Thermal Neutron Imaging Using A New Pad-Based Position Sensitive Neutron Detector

Thermal Neutron Imaging Using A New Pad-Based Position Sensitive Neutron Detector PDF Author:
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Languages : en
Pages :

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Thermal neutrons (with mean energy of 25 meV) have a scattering mean free path of about 20 m in air. Therefore it is feasible to find localized thermal neutron sources up to ~30 m standoff distance using thermal neutron imaging. Coded aperture thermal neutron imaging was developed in our laboratory in the nineties, using He-3 filled wire chambers. Recently a new generation of coded-aperture neutron imagers has been developed. In the new design the ionization chamber has anode and cathode planes, where the anode is composed of an array of individual pads. The charge is collected on each of the individual 5x5 mm2 anode pads, (48x48 in total, corresponding to 24x24 cm2 sensitive area) and read out by application specific integrated circuits (ASICs). The high sensitivity of the ASICs allows unity gain operation mode. The new design has several advantages for field deployable imaging applications, compared to the previous generation of wire-grid based neutron detectors. Among these are the rugged design, lighter weight and use of non-flammable stopping gas. For standoff localization of thermalized neutron sources a low resolution (11x11 pixel) coded aperture mask has been fabricated. Using the new larger area detector and the coarse resolution mask we performed several standoff experiments using moderated californium and plutonium sources at Idaho National Laboratory. In this paper we will report on the development and performance of the new pad-based neutron camera, and present long range coded-aperture images of various thermalized neutron sources.

Thermal Neutron Imaging Using A New Pad-Based Position Sensitive Neutron Detector

Thermal Neutron Imaging Using A New Pad-Based Position Sensitive Neutron Detector PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Thermal neutrons (with mean energy of 25 meV) have a scattering mean free path of about 20 m in air. Therefore it is feasible to find localized thermal neutron sources up to ~30 m standoff distance using thermal neutron imaging. Coded aperture thermal neutron imaging was developed in our laboratory in the nineties, using He-3 filled wire chambers. Recently a new generation of coded-aperture neutron imagers has been developed. In the new design the ionization chamber has anode and cathode planes, where the anode is composed of an array of individual pads. The charge is collected on each of the individual 5x5 mm2 anode pads, (48x48 in total, corresponding to 24x24 cm2 sensitive area) and read out by application specific integrated circuits (ASICs). The high sensitivity of the ASICs allows unity gain operation mode. The new design has several advantages for field deployable imaging applications, compared to the previous generation of wire-grid based neutron detectors. Among these are the rugged design, lighter weight and use of non-flammable stopping gas. For standoff localization of thermalized neutron sources a low resolution (11x11 pixel) coded aperture mask has been fabricated. Using the new larger area detector and the coarse resolution mask we performed several standoff experiments using moderated californium and plutonium sources at Idaho National Laboratory. In this paper we will report on the development and performance of the new pad-based neutron camera, and present long range coded-aperture images of various thermalized neutron sources.

A New Pad-Based Neutron Detector for Stereo Coded Aperture Thermal Neutron Imaging

A New Pad-Based Neutron Detector for Stereo Coded Aperture Thermal Neutron Imaging PDF Author:
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Category :
Languages : en
Pages :

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Response of a New Pad-based Neutron Detector Developed for Coded Aperture Thermal Neutron Imaging

Response of a New Pad-based Neutron Detector Developed for Coded Aperture Thermal Neutron Imaging PDF Author:
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Category :
Languages : en
Pages :

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Position-sensitive Detection of Thermal Neutrons

Position-sensitive Detection of Thermal Neutrons PDF Author: Pierre Convert
Publisher:
ISBN:
Category : Neutron counters
Languages : en
Pages : 460

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Neutron Detectors for Scattering Applications

Neutron Detectors for Scattering Applications PDF Author: Yacouba Diawara
Publisher: Springer Nature
ISBN: 3031365461
Category : Science
Languages : en
Pages : 257

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Book Description
This book covers the most common neutron detectors used in neutron scattering facilities and all of those in use at Oak Ridge National Lab. It starts describing the facilities, instruments and the critical detector parameters needed by various instruments. Then the key components of the 3He-based linear position-sensitive detectors as well as on their electronics, which require particular attention to signal processing and noise reduction, are introduced. One chapter is dedicated to the 3He alternatives where scintillators play a critical role. It also covers emerging neutron detection technologies including semiconductors, vacuum-based devices and their associated readouts, which will be required in the future for high rate and high-resolution neutron detectors. The authors explain the logic behind the choice of materials as well as the various constraints that neutron detectors must respect to be useful. Some of these constraints, such as efficiency and gamma-ray sensitivity are common to all neutron counters while others, like timing resolution, dynamic range, and peak counting rate, depend on the applications. The book guides experts, the nuclear science community, and young scholars through the physical processes and the required electronics in a way that is accessible for those not professionally involved in designing detector’s components and electronic circuits.

A New Position-sensitive Detector for Thermal and Epithermal Neutrons

A New Position-sensitive Detector for Thermal and Epithermal Neutrons PDF Author: Alan Paul Jeavons
Publisher:
ISBN:
Category : Neutron counters
Languages : en
Pages : 24

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Phase I - Final Report

Phase I - Final Report PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 25

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Book Description
A position sensitive neutron detector was designed and fabricated with bundles of individual detector elements with diameters of 120 mm. These neutron scintillating fibers were coupled with optoelectronic arrays to produce a ''Fiber Detector.'' A fiber position sensitive detector was completed and tested with scattered and thermal neutrons. Deployment of improved 2D PSDs with high signal to noise ratios at lower costs per area was the overall objective of the project.

רבי ועלוול

רבי ועלוול PDF Author:
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Category :
Languages : en
Pages :

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Characterisation of a Position Sensitive Thermal Neutron Detector

Characterisation of a Position Sensitive Thermal Neutron Detector PDF Author: Laura Boyd
Publisher:
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Category :
Languages : en
Pages :

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Thermal Neutron Detectors with Discrete Anode Pad Readout

Thermal Neutron Detectors with Discrete Anode Pad Readout PDF Author:
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Category :
Languages : en
Pages :

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A new two-dimensional thermal neutron detector concept that is capable of very high rates is being developed. It is based on neutron conversion in 3He in an ionization chamber (unity gas gain) that uses only a cathode and anode plane; there is no additional electrode such as a Frisch grid. The cathode is simply the entrance window, and the anode plane is composed of discrete pads, each with their own readout electronics implemented via application specific integrated circuits. The aim is to provide a new generation of detectors with key characteristics that are superior to existing techniques, such as higher count rate capability, better stability, lower sensitivity to background radiation, and more flexible geometries. Such capabilities will improve the performance of neutron scattering instruments at major neutron user facilities. In this paper, we report on progress with the development of a prototype device that has 48 x 48 anode pads and a sensitive area of 24cm x 24cm.