freezing a particle system ??

I have a lightsaber with the blade made up of two particle systems and two lattices.
I also added a node composition to the blade’s render layer.

I want to animate it but the blade(the particle system) is soft and won’t stay straight.

The question is: how can I freeze the particle systems in the instance they are in the picture so I can animate the whole thing and make it look like a real lightblade?