20.500.12556/DiRROS-28778 Water activation measurements in JET basement during DD and DT operations In water-cooled D–T fusion tokamaks such as the Joint European Torus (JET), neutron activation of flowing water produces short-lived radionuclides that generate a distributed high-energy gamma and neutron radiation source in the water cooling circuit. The energy and intensity of the source are crucial factors in the design of cooling and shielding systems in future water-cooled deuterium–tritium fusion tokamaks such as ITER. While several past experiments provide fusion-relevant experimental data on water activation, the JET water activation experiment carried out during the 2023 DD and DT campaigns is the first such experiment in a fusion tokamak environment. In the water activation experiment at JET, two types of scintillation detectors were used to measure gamma rays from activated water in the basement below JET Octant 4. The system successfully recorded and processed data from over 1500 JET pulses, including both DD and DT operations, providing a robust data set for analyzing N-16 activity in cooling water. This manuscript describes the preparation of the JET water activation experiment, the calibration of the detectors and the analysis of the experimental data. water activation JET fluid activation fuzijski reaktorji hladilna voda true false true IOP Publishing Združeno kraljestvo Angleški jezik Slovenski jezik © 2026 The Author(s). Neznano 2026-04-07 10:14:00 2026-04-07 10:14:01 2026-04-08 03:47:40 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 30. 3. 2026; str. 1-13 iss. 3, 035023 Vol. 68, [article no.] Mar. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-10-22 2026-03-13 2026-03-24 539.1 1361-6587 10.1088/1361-6587/ae51c3 273514755 https://iopscience.iop.org/article/10.1088/1361-6587/ae51c3/pdf 1 bef61b1e-3259-11f1-b7aa-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42849 RAZ_Peric_Julijan_2026.pdf RAZ_Peric_Julijan_2026.pdf 1 F213054C5DB51CED35EA3577FD959155 45a33ba32ad22836163782a7eb38ea2d84f003d533a5ba606ba95a35508e978f 74cea752-325a-11f1-b7aa-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42851 Institut Jožef Stefan 0 0 0