When using 1.13 MHz X-ray repetition rate, SASE1 HIREX is capturing two pulses in a single frame giving the impression that there are more peaks within the spectrum than there are in reality.

This was verified by recording data with one and  two pulses per train, which are shown in attachment.

The spectral integral/intensity in GOTTHARD frame 6, the first with data, is twice larger with two pulses compared to one pulse per train (attachments 1 and 2).

The number of peaks is consistently higher with two pulses compared to one pulse (attachment 3).