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Computer Simulation of Bubble Growth in Metals Due to He.

DE2001780304

Publication Date	2001
Personal Author	Foiles, S. M.; Hoyt, J. J.
Page Count	28
Abstract	Atomistic simulations of the growth of helium bubbles in metals are performed. The metal is represented by embedded atom method potentials for palladium. The helium bubbles are treated via an expanding repulsive spherical potential within the metal lattice. The simulations predict bubble pressures that decrease monotonically with increasing helium to metal ratios. The swelling of the material associated with the bubble growth is also computed. It is found that the rate of swelling increases with increasing helium to metal ratio consistent with experimental observations on the swelling of metal tritides. Finally, the detailed defect structure due to the bubble growth was investigated. Dislocation networks are observed to form that connect the bubbles. Unlike early model assumptions, prismatic loops between the bubbles are not retained. These predictions are compared to available experimental evidence.
Keywords	Metals Bubble growth Helium Computerized simulation Dislocations Palladium Swelling Tritides Interstitial helium generation
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Sandia National Labs., Albuquerque, NM.; Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200125
Contract Number	AC04-94AL85000

Computer Simulation of Bubble Growth in Metals Due to He.

Computer Simulation of Bubble Growth in Metals Due to He.
DE2001780304

Publication Date	2001
Personal Author	Foiles, S. M.; Hoyt, J. J.
Page Count	28
Abstract	Atomistic simulations of the growth of helium bubbles in metals are performed. The metal is represented by embedded atom method potentials for palladium. The helium bubbles are treated via an expanding repulsive spherical potential within the metal lattice. The simulations predict bubble pressures that decrease monotonically with increasing helium to metal ratios. The swelling of the material associated with the bubble growth is also computed. It is found that the rate of swelling increases with increasing helium to metal ratio consistent with experimental observations on the swelling of metal tritides. Finally, the detailed defect structure due to the bubble growth was investigated. Dislocation networks are observed to form that connect the bubbles. Unlike early model assumptions, prismatic loops between the bubbles are not retained. These predictions are compared to available experimental evidence.
Keywords	Metals Bubble growth Helium Computerized simulation Dislocations Palladium Swelling Tritides Interstitial helium generation
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Sandia National Labs., Albuquerque, NM.; Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200125
Contract Number	AC04-94AL85000