Influence of VPT Treatment on Microscopic Distribution of Trace Metal Contaminants and its Effect on TXRF Measurement

2018 ◽  
Vol 282 ◽  
pp. 309-313
Author(s):  
Rikiichi Ohno ◽  
Koichiro Saga
Keyword(s):  
Total Reflection ◽  
Detection Sensitivity ◽  
X Rays ◽  
Liquid Drops ◽  
X Ray ◽  
Condensed Form ◽  
Metal Atoms ◽  
Trace Metal Contaminants ◽  
Reflection Intensity ◽  
Microscopic Distribution

We have found that to the detection sensitivity of Total reflection X-ray fluorescent spectrometry (TXRF), the total volume of trace particles generated by vapor phase treatment (VPT) must be increased and metal atoms need to be included in the particles. The detection sensitivity for Cu is enhanced by assisting Cu ionization in the liquid drops condensed form the vapor. We consider that since incident and reflected X-rays resonate 30nm from the surface, the total reflection intensity of metals included in the particles is enhanced.

Contribution of x-ray total reflection to the background intensity in EPMA

1990 ◽  
Vol 48 (2) ◽  
pp. 202-203
Author(s):  
Werner P. Rehbach ◽  
Peter Karduck
Keyword(s):  
Atomic Number ◽  
Target Material ◽  
Total Reflection ◽  
Background Intensity ◽  
X Rays ◽  
Characteristic Radiation ◽  
X Ray

In the EPMA of soft x rays anomalies in the background are found for several elements. In the literature extremely high backgrounds in the region of the OKα line are reported for C, Al, Si, Mo, and Zr. We found the same effect also for Boron (Fig. 1). For small glancing angles θ, the background measured using a LdSte crystal is significantly higher for B compared with BN and C, although the latter are of higher atomic number. It would be expected, that , characteristic radiation missing, the background IB (bremsstrahlung) is proportional Zn by variation of the atomic number of the target material. According to Kramers n has the value of unity, whereas Rao-Sahib and Wittry proposed values between 1.12 and 1.38 , depending on Z, E and Eo. In all cases IB should increase with increasing atomic number Z. The measured values are in discrepancy with the expected ones.

How to Use the Features of Total Reflection of X-Rays for Energy Dispersive XRF

1988 ◽  
Vol 32 ◽  
pp. 105-114 ◽  
Author(s):  
H. Schwenke ◽  
W. Berneike ◽  
J. Knoth ◽  
U. Weisbrod
Keyword(s):  
Thin Films ◽  
Penetration Depth ◽  
Fluorescence Analysis ◽  
Total Reflection ◽  
X Rays ◽  
X Ray ◽  
Characteristic Features ◽  
Respective Characteristic ◽  
Nanometer Regime ◽  
Sensitive Method

AbstractThe total reflection of X-rays is mainly determined by three parameters , that is the orltical angle, the reflectivity and the penetration depth. For X-ray fluorescence analysis the respective characteristic features can be exploited in two rather different fields of application. In the analysis of trace elements in samples placed as thin films on optical flats, detection limits as low as 2 pg or 0.05 ppb, respectively, have been obtained. In addition, a penetration depth in the nanometer regime renders Total Reflection XRF an inherently sensitive method for the elemental analysis of surfaces. This paper outlines the main physical and constructional parameters for instrumental design and quantitation in both branches of TXRF.

X–ray absorption fine structure (XAFS) of Si wafer measured using total reflection X–rays

1999 ◽  
Vol 54 (1) ◽  
pp. 215-222 ◽  
Author(s):  
Jun Kawai ◽  
Shinjiro Hayakawa ◽  
Yoshinori Kitajima ◽  
Yohichi Gohshi
Keyword(s):  
Fine Structure ◽  
Total Reflection ◽  
X Rays ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption ◽  
Si Wafer

scholarly journals Nanofocusing Optics for an X-Ray Free-Electron Laser Generating an Extreme Intensity of 100 EW/cm2 Using Total Reflection Mirrors

2020 ◽  
Vol 10 (7) ◽  
pp. 2611
Author(s):  
Hirokatsu Yumoto ◽  
Yuichi Inubushi ◽  
Taito Osaka ◽  
Ichiro Inoue ◽  
Takahisa Koyama ◽  
...  
Keyword(s):  
Photon Energy ◽  
Pulse Energy ◽  
Free Electron ◽  
Free Electron Laser ◽  
Total Reflection ◽  
Experimental Chamber ◽  
X Rays ◽  
X Ray ◽  
Set Up ◽  
Focused Beam

A nanofocusing optical system—referred to as 100 exa—for an X-ray free-electron laser (XFEL) was developed to generate an extremely high intensity of 100 EW/cm2 (1020 W/cm2) using total reflection mirrors. The system is based on Kirkpatrick-Baez geometry, with 250-mm-long elliptically figured mirrors optimized for the SPring-8 Angstrom Compact Free-Electron Laser (SACLA) XFEL facility. The nano-precision surface employed is coated with rhodium and offers a high reflectivity of 80%, with a photon energy of up to 12 keV, under total reflection conditions. Incident X-rays on the optics are reflected with a large spatial acceptance of over 900 μm. The focused beam is 210 nm × 120 nm (full width at half maximum) and was evaluated at a photon energy of 10 keV. The optics developed for 100 exa efficiently achieved an intensity of 1 × 1020 W/cm2 with a pulse duration of 7 fs and a pulse energy of 150 μJ (25% of the pulse energy generated at the light source). The experimental chamber, which can provide different stage arrangements and sample conditions, including vacuum environments and atmospheric-pressure helium, was set up with the focusing optics to meet the experimental requirements.

Using a Polycapillary Optic as a Spatial Filter to Improve Micro Xray Analysis in Low-Vacuum and Environmental SEM Systems

2001 ◽  
Vol 7 (S2) ◽  
pp. 700-701
Author(s):  
Ning Gao ◽  
David Rohdeb
Keyword(s):  
Energy Dispersive Spectrometer ◽  
Spatial Filter ◽  
Image Contrast ◽  
Detection Sensitivity ◽  
X Rays ◽  
High Background ◽  
X Ray ◽  
Curved Channels ◽  
Probe Form ◽  
Environmental Sem

An inevitable consequence of the presence of the gas in the sample chamber of a low-vacuum scanning electron microscope (LV-SEM) and environmental SEM (ESEM) is the electron beam broadening due to the scattering in the gas. The electron broadening has a large impact on x-ray analysis because the fluorescent characteristic x rays generated far from the center of the electron probe form a high background, which reduces the detection sensitivity of x-ray analysis and degrades the x-ray image contrast. We report in this paper of using a polycapillary focusing x-ray optic between the sample and the energy-dispersive spectrometer as a spatial filter to filter out unwanted x-rays generated far from the specimen. As a result, the x-ray image contrast and the detection sensitivity of the system were notably improved.A polycapillary focusing optic collects a large solid angle of x rays from an x-ray source of small area at its input focus, guide them through the curved channels by multiple external total reflections, and focus them to the output focus.

Measurements of Soft and Ultrasoft X-Rays with Total Reflection Monochromator

1986 ◽  
Vol 30 ◽  
pp. 213-223
Author(s):  
Tomoya Arai
Keyword(s):  
Gas Flow ◽  
Bragg Reflection ◽  
Optical Resolution ◽  
Fluorescence Analysis ◽  
Total Reflection ◽  
X Rays ◽  
Light Elements ◽  
Lower Intensity ◽  
Measured Intensity ◽  
X Ray

The development of X-ray spectrographic analysis of light elements, which are O, C and B, has bee n performed for many applications using an end-window type X-ray tube with Rh-target and thin Be-window, wavelength dispersing devices, which are synthetic multilayers or total reflection mirror (with a specific filter) and a gas flow proportional counter with a thin film window. In Fig. 1 factors related to the intensity measurements in X-ray fluorescence analysis are shown. The excitation efficiency in the soft and ultrasoft X-ray region is very low because of the lower intensity of primary X-rays and low fluorescence yield of light elements. Instead of the wavelength dispersive method of Bragg reflection, having high resolution and low reflectivity, monochromatization combining total reflection by a selected mirror and an appropriate filter offered an alternate approach in order to increase measured intensity with reasonable optical resolution. Synthetic multilayers which have higher resolution and lower intensity compared with the performance of the mirror method have become popular for the detection of soft and ultrasoft X-ray region.

Bent crystal Laue analyser combined with total reflection fluorescence X-ray absorption fine structure (BCLA + TRF-XAFS) and its application to surface studies

2020 ◽  
Vol 27 (6) ◽  
pp. 1618-1625
Author(s):  
Yuki Wakisaka ◽  
Bing Hu ◽  
Daiki Kido ◽  
Md. Harun Al Rashid ◽  
Wenhan Chen ◽  
...  
Keyword(s):  
Fine Structure ◽  
Sudden Change ◽  
Fluorescence Emission ◽  
Total Reflection ◽  
X Rays ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Bent Crystal ◽  
Absorption Fine ◽  
X Ray Absorption

A bent crystal Laue analyser (BCLA) is an X-ray energy analyser used for fluorescence X-ray absorption fine-structure (XAFS) spectroscopy to separate the fluorescence X-ray emission line of a target atom from the elastic scattering X-rays and other fluorescence emission lines. Here, the feasibility of the BCLA for total reflection fluorescence XAFS (TRF-XAFS), which has a long X-ray footprint on the substrate surface owing to grazing incidence, was tested. The focal line of the BCLA was adjusted on the X-ray footprint and the XAFS signal for one monolayer of Pt deposited on a 60 nm Au film with high sensitivity was obtained. Although range-extended XAFS was expected by the rejection of Au fluorescence arising from the Au substrate, a small glitch was found in the Au L 3 edge because of the sudden change of the complex refraction index of the Au substrate at the Au edge. This abnormal spectrum feature can be removed by reflectivity correction using Au foil absorption data. BCLA combined with TRF-XAFS spectroscopy (BCLA + TRF-XAFS) is a new technique for the in situ surface analysis of highly dispersed systems even in the presence of a liquid overlayer.

Quantitative analysis with a two-detector measuring system in in-air PIXE-design to improve detection sensitivity at low energies

2013 ◽  
Vol 23 (01n02) ◽  
pp. 55-67 ◽  
Author(s):  
K. Sera ◽  
S. Goto ◽  
C. Takahashi ◽  
Y. Saitoh
Keyword(s):  
Quantitative Analysis ◽  
Production Cross ◽  
Detection Sensitivity ◽  
Measuring System ◽  
X Rays ◽  
Standard Material ◽  
X Ray ◽  
New Device ◽  
Low Energies ◽  
Improve Detection Sensitivity

In this paper, a two-detector measuring system in in-air PIXE system composed of two Si(Li) detectors has been developed for simultaneous measurement of low- and high-Z elements. In order to improve detection sensitivity of the detector for low energy region, a new device which is attached at the tip of the detector has been designed. It is made of acryl and has a thin end on which a 1.5 μm-thick Mylar film is stuck. As a result, it exhibited a miraculous effect in improving detection sensitivity at low energies and it became possible to detect K X-rays of aluminium. In order to perform quantitative analysis in in-air system, we have measured detection efficiencies for the two Si(Li) detectors including the effect of X-ray absorption in air on the basis of the method that we developed. Concerning the beam energy at the target and corresponding X-ray production cross-sections, the same values as were reported in the previous paper were applicable since conditions of irradiating system were unchanged. It was confirmed that the new method allows us to quantitatively analyze all the elements heavier than aluminum and to obtain mostly the same results as those by in-vacuum PIXE for various kinds of samples. Accuracy of analysis was also confirmed by using a standard material.

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