Neutron importance estimation via new recursive Monte Carlo method for deep penetration neutron transport

Tuya, D.; Nagaya, Yasunobu

Nuclear Science and Engineering, 15 Pages, 2023/00

https://doi.org/10.1080/00295639.2023.2233850

In Monte Carlo neutron transport calculations for local response or deep penetration problems, some estimation of an importance function is generally required in order to improve their efficiency. In this work, a new recursive Monte Carlo (RMC) method, which is partly based on the original RMC method, for estimating an importance function for local variance reduction (i.e., source-detector type) problems has been developed. The new RMC method has been applied to two sample problems of varying degrees of neutron penetrations, namely a one-dimensional iron slab problem and a three-dimensional concrete-air problem. The biased Monte Carlo calculations with variance reduction parameters based on the obtained importance functions by the new RMC method have been performed to estimate detector responses in these problems. The obtained results are in agreement with those by the reference unbiased Monte Carlo calculations. Furthermore, the biased calculations offered an increase in efficiency on the order of 1 to 10 in terms of the figure of merit (FOM). The results also indicated that the efficiency increased as the neutron penetration became deeper.

Shielding experiments and analyses on proton accelerator facility at TIARA

Nakashima, Hiroshi; Sakamoto, Yukio*; Tanaka, Shunichi; Tanaka, Susumu; Baba, Mamoru*; Nakamura, Takashi*; Hirayama, Hideo*; Shin, Kazuo*; JAERI-Universities Collaboration Working Group for Accelerator Shielding Study

Proceedings of 6th International Meeting on Nuclear Applications of Accelerator Technology (AccApp '03), p.959 - 968, 2003/00

In order to validate shielding design methods on proton accelerator facilities, a series of shielding experiments in several tens of MeV energy region were carried out at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) of Japan Atomic Energy Research Institute (JAERI). The experiments include thick target neutron yield (TTY) measurements by charged particles, deep penetration experiments on concrete, steel and polyethylene shields using p-Li monoenergetic neutron source and radiation streaming experiment at a labyrinth of TIARA using p-Cu white neutron source. These experimental results are compared with calculation results with some high-energy particle transport codes such as MCNPX and NMTC/JAERI. The TTY measurements were analyzed by a code developed by Shin with a moving source model, and the streaming experiment was also analyzed by the DUCT-III code based on Shin's equation. This paper reviews the experimental results and the analyses on the results.

Calculation of Neutron Penetration through Graphite Medium with Monte Carlo Code MCNP

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JAERI-M 86-055, 37 Pages, 1986/03

JAERI-M-86-055.pdf:0.9MB

no abstracts in English

Effect of Fe-56 anisotropic scattering on neutron penetration

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Journal of Nuclear Science and Technology, 20(5), p.435 - 438, 1983/00

https://doi.org/10.3327/jnst.20.435

no abstracts in English