A VISAR Velocity Interferometer System at MRL for Slapper Detonator and Shockwave Studies
Abstract
This report describes the commissioning and appraisal of a conventional 3-detector VISAR velocity interferometer system (Systems, Science, and Software, Model 3SLVI-401) for measuring the velocity-time histories of small plastic flyer plates produced by exploding bridge foil generators. Proper treatment of the flyer surface to diffusely reflect the laser beam was found to be important. Roughening the surface with a miniature grit-blaster produced the best results. Peak velocities in the range 1500 m/s to 3900 m/s were obtained for small- and medium-scale flyers (bridge widths of 0.25 mm and 1.5 mm, respectively). Accelerations were in the range 10 Gm/s2 to 100 Gm/s2. The uncertainty of the measurements was found to be related to the limited high- frequency response (less than 100 MHz) of the photodetectors. After replacement of the original non-flat beamsplitter, the arms of the interferometer were not quite compensated. A modified VISAR velocity equation that allows for the effective etalon length of the lambda/8 waveplate/beamsplitter combination is derived.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1991
- Accession Number
- ADA250372
Entities
People
- David J. Hatt
Organizations
- Defence Science and Technology Group