High efficiency plastic scintillator detector with wavelength-shifting fiber readout for the GLAST Large Area Telescope

This paper describes the design and performance studies of the scintillator tile detectors for the anti-coincidence detector (ACD) of the Large Area Telescope (LAT) on the Gamma ray Large Area Space Telescope (GLAST), scheduled for launch in early 2008. The scintillator tile detectors utilize wavelength-shifting fibers and have dual-photomultiplier-tube readout. The design requires highly efficient and uniform detection of singly charged relativistic particles over the tile area and must meet all requirements for a launch, as well as operation in a space environment. We present here the design of three basic types of tiles used in the ACD, ranging in size from similar to 450 to similar to 2500 cm(2), all similar to 1cm thick, with different shapes, and with photoelectron yield of similar to 20 photoelectrons per minimum ionizing particle at normal tile incidence, uniform over the tile area. Some tiles require flexible clear fiber cables up to 1.5m long to deliver scintillator light to remotely located photomultiplier tubes. (c) 2007 Elsevier B.V. All rights reserved.