MEASUREMENTS OF THE REDUCED FORCE COEFFICIENTS FOR H-2, N-2, CO, AND CO2 INCIDENT UPON A SOLAR PANEL ARRAY MATERIAL, SIO2-COATED KAPTON, KAPTON, AND Z-93-COATED AL
Sr. Cook et al., MEASUREMENTS OF THE REDUCED FORCE COEFFICIENTS FOR H-2, N-2, CO, AND CO2 INCIDENT UPON A SOLAR PANEL ARRAY MATERIAL, SIO2-COATED KAPTON, KAPTON, AND Z-93-COATED AL, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 58(1), 1998, pp. 492-503
The reduced force coefficients were measured for H-2, N-2, CO, and CO2
incident upon a solar panel array material, SiO2-coated Kapton, Kapto
n, and Z-93-coated Al. The coefficients were determined by measuring b
oth the magnitude and direction of the force exerted on the surfaces b
y molecular beams of the gases. Measurements were made at angles of in
cidence of 0 degrees, 25 degrees, 50 degrees, 75 degrees: and 85 degre
es. The forces were measured using a torsion balance with the surfaces
mounted on the end of the lever arm. The absolute flux densities of t
he molecular beams were measured using a second torsion balance with a
beam stop mounted on the lever arm that nullified the force of the sc
attered molecules. Flux measurements were also made using the effusive
method. Standard time-of-flight techniques were used to determine the
flux-weighted average velocities of the molecular beams. These veloci
ties ranged from 1670 to 4620 m/s. The overall uncertainty in the redu
ced force coefficient measurements was estimated to be less than +/-10
%. These measurements were used to obtain the magnitude and direction
of the flux-weighted average velocity of the scattered molecules, and
also the flux-weighted translational kinetic energy of the scattered m
olecules. Analysis of this information provided insight into the micro
scopic details of the gas-surface interaction potential energy surface
.