Neoclassical theory [Galeev-68, Hinton-76] sets a lower bound on transport in toroidal plasmas. In the case of three-dimensional devices, neoclassical transport may become even dominant as the temperature of the plasma increases, due to the unfavorable temperature scaling of the transport coefficients. Hence, the comprehensive study of neoclassical transport is a necessary condition for both the understanding of reactor-relevant regimes and the design of future reactors.

Calculating neoclassical transport implies solving the Drift Kinetic Equation (DKE) [Hinton-76]. Apart from some particular limits in the parameter space, the DKE cannot be solved analytically, and one has to resort to numerical computations. Within this project, we will address the problems with the following tools:

– **DKES** [HIrshman-86], a neoclassical transport code based on the radially local and monoenergetic approach. It is complemented with numerical algorithms that guarantee momentum conservation [Maassberg-09].

– **FORTEC-3D** [Satake-06], a delta-f global Monte Carlo neoclassical code developed at NIFS, which allows to remove the local and monoenergetic approximations.

– **EUTERPE** [Kleiber-12], a delta-f global gyrokinetic code developed at IPP (see Gyrokinetic Simulations).

When possible, these simulations will be complemented with semianalytical calculations of simplified versions of the DKE for the exact geometry of TJ-II.

**References**

[Galeev-68] A. A. Galeev and R. Z. Sagdeev, *Sov. Phys.-JETP *26, 233 (1968).

[Hinton-76] F.L. Hinton and R.D. Hazeltine, *Rev. Mod. Phys. *48, 239 (1976).

[HIrshman-86] S.P. Hirshman, K.C. Shaing, W.I. van Rij, C.O. Beasley and E.C. Crume, Phys. Fluid 29, 2951 (1986).

[Maasberg-09] H. Maassberg, C.D. Beidler and Y. Turkin, Phys. Plasmas **16,** 072504 (2009).

[Satake-06] S. Satake M. Okamoto, N. Nakajima, H. Sugama and M. Yokoyama, Plasma and Fusion Res. 1, 002 (2006).

[Kleiber-12] R. Kleiber and R. Hatzky, Comput. Phys. Commun. 183, 305 (2012).