Building the Scintillators

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A complete detection system requires not only a drift chamber (the tubes and all the hardware supporting them) but also a trigger. The trigger gives a very fast signal that simply announces the passage of a particle. This is needed so we know when to read out data from the chamber. The triggering is done with a scintillator, a sheet of special plastic that gives off light when a charge particle passes through. The light is channeled to a photodetector that senses very small numbers of photons. The whole system through which the light passes needs to be very clear plastic with every edge polished completely. Later the whole thing is covered in reflective foil and then a light tight covering.