Application of Advanced Nuclear Emulsion Technique to Fusion Neutron Diagnostics

Nakayama, Yoshiaki; Tomita, Hideki; Morishima, Keisuke; Yamashita, Fumitaka; Hayashi, S.; Cheon, MunSeong; Isobe, M.; Ogawa, K.; Naka, Takashi; Nakano, T.; Nakamura, Mitsuhiro; Kawarabayashi, Jun; Iguchi, Tetsuo; Ochiai, Kentaro

doi:10.1016/j.phpro.2015.11.093

Cited by 4 publications

(2 citation statements)

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“…Therefore, the advanced study of EPs performed in the large tokamaks is expected in stellarators and helical systems using the LHD. To conduct the EP study, development and prior evaluations of the neutron flux monitor [21][22][23][24], the neutron camera based on a scintillation detector [25][26][27][28] and on nuclear emulsion [29][30][31][32], and the neutron energy spectrometer [33,34] have been performed. Furthermore, the simulation of 3.5 MeV alpha particle confinement using 1 MeV tritons created by deuterium-deuterium (DD) reactions is possible for the first time in the stellarator/heliotron devices.…”

Section: Introductionmentioning

confidence: 99%

Energetic ion confinement studies using comprehensive neutron diagnostics in the Large Helical Device

et al. 2019

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Understanding of energetic particle (EP) confinement is one of the critical issues in realizing fusion reactor. In stellarator/helical devices, the research on EP confinement is one of the key topics to obtain better confinement by utilizing the flexibility of three-dimensional magnetic field. Study of EP transport in the Large Helical Device (LHD) has been performed by means of escaping EP diagnostics in hydrogen plasma operation. By starting deuterium operation of the LHD, confinement study of EPs has progressed remarkably by using newly developed comprehensive neutron diagnostics providing the information of EPs confined in the core region. The total neutron emission rate (Sn) increases due to the relatively low deviation of beam ion orbit from the flux surface with the inward shift of the magnetic axis. Sn has the peak around the electron density of 2×10 19 m -3 to 3×10 19 m -3 , as predicted. It is found that the fraction of beam-beam components in Sn is evaluated to be approximately 20% by the Fokker-Planck models TASK/FP in the plasma with both co-and counter-neutral beam injections. The equivalent fusion gain in DT plasma achieved 0.11 in a negative-ion-based neutral beam heated 2 plasma. Time evolution of Sn following the short pulse neutral beam injection into the electroncyclotron-heated low-beta plasma is reproduced by drift kinetic simulation, indicating that transport of beam ion injected by short pulse neutral beam can be described with neoclassical models in magnetohydrodynamic quiescent low-beta plasmas. The vertical neutron camera works successfully, demonstrating that in the co-neutral beam injected plasma, neutron emission profile shifts according to magnetic axis position. The shift of the neutron emission profile is reproduced by orbit-following models. The triton burnup study is performed for the first time in stellarator/heliotron so as to understand the alpha particle confinement. It is found that the triton burnup ratio, which largely increases at inward shifted configurations due to the better triton orbit and better plasma performance in inward shifted configuration is similar to that measured in tokamak having a similar minor radius with the LHD. We study the confinement capability of EPs toward a helical reactor in magnetohydrodynamic -quiescent region and expansion of the energetic-ion physics study in toroidal fusion plasmas.

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Section: Introductionmentioning

confidence: 99%

Energetic ion confinement studies using comprehensive neutron diagnostics in the Large Helical Device

et al. 2019

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“…In recent advanced nuclear emulsion technique, large area of the emulsion plate can be analyzed by an automated scanning system [1][2][3] and numerous recoiled tracks can be recognized quickly. We have demonstrated a fast neutron detection using the state-of-the-art nuclear emulsion technique [1][2][3][4][5][6][7][8]. One of these applications, a fast neutron camera using a nuclear emulsion with a pinhole collimator was installed at the magnetic fusion experimental device KSTAR (Korea Superconducting Tokamak Advanced Research) and measurement of emission profile of 2.5 MeV neutron generated from DD fusion reaction in the KSTAR plasma was demonstrated [7,8].…”

Section: Introductionmentioning

confidence: 99%

Fast Neutron Imaging Telescope Using Statistical Reconstruction in Nuclear Emulsion

Watanabe

Tomita

Yoshimoto

et al. 2019

Proceedings of the Second International Symposium on Radiation Detectors and Their Uses (ISRD2018)

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Novel fast neutron imaging concept with statistical reconstruction for analysis of recoiled proton tracks in nuclear emulsion is proposed. For each recoiled proton track event, incident neutron direction can be constrained on a cone with axis of a recoiled proton track and an opening angle derived from both an estimated neutron energy and a recoiled proton energy. As in the Compton imaging method, a position of fast neutron source can be identified by intersection of event cones if appropriate information of the incident neutron energy is given. In reconstructed image obtained by this method for a 252 Cf source, single peak was appeared with the estimated neutron energy of lower than 1.5 MeV.

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Application of nuclear emulsions for the identification of multi-MeV protons in laser ion acceleration experiments

Asai

Kanasaki

Jinno

et al. 2019

High Energy Density Physics

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Application of Advanced Nuclear Emulsion Technique to Fusion Neutron Diagnostics

Cited by 4 publications

References 4 publications

Energetic ion confinement studies using comprehensive neutron diagnostics in the Large Helical Device

Energetic ion confinement studies using comprehensive neutron diagnostics in the Large Helical Device

Fast Neutron Imaging Telescope Using Statistical Reconstruction in Nuclear Emulsion

Application of nuclear emulsions for the identification of multi-MeV protons in laser ion acceleration experiments

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