Time-Resolved Thermal And Acoustic Pulse-Echo Measurements In Condensed Matter

1987 ◽  
Author(s):  
Gary L. Eesley ◽  
Carolyn A. Paddock ◽  
Bruce M. Clemens
Keyword(s):  
Condensed Matter ◽  
Acoustic Pulse ◽  
Time Resolved ◽  
Pulse Echo

scholarly journals THE STUDY OF THE INFLUENCE OF X-RAY IRRADIATION ON DISLOCATION CHARACTERISTICS IN LiF CRYSTALS

2021 ◽  
pp. 21-25
Author(s):  
О.M. Petchenko ◽  
G.О. Petchenko ◽  
S.M. Boiko ◽  
А.S. Litvinenko
Keyword(s):  
Irradiation Time ◽  
Acoustic Pulse ◽  
Residual Deformation ◽  
Ultrasound Velocity ◽  
Wide Frequency Range ◽  
Effective Length ◽  
Acoustic Characteristics ◽  
Frequency Branch ◽  
Attenuation Mechanism ◽  
Pulse Echo

The dependences of the absorption α and the ultrasound velocity in LiF single crystals with residual deformation ε = 0.65% at 300 K in the range of radiation doses 0...1057 R were studied using the acoustic pulse echo method at a frequency of 7.5 MHz. Based on the results of measurements of the acoustic characteristics, the absolute values of the parameters of the dislocation structure – the average effective length of the dislocation loop L and the dislocation density Λ and their dependences on the irradiation time are determined. The calculated characteristics are compared with the previously obtained results for the high-frequency branch of the damped dislocation resonance and using the selective etching method. The revealed noticeable discrepancy in the values of these parameters is explained by the impossibility of describing a single attenuation mechanism for acoustic measurements carried out in a wide frequency range.

Generation and Propagation of a Picosecond Acoustic Pulse at a Buried Interface: Time-Resolved X-Ray Diffraction Measurements

2005 ◽  
Vol 95 (24) ◽  
Author(s):  
S. H. Lee ◽  
A. L. Cavalieri ◽  
D. M. Fritz ◽  
M. C. Swan ◽  
R. S. Hegde ◽  
...  
Keyword(s):  
Acoustic Pulse ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray

Acoustic pulse echo measurements at 200 MHz

1977 ◽  
Vol 30 (2) ◽  
pp. 78-80 ◽  
Author(s):  
B. T. Khuri‐Yakub ◽  
G. S. Kino
Keyword(s):  
Acoustic Pulse ◽  
Pulse Echo

Average acoustic pulse dispersion length in condensed matter channels

2006 ◽  
Vol 86 (20) ◽  
pp. 3043-3060 ◽  
Author(s):  
D. Hazony ◽  
Y. Hazony ◽  
J. Lawrence Katz ◽  
G. Welsch
Keyword(s):  
Condensed Matter ◽  
Acoustic Pulse

Ultrasonic Reflectivity Imaging in Three Dimensions: Reconstruction with Spherical Transducer Arrays

1979 ◽  
Vol 1 (3) ◽  
pp. 210-231 ◽  
Author(s):  
Stephen J. Norton ◽  
Melvin Linzer
Keyword(s):  
Signal To Noise Ratio ◽  
Acoustic Pulse ◽  
Cutoff Frequency ◽  
Three Dimensional ◽  
Point Sources ◽  
Three Dimensions ◽  
Reconstruction Process ◽  
Dimensional Reconstruction ◽  
Reflectivity Data ◽  
Pulse Echo

Three-dimensional backprojection for reconstructing acoustic reflectivity within a volume is examined. The reflectivity data are acquired by means of a spherical array of point sources-receivers which encloses the object under study. Reconstruction of the image is obtained by back-projecting the recorded pulse-echo data over spherical surfaces in image space. An analytical expression for the point spread function (PSF) generated by the backprojection process has been derived. This expression was evaluated for several different choices of the acoustic pulse: a narrowband pulse, wideband pulse, and two analytically-derived optimum pulses which provide the best sidelobe response and a mainlobe width equal to approximately 0.4Λc, where Λc is the wavelength corresponding to the upper cutoff frequency of the pulse. Excellent agreement was obtained between the theoretical PSF's for the different pulses and those obtained by computer simulation. A number of potential advantages of direct three-dimensional reconstruction relative to two-dimensional tomographic techniques are discussed, including (1) high resolution in three dimensions (2) the possibility of incorporating refraction effects in the reconstruction process (3) reduced sensitivity to limited viewing anglesand (4) improved signal-to-noise ratio (thus minimizing requirements for data redundancy).

scholarly journals Soft Matter Sample Environments for Time-Resolved Small Angle Neutron Scattering Experiments: A Review

2021 ◽  
Vol 11 (12) ◽  
pp. 5566
Author(s):  
Volker S. Urban ◽  
William T. Heller ◽  
John Katsaras ◽  
Wim Bras
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
High Intensity ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Condensed Matter ◽  
Large Body ◽  
Soft Condensed Matter ◽  
Time Resolved ◽  
Neutron Sources

With the promise of new, more powerful neutron sources in the future, the possibilities for time-resolved neutron scattering experiments will improve and are bound to gain in interest. While there is already a large body of work on the accurate control of temperature, pressure, and magnetic fields for static experiments, this field is less well developed for time-resolved experiments on soft condensed matter and biomaterials. We present here an overview of different sample environments and technique combinations that have been developed so far and which might inspire further developments so that one can take full advantage of both the existing facilities as well as the possibilities that future high intensity neutron sources will offer.

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