8 shows residuals for the fits of Fig. 3, highlighting how the variable RLC fit is an improvement over the fixed RLC fit.

The fixed RLC fits were of the form $$\begin{aligned}
   \label{FixedRLC}I(t) = 
\begin{cases}
0, & t < t_0 \\
I_0 + A_0 \, e^{-(t-t_0)/\tau} \sin[\omega (t-t_0)], 
& t \geq t_0. 
\end{cases}\end{aligned}$$ For all current and voltage data, the time axis origin was manually set to match the time of the first signal observed on the oscilloscope. Fitting of the current data in Fig. 3(b) and Fig. 7 excluded the first 3 $\mu$s of data because of current transformer bandwidth limitations. Likewise, fitting of the voltage data in Fig. 4 excluded the first 2$\mu$s because of capacitive-pickup probe limitations.

The variable RLC fits used a modified version of (\[trialfn\]) described above that includes an offset, $$\begin{aligned}
   \label{VariableRLC}y(t) = 
\begin{cases}
0, & t < t_0 \\
y_0 + A_0 \, e^{-B(t-t_0)} \cos[D(t-t_0) + \phi_0]. 
& t \geq t_0, 
\end{cases}\end{aligned}$$ As before, the time axis origin was manually set to match the time of the first signal observed on the oscilloscope. However, here $t_0$ was manually set to zero before fitting.

Fig. 9 shows reconstructed capacitances for the data of Figs. 