https://doi.org/10.1051/epjconf/202429401009
Validation of the Monte Carlo model of the LOENIEv2 long counter for absolute efficiency calculation
1 CEA Cadarache, DES/IRESNE/DER/SPRC/LEPh, 13108 Saint Paul Lez Durance Cedex, France.
2 CEA Cadarache, DES/IRESNE/DER/SPESI/LP2E, 13108 Saint Paul Lez Durance Cedex, France.
* Corresponding author: pierre.leconte@cea.fr
Published online: 17 April 2024
LOENIEv2 is a long counter detector used for delayed neutron (DN) measurements. It is composed of sixteen 3He tubes embedded in a cylindrical high-density polyethylene (HDPE) matrix. Thanks to a special arrangement of the 3He tubes in three concentric rings, relative variations of the total efficiency as low as 2% can be reached over the [0.1 – 1 MeV] energy range. This paper addresses the development of a Monte-Carlo model of the detector and its validation thanks to calibrated neutron source measurements, performed at the NPL institute. These sources are in the form of small cylinders containing either a spontaneous fission material (252Cf) or a radioactive material producing neutron through (Α,n) reactions (AmLi, AmB, AmF, AmBe). These sources are well characterized in emission rate, spectrum and anisotropy so that they can used as standards for efficiency calibration. Using the JEFF-3.3 nuclear data library, the calculation of the detector absolute efficiency is validated within experimental uncertainties. The averaging of [C/E-1] values between the different sources end up to an estimated bias of -0.3% with an uncertainty of ±0.6% (1σ) over the range [0.5 – 4.1 MeV].
© The Authors, published by EDP Sciences, 2024
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
