scholarly journals Dependence of the Beer-Lambert absorption law on monochromatic radiation: An experiment of spectrophotometry

1967 ◽  
Vol 44 (11) ◽  
pp. 699
Author(s):  
E. S. Hanrahan
Keyword(s):  
Monochromatic Radiation ◽  
Absorption Law

A linearity test for thick specimens imaged by HVEM over a 180° angular range

1991 ◽  
Vol 49 ◽  
pp. 552-553
Author(s):  
Yu Liu
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Angular Range ◽  
Two Dimensional ◽  
Back Projection ◽  
Line Integral ◽  
Exponential Law ◽  
Transmission Electron ◽  
Absorption Law ◽  
Linearity Test

The image obtained in a transmission electron microscope is the two-dimensional projection of a three-dimensional (3D) object. The 3D reconstruction of the object can be calculated from a series of projections by back-projection, but this algorithm assumes that the image is linearly related to a line integral of the object function. However, there are two kinds of contrast in electron microscopy, scattering and phase contrast, of which only the latter is linear with the optical density (OD) in the micrograph. Therefore the OD can be used as a measure of the projection only for thin specimens where phase contrast dominates the image. For thick specimens, where scattering contrast predominates, an exponential absorption law holds, and a logarithm of OD must be used. However, for large thicknesses, the simple exponential law might break down due to multiple and inelastic scattering.

scholarly journals X-ray imaging of silicon die within fully packaged semiconductor devices

2021 ◽  
pp. 1-7
Author(s):  
Brian K. Tanner ◽  
Patrick J. McNally ◽  
Andreas N. Danilewsky
Keyword(s):  
Synchrotron Radiation ◽  
Feasibility Studies ◽  
Monochromatic Radiation ◽  
X Ray Diffraction ◽  
Divergent Beam ◽  
X Ray ◽  
X Ray Imaging ◽  
Setting Process ◽  
Diffraction Imaging ◽  
Lattice Planes

X-ray diffraction imaging (XRDI) (topography) measurements of silicon die warpage within fully packaged commercial quad-flat no-lead devices are described. Using synchrotron radiation, it has been shown that the tilt of the lattice planes in the Analog Devices AD9253 die initially falls, but after 100 °C, it rises again. The twist across the die wafer falls linearly with an increase in temperature. At 200 °C, the tilt varies approximately linearly with position, that is, displacement varies quadratically along the die. The warpage is approximately reversible on cooling, suggesting that it has a simple paraboloidal form prior to encapsulation; the complex tilt and twisting result from the polymer setting process. Feasibility studies are reported, which demonstrate that a divergent beam and quasi-monochromatic radiation from a sealed X-ray tube can be used to perform warpage measurements by XRDI in the laboratory. Existing tools have limitations because of the geometry of the X-ray optics, resulting in applicability only to simple warpage structures. The necessary modifications required for use in situations of complex warpage, for example, in multiple die interconnected packages are specified.

Geometric Factors for Radiative Heat Transfer Through an Absorbing Medium in Cartesian Co-ordinates

1960 ◽  
Vol 82 (4) ◽  
pp. 360-368 ◽  
Author(s):  
A. K. Oppenheim ◽  
J. T. Bevans
Keyword(s):  
Radiative Heat ◽  
Unit Area ◽  
Diffuse Radiation ◽  
Radiation Beam ◽  
Actual Distribution ◽  
Absorbing Medium ◽  
One Dimensional ◽  
Geometric Factors ◽  
Absorption Law ◽  
Dimensional Integral

Heat flux conveyed by diffuse radiation from surface A1 and A2 through an absorbing medium is expressed by the relation Q1−2=J1 ∫A1×A2f(l12)(cosθ1cosθ2/πl122)dA1dA2 where J1 is the radiosity of A1 (sum of the emitted, reflected, and transmitted flux per unit area), l12 is the radiation beam (the distance between surface elements dA1 and dA2), θ1 and θ2 are the angles between the radiation beam and the normals to the surface elements, and f(l12) is the function describing the absorption law. The foregoing four-dimensional integral is transformed into a sum of one-dimensional integrals for the cases of opposite-parallel and adjoining-perpendicular rectangles. The results are suitable for numerical integration with any total absorption law obtained from the actual distribution of monochromatic absorptivities over the whole spectrum.

Spectral shape of quasi-monochromatic radiation from electron colliding with tightly focused laser pulses

Laser Physics ◽  
2021 ◽  
Vol 31 (6) ◽  
pp. 065403
Author(s):  
Jiawei Zhuang ◽  
Yiqiu Wang ◽  
Conglin Wang ◽  
Yunfeng Cai ◽  
Youwei Tian
Keyword(s):  
Laser Pulses ◽  
Spectral Shape ◽  
Monochromatic Radiation

TUNABLE COHERENT RADIATION FROM TERAHERTZ TO MICROWAVE BY MIXING TWO INFRARED FREQUENCIES IN A 47-MM-LONG GaSe CRYSTAL

2006 ◽  
Vol 16 (02) ◽  
pp. 589-595 ◽  
Author(s):  
WEI SHI ◽  
YUJIE J. DING
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Peak Power ◽  
Power Conversion ◽  
Coherent Radiation ◽  
Monochromatic Radiation ◽  
Frequency Tunability ◽  
Photon Conversion ◽  
Tunable Coherent Radiation ◽  
Infrared Frequencies

By mixing two infrared radiations near 1 μm in a 47-mm-long GaSe crystal, we efficiently generated a monochromatic radiation which has frequency tunability from 4.51 THz down to 53 GHz. The highest peak power produced by us is 389 W at 203 μm (1.48 THz), which corresponds to the photon conversion efficiency of 19% (the power conversion efficiency of 0.098%).

Study of the spatial distribution of minority carrier diffusion length in epiplanar detector structures

2015 ◽  
Vol 23 (4) ◽  
Author(s):  
T. Piotrowski ◽  
M. Węgrzecki ◽  
M. Stolarski ◽  
T. Krajewski
Keyword(s):  
Spatial Distribution ◽  
Minority Carrier ◽  
Diffusion Length ◽  
Silicon Detector ◽  
Monochromatic Radiation ◽  
Minority Carrier Diffusion Length ◽  
Carrier Diffusion ◽  
Spot Diameter ◽  
Photoelectric Current ◽  
Effective Carrier

AbstractOne of the key parameters determining detection properties of silicon PIN detector structures (pThe paper presents a method for measuring the spatial distribution of effective carrier diffusion length in silicon detector structures, based on the measurement of photoelectric current of a non-polarised structure illuminated (spot diameter of 250 μm) with monochromatic radiation of two wavelengths λ

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