FOCUSED INTERPLANETARY TRANSPORT OF SIMILAR-TO-1 MEV SOLAR ENERGETIC PROTONS THROUGH SELF-GENERATED ALFVEN WAVES

We present a model of the focused transport of approximately 1 MeV sol ar energetic protons through interplanetary Alfven waves that the prot ons themselves amplify or damp. It is based on the quasi-linear theory but with a phenomenological pitch angle diffusion coefficient in the ''resonance gap.'' For initial Alfven wave distributions that give mea n free paths greater than approximately 0.5 AU for approximately 1 MeV protons in the inner heliosphere, the model predicts greater than rou ghly an order of magnitude amplification (damping) in the outward (inw ard) propagating resonant Alfven waves at less than or similar to 0.3 AU heliocentric distance. As the strength of proton source is increase d, the peak differential proton intensity at approximately 1 MeV at 1 AU increases to a maximum of approximately 250 particles (cm2 s sr MeV )-1 and then decreases slowly. It may be attenuated by a factor of 5 o r more relative to the case without wave evolution, provided that the proton source is sufficiently intense that the resulting peak differen tial intensity of approximately 1 MeV protons at 1 AU exceeds approxim ately 200 particles (cm2 s sr MeV)-1. Therefore, in large solar proton events, (1) one may have to take into account self-amplified waves in studying solar particle propagation, (2) the number of accelerated pr otons escaping from a flare or interplanetary shock may have been unde restimated in past studies by a significant factor, and (3) accelerate d protons escaping from a traveling interplanetary shock at r less tha n or similar to 0.3 AU should amplify the ambient hydromagnetic waves significantly to make the shock an efficient accelerator, even if init ially the mean free path is greater than or similar to 1 AU.