Fluctuation properties of strength function associated with the giant quadrupole resonance in 208Pb

We performed fluctuation analysis by means of the local scaling dimension for the strength function of the isoscalar (IS) giant quadrupole resonance (GQR) in 208Pb where the strength function is obtained by the shell model calculation including 1p1h and 2p2h configurations. It is found that at almost all energy scales, fluctuation of the strength function obeys the Gaussian orthogonal ensemble (GOE) random matrix theory limit. This is contrasted with the results for the GQR in 40Ca, where at the intermediate energy scale about 1.7 MeV a deviation from the GOE limit was detected. It is found that the physical origin for this different behavior of the local scaling dimension is ascribed to the difference in the properties of the damping process.Comment: 10 pages, 14 figures, submitted to Physical Review

Development of a novel integrated model GOTRESS+ for predictions and assessment of JT-60SA operation scenarios including the pedestal

A novel integrated model GOTRESS+ has been developed, which consists of the iterative transport solver GOTRESS as a kernel of the integrated model, the equilibrium and current profile alignment code ACCOME and the neutral beam heating/current-drive code OFMC. GOTRESS is able to robustly find out an exact solution of the stationary-state transport equations even with a stiff turbulent transport model, taking advantage of global optimization techniques such as a genetic algorithm. GOTRESS+ is then suitable for self-consistently assessing the stationary-state plasma performance of JT-60SA as well as ITER and DEMO or validating their feasibility. Recently GOTRESS+ has been extended to incorporate the in-house EPED1 model exploiting the MHD stability code MARG2D and is now able to predict the plasma profiles even with the pedestal over the entire region from the magnetic axis to the plasma boundary in a self-consistent manner. The two JT-60SA operation scenarios including the ITER-like inductive scenario and the high β fully non-inductively current driven scenario have been assessed by GOTRESS+ with the CDBM turbulent transport model and then were found to be feasible with most of the target dimensionless parameters met

Non-ideal Ballooning Mode Instability with Real Electron Inertia

Impacts of electron inertia with an electron skin depth (ESD) longer than the realistic value used in early numerical studies on non-ideal ballooning modes (NIBMs) are numerically investigated by a linearized 3-field reduced MHD model. In this paper, 4 different ESDs,are used for an resistivity dependence study of the growth rate of NIBMs, where de s the real ESD and d*e = 10 corresponds to an order of ESD used in a numerical study on collisionless ballooning mode (CBM) reported in [Kleva and Guzdar Phys. Plasmas 6, 116 (1999)]. In the case with the real ESD d*e = de, a transition from resistive ballooning mode (RBM) to CBM occurs in the edge relevant resistivity regime, while the electron inertia effect is overestimated and the growth rate is almost independent of resistivity in the cases with d∗e =√10de and 10de. These results indicate that the real ESD is one of key factors for the edge stability and turbulence analysis

Plasma physics and control studies planned in JT-60SA for ITER and DEMO operations and risk mitigation

Lista completa de autores: Yoshida, M. ; Giruzzi, G.; Aiba, N.; Artaud, J. F.; Ayllon-Guerola, J.; Balbinot, L.; Beeke, O.; Belonohy, E.; Bettini, P.; Bin, W.; Bierwage, A.; Bolzonella, T.; Bonotto, M.; Boulbe, C.; Buermans, J.; Chernyshova, M.; Coda, S.; Coelho, R.; Davis, S.; Day, C.; De Tommasi, G.; Dibon, M.; Ejiri, A.; Falchetto, G.; Fassina, A.; Faugeras, B.; Figini, L.; Fukumoto, M.; Futatani, S.; Galazka, K.; García, J.; García-Muñoz, M.; Garzotti, L.; Giacomelli, L.; Giudicotti, L.; Hall, S.; Hayashi, N.; Hoa, C.; Honda, M.; Hoshino, K.; Iafrati, M.; Iantchenko, A.; Ide, S.; Iio, S.; Imazawa, R.; Inoue, S.; Isayama, A.; Joffrin, E.; Kamiya, K.; Ko, Y.; Kobayashi, M.; Kobayashi, T.; Kocsis, G.; Kovacsik, A.; Kurki-Suonio, T.; Lacroix, B.; Lang, P.; Lauber, P.; Louzguiti, A.; Luna, E. de la; Marchiori, G.; Mattei, M.; Matsuyama, A.; Mazzi, S.; Mele, A.; Michel, F.; Miyata, Y.; Morales, J.; Moreau, P.; Moro, A.; Nakano, T.; Nakata, M.; Narita, E.; Neu, R.; Nicollet, S.; Nocente, M.; Nowak, S.; Orsitto, F. P.; Ostuni, V.; Ohtani, Y.; Oyama, N.; Pasqualotto, R.; Pegourie, B.; Perelli, E.; Pigatto, L.; Piccinni, C.; Pironti, A.; Platania, P.; Ploeckl, B.; Ricci, D.; Roussel, P.; Rubino, G.; Sano, R.; Sarkimaki, K.; Shinohara, K.; Soare, S.; Sozzi, C.; Sumida, S.; Suzuki, T.; Suzuki, Y.; Szabolics, T.; Szepesi, T.; Takase, Y.; Takech, M.; Tamura, N.; Tanaka, K.; Tanaka, H.; Tardocchi, M.; Terakado, A.; Tojo, H.; Tokuzawa, T.; Torre, A.; Tsujii, N.; Tsutsui, H.; Ueda, Y.; Urano, H.; Valisa, M.; Vallar, M.; Vega, J.; Villone, F.; Wakatsuki, T.; Wauters, T.; Wischmeier, M.; Yamoto, S.; Zani, L.A large superconducting machine, JT-60SA has been constructed to provide major contributions to the ITER program and DEMO design. For the success of the ITER project and fusion reactor, understanding and development of plasma controllability in ITER and DEMO relevant higher beta regimes are essential. JT-60SA has focused the program on the plasma controllability for scenario development and risk mitigation in ITER as well as on investigating DEMO relevant regimes. This paper summarizes the high research priorities and strategy for the JT-60SA project. Recent works on simulation studies to prepare the plasma physics and control experiments are presented, such as plasma breakdown and equilibrium controls, hybrid and steady-state scenario development, and risk mitigation techniques. Contributions of JT-60SA to ITER and DEMO have been clarified through those studies.Comisión Europea - EURATOM 63305

Analysis of ELM stability with extended MHD models in JET, JT-60U and future JT-60SA tokamak plasmas

The stability with respect to a peeling–ballooning mode (PBM) was investigated numerically with extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI code was used to analyze the linear stability, including the effects of rotation and ion diamagnetic drift ( *w i), in JET-ILW and JT-60SA plasmas, and the JOREK code was used to simulate nonlinear dynamics with rotation, viscosity and resistivity in JT-60U plasmas. It was validated quantitatively that the ELM trigger condition in JET-ILW plasmas can be reasonably explained by taking into account both the rotation and *w i effects in the numerical analysis. When deuterium poloidal rotation is evaluated based on neoclassical theory, an increase in the effective charge of plasma destabilizes the PBM because of an acceleration of rotation and a decrease in *w i. The difference in the amount of ELM energy loss in JT-60U plasmas rotating in opposite directions was reproduced qualitatively with JOREK. By comparing the ELM affected areas with linear eigenfunctions, it was confirmed that the difference in the linear stability property, due not to the rotation direction but to the plasma density profile, is thought to be responsible for changing the ELM energy loss just after the ELM crash. A predictive study to determine the pedestal profiles in JT-60SA was performed by updating the EPED1 model to include the rotation and *w i effects in the PBM stability analysis. It was shown that the plasma rotation predicted with the neoclassical toroidal viscosity degrades the pedestal performance by about 10% by destabilizing the PBM, but the pressure pedestal height will be high enough to achieve the target parameters required for the ITER-like shape inductive scenario in JT-60SA.JSPS KAKENHI 15K06656EURATOM 63305

Fluctuation properties of strength functions associated with giant resonances

We performed fluctuation analysis by means of the local scaling dimension for the strength function of the isoscalar (IS) and the isovector (IV) giant quadrupole resonances (GQR) in $^{40}$Ca, where the strength functions are obtained by the shell model calculation within up to the 2p2h configurations. It is found that at small energy scale, fluctuation of the strength function almost obeys the Gaussian orthogonal ensemble (GOE) random matrix theory limit. On the other hand, we found a deviation from the GOE limit at the intermediate energy scale about 1.7MeV for the IS and at 0.9MeV for the IV. The results imply that different types of fluctuations coexist at different energy scales. Detailed analysis strongly suggests that GOE fluctuation at small energy scale is due to the complicated nature of 2p2h states and that fluctuation at the intermediate energy scale is associated with the spreading width of the Tamm-Dancoff 1p1h states.Comment: 14 pages including 13figure