Neutronic Analysis of Fusion Tokamak Devices by PHITS

Abstract

A complete 3D neutronic analysis by PHITS (Particle and Heavy Ion Transport code System) has been performed for fusion tokamaku devices such as JT-60U device and JT-60 Superconducting tokamak device (JT-60 Super Advanced). The mono-energetic neutrons (E n =2.45 MeV) of the DD fusion devices are used for the neutron source in the analysis. The visual neutron flux distribution for the estimation of the port streaming and the dose rate around the fusion tokamak devices has been calculated by the PHITS. The PHITS analysis makes it clear that the effect of the port streaming of superconducting fusion tokamak device with the cryostat is crucial and the calculated neutron spectrum results by PHITS agree with the MCNP-4C2 results.

Comparison between simulations using the PHITS code and activated materials analysis toward JT-60SA radiation safety assessment

“…The plasma parameters are as follows: R p is the major radius (= 347.0 cm), a p is the minor radius (= 98.0 cm), Z p is the vertical shift of the plasma center (= 17.0 cm), and is the ellipticity (= 1.40) [2]. In addition, we considered the plasma triangularity in the expressions.…”

“…In DD discharges, the reactions D(D,n) 3 He and D(D,p)T have equal probability, which implies that tritons (T) are generated at the same rate as the 2.45-MeV neutrons in a DD plasma. When the confined tritons slow down and are thermalized in the DD plasma, a T(D,n)alpha reaction is possible, thereby generating a 14.1 MeV neutron, which can be measured using the foil activation technique.…”

“…We assess the applicability of the PHITS code to radiation shielding design, neutronics analysis and ion transports in materials used in fusion tokamak devices. Although we have used PHITS for neutronics analysis and radiation shielding design in fusion tokamak devices [2,3], the experimental data has not yet been compared with the simulation results from PHITS analysis.…”

Conceptual Radiation Shielding Design of Superconducting Tokamak Fusion Device by PHITS

“…So, the radiation shielding conceptual design of superconducting tokamak device such as JT-60SA not only consider the structure of the vacuum vessel and the cryostat, but also have to assess the effect of the port streaming by the 3D neutron and photon transport analysis with PHITS. 9) In this paper, we discuss the neutron and the photon transport analysis with the effects of the streaming and the additional shielding by PHITS for the conceptual radiation shielding design of superconducting tokamak fusion device such as JT-60SA. The objectives are to investigate the availability and the advantage of PHITS for the shielding design of superconducting tokamak fusion device.…”

An in-situ Relative Calibration Method for Thomson Scattering Diagnostics Using a Double-Pass Scattering System

“…2 (c), the red line represents irradiated fibers measured after 18 years of DD plasma operation in JT-60U. The absorbed doses of neutron and γ-ray were estimated to be 1.5 × 10 4 Gy (4.0 × 10 18 n/m 2 in fluence) and 4.0 × 10 2 Gy, respectively, by three-dimensional neutronics calculation [11] at the port position where the collection optics and fibers were installed. When C j is treated as unity for the non-irradiated fiber, the degradation factors can be expressed as…”