Report: New radiation detectors not much better

The report from the National Research Council echoes concerns raised by Congress and the Government Accountability Office about the government's next generation radiation detectors. It says the new machines are only marginally better than monitors already at U.S. ports for detecting hidden nuclear material — but would cost more than twice as much.

A popular method for the detection of gamma-rays involves the use of crystal scintillators. The general description of a scintillator is a material that emits low-energy (usually in the visible range) photons when struck by a high-energy charged particle. When used as a gamma-ray detector, the scintillator does not directly detect the gamma-rays. Instead, the gamma-rays produce charged particles in the scintillator crystals which interact with the crystal and emit photons. These lower energy photons are subsequently collected by phototransistors....

And

Bridgman CdTe and CdZnTe crystal growth, with cadmium vapor pressure control, is applied to production of semiconductor gamma radiation detectors. Crystals are highly donor doped and highly electrically conducting. Annealing in tellurium vapors transforms them into a highly compensated state of high electrical resistance and high sensitivity to gamma radiation. N-type detectors, equipped with ohmic contacts, and a grounded guard ring around the positive contact, are not sensitive to hole trapping. Conductivity control, by the doping level, optimizes the detector operation by trade-off between electrons’ lifetime and electrical resistance.

IOW - the old school way.

New tech
Polyaniline/poly acid acrylic thin film composites

Cost - lots

Better? Seems not so much.

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