Accession Number : AD0800327

Title :   SHOCK TUBE PERFORMANCE OF A LANGMUIR PROBE SUITABLE FOR BALLISTIC RANGE APPLICATIONS,

Corporate Author : AVCO EVERETT RESEARCH LAB INC EVERETT MA

Personal Author(s) : Locke, E. ; Plotkin, K.

Report Date : SEP 1966

Pagination or Media Count : 9

Abstract : The shock tube performance of a Langmuir probe suitable for temporal electron density measurements in a large ballistic range is presented. The positively biased probe is designed to utilize a 0.001 in. wire held in tension as an electron collector in a 1000 K, for 3 torr turbulent wake which has a 0.004 in. mean free path. Preliminary measurements of the probe characteristics were made in a shock tube at an initial pressure of 0.02 torr and shock speed of 4.5 mm/microsec. Under these conditions, the mean free path of the test gas was 0.011 in., and the electron number density was 2.5 x 10 to the 11th power/cu cm. Because of the higher dynamic pressure in the shock tube, 0.005 in. wire was used and remained intact throughout the series of runs. Data taken over a range of probe voltages from low electron currents to saturation current were in satisfactory agreement with theoretical calculations based on equilibrium electron density.

Descriptors :   (*LANGMUIR PROBES, ELECTRON DENSITY), (*SHOCK TUBES, LANGMUIR PROBES), BALLISTICS, ELECTRONS, TURBULENCE, WAKE, PLASMA MEDIUM, WIRE, RANGES(FACILITIES).

Subject Categories : Test Facilities, Equipment and Methods
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE