Thermal stress in the edge cladding of Nova glass laser disks
Abstract
We calculated thermal stresses in Nova glass laser disks having light-absorbing edge cladding glass attached to the periphery with an epoxy adhesive. Our closed-form solutions indicated that, because the epoxy adhesive is only 25 ..mu..m across, it does not significantly affect the thermal stress in the disk or cladding glass. Our numerical results showed a peak tensile stress in the cladding glass of 24 MPa when the cladding glass had a uniform absorption coefficient of 7.5 cm/sup -1/. This peak value is reduced to 19 MPa if surface parasitic oscillation heating is eliminated by tilting the disk edges. The peak tensile stresses exceed the typical 7 to 14-MPa working stress for glass; however, we have not observed any disk or cladding glass failures at peak Nova fluences of 20 J/cm/sup 2/. We have observed delamination of the epoxy adhesive bond at fluences several times that which would occur on Nova. Replacement laser disks will incorporate cladding with a reduced absorption coefficient of 4.5 cm/sup -1/. Recent experiments show that this reduced absorption coefficient is satisfactory.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab., CA (USA)
- OSTI Identifier:
- 5915004
- Report Number(s):
- UCRL-96662; CONF-871007-3
ON: DE88000425
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Conference
- Resource Relation:
- Conference: 12. symposium on fusion engineering, Monterey, CA, USA, 12 Oct 1987; Other Information: Paper copy only, copy does not permit microfiche production
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; 36 MATERIALS SCIENCE; LASER MATERIALS; THERMAL STRESSES; ABSORPTION; ADHESIVES; CLADDING; NOVA FACILITY; TEMPERATURE DISTRIBUTION; DEPOSITION; MATERIALS; STRESSES; SURFACE COATING; 420300* - Engineering- Lasers- (-1989); 360603 - Materials- Properties
Citation Formats
Pitts, J H, Kong, M K, and Gerhard, M A. Thermal stress in the edge cladding of Nova glass laser disks. United States: N. p., 1987.
Web.
Pitts, J H, Kong, M K, & Gerhard, M A. Thermal stress in the edge cladding of Nova glass laser disks. United States.
Pitts, J H, Kong, M K, and Gerhard, M A. Mon .
"Thermal stress in the edge cladding of Nova glass laser disks". United States. https://www.osti.gov/servlets/purl/5915004.
@article{osti_5915004,
title = {Thermal stress in the edge cladding of Nova glass laser disks},
author = {Pitts, J H and Kong, M K and Gerhard, M A},
abstractNote = {We calculated thermal stresses in Nova glass laser disks having light-absorbing edge cladding glass attached to the periphery with an epoxy adhesive. Our closed-form solutions indicated that, because the epoxy adhesive is only 25 ..mu..m across, it does not significantly affect the thermal stress in the disk or cladding glass. Our numerical results showed a peak tensile stress in the cladding glass of 24 MPa when the cladding glass had a uniform absorption coefficient of 7.5 cm/sup -1/. This peak value is reduced to 19 MPa if surface parasitic oscillation heating is eliminated by tilting the disk edges. The peak tensile stresses exceed the typical 7 to 14-MPa working stress for glass; however, we have not observed any disk or cladding glass failures at peak Nova fluences of 20 J/cm/sup 2/. We have observed delamination of the epoxy adhesive bond at fluences several times that which would occur on Nova. Replacement laser disks will incorporate cladding with a reduced absorption coefficient of 4.5 cm/sup -1/. Recent experiments show that this reduced absorption coefficient is satisfactory.},
doi = {},
url = {https://www.osti.gov/biblio/5915004},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {9}
}