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Calculating the shrapnel generation and subsequent damage to first wall and optics components for the National Ignition Facility (open access)

Calculating the shrapnel generation and subsequent damage to first wall and optics components for the National Ignition Facility

The purpose of this work is to computationally assess the threat from shrapnel generation on the National Ignition Facility (NIF) first wall, final optics, and ultimately other target chamber components. Shrapnel is defined as material.that is in a solid, liquid, or clustered-vapor phase with sufficient velocity to become a threat to exposed surfaces as a consequence of its impact. Typical NIF experiments will be of two types, low neutron yield shots in which the capsule is not cryogenically cooled, and high yield shots for which cryogenic cooling of the capsule is required. For non-cryogenic shots, shrapnel would be produced by spaIIing, melting and vaporizing of ``shine shields`` by absorption and shock wave loading following 1-{omega} and 2-{omega} laser radiation. For cryogenic shots, shrapnel would be generated through shock wave splitting, spalling, and droplet formation of the cryogenic tubes following neutron energy deposition. Motion of the shrapnel is determined not only by particle velocities resulting from the neutron deposition, but also by both x-ray and debris loading arising from explosion of the hohlraum. Material responses of different target area components are computed from one- dimensional and two-dimensional stress wave propagation codes. Well developed rate-dependent spall computational models are used for stainless …
Date: August 6, 1996
Creator: Tokheim, R. E.; Seaman, L.; Cooper, T.; Lew, B.; Curran, D. R.; Sanchez, J. et al.
System: The UNT Digital Library