2019 Volume 14 Pages 2403010
A new closure model for the parallel conductive heat flux of the perpendicular component of ion energy (qi,⊥) is proposed which considers the effect of the spontaneous parallel gradient of the perpendicular ion temperature in inhomogeneous magnetic fields. Profiles of plasma parameters and the particle confinement efficiency are compared between the new qi,⊥ model and a conventional one in a simple mirror system. It is found that the conservation of the magnetic moment is reproduced with the new qi,⊥ model. Comparisons of ion power flux profiles show that the new qi,⊥ model changes the direction of qi,⊥ keeping the spontaneous parallel gradient of the perpendicular ion temperature. Almost linear relations between the particle confinement time and the ion-ion Coulomb collision time are also obtained with both qi,⊥ models.