The best way of doing this is to use "Streaming" mode to capture a large number of samples on screen and then "Zoom" in to view the details.
You do not say how long you wish to record or at what sample rate but a a start try:-
First set up the "Requested number of samples":- 100MS
Collection Time:- 1 s/div
This will give you a 10 second capture at about 10 MS/sec.
You can also have a longer capture:-
Collection Time:- 10 s/div
This will give you a 100 second capture at about 1 MS/sec.
Collection Time:- 100 s/div
This will give you a 16 mins 40 second capture at about 100 kS/sec.
Use the "Zoom" functions to view the individual pulses in detail, there will be a lot of them!