Accession Number : AD0767419

Title :   Monte Carlo Simulation of Ion Collection by a Rocket-Borne Mass Spectrometer for Collisionless and Transitional Flowfields.

Descriptive Note : Final rept. (Part 2), 1 Jan-30 Jun 73,

Corporate Author : TRW SYSTEMS GROUP REDONDO BEACH CALIF

Personal Author(s) : Sugimura,Takashi ; Vogenitz,Frank W.

Report Date : JUL 1973

Pagination or Media Count : 57

Abstract : Monte Carlo calculations of ion collection by a rocket-borne mass spectrometer have been completed for the collisionless case for the following range of parameters: Debye number 0.01 to 1000, speed ratio 0.1 to 3.1 and nondimensional potential -10 to -200. Calculations made in the transition regime show that minimum altitude at which the free molecule flow assumption is valid is approximately 120 km. A calculation at 70 km corresponding to a Knudsen number 0.007 indicates that the flowfield can be characterized as near-continuum but one in which the rarefaction effects are still important. The study demonstrates that the Monte Carlo technique is an efficient method to determine ion collection over the complete range of the flight parameters: Knudsen number, Debye number, plate potential, and speed ratio. (Modified author abstract)

Descriptors :   (*SAMPLING, IONS), (*MASS SPECTROSCOPY, *IONOSPHERE), FLOW FIELDS, MONTE CARLO METHOD, DENSITY, KNUDSEN NUMBER, SOUNDING ROCKETS, ATMOSPHERIC SOUNDING, UPPER ATMOSPHERE

Subject Categories : Atmospheric Physics
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE