The optimization and γ-ray effects of the neutron imaging plate

The energy dependence of gamma-ray sensitivity of a neutron imaging plate (NIP) has been measured. The gamma-ray sensitivity is equivalent to one half that of a thermal neutron at a gamma-ray energy less than 300 keV, and 1/40 at greater than 300 keV. The shielding of the NIP, by lead, from gamma rays in the experimental hall of the reactor JRR-3M of the Japan Atomic Energy Research Institute (JAERI) was measured. It was found that lead of thickness 40 mm is sufficient to reduce the gamma-ray background to 1/10 on a normalized scale. Covering the NIP with lead foil of thickness 1 mm results in a decrease of the gamma-ray background without reduction of the neutron signal.

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Performance assessment of imaging plates for the JHR transfer Neutron Imaging System

EPJ Web of Conferences ◽

10.1051/epjconf/201817004021 ◽

2018 ◽

Vol 170 ◽

pp. 04021

Author(s):

E. Simon ◽

P. Guimbal

Keyword(s):

Performance Assessment ◽

Dynamic Range ◽

Imaging System ◽

Computed Radiography ◽

High Sensitivity ◽

High Dynamic Range ◽

Neutron Imaging ◽

Imaging Plate ◽

Intimate Contact ◽

Imaging Plates

The underwater Neutron Imaging System to be installed in the Jules Horowitz Reactor (JHR-NIS) is based on a transfer method using a neutron activated beta-emitter like Dysprosium. The information stored in the converter is to be offline transferred on a specific imaging system, still to be defined. Solutions are currently under investigation for the JHR-NIS in order to anticipate the disappearance of radiographic films commonly used in these applications. We report here the performance assessment of Computed Radiography imagers (Imaging Plates) performed at LLB/Orphée (CEA Saclay). Several imaging plate types are studied, in one hand in the configuration involving an intimate contact with an activated dysprosium foil converter: Fuji BAS-TR, Fuji UR-1 and Carestream Flex XL Blue imaging plates, and in the other hand by using a prototypal imaging plate doped with dysprosium and thus not needing any contact with a separate converter foil. The results for these imaging plates are compared with those obtained with gadolinium doped imaging plate used in direct neutron imaging (Fuji BAS-ND). The detection performances of the different imagers are compared regarding resolution and noise. The many advantages of using imaging plates over radiographic films (high sensitivity, linear response, high dynamic range) could palliate its lower intrinsic resolution.

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An imaging-plate detector for small-angle neutron scattering

Journal of Applied Crystallography ◽

10.1107/s0021889800009067 ◽

2000 ◽

Vol 33 (5) ◽

pp. 1253-1261 ◽

Cited By ~ 5

Author(s):

Y. T. Cheng ◽

D. F. R. Mildner ◽

H. H. Chen-Mayer ◽

V. A. Sharov ◽

C. J. Glinka

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Imaging Techniques ◽

Neutron Imaging ◽

Small Samples ◽

Imaging Plate ◽

Position Sensitive ◽

Transfer Method ◽

Imaging Plates

Small-angle neutron scattering (SANS) measurements have been performed on long-flight-path pinhole-collimation SANS instruments using, as a two-dimensional position-sensitive detector, both a neutron imaging plate, incorporating gadolinium, and a two-step transfer method, with dysprosium foil as the image transfer medium. The measurements are compared with corresponding data taken using conventional position-sensitive gas proportional counters on the SANS instruments in order to assess the viability of the imaging techniques. The imaging plates have pixel sizes of about two orders of magnitude smaller than those of the gas proportional counter. The reduced pixel size provides definite advantages over the gas counter in certain specific situations, namely when limited space necessitates a short sample-to-detector distance, when only small samples (comparable in size to the detector pixels) are available, or when used in conjunction with focusing beam optics.

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Performance of a multi-wavelength monochromator system for neutron single-crystal and powder diffraction

Journal of Applied Crystallography ◽

10.1107/s0021889899016829 ◽

2000 ◽

Vol 33 (2) ◽

pp. 291-295 ◽

Cited By ~ 1

Author(s):

F. U. Ahmed ◽

I. Tanaka ◽

N. Niimura

Keyword(s):

Neutron Diffraction ◽

Single Crystal ◽

Collection Efficiency ◽

Neutron Imaging ◽

Imaging Plate ◽

Multiple Reflections ◽

Multi Wavelength ◽

Sample Position ◽

Diffraction Patterns ◽

Point Detector

In order to improve significantly data collection efficiency, the advantages of using multi-wavelengths in single-crystal neutron diffraction as well as in powder neutron diffraction were established by experiments using a stacked monochromator assembly of two elastically bent perfect Si(111) and Si(220) crystals. The TAS-2 spectrometer on JRR-3M at JAERI (Japan Atomic Energy Research Institute) was employed for these experiments. Each crystal was elastically bent in order to increase the flux density at the sample position. Two wavelengths, λ1= 1.80 Å for Si(220) and λ2= 2.94 Å for Si(111), were selected. The alignment of the stacked monochromator was successful and a well defined rocking curve of approximately 0.3° full width at half-maximum (FWHM) was obtained. Diffraction patterns of Si powder were collected using the TAS-2 point detector as well as a neutron imaging plate (NIP) detector to compare the relative performance of the two detector systems. With the NIP detector, it was possible to acquire multiple reflections simultaneously with better intensity, better statistics and higher spatial resolution with an open geometry. The NIP detector was used to obtain the diffraction pattern of a single crystal of the organic compound piperidine cobaloxime. For the systems investigated in this study, it was possible to assign unambiguously rings or spots to diffraction by λ1or by λ2in the case of powder and single-crystal diffraction.

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An upgraded neutron diffractometer (BIX-IM) for macromolecules with a neutron imaging plate

Journal of Physics and Chemistry of Solids ◽

10.1016/s0022-3697(99)00188-2 ◽

1999 ◽

Vol 60 (8-9) ◽

pp. 1623-1626 ◽

Cited By ~ 8

Author(s):

I Tanaka ◽

K Kurihara ◽

Y Haga ◽

Y Minezaki ◽

S Fujiwara ◽

...

Keyword(s):

Neutron Imaging ◽

Imaging Plate ◽

Neutron Diffractometer

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Application of neutron imaging plate and neutron CT methods on nuclear fuels and materials

IEEE Transactions on Nuclear Science ◽

10.1109/tns.2005.844297 ◽

2005 ◽

Vol 52 (1) ◽

pp. 313-316 ◽

Cited By ~ 11

Author(s):

R. Yasuda ◽

M. Matsubayashi ◽

M. Nakata ◽

K. Harada ◽

H. Amano ◽

...

Keyword(s):

Neutron Imaging ◽

Imaging Plate ◽

Nuclear Fuels

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A high-performance neutron diffractometer for biological crystallography (BIX-3)

Journal of Applied Crystallography ◽

10.1107/s0021889801017745 ◽

2002 ◽

Vol 35 (1) ◽

pp. 34-40 ◽

Cited By ~ 62

Author(s):

I. Tanaka ◽

K. Kurihara ◽

T. Chatake ◽

N. Niimura

Keyword(s):

High Performance ◽

Signal To Noise Ratio ◽

Neutron Imaging ◽

Bragg Diffraction ◽

Imaging Plate ◽

Biological Macromolecules ◽

Hydrogen Atoms ◽

Neutron Diffractometer ◽

Technical Innovations ◽

Neutron Protein Crystallography

A high-performance neutron diffractometer for biological crystallography (BIX-3) has been constructed at JRR-3M in the Japan Atomic Energy Research Institute (JAERI) in order to determine the hydrogen-atom positions in biological macromolecules. It uses several recent technical innovations, such as a neutron imaging plate and an elastically bent silicon monochromator developed by the authors. These have made it possible to realise a compact vertical arrangement of the diffractometer. Diffraction data have been collected from the proteins rubredoxin and myoglobin in about one month, to a resolution of 1.5 Å. The data were good enough to identify the hydrogen atoms with high accuracy. By adopting a crystal-step scan method for measuring Bragg diffraction intensities, the signal-to-noise ratio was much better than that of the Laue method. This shows that BIX-3 is one of the best-performing machines for neutron protein crystallography in the world today.

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