Atomic and nuclear physics - Frederiksen

124Atomic and nuclear physicsGamma spectroscopyA host of new experiments opens up when you are able to measure the energy of gamma quanta instead of just counting them.Unfortunately, the equipment needed for gamma spectroscopy has traditionally been too expensive for many high schools. Theproducts presented on these pages reduce the costs to a manageable amount.A gamma spectrometer consists of two parts: An energy sensitive detector and equipment to process the output from thedetector – typically feeding data to a computer.A widespread detector type is the scintillation detector.An incoming gamma quantum deposits its energy in a so-called scintillation crystal, causing it to emit a tiny gleam of visible light.The light is detected by a sensitive photo cell (a photomultiplier), giving rise to an electric pulse. The electric output is proportionalto the energy deposited inside the crystal.A multichannel analyzer (MCA) sorts the incoming pulses from an energy sensitive detector into a large number of channelsaccording to their sizes. When the channel counts are plotted versus the channel number, the result is an energy spectrum.Multichannel AnalyzerThe Frederiksen MCA features 1024 channels, variable analogand digital gain, a variable integration time and built-in logic toreject “pile up” (a pulse starting on top of the previous one).This hardware based MCA handles count rates exceeding 10MHz, meaning that the MCA will hardly ever be a bottle-neck!The Frederiksen MCA and the accompanying softwareare especially suited for the 5185.00 scintillation detectormentioned below, but an auxiliary input can be used withthe anode signal from a traditional photomultiplier tube. Thisenables you in many cases to reuse a scintillation detector fromolder equipment with obsolete MCA hardware (or software).Software included (MS Windows only).5180.00 Multichannel Analyzer5180.00®science