M-L band x-rays (3–3.5 KeV) from palladium coated targets for isochoric radiative heating of thin foil samples

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.

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Radiative heating of low-Zsolid foils by laser-generated x rays

Physical Review E ◽

10.1103/physreve.52.6703 ◽

1995 ◽

Vol 52 (6) ◽

pp. 6703-6716 ◽

Cited By ~ 12

Author(s):

K. Eidmann ◽

I. B. Földes ◽

Th. Löwer ◽

J. Massen ◽

R. Sigel ◽

...

Keyword(s):

Radiative Heating ◽

X Rays

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Energy dispersive microprobe analysis of intracellular mineral deposits in rat bone

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008420x ◽

1978 ◽

Vol 36 (2) ◽

pp. 666-667

Author(s):

D.W. Dempster ◽

W.A.P. Nicholson ◽

H.Y. Elder ◽

D.A.S. Smith ◽

R.P. Ferrier

Keyword(s):

Microprobe Analysis ◽

Detection Efficiency ◽

Thin Foil ◽

Energy Dispersive ◽

X Rays ◽

X Ray ◽

Small Areas ◽

System A ◽

Transmission Electron ◽

Close Proximity

The use of an energy dispersive X-ray microanalytical system (EDX) attached to a conventional transmission electron microscope (TEM) allows images of good morphological resolution from ultra-thin specimens and spectra of all detectable elements to be obtained simultaneously at radiation doses which are low compared to wavelength dispersive detectors. For reasons of detection efficiency the solid angle subtended from the specimen to the detector is maximised (∼0.l sterad) in our system, a LINK SYSTEMS 290 with a 30mm2Si(Li) crystal fitted to a JEOL JEM lOOC. However, with this type of system the recorded spectrum has contributions not only from the small areas which can be probed but also from scattered electrons, and X-rays originating in the surrounding specimen, the specimen support system and the microscope environment of the specimen. The problem is particularly acute in projects, such as the present, where it is necessary to detect and determine the ratios of elements (Ca and P) in small quantities in close proximity to relatively massive concentrations of the same elements.Modifications to our system have been described (Nicholson et al., 1977a;Biddlecombe et al., 1977) which greatly improve the peak/background ratios for quantitative analysis and eliminate all of the specific peaks of non-specimen origin. For ease of maintenance the JEOL 100C is fitted with thin foil condenser apertures (10μm thick molybdenum) as standard. At the accelerating voltage used in this study (80 keV) a considerable number of electrons are transmitted by these apertures and with the electron probe placed adjacent to fully mineralized bone the scattered electrons were responsible for generation of sizeable Ca and P signals. We have replaced the standard foils with thick (0.25 mm) molybdenum apertures.

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Conversion of laser light into x rays in thin foil targets

Physical Review A ◽

10.1103/physreva.41.3270 ◽

1990 ◽

Vol 41 (6) ◽

pp. 3270-3280 ◽

Cited By ~ 34

Author(s):

P. Celliers ◽

K. Eidmann

Keyword(s):

Laser Light ◽

Thin Foil ◽

X Rays

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“Casino V2.0 : An Advance Simulation Tool for Scanning Electron Microscope Users”

Microscopy and Microanalysis ◽

10.1017/s1431927600029494 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 684-685

Author(s):

D. Drouin ◽

A.R. Couture ◽

R. Gauvin

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Cross Sections ◽

Thin Foil ◽

Single Scattering ◽

X Rays ◽

Backscattered Electron ◽

Version 2.0 ◽

The Moment ◽

Scanning Electron

The topic of this paper is to present a new Windows™ environment version of the CASINO Monte Carlo program. The goal of this program is to assist scanning electron microscope users in their routine analysis and also in more advanced topic such as electron beam lithography for example. Based on a single scattering algorithm, this software is specially designed for low beam interaction in a bulk and thin foil. This program uses tabulated Mott elastic cross-sections, which benefit of both fast calculation and accurate interaction at low beam energy. At the moment CASINO can either be used to generate X-rays or backscattered electron signals. The program used simple two-dimension geometry to represent real sample. in this version, vertical and horizontal planes can be generated to allow cross-section representation or multi-layers analysis. Then beam can be scanned across different regions to produce X-ray linescan or bascattered electron profiles.Many new convenient features have been added to the version 2.0 of CASINO. The new interface lets the users to consult the results as the simulation is still in progress.

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The standard hole-count test: A progress report

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087914 ◽

1991 ◽

Vol 49 ◽

pp. 720-721

Author(s):

C. E. Lyman ◽

D. W. Ackland

Keyword(s):

Standard Specimen ◽

Analytical Electron Microscopy ◽

Thin Foil ◽

X Rays ◽

Absolute Value ◽

X Ray ◽

Disk Specimen ◽

Illumination System ◽

Analytical Electron ◽

Order Of Magnitude

Analytical electron microscopy (AEM) was well served by the original hole count test that prompted microscope manufacturers to reduce, by an order of magnitude, spurious x-ray generation in the specimen. This spurious x-ray signal is caused by hard x-rays or uncollimated electrons from the illumination system and is typically generated over the entire specimen regardless of where the electron probe is placed for analysis. The original test was performed on an ion-milled thin foil disk specimen of Ag or Mo, but the absolute value of hole count was dependent upon both specimen and operator. To make progress in die reduction of spurious xrays at intermediate voltages (if the problem is present), a hole-count test on a standard specimen that does not require operator judgement would be useful. The ultimate goal would be to reduce spurious x-rays to a level that would not affect any experiment on any specimen.

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Instrument Design and Image Reconstruction For A Laboratory X-Ray Microtomograph

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181348 ◽

1990 ◽

Vol 48 (1) ◽

pp. 518-519

Author(s):

Roger H. Johnson ◽

Alan C. Nelson ◽

David H. Burns

Keyword(s):

Low Cost ◽

Three Dimensional ◽

Thin Foil ◽

Cone Beam ◽

X Rays ◽

Two Dimensional ◽

Rotating Shaft ◽

Data Set ◽

Solid State Detector ◽

X Ray

X-ray microscopy has received considerable attention over the years, since it has the potential of producing high-resolution images of thick specimens in air. We are developing an x-ray microtomograph for three-dimensional imaging of small biological specimens. The instrument, shown in Figure 1, has much in common with projection x-ray microscopes of decades past, but incorporates several technological advances of recent years to partially overcome the limitations of the older instruments. The most important of these are the use of a planar solid-state detector and the provision for volume reconstruction. We describe the design for a relatively low-cost instrument intended for 3-D imaging of biological specimens up to ten cubic millimeters in size.The x-ray source for the microtomograph consists of a modified SEM. The electron beam, in spot mode and focused to about ten nanometers, impinges on a thin foil target to produce an emergent, low-intensity cone beam of characteristic and Bremsstrahlung x-rays. The foil resides in close proximity to an optional aluminum filter and a thin beryllium window which terminates the evacuated electron column. The specimen is mounted on a precision rotating shaft within two millimeters of the target foil. A two-dimensional detector is placed ten to forty centimeters from the sample, providing direct projection magnifications of up to 200 times. Two-dimensional projection views are collected at each of many angular orientations as the sample is rotated through 360 degrees. Cone beam backprojection algorithms are then applied to reconstruct a threedimensional data set.

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Applications of the Van Cappellen technique for thin-foil microanalysis to the measurement of x-ray calibration factors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012549x ◽

1987 ◽

Vol 45 ◽

pp. 112-113

Author(s):

G.J.C. Carpenter ◽

O.T. Woo

Keyword(s):

Materials Science ◽

Analytical Electron Microscopy ◽

Thin Foil ◽

X Rays ◽

Indirect Measure ◽

X Ray ◽

Mass Thickness ◽

Absolute Mass ◽

Different Thickness ◽

Concentration Ratios

The Cliff-Lorimer technique for thin foil microanalysis using X-rays is widely used in materials science applications of analytical electron microscopy. However, the corrections for absorption and (less commonly) fluorescence that may be necessary to obtain quantitative data are inconvenient to perform and can be prone to errors. Recently, a methodology has been developed by Van Cappellan that overcomes these difficulties. Termed “parameterless”, because no external measurements are necessary apart from the X-ray intensities, the technique requires spectra to be collected from areas of different thickness of the phase of interest. The characteristic X-ray intensities are used to obtain uncorrected concentration ratios for the elements of interest, using the Cliff-Lorimer equation. The absolute X-ray intensities give an indirect measure of mass thickness. However, calculations of absolute mass thickness are avoided, simply by plotting the concentration ratios against intensity and extrapolating to zero intensity, which corresponds to zero mass thickness.

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MeV bremsstrahlung X rays from intense laser interaction with solid foils

Laser and Particle Beams ◽

10.1017/s0263034618000551 ◽

2018 ◽

Vol 36 (4) ◽

pp. 502-506 ◽

Cited By ~ 5

Author(s):

S. Palaniyappan ◽

D. C. Gautier ◽

B. J. Tobias ◽

J. C. Fernandez ◽

J. Mendez ◽

...

Keyword(s):

Thin Foil ◽

Intense Laser ◽

Nanosecond Laser ◽

Nuclear Materials ◽

X Rays ◽

Laser Interaction ◽

Incident Laser ◽

X Ray ◽

Order Of Magnitude ◽

Fs Laser

AbstractLaser-based compact MeV X-ray sources are useful for a variety of applications such as radiography and active interrogation of nuclear materials. MeV X rays are typically generated by impinging the intense laser onto ~mm-thick high-Z foil. Here, we have characterized such a MeV X-ray source from 120 TW (80 J, 650 fs) laser interaction with a 1 mm-thick tantalum foil. Our measurements show X-ray temperature of 2.5 MeV, flux of 3 × 1012 photons/sr/shot, beam divergence of ~0.1 sr, conversion efficiency of ~1%, that is, ~1 J of MeV X rays out of 80 J incident laser, and source size of 80 m. Our measurement also shows that MeV X-ray yield and temperature is largely insensitive to nanosecond laser contrasts up to 10−5. Also, preliminary measurements of similar MeV X-ray source using a double-foil scheme, where the laser-driven hot electrons from a thin foil undergoing relativistic transparency impinging onto a second high-Z converter foil separated by 50–400 m, show MeV X-ray yield more than an order of magnitude lower compared with the single-foil results.

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