having a particle fade out

[Kman]

i've been working on making a new particle for a certain effect in my mod but for it to really work effectively it has to gradually fade out as you get closer to it. i've gotten pretty much everything else that needs to be done for it set up except for this which has been causing me a ton of problems, im aware that in the level editor you can edit the min start/mind end values for a particle, but it seems no matter how i use those numbers it always cuts out very abruptly as i approach the min end distance, basically making the min start value useless.

my only guess is that this is some property that you have to set for the particle in the particleeditor to determine how it fades, but i can't find anything within it that seems to indicate that function. can anyone help me out here???