An important element in the development of advanced neutron detectors is the synthesis and characterization of improved, highly efficient neutron-scintillating materials. The research described here concerns the development of elastic, transparent, and thick film neutron scintillators with high Li+6 loading through room-temperature sol-gel processing. The room-temperature sol-gel processing allows an easy integration of such scintillating materials into electronic detecting devices. The lithium-6 salicylate di-ureasil xerogels developed here show promise for the fabrication of large area neutron detectors and have high potential for use in in situ monitoring and imaging of fissile materials and radioactive contaminants.

A micromechanical sensor for charged-particle flux detection utilizing the extreme force sensitivity of microcantilevers is demonstrated with alpha particles. The latter create a charge buildup on an electrically isolated collection plate, a metallic sphere. The cantilever detector measures the electric field emanating from the charge collection sphere using variations in mechanical parameters. Results are compared with responses due to fixed voltages on the sphere. Parameters investigated include cantilever deflection due to total charge and frequency and damping rate variation due to electrostatic force gradient. The minimum detectable particle fluence using this technique was calculated to be around 1000 particles in air, or about 3.2×10−4 pC.

The Micromegas is a type of ionising radiation detector that consists of a gas chamber sandwiched between two parallel plate electrodes, with the gas chamber divided by a Frisch grid into drift and amplification gaps. Investigators have applied it to a number of different applications, such as charged particle, X-ray and neutron detection. A Micromegas device has been tested as a neutron beam monitor at CERN and is expected to be used for that purpose at the Spallation Neutron Source (SNS) under construction in Oak Ridge, TN. For the Micromegas to function effectively as neutron beam monitor, it should cause minimal disruption to the neutron beam in question. Specifically, it should scatter as few neutrons as possible and avoid neutron absorption when it does not contribute to generating useful information concerning the neutron beam. Here, we present the results of Monte Carlo calculations of the effect of different types of wall materials and detector gases on neutron beams and suggest methods for minimising disruption to the beam.

A new transparent neutron‐scintillating material has been developed based on polystyrene‐block‐poly(ethylene oxide). The unique self‐assembly structure of the block copolymer makes it possible to dope hydrophilic Li+ in the ethylene‐oxide domain and hydrophobic organic fluors in the styrene domain (see Figure).