Collisional losses of electrons from an adiabatic trap in a plasma with a positive potential

Abstract

The author obtains analytical expressions for the collisional losses of electrons and their energy from an adiabatic trap when the plasma has a high positive potential. The expressions are derived on the basis of an approximate solution of the Fokker-Planck equation, which yields more reliable results than those obtained with the estimative formulas used in a number of other works. In addition, an expression is obtained for the mean energy of the electrons escaping from the trap.

Alpha channeling in rotating plasma with stationary waves

“…2 Deuterons scatter into the loss cone after a time τ D ≈ τ ii exp W ED 1 − R −1 m /T i , where τ ii is the ion-ion collision time and R m is the mirror ratio, and tritons have a similar dependence. 28 In the plasma described above, τ ii = 1 s, so that τ D = 55 s and τ T = 400 s. The fusion timescale is τ f us = 300 s. Combining these times with the simulated parameters and a plasma length of 40 m, we expect the power lost to be approximately 110 kW. If each fusion event produces 1.38 MeV of potential energy and requires 1 MeV, the net power from alpha particles left in the potential will be 150 kW, exceeding the power loss.…”

Wave-Driven Rotation in Centrifugal Mirrors

“…The ion confinement time is ν i ≈ ν i e 1−R , using the Pastukhov factor for the confining potential and our previous relationship between W E0 and T i , assuming T e T i [18]. The fusion time is simply ν f us = n i σv /4.…”

Recent progress of plasma confinement and heating studies in the gas dynamic trap

“…In an idealized mirror trap, where plasma jet flows through the magnetic mirror into open space, electron heat losses show favorable behavior: convective law Qe ~ Te 3/2 and 5.3 Te per lost electron [13]. In real machines, however, interaction of plasma outflow with surfaces and with background neutral gas argued to cause substantial increase of electron heat losses [12].…”