Deactivating a ParticleSystem

Hi,

This is probably going to be a stupid question, but I need to stop a particle system emitter creating new particles (but let the already generated particles stay for their natural lifetime).

I’ve checked the forum, and all the posts say to call “Deactivate” on the particle system, But the node doesn’t list anywhere (either pulling off from particle system reference node, or simply right clicking on the blueprint, even with context sensitive switched off. The only deactivate node that is listed is “Deactivate Reverb Effect”. Any ideas, is this call deprecated?

Thanks…