Accession Number:

ADA088112

Title:

Measurements of the Effects of Shock Pressure on Two Insulators: AgI and Kapton

Descriptive Note:

Final rept. 1 Jan 78-30 Jun 80

Corporate Author:

WASHINGTON STATE UNIV PULLMAN DEPT OF PHYSICS

Personal Author(s):

Report Date:

1980-07-01

Pagination or Media Count:

51.0

Abstract:

The electrical conductivity of AgI has been measured at pressures between 7.79 and 40.9 kbar. Thin disk-shaped samples were prepared by pressing 99.99 pure AgI powder at 4 kbars for three hours. The samples were impacted in a gas gun, and the resistance was measured between electrodes that had been vacuum deposited on the front and rear surfaces of the samples. The data from these experiments are characterized by a rapid decrease in resistance as the shock wave reaches the front electrode, followed by a further decrease as the shock wave travels through the sample and rear electrode into a backing plate of AgI. The resistance reaches a steady value several micro sec after the shock wave has traversed the sample and while the sample is still in a state of steady pressure. The steady value of resistivity decreases with increasing pressure. Resistance of Kapton films .00105 and .00305 inches thick have been measured with the film compressed between two copper plates. Pressures ranged from 40 to 150 kbars. Resistivity decreased in two steps by 10 to 12 orders of magnitude final resistivity decreases monotonically with increasing pressure. The results are in general agreement with Grahams model of bond scission in polymers, and there is some suggestion of separate contributions by surface and volume effects to the final resistivity. Author

Subject Categories:

  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE