Measurement of the{sup 3}He permeability of DT-filled fused silica inertial confinement fusion (ICF) targets to study the effects of{sup 3}He on neutron emission during implosion
- Los Alamos National Laboratory, MS-C927, P. O. Box 1663, Los Alamos, NM 87545 (United States)
A set of laser implosion experiments were conducted at the OMEGA laser at the Univ. of Rochester, Laboratory for Laser Energetics (LLE) to study the effect of He concentration in DT-filled target shells on fusion yield in ICF implosions.. Eleven laser fusion shells consisting of 1100-{mu}m diameter, hollow, fused silica spheres with 4.6 to 4.7-{mu}m-thick walls were loaded with 520 kPa of deuterium-tritium (DT) and then with {sup 3}He (101.3 or 520 kPa). The {sup 3}He permeabilities of the shells were determined by measuring the pressure rate of rise into a system with known volume. A mathematical method was developed that relied on the experimental fill pressure and time, and the rate of rise data to solve differential equations using MathCAD to simultaneously calculate {sup 3}He permeability and initial {sup 3}He partial pressure inside the shell. Because of the high permeation rate for {sup 3}He out of the shells compared to that for DT gas, shells had to be recharged with {sup 3}He immediately before being laser imploded or 'shot' at LLE. The {sup 3}He partial pressure in each individual shell at shot time was calculated from the measured {sup 3}He permeability. Two different partial pressures of {sup 3}He inside the shell were shown to reduce neutron and gamma yields during implosion. (authors)
- OSTI ID:
- 22109413
- Journal Information:
- Fusion Science and Technology, Vol. 54, Issue 2; Conference: 8. international conference on tritium science and technology, Rochester, NY (United States), 16-21 Sep 2007; Other Information: Country of input: France; 10 refs; ISSN 1536-1055
- Country of Publication:
- United States
- Language:
- English
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