Whistler mode noise in Jupiter's inner magnetosphere

The distinctive 'hat shape' of equatorial pitch angle distributions constructed from Pioneer 10 and 11 Jupiter observations of energetic electrons E/sub e/>21 MeV and E/sub e/>31 MeV at L=3 is examined from the point of view of pitch angle diffusion by resonant interaction with a band-limited spectrum of whistler mode noise. In this picture, the pitch angle profiles are consistent with whistler mode noise limited to frequencies below an upper cutoff frequency 2.8< or approx. =∫/sub c/< or approx. =4.6kHz. Equatorial linear growth 30.5γ/sub max,/ is approximately 2--10 kHz a L=3 and falls smoothly to 0.2--2 kHz at L =10. Raytracing of nonducted whistlers of characteristic frequencies 1-4 kHz generated at the magnetic equator and propagated through a finite temperature (100--400 eV) hydrogen plasma cengrifugally confined near the magnetic equatorial plane shows that wave phase speed decrease to near or below electron thermal speeds before high-latitude reflection can occur. Wave growth in this case is limited to a disclike region centered about the magnetic equator. The amplitude growth of the most unsable whistlers propagating across the growth region parallel to the magnetic field is approx.exp