Cathodoluminescence Microanalysis of the Distribution of defects induced in fused silica by UV laser pulses and after damage mitigation treatment with a CO2 laser [electronic resource]
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| Online Access: |
Online Access (via OSTI) |
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| Corporate Author: | |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Department of Energy ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2004.
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| Subjects: |
| Abstract: | Point defects are induced in high quality optical-grade fused silica by high fluence (>30 J/cm²) 355nm laser pulses. The microscopic depth distribution of laser irradiation induced defects has been nondestructively determined using Cathodoluminescence (CL) microanalysis. CL emissions have been observed at 1.9eV, 2.2eV, 2.7eV and 4.4eV. In addition following CO² laser treatment for damage mitigation an emission at 3.2eV is also observed. The CL emissions have been identified with the NBOHC (non-bridging oxygen hole center), the STE (self-trapped exciton), an ODC (oxygen-deficient center) and an aluminum impurity centre. The spatially resolved CL data is consistent with damage initiation at the exit surface. The concentration of 355 nm laser induced defects is greatest at the surface and monotonically decays to pre-irradiation levels at ≈10 {micro}m depth below the surface. With CO² processing to mitigate damage, the defect concentration and spatial distribution is reduced to a maximum depth of ≈6{micro}m. CL microanalysis provides a sensitive and nondestructive method of assessing the magnitude and submicron distribution of irradiation induced damage in technologically important materials. |
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| Item Description: | Published through SciTech Connect. 03/10/2004. "ucrl-jrnl-204432" Journal of Applied Physics 97 ISSN 0021-8979; JAPIAU FT. Stevens-Kalceff, M; Wong, J. |
| Physical Description: | page(s) pp. 113519 : digital, PDF file. |