Figure 14.

Rise time versus machine setting pressure levels for most of the machine settings using the long standoff. The rise time of the shock front of the electromagnetic source at a range of machine output settings is measured from averaged waveforms obtained at the beam focus. Rise time called “derivative definition” was calculated at the 36% level of the derivative of the pressure wave based on Fig. 3. The “traditional definition” is the standard rise time from 10% to 90% of p⁺. Settings between no. 2 and no. 1 (Table TABLE I.) are difficult to detect since the signal is very noisy and the noise level is comparable to the amplitude when the derivative is calculated. A more powerful derivative method could be implemented to calculate rise times in these low amplitude sinusoidal-like waveforms.