Trying to fade out remaining particles after deactivation of particle system.

Very much a beginner here, please forgive my limited understanding of these systems.

I have a large nebula-like cloud of particles in a spaceship-based game I’m working on in an intro class. When the player flies into this cloud they can “gather” a resource from it, which deactivates the particle system upon completion. Because the largest “cloud” particles are very long-lived (2 minutes), a cloud that has already been harvested can mislead a player into flying over to it to attempt to harvest it again (there are other shorter-lived particles in the system, but they aren’t as obvious from a distance.)

I am struggling to figure out how to fade out these existing particles much faster (5-10 seconds max) after disabling the system. I suspect a vector parameter multiplied on the existing alpha channel should be useful here, but I’m stumped on how to set it up in the blueprint.

Any help would be much appreciated.

Thank you.