Fig. 3
From: Experimental demonstration of tractor millimeter wave beam propulsion

Plasma formations with different pulse widths at 210 kW. The hollow observation window is placed on the thruster, and the integral images are captured using a digital camera. The millimeter-wave beam is irradiated from the right to the left side. The pulse widths of the incident beam are varied in a range of 0.6–2.5 ms.