scholarly journals Semiconductor X-Ray Detectors

1998 ◽  
Vol 6 (6) ◽  
pp. 8-12
Author(s):  
Rob Sareen
Keyword(s):  
Silicon Detector ◽  
X Rays ◽  
Lead Iodide ◽  
X Ray ◽  
High Purity Germanium ◽  
Transition Edge ◽  
New Concepts ◽  
Edge Detectors ◽  
Measuring Tool ◽  
Ccd Arrays

Detection of characteristic x-rays is a fascinating and challenging subject. From its early beginnings with gas proportional counters it has evolved, like many branches of technology, into the use of a variety of semiconductors.The lithium compensated silicon detector [Si(Li)] has been the predominant measuring tool over the last two decades, in the last five years, increasing numbers of high purity germanium detectors (HPG) have appeared and more recently a plethora of new materials and concepts are seeing a successful introduction. Among these newer materials are compound semiconductors like mercuric iodide, cadmium telluride, cadmium zinc telluride, gallium arsenide, lead iodide, indium phosphide and diamond. Among the new concepts are Bolometers, Transition Edge Detectors, Drift Detectors, PIN Diodes, CCD arrays and PN CCD arrays.

scholarly journals Micrometer-resolution imaging using MÖNCH: towards G2-less grating interferometry

2016 ◽  
Vol 23 (6) ◽  
pp. 1462-1473 ◽  
Author(s):  
Sebastian Cartier ◽  
Matias Kagias ◽  
Anna Bergamaschi ◽  
Zhentian Wang ◽  
Roberto Dinapoli ◽  
...  
Keyword(s):  
High Resolution ◽  
Silicon Detector ◽  
Limiting Factor ◽  
X Rays ◽  
X Ray ◽  
Charge Cloud ◽  
High Resolution Images ◽  
Resolution Imaging ◽  
Hybrid Silicon ◽  
Small Pixel

MÖNCH is a 25 µm-pitch charge-integrating detector aimed at exploring the limits of current hybrid silicon detector technology. The small pixel size makes it ideal for high-resolution imaging. With an electronic noise of about 110 eV r.m.s., it opens new perspectives for many synchrotron applications where currently the detector is the limiting factor,e.g.inelastic X-ray scattering, Laue diffraction and soft X-ray or high-resolution color imaging. Due to the small pixel pitch, the charge cloud generated by absorbed X-rays is shared between neighboring pixels for most of the photons. Therefore, at low photon fluxes, interpolation algorithms can be applied to determine the absorption position of each photon with a resolution of the order of 1 µm. In this work, the characterization results of one of the MÖNCH prototypes are presented under low-flux conditions. A custom interpolation algorithm is described and applied to the data to obtain high-resolution images. Images obtained in grating interferometry experiments without the use of the absorption grating G2are shown and discussed. Perspectives for the future developments of the MÖNCH detector are also presented.

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.

scholarly journals X-ray shielding by a novel garment woven with melt-spun monofilament weft yarn containing lead and tin particles

2017 ◽  
Vol 89 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Majid Mirzaei ◽  
Mohammad Zarrebini ◽  
Ahmad Shirani ◽  
Mohsen Shanbeh ◽  
Sedigheh Borhani
Keyword(s):  
Germanium Detector ◽  
Radiation Shielding ◽  
Metal Particles ◽  
Weft Yarn ◽  
X Rays ◽  
X Ray ◽  
High Purity Germanium ◽  
Melt Spun ◽  
Polypropylene Monofilament ◽  
And Storage

Conventional lead aprons are rather heavy and uncomfortable for the wearer and also crack easily due to bending during both usage and storage. Coating of textiles with certain compounds provides protection against ionizing radiation. However, coated garments may have reduced flexibility and breathability. The principle aim of this study is development of a lightweight textile-based X-ray radiation shielding. The shielding fabric, while capable of significantly attenuating X-rays, relative to current conventional aprons is more intrinsically flexible, breathable, economical, easy to maintain, and crack resistant. Samples of fabrics were woven using melt-spun polypropylene monofilament yarns containing lead and tin particles. Shielding properties of the samples was measured using a high-purity germanium detector. Results showed that the samples composed of higher metal particles concentration and higher metal density and atomic number exhibited higher attenuation capability. Mechanical properties of the samples were evaluated. Furthermore, insignificant changes in the attenuation capability of samples due to abrasion and laundering processes occurred.

scholarly journals Low noise low power readout circuit for soft X ray detection

2003 ◽  
Vol 1 (03) ◽  
Author(s):  
A. Cerdeira-Estrada ◽  
A. De Luca ◽  
A. Cuttin ◽  
R. Mutihac
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Theoretical Calculations ◽  
Silicon Detector ◽  
Low Noise ◽  
Experimental Results ◽  
X Rays ◽  
Readout Circuit ◽  
X Ray ◽  
Low Power Cmos

A new low power CMOS ASIC for the detection of X-rays was optimized for low power and low noise. Theoretical calculations and optimizations are presented and compared with experimental results. Noise as low as 120+25*Cin [pF] ENC rms was obtained including a silicon detector of 1.3 pF and 0.3nA of leakage. The power consumption is less than 100 W. Other circuit parameters are also shown.

Silicon Detector System for X-Ray Pulse Calorimetry of Laser-Produced Plasmas*

1974 ◽  
Vol 18 ◽  
pp. 213-221 ◽  
Author(s):  
J. H. McQuaid ◽  
C. E. Violet ◽  
J. Petruzzi
Keyword(s):  
Silicon Detector ◽  
Direct Conversion ◽  
X Rays ◽  
Electron Pairs ◽  
Analog To Digital ◽  
X Ray ◽  
New Type ◽  
A Charge ◽  
Readout Scheme ◽  
Charge Sensitive Preamplifier

AbstractThe instrumentation for measuring x-ray yields from laser produced plasma is described. This new type of calorimeter is composed of a silicon detector, a charge-sensitive preamplifier and an analog-to-digital readout scheme for multiplexing up to ten detector outputs.X-rays interacting with the detector produce hole-electron pairs in proportion to the total energy lost in the detector (∼1012 eV). In this application the detector can be characterized as a solid-state ionization chamber. The detector signal is coupled to a charge-sensitive preamplifier which generates a voltage pulse proportional to the x-ray energy absorbed. In this way the x-ray energy is measured by “direct conversion” rather than measuring the temperature rise due to an energy flux.

Charged Particle Induced X-Ray Analysis of Malaria Infected Blood

1974 ◽  
Vol 18 ◽  
pp. 343-352
Author(s):  
B. K. Barnes ◽  
R. M. Coleman ◽  
G. H. R. Kegel ◽  
P. W. Quinn ◽  
N. J. Rencricca
Keyword(s):  
Charged Particle ◽  
Unit Volume ◽  
Silicon Detector ◽  
Red Cells ◽  
X Rays ◽  
Infected Blood ◽  
X Ray ◽  
On Line ◽  
Computer Based ◽  
Mev Protons

AbstractBlood samples from normal and Plasmodium berghei infected mice are being analyzed for trace elements by charged particle induced x-rays. Approximately 0.25 ml of the sample (whole blood, washed red cells, or plasma) is dry ashed. The ashes are mounted on a 0.003 inch Kapton foil. The analysis is performed by bombardment of the samples by a beam of 2.0 MeV protons and detection of the characteristic x-rays by a 175-eV-resolution lithium-drifted silicon detector. The data are analyzed by an on-line PDP-9 computer-based data acquisition system. Results indicate an increase in the K, Ca, Cu, and Zn per unit volume of the red cells of the malaria infected mice relative to the amounts measured for uninfected blood, and a decrease in the K, Ca, and Fe and an increase in the Cu per unit volume in the plasma of the infected mice.

Going Nondispersive

1998 ◽  
Vol 4 (S2) ◽  
pp. 162-163
Author(s):  
Kurt F. J. Heinrich
Keyword(s):  
Electron Probe ◽  
Single Channel ◽  
Pulse Height ◽  
Silicon Detector ◽  
X Rays ◽  
X Ray ◽  
Energy Dispersion Spectrometer ◽  
Elementary Analysis ◽  
Geiger Muller Counter ◽  
Pulse Height Analysis

In February 1968 Ray Fitzgerald, Klaus Keil and myself published in Science a communication titled “Solid-State Energy-Dispersion Spectrometer for Electron Microprobe X-ray Analysis”. The authors describe the use of a lithium-drifted silicon detector for the direct identification of x-rays, without a diffracting crystal, in an electron probe. The subject of this paper was to modify profoundly the development of x-ray microanalysis in the years to follow.Pulse-height analysis of gamma rays detected in scintillation counters was widely used at the time. For radiation of energies below 30 keV, gas proportional counters were also employed. In elementary analysis by x-rays the poor energy resolution of these detectors limited the application of such a procedure, although single-channel pulse height analysis was employed as an adjunct to crystal spectrometers.In 1951, Raymond Castaing in his thesis described his invention of the electron probe microanalyzer, created by adding to a transmission electron microscope a curved-crystal spectrometer which focused the x-rays emitted by the specimen into a Geiger-Muller counter.

MEASUREMENT OF GERMANIUM ESCAPE PEAKS IN PIXE SPECTRA RECORDED USING HIGH PURITY Ge (HPGe) DETECTOR

2009 ◽  
Vol 19 (01n02) ◽  
pp. 67-76
Author(s):  
SANJIV KUMAR ◽  
G. L. N. REDDY ◽  
V. S. RAJU
Keyword(s):  
Quantitative Analysis ◽  
High Purity ◽  
Hpge Detector ◽  
X Rays ◽  
Pixe Analysis ◽  
Escape Peak ◽  
X Ray ◽  
High Purity Germanium ◽  
Experimental Values

This paper deals with studies on Ge K α and K β escape peaks in particle induced X-ray emission (PIXE) spectra recorded by a high purity germanium (HPGe) detector. A knowledge of the energies and intensities of these escape peaks is desirable for accurate qualitative as well as quantitative analysis of elements by PIXE. The spectral interferences caused by Ge K escape peaks in the determination of Fe in U by PIXE are highlighted for illustration. A simple theoretical approach based on the production of Ge K X-rays inside the Ge crystal of the detector during the process of detection of the incident characteristic X-rays and the subsequent escape of a fraction of the produced radiations from the crystal, is described to calculate the intensity ratio of the Ge escape peak to its parent characteristic X-rays. The calculated values are in agreement with the experimental values and those estimated using the formulation provided in GUPIX software for PIXE. The Ge K escape peaks are very prominent; the intensities of Ge K α escape peaks, from bromine to silver, range from 15% to 6% of those of their respective K α X-rays. These intensities are, in general, considerably higher compared to those of Si escape peaks in spectra recorded by Si ( Li ) detector. Ge K escape peaks therefore may give rise to severe interferences. The present approach provides a precise (~8%) determination of the intensity of an escape peak and thereby facilitates a reliable PIXE analysis.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

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