Total reflection and surface scattering of soft X-rays on the Si-SiO2system and hexagonal BN crystal

1995 ◽  
Vol 7 (14) ◽  
pp. 2731-2744 ◽  
Author(s):  
E Filatova ◽  
A Stepanov ◽  
C Blessing ◽  
J Friedrich ◽  
R Barchewitz ◽  
...  
Author(s):  
Werner P. Rehbach ◽  
Peter Karduck

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.


1988 ◽  
Vol 32 ◽  
pp. 105-114 ◽  
Author(s):  
H. Schwenke ◽  
W. Berneike ◽  
J. Knoth ◽  
U. Weisbrod

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.


1929 ◽  
Vol 33 (4) ◽  
pp. 463-466 ◽  
Author(s):  
Hiram W. Edwards
Keyword(s):  
X Rays ◽  

1999 ◽  
Vol 54 (1) ◽  
pp. 215-222 ◽  
Author(s):  
Jun Kawai ◽  
Shinjiro Hayakawa ◽  
Yoshinori Kitajima ◽  
Yohichi Gohshi

2020 ◽  
Vol 10 (7) ◽  
pp. 2611
Author(s):  
Hirokatsu Yumoto ◽  
Yuichi Inubushi ◽  
Taito Osaka ◽  
Ichiro Inoue ◽  
Takahisa Koyama ◽  
...  

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.


1986 ◽  
Vol 30 ◽  
pp. 213-223
Author(s):  
Tomoya Arai

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.


1993 ◽  
Vol 61 (1-2) ◽  
pp. 195-198 ◽  
Author(s):  
Yu. Emelyanov ◽  
V. Khat'ko ◽  
A. Lunevich ◽  
I. Globa

1985 ◽  
Author(s):  
F. E. Christensen ◽  
N. J. Westergaard ◽  
H. W. Schnopper
Keyword(s):  
X Rays ◽  

2020 ◽  
Vol 27 (6) ◽  
pp. 1618-1625
Author(s):  
Yuki Wakisaka ◽  
Bing Hu ◽  
Daiki Kido ◽  
Md. Harun Al Rashid ◽  
Wenhan Chen ◽  
...  

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.


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