How fast are the pulses?
Years ago, before digital scopes, I looked at fast single-shot pulses on an analog scope by forming black construction paper into a tube and taping over the CRT to block ambient light. Then you turn up the CRT brightness, as BrownOut suggested, place you face over the tube to block as much light as possible, and observe the pulse. The CRT phosphor generally has enough persistence to show a faint outline of the pulse for several seconds after it passes.