Glass Bead Calorimeter and Fiber Optic Readout

Large volume calorimeters are traditionally based on construction from high-density material or a “sandwich” construction of alternating layers of active and passive material. Dense scintillating material, made from materials such as BGO or lead-glass, is too costly to be used on a very large scale. In sandwich technology, energy resolution is often reduced due to a large fraction of the signal occurring in the passive material. A glass bead calorimeter could improve the resolution of the sandwich design by intermixing the active liquid scintillator and passive glass beads while maintaining a low cost. Signal gathered in the glass bead scintillator can then be read out directly by a photomultiplier tube or through wavelength shifting fibers. The signal loss from the indirect measurement via different configurations of fibers is also examined in this study. Tests at Northwestern University have confirmed the desired attributes of the glass bead calorimeter, and a prototype is currently under construction for future studies in a Test Beam at Fermilab National Accelerator. Similarly, additional tests of the fiber readout are being conducted to be utilized in the future prototype.