First image from lead ions' collisions

First collisions of lead ions seen by the ALICE experiment on 07.11.2010 recorded by its innermost detector, the Inner Tracking System.
The shaded structures represent a perspective view of the detector elements. The lines are the reconstructed particle trajectories and the colour scale indicates the energy of the particles.

Such collisions produce an unprecedented number of particles, reaching thousands per collision.

Credits: ALICE experiment, CERN

More images: http://aliceinfo.cern.ch/Public/en/Chapter1/fhied.html