Optimal signal-to-noise ratios for soft x-ray lensless imaging

2009 ◽  
Vol 34 (5) ◽  
pp. 650 ◽  
Author(s):  
R. Rick ◽  
A. Scherz ◽  
W. F. Schlotter ◽  
D. Zhu ◽  
J. Lüning ◽  
...  
Keyword(s):  
Signal To Noise ◽  
Lensless Imaging ◽  
X Ray ◽  
Optimal Signal

scholarly journals Post-sample aperture for low background diffraction experiments at X-ray free-electron lasers

2017 ◽  
Vol 24 (6) ◽  
pp. 1296-1298 ◽  
Author(s):  
Max O. Wiedorn ◽  
Salah Awel ◽  
Andrew J. Morgan ◽  
Miriam Barthelmess ◽  
Richard Bean ◽  
...  
Keyword(s):  
Single Particle ◽  
Signal To Noise Ratio ◽  
Free Electron Lasers ◽  
Signal To Noise ◽  
X Ray ◽  
X Ray Imaging ◽  
Imaging Experiment ◽  
Particle Imaging ◽  
Single Particle Imaging ◽  
Optimal Signal

The success of diffraction experiments from weakly scattering samples strongly depends on achieving an optimal signal-to-noise ratio. This is particularly important in single-particle imaging experiments where diffraction signals are typically very weak and the experiments are often accompanied by significant background scattering. A simple way to tremendously reduce background scattering by placing an aperture downstream of the sample has been developed and its application in a single-particle X-ray imaging experiment at FLASH is demonstrated. Using the concept of a post-sample aperture it was possible to reduce the background scattering levels by two orders of magnitude.

scholarly journals Short-pulse laser-driven x-ray radiography

2016 ◽  
Vol 4 ◽  
Author(s):  
E. Brambrink ◽  
S. Baton ◽  
M. Koenig ◽  
R. Yurchak ◽  
N. Bidaut ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Short Pulse ◽  
Incident Angle ◽  
Laboratory Astrophysics ◽  
Signal To Noise ◽  
High Quality ◽  
X Ray ◽  
Short Pulse Laser ◽  
Short Pulse Lasers

We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pulse laser on the x-ray source target. The setup has been tested with various x-ray source target materials and different laser wavelengths. Signal to noise ratios are presented as well as achieved spatial resolutions. The high quality of our technique is illustrated on a plasma flow radiograph obtained during a laboratory astrophysics experiment on POLARs.

scholarly journals Geometric Approach to Analytic Marginalisation of the Likelihood Ratio for Continuous Gravitational Wave Searches

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 174
Author(s):  
Karl Wette
Keyword(s):  
Gravitational Wave ◽  
Likelihood Ratio ◽  
Signal To Noise Ratio ◽  
Geometric Approach ◽  
The Other ◽  
Efficient Computation ◽  
Likelihood Ratios ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Optimal Signal

The likelihood ratio for a continuous gravitational wave signal is viewed geometrically as a function of the orientation of two vectors; one representing the optimal signal-to-noise ratio, and the other representing the maximised likelihood ratio or F-statistic. Analytic marginalisation over the angle between the vectors yields a marginalised likelihood ratio, which is a function of the F-statistic. Further analytic marginalisation over the optimal signal-to-noise ratio is explored using different choices of prior. Monte-Carlo simulations show that the marginalised likelihood ratios had identical detection power to the F-statistic. This approach demonstrates a route to viewing the F-statistic in a Bayesian context, while retaining the advantages of its efficient computation.

Cancellation method to improve signal to noise ratio of an electrodeless microwave-biased ZnO single crystal x-ray detector

2022 ◽  
Vol 93 (1) ◽  
pp. 015006
Author(s):  
Xiaolong Zhao ◽  
Ming Ye ◽  
Zhi Cao ◽  
Danyang Huang ◽  
Tingting Fan ◽  
...  
Keyword(s):  
Single Crystal ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
X Ray ◽  
Noise Ratio ◽  
Zno Single Crystal

scholarly journals Erratum: “Signal-to-noise ratio in x-ray dark-field imaging using a grating interferometer” [J. Appl. Phys. 110, 053105 (2011)]

2011 ◽  
Vol 110 (10) ◽  
pp. 109902 ◽  
Author(s):  
Michael Chabior ◽  
Tilman Donath ◽  
Christian David ◽  
Manfred Schuster ◽  
Christian Schroer ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Dark Field ◽  
Signal To Noise ◽  
X Ray ◽  
Dark Field Imaging ◽  
Grating Interferometer ◽  
Noise Ratio ◽  
Field Imaging

scholarly journals Improvement of SAXS Lab Equipment by Using Scatterless Apertures

2014 ◽  
Vol 70 (a1) ◽  
pp. C1330-C1330
Author(s):  
Joerg Wiesmann ◽  
Andreas Kleine ◽  
Christopher Umland ◽  
André Beerlink ◽  
Juergen Graf ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Experimental Setup ◽  
High Flux ◽  
Signal To Noise ◽  
Minimum Diameter ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Beam Stop ◽  
Synchrotron Beamlines

Parasitic scattering caused by apertures is a well-known problem in X-ray analytics, which forces users and manufacturers to adapt their experimental setup to this unwanted phenomenon. Increased measurement times due to lower photon fluxes, a lower resolution caused by an enlarged beam stop, a larger beam defining pinhole-to-sample distance due to the integration of an antiscatter guard and generally a lower signal-to-noise ratio leads to a loss in data quality. In this presentation we will explain how the lately developed scatterless pinholes called SCATEX overcome the aforementioned problems. SCATEX pinholes are either made of Germanium or of Tantalum and momentarily have a minimum diameter of 30µm. Thus, these novel apertures are applicable to a wide range of different applications and X-ray energies. We will show measurements which were performed either at home-lab small angle X-ray scattering (SAXS) systems such as the NANOSTAR of Bruker AXS or at synchrotron beamlines. At the PTB four-crystal monochromator beamline at BESSY II data was collected for a comparison of conventional pinholes, scatterless Germanium slit systems and SCATEX pinholes. At the Nanofocus Endstation P03 beamline at PETRA III we compared the performance of our SCATEX apertures with conventional Tungsten slit systems under high flux density conditions.

Diffracted Beam Monochromators for Powder Diffractometry

1970 ◽  
Vol 14 ◽  
pp. 38-56
Author(s):  
E. M. Proctor ◽  
T. C. Furnas ◽  
W. F. Loranger
Keyword(s):  
Preferred Orientation ◽  
Signal To Noise ◽  
X Ray ◽  
Direct Beam ◽  
Vertical Divergence ◽  
Oriented Samples ◽  
Efficiency And Effectiveness ◽  
Slit System ◽  
Bent Crystals ◽  
Selection Of

AbstractThe efficiency and effectiveness of diffracted beam x-ray monochromators used in powder diffractometry have been described in so many ways that much confusion exists regarding their true performance. Although significant improvements in signal to noise ratios are readily achievable, and they offer a solution to the sample fluorescence problem, it is not without sacrifice to total intensity or achievable resolution or both. This paper discusses and describes a series of comparisons between filtered direct beam, LiF and graphite monochromators.These comparisons include the considerations necessary for the appropriate selection of diffracted beam slit system, the effect of vertical divergence as a function of two theta for singly bent crystals, the effects of a non-uniformity of contribution over the length of the crystal, and the geometry necessary for the singly bent and doubly bent crystals. The total intensity and the resolution of LiF and graphite are discussed, in particular, it is noted that the performance of monochromators with randomly oriented samples is quite different than their performance with samples showing preferred orientation or grain effects.A new diffracted beam monochromator based on the Rowland focusing geometry is described.

Optical gain signal-to-noise ratio transfer efficiency as an index for ranking of phosphor- photodetector combinations used in X-ray medical imaging

2004 ◽  
Vol 78 (6) ◽  
pp. 915-919 ◽  
Author(s):  
N. Kalivas ◽  
L. Costaridou ◽  
I. Kandarakis ◽  
D. Cavouras ◽  
C.D. Nomicos ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Signal To Noise Ratio ◽  
Optical Gain ◽  
Transfer Efficiency ◽  
Signal To Noise ◽  
X Ray ◽  
Noise Ratio

Registration of the rotation axis in X-ray tomography

2015 ◽  
Vol 22 (2) ◽  
pp. 452-457 ◽  
Author(s):  
Yimeng Yang ◽  
Feifei Yang ◽  
Ferdinand F. Hingerl ◽  
Xianghui Xiao ◽  
Yijin Liu ◽  
...  
Keyword(s):  
Rotation Axis ◽  
Signal To Noise Ratio ◽  
Geological Samples ◽  
Signal To Noise ◽  
High Demand ◽  
X Ray ◽  
Data Registration ◽  
Reconstruction Quality ◽  
Tomographic Data

There is high demand for efficient, robust and automated routines for tomographic data reduction, particularly for synchrotron data. Registration of the rotation axis in data processing is a critical step affecting the quality of the reconstruction and is not easily implemented with automation. Existing methods for calculating the center of rotation have been reviewed and an improved algorithm to register the rotation axis in tomographic data is presented. The performance of the proposed method is evaluated using synchrotron-based microtomography data on geological samples with and without artificial reduction of the signal-to-noise ratio. The proposed method improves the reconstruction quality by correcting both the tilting error and the translational offset of the rotation axis. The limitation of this promising method is also discussed.

Sign in / Sign up

Export Citation Format

Share Document