Over the last three decades Ren-Yuan Zhu and his colleagues have been involved in the successful development
of scintillating crystals for precision crystal electromagnetic calorimeters in high energy physics,
such as the L3 BGO, BaBar CsI(Tl) and CMS PWO. Several Advanced Detector Research awards and Collider
Detector Research and Development awards were received from the DOE Science Office for the development of PWO,
LSO/LYSO and other cost-effective crystals for future HEP experiments at the energy and intensity frontiers.
In 2009, Ren-Yuan Zhu established a program for crystal development in the Caltech HEP program. The main goal of
this program is to develop inorganic scintillator-based novel detector concepts for future HEP experiments,
such as an LSO/LYSO crystal-based total absorption and sampling calorimeter concept, a barium fluoride crystal-based very
fast crystal calorimeter concept, and a cost-effective inorganic scintillator-based homogeneous hadronic calorimeter
concept. Recent emphasis of this program is devoted to the development of yttrium doped barium fluoride crystals featured
with a sub-ns FWHM pulse width, a factor of thirty suppression for its slow scintillation component with 600 ns decay time
and excellent radiation hardness, as well as LuAG ceramics with excellent radiation hardness. This work is
supported by the U.S. Department of Energy, Office of High Energy Physics program under Award Number DE-SC0011925.