mass/charge ratio, given by the normalised parameters For electrons a$_{z}$ = τ$_{z}$ = − 1 and µ$_{z}$ = − m$_{e}$/M$_{i}$ . For the main ions a$_{z}$ = µ$_{z}$ = 1 while τ$_{z}$ = τ$_{i}$ is kept as a parameter. For the trace ions a$_{z}$ = 0 is always taken. For hot trace ions τ$_{z}$ is large while µ$_{z}$ is still moderate. The species gyroradius ρ$_{z}$ is given by ( ρ$_{z}$/ρ$_{s}$ ) 2 = µ$_{z}$τ$_{z}$ , which is always small for electrons, close to unity for main ions, and can be moderate or large for trace ions. For this study a simplified geometry is taken with B = 1 except in curvature terms, so magnetic pumping and shaping effects [37] are neglected. Since dynamics at the electron gyroradius scale are neglected the gyroaveraging effects on ˜ A$_{‖}$ are not treated. The moment equations are given by a$_{z}$ = Zn$_{z}$ n$_{e}$ τ$_{z}$ = T$_{z}$ ZT$_{e}$ µ$_{z}$ = M$_{z}$ ZM$_{i}$ . (2) $^{∂}$˜ n$_{z}$ ∂t + u$_{E}$ $^{·∇}$˜ n$_{z}$ + w$_{E}$ ·∇ ˜ T$_{z}$$_{⊥}$ + $^{∇$_{‖}$}$˜ u$_{z}$$_{‖}$ = K ( ˜ φ$_{G}$ + ˜ Ω$_{G}$ 2 + τ$_{z}$ ˜ p$_{z}$$_{‖}$ + ˜ p$_{z}$$_{⊥}$ 2 ) (3) ∂ ∂t ( β$_{e}$ ˜ A$_{‖}$ + $^{µ$_{z}$}$˜ u$_{z}$$_{‖}$ ) + µ$_{z}$ u$_{E}$ $^{·∇}$˜ u$_{z}$$_{‖}$ + µ$_{z}$ w$_{E}$ $^{·∇}$˜ q$_{z}$$_{⊥}$ + ∇$_{‖}$ ( ˜ φ$_{G}$ + $^{τ$_{z}$}$˜ p$_{z}$$_{‖}$ ) = µ$_{z}$τ$_{z}$ K ( $^{4}$˜ u$_{z}$$_{‖}$ $^{+ 2}$˜ q$_{z}$$_{‖}$ + ˜ q$_{z}$$_{⊥}$ 2 ) − R$_{ei}$ (4) 1 2 ∂ ˜ T$_{z}$$_{‖}$ ∂t + 1 2 u$_{E}$ ·∇ ˜ T$_{z}$$_{‖}$ + ∇$_{‖}$ $^{(}$˜ u$_{z}$$_{‖}$ + ˜ q$_{z}$$_{‖}$ ) = K ( φ$_{G}$ + $^{τ$_{z}$}$˜ p$_{z}$$_{‖}$ + 2 τ$_{z}$ T$_{z}$$_{‖}$ 2 ) − S Δ (5) ∂ ˜ T$_{z}$$_{⊥}$ ∂t + u$_{E}$ ·∇ ˜ T$_{z}$$_{⊥}$ + w$_{E}$ ·∇ $^{(}$˜ n$_{z}$ + 2 ˜ T$_{z}$$_{⊥}$ ) + $^{∇$_{‖}$}$˜ q$_{z}$$_{⊥}$ = K ( ˜ φ$_{G}$ + ˜ Ω$_{G}$ + $^{τ$_{z}$}$˜ p$_{z}$$_{⊥}$ 2 + 3 ˜ Ω$_{G}$ + τ$_{z}$ ˜ T$_{z}$$_{⊥}$ 2 ) + S Δ (6) µ$_{z}$ $^{∂}$˜ q$_{z}$$_{‖}$ ∂t + µ$_{z}$a$_{L}$ $^{(}$˜ q$_{z}$$_{‖}$ ) + µ$_{z}$ u$_{E}$ $^{·∇}$˜ q$_{z}$$_{‖}$ + 3 2 τ$_{z}$ ∇$_{‖}$ ˜ T$_{z}$$_{‖}$ = µ$_{z}$τ$_{z}$ K ( $^{3}$˜ u$_{z}$$_{‖}$ $^{+ 8}$˜ q$_{z}$$_{‖}$ 2 ) − K$_{‖}$ − K Δ (7) 6