A thought follows about the nature of the compartment, i.e. volume,
close to the film, and its importance to experimental controls.
The following is a simple diffusion model of the compartment close to
the film.
Pd--->T_in----->compartment-------> T_out + gas_out
^
|
gas_in
The compartment has volume based flow rates T_in, T_out, gas_in and
gas_out, where we can assume over a short time interval involved the
Pd has a fixed flow rate of T_in into the compartment. The
compartment is not fully sealed, so there is diffusion of ambient gas
into and out of the compartment, and a diffusion of T out of the
compartment as well.
At equilibrium, the compartment maintains equilibrium pressure, so, :
T_in + gas_in = T_out + gas out
At equilibrium we also have:
T_in = T_out
so:
gas_in = gas_out
The concentration ratio of the gasses in the compartment at
equilibrium becomes
R = T_in / gas_in.
This means the tighter the seal around the compartment the higher the
concentration of the T, the higher its partial pressure.
The partial pressure p(T) of the T in the compartment, p(T) is:
p(T) = R * [p(T) + p(gas)]
which at pressure P is:
p(T) = R * P
Given the compartment is shallow, the exposure rate of the film Ef is
proportional to the mass of T, and thus to its partial pressure times
its density:
Ef = p(T) * (density of T at P) = R * P * (density of T at P)
The higher the pressure the larger the exposure rate. The better the
compartment seal, the better the exposure rate. For very shallow
compartments, less than the beta mean free path, the thicker the
compartment, the larger the exposure rate.
Now, this might indicate a small flaw in the two experiments with the
voltage applied. The control run should have been a run with the
applied voltage zero. The compartment seal may have been very good,
and the thickness just right to get a high T exposure rate. If the
fogging at 0 volts matches those at positive and negative voltages,
then the effect is not voltage related at all. A lack of this
control data invalidates any conclusion based on field related data.
Regards,
Horace Heffner
