Development of divertor simulation research in the GAMMA 10/PDX tandem mirror

Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Particle transport of LHD

Tanaka, Kenji*; Kawahata, Kazuo*; Tokuzawa, Tokihiko*; Akiyama, Tsuyoshi*; Yokoyama, Masayuki*; Shoji, Mamoru*; Michael, C. A.*; Vyacheslavov, L. N.*; Murakami, Sadayoshi*; Wakasa, Arimitsu*; et al.

Fusion Science and Technology, 58(1), p.70 - 90, 2010/07

https://doi.org/10.13182/FST10-A10795

Particle confinement processes were studied in detail on LHD. Diffusion coefficients (D) and convection velocities (V) were estimated from density modulation experiments. The magnetic configuration and collisionality were widely scanned in order to investigate parameter dependences of D and V. In order to study the effect of the magnetic configuration, magnetic axis positions (R) were scanned from 3.5 m to 3.9 m. This scan changed the magnetic ripples quite significantly, enabling the effects of neoclassical properties on measured values to be widely elucidated. Dependences of electron temperature (T) and helically trapped normalized collsionality (), where =1 indicates a rough boundary between the 1/ and plateau regimes, were examined using the heating power scan of neutral beam injection (NBI). It was found out that generally larger (or smaller) contributions of neoclassical transport resulted in more hollow (or peaked) density profiles. The larger neoclassical contribution was found to be situated at a more outwardly shifted R for the same T, and higher T or lower at each R. However, it is to be noted that R=3.5 m showed different characteristics from these trends in that this case showed a more peaked density profile at higher T.

MeV -ray generation from backward Compton scattering at SPring-8

Kawase, Keigo; Arimoto, Yasushi*; Fujiwara, Mamoru; Okajima, Shigeki*; Shoji, Masazumi*; Suzuki, Shinsuke*; Tamura, Kazuhiro*; Yorita, Tetsuhiko*; Okuma, Haruo*

Nuclear Instruments and Methods in Physics Research A, 592(3), p.154 - 161, 2008/07

https://doi.org/10.1016/j.nima.2008.04.008

A test experimental line at SPring-8 has been constructed for the generation of backward Compton scattered (BCS) -ray by head-on collision between an 8 GeV electron beam and a far-infrared (FIR) laser. For the FIR laser, we use a continuous-wave methanol laser optically pumped by a carbon dioxide () laser. The FIR laser output power achieved is 1.6 W at maximum for 118.8 m lasing; this value is the highest in the case of this type of laser. As a result of the direct measurement, the generated BCS -ray flux was found to be about photons/s. This value is consistent with the estimation calculated by taking into account the input laser power and the transmittance of the laser transport system.