U.S. Department of EnergyOffice of Scientific and Technical Information
High-frequency acoustic sensors for operation in a gaseous medium. Final report
Abstract
Photothermal microscopy is a technique for measuring thermal properties on a small scale by using focused laser beams as heat sources and as temperature probes. Typically used for nondestructive evaluation (NDE) of materials, its main advantage is its ability to measure types of flaws that are not visible optically or acoustically. Because of the optical nature of photothermal microscopy, sub-micron resolutions can be obtained in many of these thermal measurements. The greatest limitation of these systems is their relatively poor signal-to-noise ratios and, consequently, slow imaging speeds. To circumvent this problem, a variety of approaches to the detection of thermal waves has been pursued in recent years. This thesis compares the relative merits of a common class of techniques that rely on direct observation of physical changes in the heated sample, including a novel approach to interferometric measurement of the thermal expansion. It is found that the optimum approach depends not only on the physical properties of the sample being studies, but also upon the resolution of the experiment and the damage threshold of the specimen. Finally, this dissertation describes the applications of photothermal microscopy to the study of the anisotropic thermal properties of the new high-{Tc} superconductors. By addingmore »
- Authors:
- Publication Date:
- Research Org.:
- Stanford Univ., CA (United States). Edward L. Ginzton Lab.
- Sponsoring Org.:
- USDOE, Washington, DC (United States)
- OSTI Identifier:
- 10192194
- Report Number(s):
- DOE/ER/13797-T1; GL-4979
ON: DE95002123; BR: KC0401030; TRN: AHC29428%%69
- DOE Contract Number:
- FG03-87ER13797
- Resource Type:
- Technical Report
- Resource Relation:
- Other Information: PBD: [1990]
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; 36 MATERIALS SCIENCE; MICROSCOPY; BISMUTH OXIDES; THERMODYNAMIC PROPERTIES; CALCIUM OXIDES; STRONTIUM OXIDES; COPPER OXIDES; PROGRESS REPORT; NONDESTRUCTIVE TESTING; LASER RADIATION; SPATIAL RESOLUTION; PERFORMANCE; INTERFEROMETRY; PHOTODETECTORS; 420500; 360204; MATERIALS TESTING; PHYSICAL PROPERTIES
Citation Formats
Kino, G S. High-frequency acoustic sensors for operation in a gaseous medium. Final report. United States: N. p., 1990.
Web. doi:10.2172/10192194.
Kino, G S. High-frequency acoustic sensors for operation in a gaseous medium. Final report. United States. https://doi.org/10.2172/10192194
Kino, G S. 1990.
"High-frequency acoustic sensors for operation in a gaseous medium. Final report". United States. https://doi.org/10.2172/10192194. https://www.osti.gov/servlets/purl/10192194.
@article{osti_10192194,
title = {High-frequency acoustic sensors for operation in a gaseous medium. Final report},
author = {Kino, G S},
abstractNote = {Photothermal microscopy is a technique for measuring thermal properties on a small scale by using focused laser beams as heat sources and as temperature probes. Typically used for nondestructive evaluation (NDE) of materials, its main advantage is its ability to measure types of flaws that are not visible optically or acoustically. Because of the optical nature of photothermal microscopy, sub-micron resolutions can be obtained in many of these thermal measurements. The greatest limitation of these systems is their relatively poor signal-to-noise ratios and, consequently, slow imaging speeds. To circumvent this problem, a variety of approaches to the detection of thermal waves has been pursued in recent years. This thesis compares the relative merits of a common class of techniques that rely on direct observation of physical changes in the heated sample, including a novel approach to interferometric measurement of the thermal expansion. It is found that the optimum approach depends not only on the physical properties of the sample being studies, but also upon the resolution of the experiment and the damage threshold of the specimen. Finally, this dissertation describes the applications of photothermal microscopy to the study of the anisotropic thermal properties of the new high-{Tc} superconductors. By adding a high-vacuum cryostat to the microscope, the authors have been able to study the influence of the superconducting transition on the thermal conductivity. The measurements of the anisotropic thermal conductivity demonstrate that the heat flow along the superconducting planes is enhanced below the transition, and that no such enhancement exists in the non-superconducting direction. Material examined was Bi-Ca-Sr-Cu-O.},
doi = {10.2172/10192194},
url = {https://www.osti.gov/biblio/10192194},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Dec 31 00:00:00 EST 1990},
month = {Mon Dec 31 00:00:00 EST 1990}
}