Using looping algorithms

Hello everyone, 

I am a beginner in Grasshopper and I need to model my magnetic experiment which looks similar to the work of Michael Pryor ( Link: https://vimeo.com/102410498) 

On the video, I guess an attractor point was used in order to get different variations of the shape. 

I would like to kindly ask if anyone could help me generate a similar shape ? (photos attached)

Many thanks