Crossed ExB-fields back-bombardment instability and ion cyclotron heating of gas-discharge plasma-streams

The article present our recent results of computer simulations and theory a nalysis concerning of dynamics of the crossed ExB-fields back-bombardment ( BKB) instability in magnetron diodes. The concept of the BKB-instability ap plied to show new explanation for known experimental data of an intense ion heating in accelerated plasma streams. Main features of the BKB-instabilit y into ion diodes are following: I) ion magnetic insulation is d(0) > r(i) where d(0) is accelerating gap across applied magnetic field B-0, r(i) = 5V (0)(0.5)/B-0 is proton Larmor radius,cm; V-0 - applied voltage, kV; B-0 - k G ; 2) E-A not equal 0 is high electric field on self or secondary emission anode electrodes; 3) main frequency oscillation of f(s) = f(ci)/2 = 0.76 B -0 MHz; 4) convert power efficiency of eta(B) = P-similar to/P-0 is up to 5 0%. Radial proton I-IF-oscillations current density of the J(ir) provided by th e BKB-instability excites magnetohydrodynamics waves. They are propagated i n the tube plasma with azimuthal velocity v(similar to theta) similar to 10 (7) cm/s (M(i)v(similar to theta)(2) similar to eV(0)) and along the B-0 wi th the v(A) similar to 4x10(7) cm/s -Alften velocity. Known experimental da ta was demonstrated a level of the HF-oscillation power which was absorbed by proton streams by ion cyclotron heating equals up to 30% total supply po wer of the I MW. Work supported by RFFI under grant 96-02-19215.