# Dr Yann Camenen

**Research Interests**

Currently, my research work focuses on cross-field transport of heat, particles and momentum in tokamak plasmas, and more precisely on the interpretation of the dependences observed in the experiments in the frame of the gyro-kinetic theory.

**Recent publications**

**Y. Camenen**, A.G. Peeters, C. Angioni, F.J. Casson, W.A. Hornsby, A.P. Snodin, D. Strintzi

*Intrinsic rotation driven by the electrostatic turbulence in up-down asymmetric plasmas
*Phys. Plasmas

**16**, 062501 (2009)

The transport of parallel momentum by small scale ﬂuctuations is intrinsically linked to symmetry breaking in the direction of the magnetic ﬁeld. In tokamaks, an up-down asymmetry in the equilibrium proves to be an efﬁcient parallel symmetry breaking mechanism leading to the generation of a net radial ﬂux of parallel momentum by the electrostatic turbulence [Y. Camenen

et al., Phys. Rev. Lett. 102, 125001 2009]. This ﬂux is neither proportional to the toroidal rotation nor to its gradient and arises from an incomplete cancellation of the local contributions to the

parallel momentum ﬂux under the ﬂux surface average. The ﬂux of parallel momentum then depends on the asymmetry of the curvature drift and on the extension of the ﬂuctuations around the

low ﬁeld side midplane. In this paper, the mechanisms underlying the generation of the ﬂux of parallel momentum are highlighted and the main dependences on plasma parameters investigated

using linear gyrokinetic simulations.

**Y. Camenen**, A.G. Peeters, C. Angioni, F.J. Casson, W.A. Hornsby, A.P. Snodin, D. Strintzi

*Transport of parallel momentum induced by current-symmetry breaking in toroidal plasmas
*Phys. Rev. Lett.

**102**, 125001 (2009)

The symmetry of a physical system strongly impacts on its properties. In toroidal plasmas, the symmetry along a magnetic ﬁeld line usually constrains the radial ﬂux of parallel momentum to zero

in the absence of background ﬂows. By breaking the up-down symmetry of the toroidal currents, this constraint can be relaxed. The parallel asymmetry in the magnetic conﬁguration then leads to an incomplete cancellation of the turbulent momentum ﬂux across a ﬂux surface. The magnitude of the subsequent toroidal rotation increases with the up-down asymmetry and its sign depends on the direction of the toroidal magnetic ﬁeld and plasma current. Such a mechanism offers new insights in the interpretation and control of the intrinsic toroidal rotation in present day experiments.

**Y. Camenen**, A.G. Peeters, C. Angioni, F.J. Casson, W.A. Hornsby, A.P. Snodin, D. Strintzi

*Impact of the background toroidal rotation on particle and heat turbulent transport in tokamak plasmas
*Phys. Plasmas

**16**, 012503 (2009)

^{ }developments in the gyrokinetic theory have shown that, in a

^{ }toroidal device, the Coriolis drift associated with the background plasma

^{ }rotation significantly affects the small scale instabilities [A. G. Peeters

^{ }et al., Phys. Rev. Lett.

**98**, 265003 (2007)]. The later study,

^{ }which focuses on the effect of the Coriolis drift on

^{ }toroidal momentum transport is extended in the present paper to

^{ }heat and particle transport. It is shown numerically using the

^{ }gyrokinetic flux-tube code GKW [A. G. Peeters and D. Strintzi,

^{ }Phys. Plasmas

**11**, 3748 (2004)], and supported analytically, that the

^{ }Coriolis drift and the parallel dynamics play a similar role

^{ }in the coupling of density, temperature, and velocity perturbations. The

^{ }effect on particle and heat fluxes increases with the toroidal

^{ }rotation (directly) and with the toroidal rotation gradient (through the

^{ }parallel mode structure), depends on the direction of propagation of

^{ }the perturbation, increases with the impurity charge number and with

^{ }the impurity mass to charge number ratio. The case of

^{ }very high toroidal rotation, relevant to spherical tokamaks, is investigated

^{ }by including the effect of the centrifugal force in a

^{ }fluid model. The main effect of the centrifugal force is

^{ }to decrease the local density gradient at the low field

^{ }side midplane and to add an extra contribution to the

^{ }fluxes. The conditions for which the inertial terms significantly affect

^{ }the heat and particle fluxes are evidenced.

A full list of publications can be found here

#### Contact Details

**Office:** PS.120

**Telephone:**

+44 (0) 2476 573874

**Fax: **

+44 (0) 2476 523672

**Email:**

y.camenen@warwick.ac.uk