No decay. Most of the time I use a tremolator (i.e. a LFO-driven “VCA”, for us old-timers) with a square shape and smoothen the edges a bit:
… that’s from the aforementioned Melda Productions Free FX Bundle (which I own in its payed version, though). If you have already installed it, just import the following track-archive of mine to get hold of “my” bursts:
Nuendo12MeldaBursts_byDietz.xml (131.7 KB)
Save it as aFX Chaín preset to keep it available quickly.
I’ve also had situations where I simply bounced 1 minute of stochastic pink noise, chopped the file into as many 200ms chunks as possible (Alt-scissor tool!), applied 1 ms fades to all ends and spread those bits across an audio channel.
HTH,