SCIENCE OBJECTIVES: THE GENESIS MISSION HAS MULTIPLE OBJECTIVES FOCUSING ON THE FLUENCE AND/OR ISOTOPES OF HIGH-MASS ELEMENTS FOR WHICH THERE ARE LITTLE OR NO DIRECT SOLAR DATA. THESE ELEMENTS (RB SR BA SM ND OS AND PB) ARE EXTREMELY IMPORTANT TO OUR CURRENT KNOWLEDGE OF THE SOLAR SYSTEM. FOR EXAMPLE 87RB-87SR 147SM-143ND AND 235 238U-232TH-206 207 208PB 187RE-187OS ISOTOPE SYSTEMS HAVE PROVIDED US WITH DEEP INSIGHTS INTO LONG TERM EVOLUTION OF PLANETS [E.G. SEE 1-3 AND REFERENCES THEREIN]. HOWEVER THE SOLAR ABUNDANCES OF THESE ELEMENTS ARE NOT KNOWN PRECISELY [4]. SPECIFICALLY WHILE WE KNOW RB/SR SM/ND U/PB TH/PB RE/OS RATIOS OF PRIMITIVE METEORITES WE DO NOT YET HAVE A GOOD IDEA OF THE CORRESPONDING SOLAR RATIOS WHICH WOULD PROVIDE A TRUE BENCHMARK FOR PLANETARY ACCRETION AND EVOLUTION SCENARIOS. SIMILARLY SOLAR ISOTOPES OF FE ARE NOT KNOWN. ALTHOUGH IT IS ASSUMED THAT FE WAS WELL MIXED IN THE SOLAR NEBULA WE HAVE NO DATA FOR UNPROCESSED FE ISOTOPES OUTSIDE OF THE INNER SOLAR SYSTEM. WE NOTE THAT SOLAR N ISOTOPES WERE MEASURED TO BE D15N = 383 (+ 8) MORE LIKE JUPITER THAN EARTH [5] AND ONLY UNEXPECTED VARIATIONS HAVE SPURRED US TO INVESTIGATE MASS-INDEPENDENT FRACTIONATION PROCESSES LIKE PHOTODISSOCIATION AND SELF-SHIELDING. WE EXPECT DIFFERENCES BETWEEN SOLAR AND TERRESTRIAL FE ISOTOPES TO BE SMALL [E.G. 6]; SPACECRAFT DATA FOR FE ISOTOPES EXIST [7] BUT ARE IMPRECISE AND WITH UNKNOWN/UNTESTABLE SYSTEMATIC ERRORS. ..TASKS: AT DARTMOUTH WE HAVE SUCCESSFULLY DETERMINED THE RULES GOVERNING THE CREATION OF SI-OXIDE LAYERS IN GENESIS (RADIATIONDAMAGED) WAFERS. THIS DISCOVERY WAS PART OF AN ALREADY FUNDED PROPOSAL TO MEASURE OS ISOTOPES IN SILICON WAFERS. THESE RULES WILL PERMIT US TO CUSTOMIZE CREATION OF ~6-7 NM THIN LAYERS OF SILICON OXIDE AND THEN REMOVE THEM WITH HF. SEQUENTIAL CLEANING OF THE WAFERS TO A DEPTH OF 13 NM WILL ALLOW US TO REMOVE DEEPLY BURIED IONS OF OS. WE WILL USE AN IDENTICAL TECHNIQUE TO CLEANLY SEPARATE FE RB SR AND LANTHANIDES AND MEASURE THEIR ABUNDANCES BY ISOTOPE DILUTION USING P-TIMS/N-TIMS. WE WILL ALSO MEASURE FE ISOTOPES AT HIGH PRECISION USING N-TIMS. ..RELEVANCE: WE ADDRESS GENESIS OBJECTIVES #9 #17 #18 AND #19 AND PLAN TO VALIDATE ASSUMPTIONS IN RADIOGENIC SYSTEMS EXTENSIVELY UTILIZED IN ASSESSING THE EVOLUTION OF THE PLANETARY MANTLES. MOREOVER FE ISOTOPES WILL ALLOW US TO TEST FOR SYSTEMATIC DIFFERENCES IN ISOTOPIC COMPOSITIONS BETWEEN SUN AND PLANETARY MATERIALS. REFERENCES: [1] WHITE W.M. (2013) GEOCHEMISTRY. WILEY-BLACKWELL; [2] FAURE G. AND MENSING T.M. (2005) ISOTOPES: PRINCIPLES AND APPLICATIONS. WILEY; [3] DICKIN A.P. (2000) RADIOGENIC ISOTOPE GEOLOGY. CAMBRIDGE; [4] LODDERS K. ET AL. (2009) IN SOLAR SYSTEM (ED: J. E. TR MPER.) LANDOLT-B RNSTEIN NEW SERIES ASTRON.&ASTROPHYS. SPRINGER; [5] MARTY B. ET AL. (2011) SCIENCE 332: 1533 1536.; [6] BOSCHLER P. (2000) REV. GEOPHYS. 38: 247-266; [7] IPAVICH ET AL. (2001) IN SOLAR&GALACTIC COMPOSITION (ED: R.F. WIMMER- SCHWEINGRUBER). AMER. INST. PHYS. .