ANALYSIS OF STATISTICAL CORRELATIONS AND INTENSITY SPIKING IN THE SELF-AMPLIFIED SPONTANEOUS-EMISSION FREE-ELECTRON LASER

The narrow band chaotic output of the self-amplified spontaneous-emission free-electron laser (SASE FEL) exhibits intensity spikes. In the linear regime before saturation, we use an approach developed by Rice to determine probability distributions for the peak values of intensity in both the time and frequency domains. We also find the average number of spikes per unit time or frequency. In addition, we derive joint probabilities for the intensity in the output pulse to have values I1 and I2 at times t1 and t2, and for the spectral intensity to have values ∼1 and ∼2 at frequencies ω1 and ω2