Guzdar-Drake Drift-Resistive Ballooning Model

The 1993 $\bf E \times B$ drift-resistive ballooning mode model by Guzdar and Drake [2] is selected

$$D^{RB} = F_1^{RB} \abs \left( 2\pi q_{a}^2 \right) \rho_e^... ...ei}\left( {R\over p} \right)\left(- {{d p }\over {d r}}\right)$$

where $F_1^{RB}=$ frb(1). Here the normalize presure gradient scale length has been substituted for the density gradient scale given in their paper following a comment made by Drake at the 1995 TTF Workshop[4]. Including diamagnetic and elongation effects, the particle diffusivity is

$$D^{RB} = F_1^{RB} \abs \left( 2\pi q_{a}^2 \right) \rho_e^2... ...{d p }\over {d r}}\right) c_9 \kappa^{c_{4}} \eqno{\tt zgddb}$$

where $\rho_e=v_e/\omega_{ce}$, $c_9 =$ cswitch(9) and and $c_4 =$ cswitch(4).

The electron and ion thermal diffusivities are taken equal taken to be an adjustable fraction of the particle diffusivity.

$$\chi_e^{RB} = F_2^{RB} \abs \left( 2\pi q_{a}^2 \right) \r... ...{d p }\over {d r}}\right) c_9 \kappa^{c_{4}} \eqno{\tt therb}$$

$$\chi_i^{RB} = F_3^{RB} \abs \left( 2\pi q_{a}^2 \right) \r... ...{d p }\over {d r}}\right) c_9 \kappa^{c_{4}} \eqno{\tt thirb}$$

where $F_2^{RB}=$ frb(2) and $F_3^{RB}=$ frb(3)