Zobrazeno 1 - 10
of 158
pro vyhledávání: '"Parra, Felix"'
Strongly driven ion-scale turbulence in tokamak plasmas is shown to be regulated by a new propagating zonal flow mode, the toroidal secondary, which is nonlinearly supported by the turbulence. The mode grows and propagates due to the combined effects
Externí odkaz:
http://arxiv.org/abs/2409.02283
Autor:
Ruiz, Juan Ruiz, Parra, Felix I., Hall-Chen, Valerian H., Belrhali, Nathan, Giroud, Carine, Hillesheim, Jon C., Lopez, Nicolas A., contributors, JET
The phenomenon of beam focusing of microwaves in a plasma near a turning-point caustic is discussed in the context of the analytical solution to the Gaussian beam-tracing equations in the 2D linear-layer problem. The location of maximum beam focusing
Externí odkaz:
http://arxiv.org/abs/2408.12919
Autor:
Ruiz, Juan Ruiz, Garcia, Jeronimo, Barnes, Michael, Dreval, Mykola, Giroud, Carine, Hall-Chen, Valerian H., Hardman, Michael R., Hillesheim, Jon C., Kazakov, Yevgen, Mazzi, Samuele, Parra, Felix I., Patel, Bhavin S., Schekochihin, Alexander A., Stancar, Ziga, Contributors, the JET, Team, the EUROfusion Tokamak Exploitation
We report the first experimental detection of a zero-frequency fluctuation that is pumped by an Alfv\'en mode in a magnetically confined plasma. Core-localized bidirectional Alfv\'en modes of frequency inside the toroidicity-induced gap (and its harm
Externí odkaz:
http://arxiv.org/abs/2407.01255
A solid target in contact with a plasma charges (negatively) to reflect the more mobile species (electrons) and thus keep the bulk plasma quasineutral. To shield the bulk plasma from the charged target, there is an oppositely (positively) charged she
Externí odkaz:
http://arxiv.org/abs/2401.07385
We present a new neoclassical transport model for large aspect ratio tokamaks where the gradient scale lengths are of the size of the poloidal gyroradius. Previous work on neoclassical transport across transport barriers assumed large density and pot
Externí odkaz:
http://arxiv.org/abs/2301.07080
Autor:
Hall-Chen, Valerian H., Parra, Felix I., Hillesheim, Jon C., Ruiz, Juan Ruiz, Crocker, Neal A., Shi, Peng, Chu, Hong Son, Freethy, Simon J., Kogan, Lucy A., Peebles, William A., Pratt, Quinn T., Rhodes, Terry L., Ronald, Kevin, Scannell, Rory, Speirs, David C., Storment, Stephen, Trisno, Jonathan
The Doppler backscattering (DBS) diagnostic, also referred to as Doppler reflectometry, measures turbulent density fluctuations of intermediate length scales. However, when the beam's wavevector is not properly aligned perpendicular to the magnetic f
Externí odkaz:
http://arxiv.org/abs/2211.17141
Autor:
Hall-Chen, Valerian H., Damba, Julius, Parra, Felix I., Pratt, Quinn T., Michael, Clive A., Peng, Shi, Rhodes, Terry L., Crocker, Neal A., Hillesheim, Jon C., Hong, Rongjie, Ni, Shikang, Peebles, William A., Png, Ching Eng, Ruiz, Juan Ruiz
We use the beam model of Doppler backscattering (DBS), which was previously derived from beam tracing and the reciprocity theorem, to shed light on mismatch attenuation. This attenuation of the backscattered signal occurs when the wavevector of the p
Externí odkaz:
http://arxiv.org/abs/2209.15303
New orbit averaged equations for low collisionality neoclassical fluxes in large aspect ratio stellarators with mirror ratios close to unity are derived. The equations retain finite orbit width effects by employing the second adiabatic invariant $J$
Externí odkaz:
http://arxiv.org/abs/2202.01318
Publikováno v:
Plasma Physics and Controlled Fusion 64, 095002 (2022)
We use beam tracing -- implemented with a newly-written code, Scotty -- and the reciprocity theorem to derive a model for the linear backscattered power of the Doppler Backscattering (DBS) diagnostic. Our model works for both the O-mode and X-mode in
Externí odkaz:
http://arxiv.org/abs/2109.10973
The Debye sheath is known to vanish completely in magnetised plasmas for a sufficiently small electron gyroradius and small angle between the magnetic field and the wall. This angle depends on the current onto the wall. When the Debye sheath vanishes
Externí odkaz:
http://arxiv.org/abs/2106.05432