Figure 2

(A) ICCD images at the first three positive pulses for the first negative pulse in the bunch with duty cycle of \(\approx 8\)%: (a1) at 12.8, (b1) 13.1, (c1) 13.3, (d1) 13.5, (e1) 15.5 and (f1) 16.1 \(\upmu\)s; (a2) at 38.8, (b2) 39.1, (c2) 39.3, (d2) 39.5, (e2) 41.5 and (f2) 42.1 \(\upmu\)s; (a3) at 64.8, (b3) 65.1, (c3) 65.3, (d3) 65.5, (e3) 67.5 and (f3) 68.1 \(\upmu\)s. ICCD exposure time is of 50 ns with 50 accumulations. The dashed contours are the tube’s borders. The time of the images correspond to Fig. 3A. (B) ICCD images at the first positive pulse in the bunch: (a1) at 3.0, (b1) 3.6, (c1) 4.0, (d1) 5.4, (e1) 6.8 and (f1) 10.2 \(\upmu\)s; (a2) at 24.0, (b2) 24.6, (c2) 25.0, (d2) 26.4, (e2) 27.8 and (f2) 28.5 \(\upmu\)s; (a3) at 44.6, (b3) 45.2, (c3) 45.6, (d3) 47.0, (e3) 48.4 and (f3) 52.0 \(\upmu\)s. ICCD exposure time is of 50 ns with 5 accumulations. The dashed contours are the tube’s borders. The time of the images correspond to Fig. 3B.