Neutron emission from water activation : experiments and modeling under fusion-relevant conditions at the KATANA facility

Peric, Julijan (author), Kotnik, Domen (author), Snoj, Luka (author), Radulović, Vladimir (author)

Jožef Stefan Institute’s water activation experiment, called KATANA, was developed to procure benchmark quality experiments on the water activation process. This paper presents the optimization process of the neutron detector holder to achieve the neutron flux measurement system with the highest detection efficiency. Water is activated by the nuclear reactions on oxygen isotopes. The active oxygen and nitrogen isotopes then decay, emitting gamma rays and neutrons with different energies. The reaction $^{17}$O(n,p)$^{17}$N is responsible for the emission of high-energy neutrons. In future fusion plants such as ITER, the neutron flux in the water cooling system will be high, with an estimated flux of approx Φ ≈ 10$^{13}$ n/cm$^2$s. Therefore, adequate shielding must be considered. The design and implementation of neutron flux measurement system at the KATANA water activation facility represents a significant step towards a better understanding of water activation processes. Despite the challenges associated with water activation experiments, the first test measurements of neutron emission during the water activation process have yielded promising results. The following results will be presented: the measured half-life for the decay of $^{17}$N, activity of $^{17}$N as a function of reactor power and water flow rate. The initial results indicate the possibility of using such a facility for the measurements of the integral cross section for the $^{17}$O(n,p)$^{17}$N reaction.

• Language: English
• Keywords: water activation, JSI, KATANA, neutron measurements, MCNP, optimization, ITER, experiments
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 7 str.
• Numbering: Vol. 216, art. 115052
• PID: 20.500.12556/RUL-168806
• UDC: 539.1
• ISSN on article: 0920-3796
• DOI: 10.1016/j.fusengdes.2025.115052
• COBISS.SI-ID: 234012931
• Publication date in RUL: 25.04.2025

Record is a part of a journal

• Title: Fusion engineering and design
• Shortened title: Fusion eng. des.
• Publisher: North Holland
• ISSN: 0920-3796
• COBISS.SI-ID: 15359237

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: jedrska fizika, KATANA, aktivacija vode