Comunicazione

# The Active Photon Converter of the STORM Collaboration.

##### Bomben L., Bandiera L., Carsi S., Lezzani G., Mangiacavalli S., Mascagna V., Prest M., Romagnoni M., Ronchetti F., Soldani M., Vallazza E.
Venerdì 16/09   15:30 - 19:00   Aula B - Maria Goeppert-Mayer   I - Fisica nucleare e subnucleare
The unique properties of oriented crystals can be exploited in order to ---among other things--- enhance the radiation produced by a high-energy electron/positron or photon crossing the crystal lattice, effectively decreasing the radiation length of the material. The STORM Collaboration intends to study this effect in different crystals, using 5-120 GeV/c electron beams. In this contribution we shall present the simulation, development and commissioning of the Active Photon Converter (APC), a detector developed by the INSULAB group and employed in the STORM beamtests. The APC will allow to estimate the average number of photons produced by a particle crossing an oriented crystal. It consists of two plastic scintillator tiles (the first acting as a veto for charged particles), readout by photomultiplier tubes and a thin ($0.2 X_{0}$) copper radiator positioned between the tiles.