Clock jitter noise should saturate below around 1E- 4 Hz

We model the clock using deterministic drifts (for low frequency behavior), and an in-band pink jitter noise. The currently implementation for this jitter noise does not saturate below 1E-4 Hz (we use 1/simulation_size); therefore we "double count" the low frequency behavior.

We should change this to saturate the jitter noise around 1E-4 or 1E-5 Hz.