Slow particles down after collision

[scott-king]

Can anyone tell me how to gradually slow particles down to a stop with each collision?  I'm using the following expression to give random rotation, mass and scale to my instanced particles.  But when the particles collide with the ground after a couple of times they come to an abrupt stop.  My resilience and friction for the collision plane and particles is set to .400 and .010 respectively.

creation:

lg_particlesShape.index = rand(0,4);

float $s = rand(.2,.75);

lg_particlesShape.instScale = $s;
lg_particlesShape.mass = $s*6;

lg_particlesShape.instRotation = <>;
lg_particlesShape.instRand = rand(-1,1);

runtime before dynamics

if(lg_particlesShape.event < 5){
    lg_particlesShape.instRotation += (<>) * lg_particlesShape.instRand;
}else{
    lg_particlesShape.velocity = <>;
    lg_particlesShape.instRotation += <>;
    lg_particlesShape.gravityField1_magnitude = 0;
    lg_particlesShape.volumeAxisField2_magnitude = 0;
}

Thanks for any help!