Design and manufacturing of the attachment of 10-micrometer fill tubes to ICF capsules
Abstract
The baseline design for cryogenic ignition capsules calls for DT fill via a fill tube just prior to the laser shot. Because the fill tube represents an asymmetry in the capsule, it must be kept as small as possible while still allowing reasonable fill times. Preliminary analysis shows that a 10-micrometer diameter glass fill tube inserted 10-micrometers into the beryllium or plastic capsule will result in acceptably small disturbances and allow ignition of the capsule on NIF. This design calls for a 3.6-micrometer fillet of suitable adhesive to hold and seal the fill tube to the capsule. At LLNL we are working to demonstrate a conventional implementation of the fill tube design. In this approach, a 3-micrometer fill hole is drilled through the capsule wall with a 12-micrometer counterbore at the surface to locate, bond and seal the fill tube. Because the desired fillet is so small with a total adhesive volume of just 0.25-pico-liters, it is necessary to machine the excess adhesive from the joint after curing. We report here on the progress to make fill tube attachments that meet the design requirements. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DPPNP1116K