Accession Number:

AD0648984

Title:

PERFORMANCE OF A MASS SPECTROMETRIC MODULATED BEAM DETECTOR FOR GAS- SURFACE INTERACTION MEASUREMENTS

Descriptive Note:

Rept. for Jan-Oct 1966

Corporate Author:

ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN

Personal Author(s):

Report Date:

1967-03-01

Pagination or Media Count:

20.0

Abstract:

The report describes the performance of an instrument designed to detect molecular flow rates in the presence of the relatively high background gas noise of a space environment chamber. The technique of molecular beam modulation employed consists of three primary elements 1 the mechanical beam modulator, 2 a quadrupole mass spectrometer, and 3 a lock-in amplifier. Molecular beam intensities of about ten billion moleculessec-sq.cm are distinguishable from noise at a background pressure of 0.0000002 torr, which corresponds to about one hundred trillion moleculessec-sq.cm. The detector performance for molecular beams of He, A, N2, and CO2 is reported. This high sensitivity makes possible the use of molecular beam techniques for direct measurements of gas condensation rates.

Subject Categories:

  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE