Browsing by Author "Nagai K"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Fabrication of disk-shaped, deuterated resorcinol/formaldehyde foam target for laser–plasma experiments
    (Cambridge University Press in association with Chinese Laser Press, 2021-06-15) Kaneyasu Y; Nagai K; Cadatal-Raduban M; Golovin D; Shokita S; Yogo A; Jitsuno T; Norimatsu T; Yamanoi K
    Resorcinol/formaldehyde (RF) foam resin is an attractive material as a low-density target in high-power laser–plasma experiments because of its fine network structure, transparency in the visible region, and low-Z element (hydrogen, carbon, and oxygen) composition. In this study, we developed disk-shaped RF foam and deuterated RF foam targets with 40–200 µm thickness and approximately 100 mg/cm3 density having a network structure from 100 nm to a few micrometers cell size. By deuteration, the polymerization rate was drastically slowed down owing to kinetic isotope effects. These targets were used in high-power laser experiments where a megaelectronvolt proton beam was successfully generated.
  • Thumbnail Image
    Item
    Fabrication of high-concentration Cu-doped deuterated targets for fast ignition experiments
    (IOP Publishing Ltd on behalf of the International Atomic Energy Agency (IAEA), 2023-01) Ikeda T; Kaneyasu Y; Hosokawa H; Shigemori K; Norimastu T; Cadatal-Raduban M; Nagai K; Kojima S; Abe Y; Miura E; Kitagawa Y; Takemura M; Wang Y; Dun J; Guo S; Asano S; Takizawa R; Fujioka S; Shiraga H; Arikawa Y; Ozaki T; Iwamoto A; Sakagami H; Sawada H; Mori Y; Yamanoi K
    In high-energy-density physics, including inertial fusion energy using high-power lasers, doping tracer atoms and deuteration of target materials play an important role in diagnosis. For example, a low-concentration Cu dopant acts as an x-ray source for electron temperature detection while a deuterium dopant acts as a neutron source for fusion reaction detection. However, the simultaneous achievement of Cu doping, a deuterated polymer, mechanical toughness and chemical robustness during the fabrication process is not so simple. In this study, we report the successful fabrication of a Cu-doped deuterated target. The obtained samples were characterized by inductively coupled plasma optical emission spectrometry, differential scanning calorimetry and Fourier transform infrared spectroscopy. Simultaneous measurements of Cu K-shell x-ray emission and beam fusion neutrons were demonstrated using a petawatt laser at Osaka University.