High aspect ratio composite structures with 48.5% thermal neutron detection efficiency

2013 ◽  
Vol 102 (6) ◽  
pp. 063505 ◽  
Author(s):  
Q. Shao ◽  
L. F. Voss ◽  
A. M. Conway ◽  
R. J. Nikolic ◽  
M. A. Dar ◽  
...  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Andrew N. Mabe ◽  
John D. Auxier ◽  
Matthew J. Urffer ◽  
Stephen A. Young ◽  
Dayakar Penumadu ◽  
...  

Thin film polystyrene composite scintillators containing LiF6 and organic fluors have been fabricated and tested as thermal neutron detectors. Varying fluorescence emission intensities for different compositions are interpreted in terms of the Beer-Lambert law and indicate that the sensitivity of fluorescent sensors can be improved by incorporating transparent particles with refractive index different than that of the polymer matrix. Compositions and thicknesses were varied to optimize the fluorescence and thermal neutron response and to reduce gamma-ray sensitivity. Neutron detection efficiency and neutron/gamma-ray discrimination are reported herein as functions of composition and thickness. Gamma-ray sensitivity is affected largely by changing thickness and unaffected by the amount of LiF6 in the film. The best neutron/gamma-ray discrimination characteristics are obtained for film thicknesses in the range 25–150 μm.


1997 ◽  
Vol 487 ◽  
Author(s):  
F. Foulon ◽  
P. Bergonzo ◽  
A. Brambilla ◽  
C. Jany ◽  
B. Guizard ◽  
...  

AbstractIn this paper, we present the results of investigations on the use of semiconductors deposited by chemical vapour deposition (CVD) for the fabrication of neutron detectors. For this purpose, 20 μm thick hydrogenated amorphous silicon (a-Si:H) pin diodes and 100 μm thick polycrystalline diamond resistive detectors were fabricated. The detectors were coupled to a neutron-charged particle converter : a layer of either gadolinium or boron (isotope 10 enriched) deposited by evaporation. We have demonstrated the capability of such neutron detectors to operate at neutron fluxes ranging from 101 to 106 neutrons/cm2.s. The fabrication of large area detectors for neutron counting or cartography through the use of multichannel reading circuits is discussed. The advantages of these detectors include the ability to produce large area detectors at low cost, radiation hardness (∼ 4 Mrad for a-Si:H and ∼ 100 Mrad for diamond), and for diamond, operation at temperatures up to 500°C. These properties enable the use of these devices for neutron detection in harsh environments. Thermal neutron detection efficiency up to 22 % and 3 % are expected by coupling a-Si:H diodes and diamond detectors to 3 μm thick gadolinium (isotope 157) and 2 μm thick boron layers, respectively.


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