THE IMPORTANCE OF INTERMEDIATE FREQUENCY WAVES (10 HZ TO 10 KHZ) IN THE EVOLUTION OF THE SOLAR WIND AND PROPAGATION OF SOLAR ENERGETIC PARTICLES IS NOT WELL UNDERSTOOD EITHER EXPERIMENTALLY OR THEORETICALLY. THIS BAND COVERS THE RANGE FROM ~0.1 FCE (ELECTRON CYCLOTRON FREQUENCY) THROUGH SEVERAL TIMES FPI (THE ION PLASMA FREQUENCY). OUR PREVIOUS STUDIES OF WAVES IN THIS RANGE HAVE REVEALED THE EXISTENCE OF TWO NEWLY IDENTIFIED WAVE MODES IN THE SOLAR WIND: (1) OBLIQUE NARROW BAND WHISTLER-MODE WAVES AT ~0.2 FCE; AND (2) ELECTROSTATIC DISPERSIVE WAVES NEAR THE ION PLASMA FREQUENCY. THESE WAVES ARE OFTEN LARGE AMPLITUDE UP TO 10S MV/M. CURRENT MODELS OF SOLAR WIND STRUCTURES INCLUDING CORONAL MASS EJECTIONS (CMES) STREAM INTERACTION REGIONS (SIRS) AND INTERPLANETARY (IP) SHOCKS AND OF PROPAGATION OF SOLAR ENERGETIC PARTICLES (SEP) DO NOT INCLUDE THE EFFECTS OF THESE WAVES. OUR PRELIMINARY TEST PARTICLE STUDIES OF THE WHISTLER-MODE WAVES INDICATE THAT THEY MAY SIGNIFICANTLY SCATTER AND/OR ENERGIZE ELECTRONS RANGING FROM 100S EV (STRAHL) UP TO MEV (SEPS). WE PROPOSE AN EXPERIMENTAL STUDY UTILIZING HIGH TIME RESOLUTION FIELDS AND PARTICLES DATA FROM THE STEREO ARTEMIS AND MMS MISSIONS. OUR OVERARCHING SCIENCE GOAL IS TO UNDERSTAND THE ROLE OF THESE INTERMEDIATE FREQUENCY WAVES IN THE DYNAMICS OF THE SOLAR WIND AND PROPAGATION OF ENERGETIC PARTICLES. WE PROPOSE TO ADDRESS THE FOLLOWING QUESTIONS: (1) WHAT FEATURES OF THE PARTICLE DISTRIBUTIONS GENERATE THE OBSERVED NARROWBAND WHISTLER-MODE WAVES AND THE ELECTROSTATIC DISPERSIVE WAVES? (2) WHAT IS THE INFLUENCE OF WAVE MODE COUPLING ON THESE WAVES? (3) DO THESE TWO WAVE TYPES OCCUR PREFERENTIALLY WITH A SPECIFIC SOLAR WIND STRUCTURE (E.G. SHOCKS CIRS) AND HOW DO THESE WAVES MODIFY THE STRUCTURES EVOLUTION? (4) CAN EITHER WAVE TYPE SIGNIFICANTLY INFLUENCE PROPAGATION OF SOLAR ENERGETIC PARTICLES? THE DISCOVERY OF THESE MODES WAS ENABLED BY THE LONG (2.1 S) 3D ELECTRIC FIELD WAVEFORM CAPTURES ON STEREO. THIS MODE WAS RUN FOR PERIODS IN 2011 AND CONTINUOUSLY BEGINNING MARCH 2017. LONGER WAVEFORM CAPTURES OBTAINED BY ARTEMIS AND MAGNETOSPHERIC MULTISCALE (MMS) WHICH ALSO INCLUDE SEARCH COIL DATA AND HIGHER TIME RESOLUTION PARTICLE DISTRIBUTIONS PROVIDE THE DATA SETS NEEDED TO MORE FULLY CHARACTERIZE THE WAVE PROPERTIES AND THEIR ASSOCIATION WITH SPECIFIC FEATURES IN THE ELECTRON AND ION DISTRIBUTIONS. OUR ANALYSIS WILL UTILIZE PRIMARILY THE BURST MODE FIELDS AND PARTICLE DATA SETS FROM THESE THREE MISSIONS WITH THE MORE CONTINUOUS SURVEY DATA SETS PROVIDING CONTEXT AND USED TO DISTINGUISH SOLAR WIND STRUCTURE TYPES. THE DATA SETS CURRENTLY PUBLICLY AVAILABLE PROVIDE THE NUMBER OF EVENTS WITH THE VARIETY OF SOLAR WIND CONDITIONS NEEDED TO ADDRESS OUR SCIENCE QUESTIONS. IN PARTICULAR WE HAVE ALREADY IDENTIFIED A SET OF EVENTS WITH BURST MODE DATA FROM THE SOLAR WIND OBSERVATIONS BY MMS FROM 10/2017 THROUGH 3/2018 AND FROM THE ARTEMIS FROM 11/2011 THROUGH 8/2017 AND STEREO-A FROM 3/2017 THROUGH 3/2018. STANDARD WAVE MODE IDENTIFICATION AND FREE ENERGY DETERMINATION TECHNIQUES WILL BE UTILIZED TOGETHER WITH LINEAR DISPERSION SOLVERS. TEST PARTICLE SIMULATIONS USING OUR EXISTING CODE WILL BE USED TO ASSESS IMPACT OF THESE WAVE TYPES ON SPECIFIC PARTICLE POPULATIONS. OUR RESEARCH IS RELEVANT TO THE STEREO GOALS TO DISCOVER THE MECHANISMS AND SITES OF ENERGETIC PARTICLE ACCELERATION IN THE INTERPLANETARY MEDIUM AND IMPROVE THE DETERMINATION OF THE STRUCTURE OF THE AMBIENT SOLAR WIND AND CHARACTERIZE THE PROPAGATION OF CMES THROUGH THE HELIOSPHERE. OUR WORK IS ALSO APPLICABLE TO THE ARTEMIS OBJECTIVE TO EXAMINE PARTICLE ACCELERATION AND TURBULENCE IN THE SOLAR WIND. WE DIRECTLY ADDRESS TWO GOALS OF THE DECADAL SURVEY: DETERMINE THE INTERACTION OF THE SUN WITH THE SOLAR SYSTEM AND THE INTERSTELLAR MEDIUM ; AND DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE.