THIS PROPOSAL IS MOTIVATED BY AND SEEKS TO EXPLAIN THE UNEXPECTED RISE IN THE POSITRON FRACTION OF THE COSMIC RAY (CR) LEPTONIC ENERGY SPECTRUM NOW CONFIRMED BY THE AMS-02 SPECTROMETER. THE NOVELTY OF THE PROPOSED STUDY IS BASED ON THE PREMISE THAT THE POSITRON AND ELECTRON SPECTRA ARE DIFFERENT BECAUSE THEY ARE ACCELERATED BY A CHARGE-SIGN SELECTIVE MECHANISM. THE VALIDITY OF THIS PREMISE WAS HINTED AT BY ANOTHER RECENT AMS-02 RESULT REVEALING A DIFFERENCE BETWEEN POSITRON AND ANTIPROTON SPECTRA WHICH BOTH ARE SECONDARY CRS BUT OF THE OPPOSITE CHARGES. THE NEW MECHANISM EXTENDS THE DIFFUSIVE SHOCK ACCELERATION (DSA) TO MAKE IT CHARGE-SIGN SELECTIVE. THE DSA OPERATING IN GALACTIC SUPERNOVA REMNANT (SNR) SHOCKS IS HELD RESPONSIBLE FOR THE PRODUCTION OF THE BULK OF THE CRS. THE NEW MECHANISM WAS FOUND TO ACCOUNT FOR THE POSITRON DATA WITH AN EXCELLENT AGREEMENT EXCEPT IN A LIMITED ENERGY RANGE BETWEEN 100-300 GEV. IN THIS RANGE THE DATA EXCEED THE THEORETICAL PREDICTION SYSTEMATICALLY. THE PROPOSAL OBJECTIVE IS TO UNDERSTAND THE NATURE OF THE POSITRON EXCESS INCLUDING THE STRIKING DISAGREEMENT WITH THE THEORY IN THE 100-300 GEV RANGE. THERE IS A POSSIBILITY THAT THE PROPOSED RESEARCH PROGRAM AIMED AT THE FURTHER DEVELOPMENT AND IMPROVEMENT OF THE NEW CR ACCELERATION MECHANISM WILL SETTLE THE CURRENT DISAGREEMENT. THE MOST INTERESTING OUTCOME OF THIS PROGRAM HOWEVER WOULD BE UPHOLDING THE CURRENT DEVIATION. IN THIS CASE AN ADDITIONAL POSITRON SOURCE NOT RELATED TO THE SNRS WILL BE REQUIRED TO EXPLAIN THE OBSERVED POSITRON EXCESS. THIS IDEA HAS BEEN CIRCULATING SINCE THE FIRST DETECTION OF THE POSITRON ANOMALY DARK MATTER AND NEARBY PULSARS HAVE BEEN SUGGESTED AS VIABLE CANDIDATES. THE CR AND PARTICLE PHYSICS COMMUNITIES ARE STILL DIVIDED OVER THE ISSUE OF WHETHER THE POSITRON ANOMALY CAN AT ALL BE EXPLAINED BY PARTICLE ACCELERATION IN SNR SHOCKS. THE OPPOSITE STAND IS TAKEN BY THE PROPONENTS OF AN EXCITING POSSIBILITY OF DARK MATTER ANNIHILATION OR DECAY. MEANWHILE THE DEBATE HAS STALLED AND THE REASON FOR THAT SEEMS TO BE TWOFOLD. FIRST THE DATA ABOVE 100 GEV ARE STILL INSUFFICIENT TO DISCRIMINATE BETWEEN MOST MODELS. THIS SHORTCOMING MAY SOON BE REMOVED WITH THE NEXT DATA RELEASE FROM THE AMS-02. ANOTHER PROBLEM IS THAT TO SUPPORT THE ASTROPHYSICAL (SNR) SOLUTION THE DSA WAS APPLIED IN ITS TRADITIONAL CHARGEINDEPENDENT FORM. THIS SIMPLIFICATION LED TO TENSION WITH THE ANTIPROTON DATA IN PARTICULAR. TO OVERCOME THIS SHORTCOMING OF THE DSA WE WILL STUDY THE ACCELERATION OF POSITRONS IN SNR SHOCKS WHICH: (I) PROPAGATE IN CLUMPY GAS MEDIA AND (II) ARE MODIFIED BY PREDOMINANTLY ACCELERATED CR PROTONS. THE CHARGE-SIGN SELECTIVITY OF THE DSA ARISES FROM AN ELECTRIC FIELD INDUCED BY THE CR PROTONS ILLUMINATING THE NEUTRAL GAS CLUMPS. THE ELECTRIC FIELD EXPELS POSITRONS FROM THE CLUMP BUT TRAPS ELECTRONS AND SECONDARY ANTIPROTONS THUS SUPPRESSING THEIR ACCELERATION. SINCE THE SHOCK IS MODIFIED IT ACCELERATES THE POSITRONS TO A HARDER SPECTRUM THAN THAT OF THE CR ELECTRONS ACCELERATED IN OTHER SNRS. MIXING THESE POPULATIONS EXPLAINS THE INCREASE IN THE POSITRON TO ELECTRON RATIO AT E>8 GEV. THIS RATIO DECREASES AT E<8 GEV BECAUSE OF A SUBSHOCK WEAKENING WHICH ALSO RESULTS FROM THE SHOCK MODIFICATION. CONTRARY TO THE EXPELLED POSITRONS MOST OF THE ANTIPROTONS ELECTRONS AND HEAVIER NUCLEI ARE LEFT UNACCELERATED INSIDE THE CLUMPS. COSMIC RAYS AND DARK MATTER ARE THE FUNDAMENTAL CONSTITUENTS OF THE UNIVERSE AND THEIR STUDIES ARE AMONG THE HIGHEST NASA SCIENTIFIC PRIORITIES.