How does the Crystal Barrel detector (at ELSA) work?

[jyoung95]

Simple explanation for non-physicist, please!

 

[mfb]

Particles (including photons) can hit the material and produce high-energetic electrons. Those travel through the material and can give some of their energy to other electrons. Those electrons then emit that energy as light, the light gets detected, and this indicates that some particle was there.
That is a very short description how scintillators work, for more details it would be interesting what exactly you want to know.