Detector Design

Detector Subteam

To accomplish the science goals of EXACT and SOCRATES, high energy photons from the sun and other cosmic sources need to be converted into usable signals. The detector subteam accomplishes this task through the design and assembly of a scintillation detector. Scintillation detectors take advantage of large crystals, cesium iodide doped with thallium in our case, which absorb the high energy photons of interest and scintillate. The process of scintillation involves an atom of the crystal absorbing a high energy photon, bringing it to an excited state. Photons corresponding to the excitation band gap of the atom are then emitted upon deexcitation. Now there are a larger number of lower energy photons which can be absorbed by a photosensitive device, a silicon photomultiplier in our case. The silicon photomultiplier converts the scintillated photons into a current pulse which is then processed by stages of electronics, yielding a signal corresponding to the initial energy of the high energy photon. The detector subsystem interfaces with the FPGA subsystem which processes the data generated.