A Spectroscopic Investigation of Combustion-Driven Implosions.
Abstract
Time and spatially-resolved spectroscopic studies have been made of imploding shock waves in a 20-cm diameter hemispherical chamber filled with 2H2+O2 mixtures at high initial pressures (7-56 atm). Changes in the initiation system (an exploding wire) have improved the precision of the focus and the reproducibility of the implosion pulse. By using the blackbody character of the plasma radiation above 3000A, the temperature structure of the implosion was determined both temporarily and spatially as a function of initial filling pressure. It was found that peak temperatures (4500-5100K), averaged over a rectangular area 3 mm x 9 mm centered near the origin, increased monotonically as a function of filling pressure, while implosion pulse duration (8.5-4.0 microseconds) underwent a monotonic decrease. The implosion pulse, normalized by the duration and temperature rise, appeared to have a nearly universal shape. The spatial gradient of temperature (dt/d(logR)), averaged over the implosion pulse duration, increased monotonically as a function of initial filling pressure. All temperature results (peak temperature, duration, and gradient) averaged 15-20% below theorectical predictions. The time history of the pressure at the origin for an initial filling pressure of 7 atm, averaged over a 6.3 mm diameter circle, was measured by using a high-pressure piezoelectric transducer. The peak pressure, about 8 kbar, is 15-20% below theoretical predictions. This result represents the first direct measurement of pressure achieved at the focus of a gas-driven hemispherical implosion.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1977
- Accession Number
- ADA041816
Entities
People
- Randy A. Roig
Organizations
- University of Toronto