Neutron scintillator materials

One of the most interesting applications of the HSAB concept consists in the prediction of the stability of the complexes formed owing to interaction of alkali metal halides with rare-earth metal halides. These systems are of great interest for the materials science of scintillation materials the said complex halides are now considered among the most promising scintillation detectors and sensors. Besides, the Li- and Gd-based materials are especially convenient as effective detectors of thermal neutrons. The compositions and stability of the formed compounds depend considerably on the kind of acids and bases from which the compound is formed. So, Li+ cation is one of the hardest cation acids, and, therefore, the formation of stable complex halides of Li and lanthanides according to reaction ... 

During the past two decades, there have been extensive investigations on the use of inorganic nanocrystals in scintillation detectors. Brown and coworkers present a survey of representative organic nanoparticles and inorganic nanocrystals embedded in various matrices, along with their performances in beta, alpha, or neutron detection. This study leads towards the ability to identify the most suitable nanoparticle-based scintillation materials for specific radiation detection purposes, and to a better understanding of how certain nanoparticle-based scintillators behave under radiation interactions. 

Commercially available, highly efficient liquid and solid scintillators were tested as standards for comparison with our samples. Ultima Gold (PerkinElmer) is a standard liquid scintillation counting cocktail, containing PPO (ca. 1 wt %) in a mixture of aromatic compounds, and phosphate and succinate surfactants. BC-400 (Bicron) is a plastic scintillator composed of organic fluors, PPO and POPOP, at <3 wt % in PVT. KG2 (Bicron) is a cerium-activated lithium silicate glass scintillator, containing 7.5 wt % of Li (95% i) as a neutron absorber, and Ce as a scintillation material. 

In order to match the light emission of scintillation materials with the spectral sensitivity of PMT, nanoparticles and inorganic nanocrystals with the emission in the range of 350-450 nm were synthesized, characterized, and applied to radiation detection. Results from the detection of beta particles, alpha particles, and neutron radiation are presented here. 

Electronic counters are devices in which absorption of an x-ray photon or a neutron generates a short electric pulse in the associated electronic circuitry. By counting the rate of generation of such pulses, the flux of the x-ray or neutron beam to which the device is exposed can be measured. These counters are the outgrowth of the initial efforts made by nuclear physicists for detection of radioactivities of materials. Most useful among them for x-ray and neutron scattering studies are the proportional and scintillation counters described in Section 2.4.1. Further elaboration on these counters led to the development of position-sensitive detectors, explained in Section 2.4.2. Very recently, a number of novel devices based on new technologies have become available, and these are briefly introduced in Section 2.4.4. 

The Bonner sphere, named after one of the first people to study its features and use it, is a neutron detector. It consists of a polyethylene sphere, at the center of which a neutron detector is placed (Lil scintillator or BF3 or He counter). With any one of these materials, the neutrons are detected through the reactions... 

Bern, H., Holzbecher, J. and Ryan, D.E. (1983). Determination of nickel in biological materials and sea water by neutron activation and liquid scintillation counting of nickel-65. Anal. Chim. Acta 152, 247-255. 

Not very advanced compared with PRDs, hand-held survey meters can be used to detect the location of the radioactive material. These meters could be engineered to possess interchangeable probes consisting of scintillation detectors and phototubes, and large-volume ionization chambers or neutron detectors. ... 

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