chemical physics of discharges - Argonne National Laboratory

Ywalls;s lo-', y'end plate = and kh = 0.100 sec-', the average atom concentration
in the discharge zone is reduced from 14% to 0.19%. It is assumed
here that the end plate has no effect on the electron and ion concentration levels
within the discharge.
k. Mass-Flux Devices
As shown above, the measurement of the absolute value of k,!, requires a
knowledge of either 7, M and D12, or M and 7'. A simpler procedure applicable
to the study of atoms requires the use of a mass-flux device such as an isothermal
calorimeter, which measures the atom flux at a given point within the
reactor zone. l9 Equation (131) becomes
Jls (atoms/cm2 sec) = - D12 "I aZ
=2+2&9L
z=L =O
62R
= 0262
CD~~I
R
Ti+!'+- L 6"R
M
cy2 %2
R
= k&c'
when M >> [k + E) . Thus, the rate of atom production can be determined bv a
mass- flux m\easur&nment provided that the value of M is known and the calori:
meter is the dominant atom sink.
5. Relative Measurements
I
(136)
Provided that certain parameters remain constant and the appropriate
inequality relationships hold, the measurement of relative values of k;, is the
easiest measurement to perform in diffusion or flow tubes. The most important
requirement is that