ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Brock Jolicoeur, Norbert Hugger, David Medich
Nuclear Technology | Volume 209 | Number 11 | November 2023 | Pages 1819-1825
Regular Research Article | doi.org/10.1080/00295450.2023.2204988
Articles are hosted by Taylor and Francis Online.
We investigate the image quality and beam intensity of thermal neutron radiography after replacing a standard single-channel neutron collimator with a compact array of microcollimators. In this study, the MCNP6 Monte Carlo computer code was used to simulate a 2 × 2-cm-area isotropic thermal neutron source, which then was collimated by an array of micron-sized neutron collimators that measured 29.8 μm in diameter and with lengths that varied from 0.6 to 3 mm. These microcollimators were spaced 30 μm apart and assembled into a 2 × 2-cm array.
The image quality of the neutron beams produced by the resulting collimator arrays was assessed by imaging the edge of a very thin (~0.01-mm) gadolinium foil to obtain the image Modulation Transfer Function (MTF). The MCNP6 resulting flux map from each simulation then was converted into a grayscale .tiff image and the image’s resulting MTF obtained using the ImageJ computer program with the imaging beam geometric unsharpness, which is a limiting factor in the image resolution determined at the 10% value of the MTF curve.
In this study, we found that a 2 × 2× 0.298-cm microcollimator, corresponding to a length-to–hole diameter ratio of 100:1 and a collimator length of 2.98 mm produced a beam with a geometric unsharpness of 32 μm. Compared to a standard single-channel collimator with a 2 × 2-cm aperture, the single-channel collimator would need to be 660 cm long to produce an equivalent geometric sharpness. Yet because of its shorter length, the imaging beam intensity from our 2.98-mm-thick collimator array was approximately 50 times greater than that of an equivalent single-channel collimator.