High-Density Glass with Tuned Scintillation/Cherenkov Response to Improve Hadron Energy Resolution in Nuclear Physics Experiments

Achieving high-quality science at nuclear physics facilities requires the measurement of particle energy with excellent calorimeter energy resolution. Particles that produce electromagnetic showers can be detected with high precision. However, there is a need to improve the energy resolution of hadron calorimetry. One of the most promising methods to achieve better performance for hadronic calorimeters is dual readout, which consists of the simultaneous measurement of signals produced by Scintillation light (S) and Cherenkov light (C) in the same detector. This method is particularly effective in homogenous crystal or glass calorimeters. Studies of crystals outfitted with optical filters to extract sufficiently pure Cherenkov signals have shown that the use of optical filters results in unacceptable losses of Cherenkov photons and the crystal absorption characteristics result in strong attenuation of the Cherenkov signals. Crystals are also prone to radiation damage, time consuming to manufacture, and relatively expensive. In comparison, radiation-hard glasses can be tuned for favorable C/S signal ratio, eliminating the need for optical filters, and thus offer great potential for both precision hadron calorimetry and significant cost reductions if competitive performance parameters can be achieved. Early tests with transparent barium-silicate glass have shown good quality and radiation hardness. Development and testing of such glasses with high optical quality and uniformity is key for inexpensive hadron calorimetry and high energy particle detection studies worldwide. Major development objectives for glass in hadron calorimeters include: UV transparency, clear discrimination of Cherenkov and Scintillation light, and low cost, less than $2/cm3. Phase I of this work will develop and demonstrate novel C/S glasses meeting these objectives and demonstrate the production technology through fabrication of larger scale samples and characterization of their performance. The work will also address optimization of aspects of the technology that affect performance characteristics to support larger scale production in subsequent phases of the project. The ability to manufacture novel high-density C/S glass will prove useful not only for hadronic calorimeters but also for homeland security applications where such scintillators would significantly reduce the false alarm rate in passive nuclear detection systems and allow for a large range of deployment. Fast response time and radiation hard glasses will find use in the scintillator market for security applications as active material for radiation portal monitors, in particular, at ports where cargo screening with large throughput is required.