continuous particle tracking

desperate

hi,

I have 2 questions:

1-I'm running a model in fluent with particle tracking. I want to inject a particle and track it for 5 seconds, but I also want to be able to see the trajectory of this particle for the whole 5 seconds and not only at the end. The method i'm using now is that I keep injecting particles for the whole 5 seconds.but after a while my computer starts running slow because i'll end up tracking hundreds of thousands of particles. Is there any other method?

2-Let's say I inject particles for a surface that I select using rosin-rammler distribution (my surface is just a square of 1600 nodes).Even if I precise the number of diameters to be 10 on that surface, when I get the step-by-step particle tracking, I get around 4900 particles for each time step. any idea why? Can somebody please tell me how to inject only 10 particles from that surface?

thank you very much!