SI(LI) and Hpg Detectors: Recent Measurements

1998 ◽  
Vol 4 (S2) ◽  
pp. 166-167
Author(s):  
R A Sareen ◽  
T Nashashibi
Keyword(s):  
Activation Energy ◽  
Electron Microscope ◽  
Band Gap ◽  
Spectral Characteristics ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
Synchrotron Beam ◽  
Energy Dispersive Microanalysis ◽  
Low Energies

Small Si (Si(Li), Intrinsic Si, PEN diodes) and Ge (HPG) planar detectors are used for measuring the energy and intensity of X-rays at low energies (below 100 keV). Applications include energy dispersive microanalysis in the electron microscope and x-ray fluorescence in tube excited systems. They are also finding increasing use on synchrotron beam lines. Both types of detector have unique and special properties and there is a wealth of information in the literature1 describing their principles of operation including their spectral characteristics.For example, the superior resolution (110 eV compared to 130 eV (FWHM) at 5.9 keV) obtained with 10 mm2 HPG detectors is a consequence of Ge's smaller band gap (0.7 eV compared to 1.1 eV eV for Si). This leads directly to a lower value for the activation energy (2.9 eV compared to 3.81 eV at 77K). Both materials have very similar Fano factors (approximately 0.11).

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

First results from the XMCD facility at the Energy-Dispersive EXAFS beamline of the Indus-2 synchrotron source

2019 ◽  
Vol 26 (2) ◽  
pp. 445-449
Author(s):  
N. Patra ◽  
U. G. P. S. Sachan ◽  
S. SundarRajan ◽  
Sanjay Malhotra ◽  
Vijay Harad ◽  
...  
Keyword(s):  
Magnetic Circular Dichroism ◽  
Energy Dispersive ◽  
X Rays ◽  
Beam Direction ◽  
Synchrotron Source ◽  
X Ray ◽  
Synchrotron Beam ◽  
First Results ◽  
Set Up ◽  
Good Agreement

Setting up of the X-ray Magnetic Circular Dichroism (XMCD) measurement facility with hard X-rays at the Energy-Dispersive EXAFS beamline (BL-08) at the Indus-2 synchrotron source is reported. This includes the design and development of a water-cooled electromagnet having a highest magnetic field of 2 T in a good field volume of 125 mm3 and having a 10 mm hole throughout for passage of the synchrotron beam. This also includes the development of an (X–Z–θ) motion stage for the heavy electromagnet for aligning its axis and the beam hole along the synchrotron beam direction. Along with the above developments, also reported is the first XMCD signal measured on a thick Gd film in the above set-up which shows good agreement with the reported results. This is the first facility to carry out XMCD measurement with hard X-rays in India.

scholarly journals ANALYSIS OF SUBMICROSCOPIC STRUCTURES BY THEIR EMITTED X-RAYS

1973 ◽  
Vol 21 (6) ◽  
pp. 580-586 ◽  
Author(s):  
E. W. DEMPSEY ◽  
F. J. AGATE ◽  
M. LEE ◽  
M. L. PURKERSON
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Semiconductor Detector ◽  
Emission Spectra ◽  
Energy Dispersive ◽  
X Rays ◽  
Sodium Potassium ◽  
X Ray ◽  
Copper Zinc ◽  
Scanning Electron

X-ray emission spectra have been recorded from several biologic tissues using a multichannel energy-dispersive analyzer with a retractible semiconductor detector coupled to a Cambridge Mark II scanning electron microscope. Particular attention has been given to the detection of silver in experimental argyria, of calcium in dermoid scales and in experimental necrosis of the kidney and of sulfur in the inner and outer portions of reptilian skin. Sulfur and chlorine have been found associated with silver in argyria. Phosphorus was associated with calcium both in the dermal scales and in necrotic areas. In addition to these elements, trace amounts of copper, zinc, lead, sodium, potassium, iron, arsenic, osmium and uranium have been detected in various normal and experimental situations. The applicability of the combined instrument to cytochemical problems is briefly discussed.

Utilization of scanning Electron Microscopy/Energy-Dispersive x-ray microanalysis to detect an immunogold labeled virus on a Transmission Electron Microscope thin sectioned sample

1994 ◽  
Vol 52 ◽  
pp. 302-303
Author(s):  
C. M. Helmick ◽  
J. F. Bailey ◽  
S. S. Ristow
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Post Infection ◽  
Tissue Sample ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
Transmission Electron ◽  
Esophageal Tissue ◽  
Scanning Electron

Since not all research facilities have access to a transmission electron microscope (TEM) / x-ray microanalysis system, a study was conducted to determine if a scanning electron microscope (SEM) equipped with an energy dispersive x-ray microanalyer would detect and quantify an immunogold labeled virus on a TEM thin sectioned sample. The objectives of the study were to first, demonstrate that a particular region (serous cardiac gland) of a thin sectioned fish esophageal tissue sample could be detected on a SEM. Secondly, we sought to demonstrate that the quantities of colloidal gold x-rays emitted were in association with the viral infected esophageal tissue at 1 and 24 hours post infection.Tissue and Immunogold labeling. Juvenile rainbow trout (Oncorhychus mykiss) were challenged in vivo at 105 pfu with Hagerman infectious hematopoietic necrosis virus (IHNV) or mocked infected with phosphate buffered saline (PBS). Fish were killed and fixed in 6% paraformaldehyde and 0.5% glutaraldehyde in 0.1 M PBS at 1 and 24 hours post infection and stored at 4°C.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

Comparison of high-angle take-off and low-angle take-off EDX detector geometry of the HF-2000 FE-TEM

1993 ◽  
Vol 51 ◽  
pp. 252-253
Author(s):  
Y. Sato ◽  
T. Hashimoto ◽  
M. Ichihashi ◽  
Y. Ueki ◽  
K. Hirose ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Field Emission ◽  
Solid Angle ◽  
Energy Dispersive ◽  
Objective Lens ◽  
X Rays ◽  
High Angle ◽  
X Ray ◽  
Detector Geometry

Analytical TEMs have two variations in x-ray detector geometry, high and low angle take off. The high take off angle is advantageous for accuracy of quantitative analysis, because the x rays are less absorbed when they go through the sample. The low take off angle geometry enables better sensitivity because of larger detector solid angle.Hitachi HF-2000 cold field emission TEM has two versions; high angle take off and low angle take off. The former allows an energy dispersive x-ray detector above the objective lens. The latter allows the detector beside the objective lens. The x-ray take off angle is 68° for the high take off angle with the specimen held at right angles to the beam, and 22° for the low angle take off. The solid angle is 0.037 sr for the high angle take off, and 0.12 sr for the low angle take off, using a 30 mm2 detector.

scholarly journals Characterizing Severely Plastically Deformed Materials Using Transmission Kikuchi Diffraction and Energy Dispersive X-ray Spectroscopy in the Scanning Electron Microscope

2013 ◽  
Vol 19 (S2) ◽  
pp. 692-693
Author(s):  
P. Trimby
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive ◽  
X Ray ◽  
Scanning Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Karakteristik Hasil Proses Nitridisasi Besi Tuang Nodular Temperatur 5500C pada Waktu Penahanan 2 Jam, 4 Jam, 6 Jam

2021 ◽  
Vol 12 (1) ◽  
pp. 13-18
Author(s):  
Wayan Sujana
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive ◽  
Fluidised Bed ◽  
X Ray ◽  
Scanning Electron

Nitridisasi merupakan suatu proses perlakuan panas termokimia yang dimana nitrogen dan amonia didifusikan kepermukaan material (ferro and non-ferro) pada temperatur 500-6000C sehingga membentuk pengerasan kulit akibat terbentuknya lapisan nitrida paduan pada permukaan. Namun pengerasan permukaan ditentukan oleh paduan dari material yang dilakukan proses nitridisasi.Tujuan Nitridisasi adalah untuk memperbaiki ketahanan aus, meningkatkan ketahanan lelah, dan memperbaiki ketahanan tehadap korosi. Proses nitidisasi ini juga dapat mengganti jenis perlakuan panas lain yang menekankan performance yang baik. Pada penelitian ini akan memanfaatkan besi cor nodular yanga akan diproses nitridisasi menggunakan fluidised bed furnace. Pada penelitian ini menggunakan pengujian distribusi kekerasan (metode vickers) untuk mengamati sejauh mana nitrogen berdifusi pada permukaan spesimen, dan pengamatan struktur mikro dengan scanning electron microscope, energy dispersive X-Ray spectroscopy (SEM-EDS).Penelitian ini akan memberikan informasi fenonema proses nitridisasi pada besi cor nodular sehingga mendapatkan suatu analisis yang sesuai dengan metode sehingga menghasilkan kualitas kekerasan permukaan yang baik.

about chemical bonding and molecular structure. This information can be used to detect th e types of organic materials present on the surface. 4.3.2.2. Raman spectroscopy (RS) [7, 8] It is used to examine the energy levels of molecules that cannot be well character-ized via infrared spectroscopy. Th e two techniques, however, are complimentary. In the RS, a sample is irradiated with a strong monochromatic light source (usu-ally a laser). Most of the radiation will scatter or "reflect off' the sample at the same energy as the incoming laser radiation. However, a small amount will scat-ter from the sample at a wavelength slightly shifted from the original wavelength. It is possible to study the molecular structure or determine the chemical identity of the sample. It is quite straightforward to identify compounds by spectral library search. Due to extensive library spectral information, the unique spectral finger-print of every compound, and the ease with which such analyses can be per-formed, the RS is a very useful technique for various applications. An important application of the RS is the rapid, nondestructive characterization of diamond, diamond-like, and amorphous-carbon films. 4.3.2.3. Scanning electron microscopy (SEM) / energy dispersive X-ra y analysis (EDX) [7, 8] The SEM produce s detailed photographs that provide important information about the surface structure and morphology of almost any kind of sample. Image analy-sis is often the first and most important step in problem solving and failure analy-sis. With SEM, a focused beam of high-energy electrons is scanned over the sur-face of a material, causing a variety of signals, secondary electrons, X-rays, photons, etc. - each of which may be used to characterize the material with re-spect to specific properties . The signals are used to modulate the brightness on a CRT display, thereb y providing a high-resolution map of the selected material property. It is a surface imaging technique, but with Energy Dispersive X-ray (EDX) it can identify elements in the near-surface region. This technique is most useful for imaging particles. 4.3.2.4. X-ray fluorescence (XRF) [7, 8] Incident X-rays are used to excite surface atoms. The atoms relax through the emission of an X-ray with energy characteristic of the parent atoms and the inten-sity proportional to the amount of the element present. It is a bulk or "total mate-rials" characterization technique for rapid, simultaneous, and nondestructive analysis of elements having an atomic number higher than that of boron. Tradi-tional bulk analysis applications include identifying metals and alloys, detecting trace elements in liquids, and identifying residues and deposits. 4.3.2.5. Total-reflection X-ray fluorescence (TXRF) [7, 8] It is a special XRF technique that provides extremely sensitive measures of the elements present in a material's outer surface. Applications include searching for metal contamination in thin films on silicon wafers and detecting picogram-levels o f arsenic, lead, mercury and cadmium on hazardous, chemical fume hoods.

2003 ◽  
pp. 43-45
Keyword(s):  
Molecular Structure ◽  
Energy Levels ◽  
Monochromatic Light ◽  
Surface Region ◽  
Carbon Films ◽  
Energy Dispersive ◽  
X Rays ◽  
Bulk Analysis ◽  
X Ray ◽  
High Resolution Map
Sign in / Sign up

Export Citation Format

Share Document