Results 261 to 270 of about 89,505 (296)

Engineering applications of Bragg-edge neutron transmission

Applied Physics A: Materials Science & Processing, 2002
The shape, magnitude and location of the Bragg edges appearing in the transmission spectrum of polycrystalline materials can be accurately determined by the time-of-flight technique, and hence information about the stress state, texture and phases present in the material is readily available.
Santisteban, J. R., Edwards, L., Fizpatrick, M. E., Steuwer, A., Withers, P. J.   +4 more
openaire   +2 more sources

Strain imaging by Bragg edge neutron transmission

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
The strain imaging by Bragg edge neutron transmission was presented. The Bragg edges appearing in the transmitted time-of-flight spectra of polycrystalline materials were recorded using a two-diemensional array of detectors. The results showed that strain imaging was possible by Bragg edge transmission analysis.
Santisteban, J. R., Edwards, L., Fitzpatrick, M. E., Steuwer, A., Withers, P. J., Daymond, M. R., Johnson, M. W., Rhodes, N., Schooneveld, E. M.   +8 more
openaire   +2 more sources

Edge-emitting quantum well laser with Bragg reflectors

Applied Physics Letters, 1995
We have fabricated edge-emitting GaAs/AlGaAs quantum well lasers in which the outer cladding layers have been replaced by multilayer Bragg reflectors. The reflectance peak spans the intrinsic spontaneous emission spectrum of the wells and there are no allowed vertical cavity modes within this spectrum.
F. Yang, P. Blood, J. S. Roberts
openaire   +1 more source

Characteristics of Edge-Emitting Bragg Reflection Waveguide Lasers

IEEE Journal of Quantum Electronics, 2010
We demonstrate experimentally the stable continuous-wave (CW) single-mode operation of Bragg reflection waveguide (BRW) lasers from 10 to 100°C. The threshold characteristics, quantum efficiency, gain, and self-heating characteristics are investigated in detail. Threefold enhancement in the optical confinement is achieved using these BRW structures for
Cunzhu Tong, Bhavin J. Bijlani, Sanaz Alali, Amr S. Helmy   +3 more
openaire   +1 more source

Texture analysis using Bragg-edge neutron transmission method

2007 IEEE Nuclear Science Symposium Conference Record, 2007
The Bragg-edge positions of an annealed sample correspond to those of a cast sample whilst the total cross section of an annealed sample is smaller than that of a cast sample. The total cross section may be influenced by the crystallite size and extinction. Multiple scattering will occur in the same crystal grain if the crystallite size is large.
K. Iwase, T. Nagata, K. Sakuma, O. Takada, T. Kamiyama, Y. Kiyanagi, K. Iwase   +6 more
openaire   +1 more source

Real Time Neutron Diffraction Experiments Using Bragg Edges

MRS Proceedings, 1994
ABSTRACTTime resolved phase transition and strain experiments have been performed on the millisecond time scale using a Bragg-edge transmission technique that has been developed at the Los Alamos National Laboratory. The precision with which lattice parameters can be determined from edge positions is sufficient to perform high-resolution strain ...
Walter J Trela, Kay Meggers, Hans G Priesmeyer   +2 more
openaire   +1 more source

Methodology for Combined Neutron Diffraction and Bragg Edge Imaging

MRS Proceedings, 2013
ABSTRACTSimultaneous use of neutron diffraction and attenuation based transmission Bragg edge imaging for strain measurements is demonstrated in this paper using the pulse neutron source at Los Alamos National Laboratory. Cylindrical samples made from ferritic steel have been subjected to in-situ elastic loading in tension and torsion.
R. Woracek, J.R. Bunn, D. Penumadu, A. Tremsin, A. Siriruk, N. Kardjilov, I. Manke, M. Boin, A. Hilger, C.R. Hubbard, B. Clausen, T.A. Sisneros   +11 more
openaire   +1 more source

Fermi-edge polaritons in Bragg multiple-quantum-well structures

Solid State Communications, 2012
Abstract The polariton propagation in one-dimensional photonic crystals and quasicrystals based on highly doped quantum-well structures has been theoretically studied. The superradiant and photonic crystal regimes have been considered and expressions for band gap edges for light waves in the Bragg structures have been obtained.
N.S. Averkiev, M.M. Glazov, M.M. Voronov
openaire   +1 more source

Transmission Bragg-Edge Measurements

1992
The transmission of polycristalline materials in a white neutron spectrum shows sharp edges as a function of neutron wavelength or time-of-flight. They correspond to the breakdown of the Bragg interference condition for those sets of lattice planes which scatter by 180 degrees. Materials stresses as well as texture will influence the position and shape
openaire   +1 more source

Neutron bragg edge imaging of phase transformations in steel

2023
Bildgebende Verfahren mit Neutronenstrahlen entwickeln sich sehr schnell und werden heute in vielen Forschungsbereichen als zerstörungsfreie Analysewerkzeuge eingesetzt. Neutronen unterscheiden sich in ihrer Wechselwirkung mit Materie stark von Elektronen, Protonen oder Röntgenstrahlen: Sie dringen gut in die meisten gängigen metallischen Werkstoffe ...
openaire   +1 more source