Urmila Shirwadkar

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In recent years, a number of materials from the elpasolite crystal family have been under development for either or both gamma ray and neutron detection. The scintillators show good energy resolution and thermal neutron detection efficiency. The latter is achieved due to the fact, that the selected compositions contain Li-6 ions. In order to effectively and(More)
Homeland security applications often require detection of both neutron and gamma radiation. A combination of two detectors registering neutrons and gammas separately is typically used. Recently, a number of scintillators from the elpasolite crystal family were proposed, that provide detection of both types of radiation. The most promising are(More)
Up to 1-in-diameter, Eu-doped CsBa<sub>2</sub>I<sub>5</sub> and BaBrI crystals have been grown using the vertical Bridgman method. Scintillation properties of the crystals up to ~ 1 &#x00D7; 1 &#x00D7; 1 cm<sup>3</sup> have been studied under gamma-ray irradiation. Systematic concentration studies have been performed for both these alkaline earth halides(More)
In this paper we report on fast-neutron detection and pulse shape discrimination with 9,10-diphenylanthracene and 1,1,4,4-tetraphenylbutadiene. Our research indicates that these organic scintillators have high light yields of up to 20,000 ph/MeV, a fast scintillation decay of about 20 ns, very good fast-neutron detection, and excellent neutron/gamma pulse(More)
A new scintillation material CS<sub>2</sub>LiLaBr<sub>6-x</sub>CI<sub>x</sub>:Ce (CLLBC:Ce) belonging to the elpasolite crystal family has been discovered and investigated at RMD. A Cs<sub>2</sub>LiLaBr<sub>4.8</sub>Cl<sub>1.2</sub>: 2% Ce crystal was grown using the melt-based, vertical Bridgman method. The first grown crystal of CLLBC:Ce is 1.5 cm in(More)
Neutron detectors are used in homeland security to improve the identification of special nuclear materials (SNM). The detection of any neutrons above the natural background is a strong indication of SNM presence. Currently, there is a significant dependence on He-3 tubes for neutron detection. These devices are simple and effective detectors; however they(More)
This paper describes detectors comprised of Cs<sub>2</sub>LiYCl<sub>6</sub>:Ce (CLYC) scintillators coupled to silicon photomultipliers (MPPC, Hamamatsu). CLYC has been developed for dual gamma ray and thermal neutron detection. MPPCs are compact detectors with a very thin profile (~2 mm), but also a small active area (6 mm &#x00D7; 6 mm). The combination(More)
A promising composition, Ce doped Cs<inf>2</inf>LiYBr<inf>6</inf> (CLYB) originally introduced by van Loef et al. has been investigated recently as a gamma-ray and neutron detector. It belongs to the elpasolite family and has a cubic structure. A single crystal of this material has been grown using the vertical Bridgman method. Scintillation properties such(More)