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Title: Radiographic detection of 100 A thickness variations in 1-. mu. m-thick coatings applied to submillimeter-diameter laser fusion targets

Abstract

We have developed x-ray radiography to measure thickness variations of coatings on laser fusion targets. Our technique is based on measuring the variation in x-ray transmission through the targets. The simplest targets are hollow glass microshells or microballoons 100 to 500 ..mu..m in diameter, that have several layers of metals or plastics, 1 to 100 ..mu..m thick. Our goal is to examine these opaque coatings for thickness variations as small as 1% or 0.1%, depending on the type of defect. Using contact radiography we have obtained the desired sensitivity for concentric and elliptical defects of 1%. This percentage corresponds to thickness variations as small as 100 A in a 1-..mu..m-thick coating. For warts and dimples, the desired sensitivity is a function of the area of the defect, and we are developing a system to detect 0.1% thickness variations that cover an area 10 ..mu..m by 10 ..mu..m. We must use computer analysis of contact radiographs to measure 1% thickness variations in either concentricity or ellipticity. Because this analysis takes so long on our minicomputer, we preselect the radiographs by looking for defects at the 10% level on a video image analysis system.

Authors:
Publication Date:
Research Org.:
Los Alamos National Lab., NM (USA). Materials Science and Technology Div.
OSTI Identifier:
5186640
Report Number(s):
LA-UR-86-2673; CONF-860856-3
ON: DE86015348
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Conference
Resource Relation:
Conference: Conference on review of progress in quantitative NDE, San Diego, CA, USA, 3 Aug 1986; Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; LASER TARGETS; X-RAY RADIOGRAPHY; COATINGS; DEFECTS; GLASS; MICROSPHERES; OPACITY; THICKNESS; DIMENSIONS; INDUSTRIAL RADIOGRAPHY; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; TARGETS; 700205* - Fusion Power Plant Technology- Fuel, Heating, & Injection Systems

Citation Formats

Stupin, D M. Radiographic detection of 100 A thickness variations in 1-. mu. m-thick coatings applied to submillimeter-diameter laser fusion targets. United States: N. p., 1986. Web.
Stupin, D M. Radiographic detection of 100 A thickness variations in 1-. mu. m-thick coatings applied to submillimeter-diameter laser fusion targets. United States.
Stupin, D M. 1986. "Radiographic detection of 100 A thickness variations in 1-. mu. m-thick coatings applied to submillimeter-diameter laser fusion targets". United States. https://www.osti.gov/servlets/purl/5186640.
@article{osti_5186640,
title = {Radiographic detection of 100 A thickness variations in 1-. mu. m-thick coatings applied to submillimeter-diameter laser fusion targets},
author = {Stupin, D M},
abstractNote = {We have developed x-ray radiography to measure thickness variations of coatings on laser fusion targets. Our technique is based on measuring the variation in x-ray transmission through the targets. The simplest targets are hollow glass microshells or microballoons 100 to 500 ..mu..m in diameter, that have several layers of metals or plastics, 1 to 100 ..mu..m thick. Our goal is to examine these opaque coatings for thickness variations as small as 1% or 0.1%, depending on the type of defect. Using contact radiography we have obtained the desired sensitivity for concentric and elliptical defects of 1%. This percentage corresponds to thickness variations as small as 100 A in a 1-..mu..m-thick coating. For warts and dimples, the desired sensitivity is a function of the area of the defect, and we are developing a system to detect 0.1% thickness variations that cover an area 10 ..mu..m by 10 ..mu..m. We must use computer analysis of contact radiographs to measure 1% thickness variations in either concentricity or ellipticity. Because this analysis takes so long on our minicomputer, we preselect the radiographs by looking for defects at the 10% level on a video image analysis system.},
doi = {},
url = {https://www.osti.gov/biblio/5186640}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 1986},
month = {Wed Jan 01 00:00:00 EST 1986}
}

Conference:
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