Synchrotron Radiation for Measurement of Contaminants on Silicon Surfaces

1993 ◽  
Vol 307 ◽  
Author(s):  
Michael C. Madden ◽  
David C. Wherry ◽  
Piero Pianetta ◽  
Sean Brennan
Keyword(s):  
Detection Limit ◽  
Synchrotron Radiation ◽  
Transition Metals ◽  
Atomic Number ◽  
Incident Radiation ◽  
Total Reflection ◽  
Silicon Surfaces ◽  
Synchrotron Source ◽  
X Ray

ABSTRACTThe detection limit for aluminum using total reflection x-ray fluorescence (TXRF) is approximately 100 times lower for a synchrotron source compared to a conventional source. The detection limit for transition metals is approximately 15 to 40 times lower depending on atomic number and energy of the incident radiation.

Update On Synchrotron Radiation TXRF: New Results

1998 ◽  
Vol 524 ◽  
Author(s):  
S. Brennan ◽  
P. Pianetta ◽  
S. Ghosh ◽  
N. Takaura ◽  
C. Wiemer ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Total Reflection ◽  
Synchrotron Source ◽  
X Ray ◽  
Non Destructive

ABSTRACTSynchrotron-based total-reflection x-ray fluorescence(SR-TXRF) has been developed as a leading technique for measuring wafer cleanliness. It holds advantages over other techniques in that it is non-destructive and allows mapping of the surface. The highest sensitivity observed thus far is 3x108 atoms/cm 2 (- 3fg) for 1000 second count time. Several applications of SR-TXRF are presented which take advantage of the energy tunability of the synchrotron source or the mapping capability.

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.

Multi-elemental analysis of produced water by synchrotron radiation total reflection X-ray fluorescence

Talanta ◽  
2008 ◽  
Vol 74 (5) ◽  
pp. 1231-1235 ◽  
Author(s):  
P.M. Pimentel ◽  
M.J. Anjos ◽  
D.M.A. Melo ◽  
M.A.F. Melo ◽  
L.M. Gonçalves Jr. ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Elemental Analysis ◽  
Produced Water ◽  
Total Reflection ◽  
X Ray

scholarly journals Multielement analysis of plant extracts with potential use in the treatment of peptic ulcers by synchrotron radiation total reflection X-ray fluorescence

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5375
Author(s):  
Leticia Diniz Vieira ◽  
Káthia Takeda da Silva ◽  
Rodrigo Sanchez Giarola ◽  
Guilherme Franco Inocente ◽  
Hélio Kushima ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Intermediate Stage ◽  
Total Reflection ◽  
New Drugs ◽  
Peptic Ulcers ◽  
X Ray ◽  
Analytical Technique ◽  
Methanolic Extracts ◽  
Synchrotron Light ◽  
Almost All

Some plants popularly employed for the treatment of peptic ulcers have proved to be attractive sources of new drugs. Despite extensive research, the pharmacological and toxicological potentials of these plants are not fully understood. In this context, the aim of this work was to analyze the multielemental composition of the methanolic extracts of three of those plants, Alchornea glandulosa (AG), Davilla elliptica (DE) and Davilla nitida (DN), with the intention of contributing to the understanding of the mechanisms of action of these extracts. For this purpose, we used the analytical technique of total reflection X-ray fluorescence (TXRF) by synchrotron radiation at the Brazilian Synchrotron Light Source (LNLS/CNPEM). It was possible to determine the concentrations of the elements: P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb and Br in all of the samples. Selenium (Se) was detected only in the DN extract. An inverse relationship between the concentrations of elements with proven effectiveness and the gastroprotective activity of extracts considering induction protocols with ethanol and non-steroidal anti-inflammatory drugs (NSAIDs) was obtained. This data suggests that the function of the extract is not only associated with providing the elements for restoring the gastric mucosa but that it also promotes the displacement of these elements from other parts of the mucosa to the damaged area. Correlations between the concentrations of the elements were also obtained. In the DE extract, which is the most effective extract for both induction protocols, the obtained correlations were above 70% among almost all of the elements, and no anticorrelations were found. For the other two extracts, in the less effective extract (AG) anticorrelations above 70% were predominantly found. Meanwhile, in the DN extract, a few high anticorrelations were found, which may explain its intermediate stage of effectiveness.

A high-resolution Weissenberg camera for X-ray synchrotron radiation

1990 ◽  
Vol 23 (5) ◽  
pp. 351-354
Author(s):  
D. Hohlwein ◽  
J. D. Axe
Keyword(s):  
Phase Transformation ◽  
High Resolution ◽  
Synchrotron Radiation ◽  
Reciprocal Space ◽  
Experimental Results ◽  
Germanium Crystal ◽  
Synchrotron Source ◽  
X Ray ◽  
High Resolution Mapping ◽  
Resolution Mapping

A photographic Weissenberg camera has been constructed which can be mounted on the 2θ arm of a four-circle diffractometer. At a distance of 0.5 m from the sample the 2θ resolution for a 100 μm crystal is 0.2 mrad (0.01°), allowing a high-resolution mapping of reciprocal space at a synchrotron source in an efficient way. As sample experimental results, a study is presented of the streak system around the 111 reflection of a perfect germanium crystal and the detection of a minute phase transformation in a single-powder grain of a high-Tc superconductor.

Low-power total reflection X-ray fluorescence spectrometer using diffractometer guide rail

2014 ◽  
Vol 30 (1) ◽  
pp. 36-39
Author(s):  
Ying Liu ◽  
Susumu Imashuku ◽  
Jun Kawai
Keyword(s):  
Detection Limit ◽  
Low Power ◽  
Power Supply ◽  
Total Reflection ◽  
Minimum Detection Limit ◽  
Guide Rail ◽  
X Ray ◽  
Fluorescence Spectrometer

An X-ray diffractometer (XRD) was modified to a low-power total reflection X-ray fluorescence (TXRF) spectrometer. This was realized by reducing the XRD tube power (3 kW) down to 10 W by a Spellman power supply. The present spectrometer consisted of a waveguide slit, Si-PIN detector, a goniometer and two Z-axis stages that were set on a diffractometer guide rail. This unit was easy in assembly. The first measurements with this spectrometer were presented. The minimum detection limit for Cr was estimated to be a few nanograms or at the level of 1013 atoms cm−2.

Determinations of low atomic number elements in real uranium oxide samples using vacuum chamber total reflection X-ray fluorescence

2015 ◽  
Vol 44 (6) ◽  
pp. 475-475
Author(s):  
Sangita Dhara ◽  
N. L. Misra ◽  
S. K. Aggarwal ◽  
Dieter Ingerle ◽  
Peter Wobrauschek ◽  
...  
Keyword(s):  
Atomic Number ◽  
Uranium Oxide ◽  
Vacuum Chamber ◽  
Total Reflection ◽  
X Ray
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