Perling lightning demo- stop end light movement

Hello, I'm trying to create a similar plasma ball thing as the poster of this question: http://answers.unity3d.com/questions/222048/plasma-ball-effect.html.

I've tried the demo provided in the post, but I got one thing I can't solve. Is it possible to make the ends of the particle streams to stop moving at the target position?

An other option would be to put the particle emitter inside a transparent sphere and have the end of stream move along the surface of that sphere, but I feel like the first option would be easier. Also just so that you know, I know only some basic c# scripting, so please bare with me.

Here's a link to the demo project. Basically I've just played with the particles and replaced the target with an empty, so all the code is same as in the example. link to demo zip