resolution allows to estimate some topsoil/rock properties, for example those related to quartz diagnostic absorption features.&lt;/p&gt;&lt;p&gt;Furthermore, recent studies have shown that multispectral data in the LWIR region allows to retrieve quantitative information on topsoil properties, such as texture, carbon and nitrogen content, especially when applying multivariate statistical models [1] [2]. This study intends to verify the potential of night and day ECOSTRESS images for topsoil properties estimation.&lt;/p&gt;&lt;p&gt;To this aim, on specific experimental fields in Central Italy, soil sampling campaigns have been conducted to assess the topsoil properties like soil texture (clay, silt, sand) and soil organic carbon (SOC).&lt;/p&gt;&lt;p&gt;First, on these experimental fields, ECOSTRESS archive images were explored to identify the images in which the sampled fields are ploughed (i.e. bare soil conditions). Second, the ECO2LSTE products [3], containing the land surface temperature and emissivity, were downloaded from the USGS web site (https://ecostress.jpl.nasa.gov/data) and atmospherically corrected. Third, the TES algorithm was applied providing emissivity images at a spatial resolution of 70 m.&lt;/p&gt;&lt;p&gt;Last, the emissivity images were used to define a prediction model (calibration and validation) by using both Partial Least Squares Regression (PLSR) and Random Forest (RF).&lt;/p&gt;&lt;p&gt;The preliminary results seem to confirm: i) the potential of ECOSTRESS LWIR data to retrieve topsoil properties valuable for agronomical purposes at the regional scale, ii) the preliminary result of the multivariate analysis like PLSR and RF to derive model for topsoil properties (mainly clay and organic content) prediction&amp;#160; at a medium resolution scale.&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;ul&gt;&lt;li&gt;[1] Notesco, G., Weksler, S., &amp; Ben-Dor, E. (2019). Mineral Classification of Soils Using Hyperspectral Longwave Infrared (LWIR) Ground-Based Data. Remote Sensing, 11(12), 1429.&lt;/li&gt; &lt;li&gt;[2] Pascucci, S., Casa, R., Belviso, C., Palombo, A., Pignatti, S., &amp; Castaldi, F. (2014). Estimation of soil organic carbon from airborne hyperspectral thermal infrared data: A case study.European journal of soil science, 65(6), 865-875.&lt;/li&gt; &lt;li&gt;[3] Silvestri, M., Romaniello, V., Hook, S., Musacchio, M., Teggi, S., &amp; Buongiorno, M. F. (2020). First Comparisons of Surface Temperature Estimations between ECOSTRESS, ASTER and Landsat 8 over Italian Volcanic and Geothermal Areas. Remote Sensing, 12(1), 184.&lt;/li&gt; &lt;/ul&gt;

scholarly journals Ageing Studies on the First Resistive-MicroMeGaS Quadruplet at GIF++ Preliminary Results

2018 ◽  
Vol 174 ◽  
pp. 04002
Author(s):  
B. Alvarez Gonzalez ◽  
M. Bianco ◽  
E. Farina ◽  
P. Iengo ◽  
F. Kuger ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Spatial Resolution ◽  
Preliminary Results ◽  
Ageing Study

A resistive-MicroMeGaS quadruplet built at CERN has been installed at the new CERN Gamma Irradiation Facility (GIF++) with the aim of carrying out a long-term ageing study. Two smaller resistive bulk-MicroMeGaS produced at the CERN PCB workshop have also been installed at GIF++ in order to provide a comparison of the ageing behavior with the MicroMeGaS quadruplet. We give an overview of the ongoing tests at GIF++ in terms of particle rate, integrated charge and spatial resolution of the MicroMeGaS detectors.

scholarly journals A continuous radon monitoring system based on a solid-state silicon detector

2007 ◽  
Vol 5 (01) ◽  
Author(s):  
R. Peña-Eguiluz ◽  
J. M. Garcí­a-Hernández ◽  
F. J. Ramí­rez-Jiménez
Keyword(s):  
Solid State ◽  
Monitoring System ◽  
Circuit Design ◽  
Electronic Circuit ◽  
Radioactive Decay ◽  
Silicon Detector ◽  
Alpha Particles ◽  
System Components ◽  
Electronic Circuit Design ◽  
Radon Monitoring

This paper describes the design of a programmable stay-alone continuous radon monitoring system able to detect, count and store the amount of alpha particles with an energy of 5.49 MeV produced by the radioactive decay of environmental radon-222. It is included the electronic circuit design, the software development as well as the user interface and the hardware ensemble of all the system components.

scholarly journals The structural parameters of bulges, bars and discs in the local Universe

2007 ◽  
Vol 3 (S245) ◽  
pp. 117-120
Author(s):  
Dimitri Alexei Gadotti
Keyword(s):  
Spatial Resolution ◽  
Structural Parameters ◽  
Image Decomposition ◽  
Effective Radius ◽  
Local Universe ◽  
Preliminary Results ◽  
Distant Galaxies ◽  
Total Luminosity ◽  
Systematic Effects ◽  
Nearby Galaxies

AbstractImage decomposition of galaxies is now routinely used to estimate the structural parameters of galactic components. In this work, I address questions on the reliability of this technique. In particular, do bars and AGN need to be taken into account to obtain the structural parameters of bulges and discs? And to what extent can we trust image decomposition when the physical spatial resolution is relatively poor? With this aim, I performed multi-component (bar/bulge/disc/AGN) image decomposition of a sample of very nearby galaxies and their artificially redshifted images, and verified the effects of removing the bar and AGN components from the models. Neglecting bars can result in a overestimation of the bulge-to-total luminosity ratio of a factor of two, even if the resolution is low. Similar effects result when bright AGN are not considered in the models, but only when the resolution is high. I also show that the structural parameters of more distant galaxies can in general be reliably retrieved, at least up to the point where the physical spatial resolution is ≈ 1.5 Kpc, but bulge parameters are prone to errors if its effective radius is small compared to the seeing radius, and might suffer from systematic effects. I briefly discuss the consequences of these results to our knowledge of the stellar mass budget in the local universe, and finish by showing preliminary results from a large SDSS sample on the dichotomy between classical and pseudo-bulges.

The Application of Neutron Topography to the Study of X-ray Sensitive Organic Crystals - a Possible Alternative to X-ray Topography.

1989 ◽  
Vol 166 ◽  
Author(s):  
M. Dudley
Keyword(s):  
Neutron Technique ◽  
Solid State ◽  
Single Crystals ◽  
Spatial Resolution ◽  
Organic Crystals ◽  
Strain Sensitivity ◽  
X Ray ◽  
Preliminary Results ◽  
Extreme Sensitivity

ABSTRACTNeutron topography has been carried out on organic single crystals of varying Xray sensitivity, in order to test the feasibility of the technique as an alternative to X-ray topography for the study of the influence of defects on the solid state reactivity of X-ray sensitive single crystals. Specimens studied include the diacetylene PTS, and Pyrene. A comparison of the strain sensitivity and spatial resolution of the neutron and X-ray based techniques is made. Preliminary results of dynamic neutron topographic studies of the UV induced polymerization in PTS are presented. These results are compared to those obtained from similar X-ray topographic studies.Results indicate that the neutron technique can be a useful ally technique to the analogous X-ray techniques in studies of the influence of defects on reactivity in specimens of moderate X-ray sensitivity. In cases of extreme sensitivity, the neutron technique is the only one available for studies of this nature.

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