STAR Beam-Beam Counter (BBC) Small Hexagonal Scintillators

The BBC scintillators were cut from 1-cm thick Kuraray SCSN-81 by Fred Pompei.  Regular hexagonal tiles were defined by cutting 2-mm wide and 5-mm deep optical isolation grooves in a Mercedes pattern from both sides of the scintillator, and then back filling these grooves with MgO2 -loaded epoxy.  Since grooves were cut on both sides, the optical isolation was complete.  After machining, the sides of the hexagons were covered with white reflecting paint to trap scintillation light within each tile.  Each scintillator surface was then covered with 1-mil thick aluminized mylar, taped to the painted scintillator edges.  The reflectors were then covered by 10-mil thick black construction paper and black electrician's tape, to make the assembly light tight.

Other features of interest are:


Last Update: 6 April 2002