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Title: The effective yield of a nuclear explosion in a small cavity in geological material: Enhanced coupling revisited

Abstract

The hydrodynamic yield of an underground nuclear explosion in a small cavity has been recalculated using computer modeling. We have considered explosions in spherical cavities having scaled radii, {ital R}/{ital W}{sup 1/3}, less than 3.5 m/kt{sup 1/3} ({ital R} is the cavity radius in meters and {ital W} is the explosion energy in kilotons) in quartz (SiO{sub 2}) using an available equation of state (Ree, 1976). These calculations show, at a scaled radius of {approx}1.5 m/kt{sup 1/3}, a maximum hydrodynamic yield substantially greater than that of an explosion in a tamped cavity (enhanced coupling) as measured by the shock time of arrival in the near field. These results are in qualitative agreement with those of earlier investigators who utilized the reduced displacement potential to evaluate coupling. We found, however, that the coupling coefficient (ratio of yield for cavity model to yield for tamped model) is significantly reduced when an improved quartz equation of state is employed. We also calculated enhanced coupling in two additional geologic materials, salt and tuff. All of the calculations mentioned above (including our initial ones) were simplified through the omission of significant thermal radiation contributions to energy and pressure in the cavity and the diffusion bymore » photon transport of energy from the explosion cavity into the adjacent rock. When we take these processes into account, we find that for a cavity radius of approximately 1.5 m/kt{sup 1/3}, near the peak of enhancement for our models with no radiation, there is instead decoupling of about 15% in SiO{sub 2}, 20% in tuff, and about 15% in salt.« less

Authors:
 [1];  [2]; ;  [3]
  1. Los Alamos National Laboratory, Los Alamos, New Mexico(US) University of New Mexico, Albuquerque (US)
  2. Los Alamos National Laboratory, Los Alamos, New Mexico and S-Cubed a Division of Maxwell Laboratories, Inc., La Jolla, California
  3. Los Alamos National Laboratory, Los Alamos, New Mexico
Publication Date:
OSTI Identifier:
5361621
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research; (USA)
Additional Journal Information:
Journal Volume: 94:B9; Journal ID: ISSN 0148-0227
Country of Publication:
United States
Language:
English
Subject:
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; UNDERGROUND EXPLOSIONS; ENERGY YIELD; COMPUTERIZED SIMULATION; DECOUPLING; DETONATIONS; EQUATIONS OF STATE; GAMMA RADIATION; NUCLEAR EXPLOSIONS; QUARTZ; ROCK CAVERNS; CAVITIES; CHALCOGENIDES; ELECTROMAGNETIC RADIATION; EQUATIONS; EXPLOSIONS; IONIZING RADIATIONS; MINERALS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; RADIATIONS; SILICON COMPOUNDS; SILICON OXIDES; SIMULATION; YIELDS; 450201* - Military Technology, Weaponry, & National Defense- Nuclear Explosions & Explosives- Containment

Citation Formats

King, D S, Freeman, B E, Eilers, D D, and Johnson, J D. The effective yield of a nuclear explosion in a small cavity in geological material: Enhanced coupling revisited. United States: N. p., 1989. Web. doi:10.1029/JB094iB09p12375.
King, D S, Freeman, B E, Eilers, D D, & Johnson, J D. The effective yield of a nuclear explosion in a small cavity in geological material: Enhanced coupling revisited. United States. doi:10.1029/JB094iB09p12375.
King, D S, Freeman, B E, Eilers, D D, and Johnson, J D. Sun . "The effective yield of a nuclear explosion in a small cavity in geological material: Enhanced coupling revisited". United States. doi:10.1029/JB094iB09p12375.
@article{osti_5361621,
title = {The effective yield of a nuclear explosion in a small cavity in geological material: Enhanced coupling revisited},
author = {King, D S and Freeman, B E and Eilers, D D and Johnson, J D},
abstractNote = {The hydrodynamic yield of an underground nuclear explosion in a small cavity has been recalculated using computer modeling. We have considered explosions in spherical cavities having scaled radii, {ital R}/{ital W}{sup 1/3}, less than 3.5 m/kt{sup 1/3} ({ital R} is the cavity radius in meters and {ital W} is the explosion energy in kilotons) in quartz (SiO{sub 2}) using an available equation of state (Ree, 1976). These calculations show, at a scaled radius of {approx}1.5 m/kt{sup 1/3}, a maximum hydrodynamic yield substantially greater than that of an explosion in a tamped cavity (enhanced coupling) as measured by the shock time of arrival in the near field. These results are in qualitative agreement with those of earlier investigators who utilized the reduced displacement potential to evaluate coupling. We found, however, that the coupling coefficient (ratio of yield for cavity model to yield for tamped model) is significantly reduced when an improved quartz equation of state is employed. We also calculated enhanced coupling in two additional geologic materials, salt and tuff. All of the calculations mentioned above (including our initial ones) were simplified through the omission of significant thermal radiation contributions to energy and pressure in the cavity and the diffusion by photon transport of energy from the explosion cavity into the adjacent rock. When we take these processes into account, we find that for a cavity radius of approximately 1.5 m/kt{sup 1/3}, near the peak of enhancement for our models with no radiation, there is instead decoupling of about 15% in SiO{sub 2}, 20% in tuff, and about 15% in salt.},
doi = {10.1029/JB094iB09p12375},
journal = {Journal of Geophysical Research; (USA)},
issn = {0148-0227},
number = ,
volume = 94:B9,
place = {United States},
year = {1989},
month = {9}
}