Transparent ceramics offer an alternative to single crystals for scintillator applications such as gamma ray
spectroscopy and radiography. We have developed a versatile, scaleable fabrication method, using Flame Spray
Pyrolysis (FSP) to produce feedstock which is readily converted into phase-pure transparent ceramics. We measure
integral light yields in excess of 80,000 Ph/MeV with Cerium-doped Garnets, and excellent optical quality.
Avalanche photodiode readout of Garnets provides resolution near 6%. For radiography applications, Lutetium
Oxide offers a high performance metric and is formable by ceramics processing. Scatter in transparent ceramics due
to secondary phases is the principal limitation to optical quality, and afterglow issues that affect the scintillation
performance are presently being addressed.
The development of faster more reliable techniques to detect radioactive contraband in a portal type scenario
is an extremely important problem especially in this era of constant terrorist threats. Towards this goal the
development of a model-based, Bayesian sequential data processor for the detection problem is discussed. In the
sequential processor each datum (detector energy deposit and pulse arrival time) is used to update the posterior
probability distribution over the space of model parameters. The nature of the sequential processor approach
is that a detection is produced as soon as it is statistically justified by the data rather than waiting for a fixed
counting interval before any analysis is performed. In this paper the Bayesian model-based approach, physics
and signal processing models and decision functions are discussed along with the first results of our research.