Beam Characterization at the Neutron Radiography Reactor PDF Download

Author: Sarah Morgan
Publisher:
ISBN:
Category : Beam dynamics
Languages : en
Pages : 86

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Category :
Languages : en
Pages :

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Book Description
The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model's energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

Author:
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ISBN:
Category :
Languages : en
Pages : 12

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The Neutron Radiography Reactor (NRAD) is a 250-kW TRIGA Reactor operated by Argonne National Laboratory and is located near Idaho Falls, Idaho. The reactor and its facilities regarding radiography are detailed in another paper at this conference; this paper summarizes neutron flux measurements and calculations that have been performed to better understand and potentially improve the neutronics characteristics of the reactor.

Author:
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Category :
Languages : en
Pages : 10

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An ongoing project to characterize the neutron beams at the Neutron Radiography Reactor (NRAD) is described in this paper. The effort has consisted of computer modelling with three dimensional diffusion theory to obtain a trail spectrum, foil activation measurements, and the use of SAND-II unfolding code. It was expected and found that diffusion theory will underpredict the fast flux. However, it is claimed that precise characterization of the entire spectrum is not necessary for comparisons among neutron radiography facilities; rather, the use of simple fast neutron indicators should be adequate. A specific example used at NRAD is the U-235/U-238 fission reaction rate ratio. A ratio such as this could be used in the same manner as the classic gold cadmium ratio for interfacility comparisons with regard to fast neutrons. 5 refs.

Author:
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ISBN:
Category :
Languages : en
Pages : 10

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Author: Garbe,U.
Publisher: Materials Research Forum LLC
ISBN: 1644900564
Category : Technology & Engineering
Languages : en
Pages : 316

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Book Description
Neutron radiography represents a powerful non-destructive testing technique that is still very much in development. The book reveals the amazing diversity of scientific and industrial applications of this technique, the advancements of the state-of-art neutron facilities, the latest method developments, and the expected future of neutron imaging.

Author: A.A. Harms
Publisher: Springer Science & Business Media
ISBN: 9401569371
Category : Science
Languages : en
Pages : 192

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Book Description
Neutron radiography has in recent years emerged as a useful and complementary technology for radiation diagnosis. It is now routinely used in industrial quality assurance and in support of selected research and developmental activities. Conferences are held on the subject, pertinent handbooks exist, and technical papers appear regularly reporting on new developments. While neutron radiography has indeed passed through the transition from a scientific curiosity to technological relevance, it is a sign of its continuing dynamic evolution that little material has appeared which provides an integrated mathematical and physical analysis of the subject possessing both an instructional as well as reference function. It is our hope that this monograph will fill this need. The distinctiveness of neutron radiography rests on the unique interactions between neutrons and nuclei. This leads to some special relationships between the material and geometrical properties of an object and the neutron radiographic image. The evolution of a technical discipline demands that specific conceptual constructs be developed and their mathematical representations examined and compared with controlled experiments. Experience has convinced us that a particular and substantial body of knowledge has accumulated endowing neutron radiography with the essential foundations of a unique mathematical and physical science. Our scientific and professional involvement in neutron radiography began some 15 years ago when the senior author (A.A.H.) found himself with convenient access to the McMaster University Nuclear Reactor and research support from the Government of Canada.

Author: Alibek Kenges
Publisher:
ISBN:
Category : Imaging systems
Languages : en
Pages : 0

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Book Description
Neutron imaging is a powerful tool in the field of non-destructive testing that utilizes unique attenuation properties of neutrons allowing through-images of some high-density objects. The Radiation Science and Engineering Center (RSEC) has had a neutron imaging facility for the last several decades. With the installation of a new core moderator assembly and new beam ports at the RSEC -- the Penn State Breazeale Reactor (PSBR) in 2018, a dedicated neutron beam port became available for a new neutron imaging facility at RSEC (RSEC -- NIF). The initial design of the beam port designated for the RSEC -- NIF was of divergent type that needed to be upgraded by means of collimator components and filters. After a thorough investigation of existing neutron imaging facilities around the world, it has been decided to collimate the beam port with convergent and divergent collimators and to filter the gamma and neutron content with the single crystal bismuth and sapphire filters. A set of system characterization experiments were conducted at the RSEC -- NIF that confirmed the system's correspondence to a Category I facility by ASTM standards. In addition to that, the collimation ratio of the new system was measured following the procedures given in the ASTM protocols and resulted in the effective L/D ratio value between 107 and 115. The thermal flux across the exit surface from the beam port at the biological shield was measured to be equal to 5.4E+06 n/cm^2-s at 1MWth reactor power. The application of the RSEC -- NIF's capabilities in neutron radiography (NR) and tomography (NT) techniques were demonstrated imaging different types of environmental samples for the presence and visualization of microplastic particles. Preliminary results of NT experiments conducted at the RSEC -- NIF have shown that this technique can be used as an intermediary step to visualize the content and spatial distribution of microplastics in the sand columns. Additionally, the NR capabilities of the RSEC -- NIF were utilized to visualize the microplastic particles in the sediment samples and used water filters. All obtained results and the continuation of research in this direction can potentially shed some light in the general research of microplastic transport mechanisms in different terrestrial and aquatic ecosystems.

Author: Shigenori Fujine
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 1046

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Book Description
Proceedings of the Third World Conference held in Osaka, Japan, May 14-18, 1989

Author: John P. Barton
Publisher: Springer Science & Business Media
ISBN: 9400938713
Category : Science
Languages : en
Pages : 902

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Book Description
Proceedings of the Second World Conference, Paris, France, June 16-20, 1986