Utilization of the vertical divergence of a beam of X-rays in a two-crystal spectrometer in X-ray spectroscopy

1968 ◽  
Vol 18 (4) ◽  
pp. 532-537 ◽  
Author(s):  
J. Hrdý
Keyword(s):  
X Rays ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Vertical Divergence

scholarly journals Development of X-ray streak camera electronics at AWRE

1986 ◽  
Vol 4 (1) ◽  
pp. 145-156 ◽  
Author(s):  
M. C. Jackson ◽  
R. D. Long ◽  
D. Lee ◽  
N. J. Freeman
Keyword(s):  
Streak Camera ◽  
Sweep Rate ◽  
Bragg Diffraction ◽  
X Rays ◽  
Crystal Spectrometer ◽  
One Dimensional ◽  
X Ray ◽  
Ramp Generator ◽  
Laser Facility ◽  
User Facility

The paper reviews a number of X-ray streak cameras developed at AWRE. These cameras are used to provide temporal and one-dimensional spatial or spectral information on X-rays emitted from laser produced plasmas. Two of these cameras have been designed to be combined with other diagnostic instrumentation; one with a Wolter X-ray microscope (×22 magnification) and the other with a Bragg diffraction crystal spectrometer. This latter instrument provides a few eV spectral resolution and ∼15 ps temporal resolution; a typical experimental application at the AWRE HELEN laser facility will be described. The paper describes the circuitry of the bipolar avalanche transistor ramp generator used to drive the streak plates of the cameras. Improvements to this include: (a) increasing the fastest streak rate to ∼10 ps mm−1 by a distributed capacitance network across each of the bipolar stacks of transistors, and (b) reducing the trigger jitter to approximately ±10 ps by the use of a new mix of transistors in the stack and a Raytheon RS 3500 avalanche transistor. Additional improvements have now been added. These include a ‘half-scan’ user facility to aid initial camera timing and direct switching to select the sweep rate of the camera.

Observations from the Hinotori mission

1991 ◽  
Vol 336 (1643) ◽  
pp. 339-347 ◽  
Keyword(s):  
Solar Flares ◽  
Bragg Diffraction ◽  
High Dispersion ◽  
X Rays ◽  
Crystal Spectrometer ◽  
Quartz Crystals ◽  
X Ray ◽  
X Ray Imaging ◽  
Imaging Telescope ◽  
First Time

The satellite Hinotori was launched in 1981 by the Institute of Space and Astronautical Science of Japan. Two major experiments on board the Hinotori satellite were a hard X-ray imaging telescope with modulation collimators, and a high dispersion soft X-ray crystal spectrometer utilizing the Bragg diffraction of X-rays on quartz crystals. These two instruments have revealed for the first time that solar flares show varying characteristics depending on the environment of flaring regions, and that flares produce plasmas as hot as 3-4 x 10 7 K.

M-SHELL X-RAY TRANSITION RATES FOR HEAVY RARE EARTH ELEMENTS

1998 ◽  
Vol 08 (04) ◽  
pp. 235-251
Author(s):  
K. SERA ◽  
K. ISHII ◽  
H. ORIHARA
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
X Rays ◽  
Transition Rates ◽  
Heavy Rare Earth ◽  
Crystal Spectrometer ◽  
Pixe Analysis ◽  
X Ray ◽  
Heavy Lanthanides ◽  
Heavy Rare Earth Elements

Partial M-x-ray production cross sections, which have not been well investigated up to the present, were measured in detail for six heavy lanthanides; Dy , Ho , Er , Tm , Yb and Lu . As a result, it is found that intensities of Mα,β lines, which are dominant among all the M-x-rays, and (M1-N2, M1-N3, M2-N4) lines agree well with those predicted by theory. However, clear discrepancy is found for Mζ and Mγ x-rays. Although it was pointed out by a PIXE analysis with a high-resolution crystal spectrometer that special attention must be paid for an analysis of Mζ and Mγ lines, it is found from the present work that it is possible to perform quantitative analysis using Mα,β lines.

Micro Fluorescent X-Ray Analyzer

1967 ◽  
Vol 11 ◽  
pp. 95-104 ◽  
Author(s):  
Toshio Shiraiwa ◽  
Nobukatsu Fujino
Keyword(s):  
Pure Nickel ◽  
X Rays ◽  
Crystal Spectrometer ◽  
Surface Conditions ◽  
X Ray ◽  
Small Areas ◽  
Sample Area ◽  
Good Ability ◽  
Powder Samples ◽  
Plastic Sample

AbstractA micro fluorescent X-ray analyzer with a focusing type of spectrometer has been developed to analyze samples of small amounts such as extracted inclusions or precipitates from metals or small areas in samples from 0.1 to 2.0 mm in diameter. This instrument is expected especially to analyze powder samples of small quantity because average values from such samples can be obtained and because surface conditions of the samples scarcely affect the results compared with their effect in electron probs microanalysis. A commercial X-ray tube is combined with a device of slits limiting incident X-rays, a focusing spectrometer with a Rowland circle of 4-in. radius, and a microscope of low magnification for observing the analyzing point on the samples. The wavelength range of the spectrometer with LiF and ADP analyzing crystals is from 1.20 to 9.94 Å, and, therefore, higher elements than aluminum in atomic number can be analyzed. The authors exerted their efforts to obtain the higher X-ray intensities in order to analyze smaller areas. The X-ray intensities obtained are satisfactory, except for light elements. For example, the detected X-ray intensity of pure nickel is 1650 cps with the use of a 0.1-mm diameter specimen, and that of pure sulfur is 52 cps with the use of a 0.1-ramdiameter specimen; however, with a 1-mm-diameter specimen, the intensity of pure nickel is over 5000 cps and that of pure sulfur is 1650 cps. These correspond to the intensities from 20-mm-diameter specimens of those elements when a flat-crystal spectrometer is used. The calibration curve for quantitative analysis generally varies with the sample area under analysis, but the same curves are obtained if the sample area is larger than 1 mm in diameter. Then, powder samples are analyzed quantitatively by using a plastic sample holder of 1-mm diameter and 0.3-mm depth. This instrument has good ability for microanalyzing trace elements by, for example, the ion-exchenge membrane method. The sensitivity represented is nearly 5000 cps/μg for Ni Kα from NiSO4 that is soaked and dried in thin rice paper. Some applications of the micro fluorescent X-ray analyzer to precipitates in steels and corrosion products are reported.

X-Ray Spectrometer for EXAFS Using a Position Sensitive Detector

1980 ◽  
Vol 24 ◽  
pp. 177-180 ◽  
Author(s):  
K. Taniguchi ◽  
K. Oka ◽  
N. Yamaki ◽  
S. Ikeda
Keyword(s):  
Position Sensitive Detector ◽  
X Rays ◽  
Sensitive Detector ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Position Sensitivity ◽  
Photodiode Array ◽  
Position Sensitive ◽  
Liquid States ◽  
X Ray Absorption

An active recording x-ray crystal spectrometer for extended x-ray absorption fine structure (EXAFS) has been built using a position sensitive detector of the self scanning photodiode array (SSPA) type. The SSPA detector has energy and position sensitivity for x-rays. The spectrometer was applied to the measurement for EXAFS of the several compounds in foil, powder and liquid states. The spectra can be obtained rapidly, and compare very well with other methods. We found that the SSPA detector is very useful for the measurement of EXAFS.

scholarly journals Dispersive Spectroscopy on AXAF

1990 ◽  
Vol 115 ◽  
pp. 339-345
Author(s):  
T.H. Markert
Keyword(s):  
Focal Plane ◽  
Focal Point ◽  
Point Sources ◽  
The Other ◽  
Bragg Angle ◽  
X Rays ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Transmission Grating ◽  
Imaging Detector

AbstractThere are two transmission grating spectrometers and one Bragg crystal spectrometer being developed for the Advanced X-ray Astrophysics Facility (MIT is building the crystal spectrometer and one of the grating spectrometers; the Laboratory for Space Research in Utrecht is responsible for the other grating spectrometer). The gratings divide the AXAF energy band (80 eV – 10 keV) into three regions (the MIT instrument contains gratings with two different periods) and attain resolving powers for point sources between 100 and 1800. The gratings are composed of arrays of small facets mounted on plates which can be inserted immediately behind the AXAF telescope. The dispersed spectra from the grating arrays are read out by one of the AXAF imaging instruments.The Bragg Crystal Spectrometer (BCS) is a focal plane instrument. One of eight selectable curved diffractors intercepts the AXAF X-ray beam as it diverges beyond the focal point X-rays that satisfy Bragg’s law are reflected from the crystal which, because of its curvature, re-focuses the beam onto an imaging detector. Narrow spectral regions are scanned by rocking the crystal over a range ~0.1 to 1°. Nearly the entire AXAF energy range can be studied by selecting the appropriate crystal and rotating it to the proper Bragg angle. The BCS achieves the highest spectral resolutions of the AXAF spectrometers: for 500 eV < E < 1600 eV, the FWHM of a narrow line (ΔE) is ≲ 1 eV.

X-Ray Double-Crystal Method of Analyzing Microstrains with BeO Single Crystals

1967 ◽  
Vol 11 ◽  
pp. 394-400
Author(s):  
Jun-ichi Chikawa ◽  
Stanley B. Austerman
Keyword(s):  
Single Crystals ◽  
Incident Beam ◽  
X Rays ◽  
Bragg Condition ◽  
Fraunhofer Diffraction ◽  
Crystal Spectrometer ◽  
Double Crystal ◽  
X Ray ◽  
The Senses

AbstractA double.crystal arrangement was employed in the symmetrical Laue arrangement [(+n, −n) setting]. A perfect BeO crystal was used for the first crystal of the double-crystal spectrometer. To obtain a high X-ray intensity, the thickness of the crystal was made to correspond to a maximum of Pendellosung interference. A slit was pieced between the first and second (specimen) crystals to select the X-rays which precisely satisfy the Bragg condition. The slit was adjusted to avoid significant Fraunhofer diffraction. In this method, the incident beam for the specimen crystal was parallel enough to obtain intrinsic rocking curves of the specimen crystal. As an application, the method was used for determination of the senses of slight strains in BeO crystals.

scholarly journals The composition of the x-rays from various metals

1917 ◽  
Vol 93 (653) ◽  
pp. 427-442 ◽  
Keyword(s):  
National Physical Laboratory ◽  
Point Of View ◽  
X Rays ◽  
Crystal Spectrometer ◽  
Cavendish Laboratory ◽  
Precise Method ◽  
X Ray ◽  
Physical Laboratory ◽  
The Subject

In a paper published in the ‘Philosophical Transactions’ in 1908, the writer described some experiments on the X-rays emitted by a variety of metals when used as anticathodes in an X-ray bulb. Among the results established was the homogeneity of a large proportion of the X-rays when the bulb was very “soft.” The absorption curves of the several homogeneous radiations revealed their identities with the characteristic “secondary” radiations which Barkla and Sadler had then recently discovered. The experiments described in the present paper are an extension of the above, and were carried out partly at the Cavendish Laboratory in 1908 and partly at the National Physical Laboratory just prior to the war. The writer’s military duties have prevented the continuation of the work, and the results are now put on record in the hope that they may help to further the progress of the subject, to which the more precise method of the crystal-spectrometer has given a great impetus from a different point of view.

scholarly journals Solar X-rays from 0.3 a.u.: the ChemiX Bragg Spectrometer on Interhelioprobe

2015 ◽  
Vol 11 (S320) ◽  
pp. 442-446 ◽  
Author(s):  
Janusz Sylwester ◽  
Marek Siarkowski ◽  
Jarosław Bąkała ◽  
Żaneta Szaforz ◽  
Mirosław Kowaliński ◽  
...  
Keyword(s):  
Active Regions ◽  
High Sensitivity ◽  
Spectral Lines ◽  
Research Centre ◽  
X Rays ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Spectral Shifts ◽  
Orbit Inclination ◽  
Academy Of Sciences

AbstractChemiX is a Bragg crystal spectrometer that will fly on the two Interhelioprobe spacecraft due for launch in 2025 and 2026. The spacecraft perihelion will be only 0.3 a.u. and the orbit inclination up to 30°, and so instruments on board will have a close view of solar active regions and flares and regions near each solar pole. The ChemiX X-ray spectrometer, built by a consortium of groups led by the Space Research Centre, Polish Academy of Sciences, will fly on each of the spacecraft, and observe X-ray spectra in the 1.5 - 9 Å range. Spectral lines in this range include resonance lines of helium-like and hydrogen-like ions of elements such as Fe, Ca, Ar, S, and Si, with less abundant elements such as K and Cl represented by weaker lines which the high sensitivity of ChemiX should be able to detect. The free–free and free–bound continua should also be detected since instrumental background will be eliminated. Three of the seven channels of ChemiX will be in a “dopplerometer” arrangement by which spatial and spectral shifts present in flare impulsive stages can be disentangled.

Sign in / Sign up

Export Citation Format

Share Document