JOINT MULTIWAVELENGTH MEASUREMENTS OF THE MATTER DISTRIBUTION IN CLUSTERS OF GALAXIES WE PROPOSE TO MAKE A COMPREHENSIVE DETERMINATION OF THE BARYONIC AND DARK MATTER DISTRIBUTION IN CLUSTERS OF GALAXIES USING A NEW METHODOLOGY DEVELOPED BY US. USING OUR TECHNIQUE IS IT POSSIBLE TO COMBINE ALL AVAILABLE MULTIWAVELENGTH DATA FOR A CLUSTER INTO A SINGLE JOINT ANALYSIS INVOLVING X-RAY HYDROSTATICS, WEAK GRAVITATIONAL LENSING, STELLAR DYNAMICS, AND THE SUNYAEV-ZEL'DOVICH EFFECT. THIS COMBINATION REPRESENTS AN IMPROVEMENT OVER EXISTING METHODS, AND CAN PROVIDE POWERFUL OBSERVATIONAL CONSTRAINTS ON THE DARK MATTER HALO SLOPE AND CONCENTRATION. WE HAVE MARSHALLED DATA FROM X-RAY OBSERVATORIES (CHANDRA, XMM-NEWTON), AS WELL AS FROM GROUND BASED OPTICAL AND RADIO FACILITIES, TO ASSEMBLE A REPRESENTATIVE SAMPLE OF 50 CLUSTERS SUITABLE FOR TESTING THE DETAILED PREDICTIONS OF CDM AND GAS SIMULATIONS. OUR FIRST GOALS ARE TO MEASURE THE LOGARITHMIC SLOPE OF THE DARK MATTER PROFILE TO AN ACCURACY OF +/- 0.2, AND TO MEASURE ITS CONCENTRATION TO AN ACCURACY OF 20%, FOR THE RELAXED CLUSTERS IN THE SAMPLE. WE ARE UNIQUE AMONG LARGE MULTIWAVELENGTH SURVEYS IN ATTEMPTING SUCH CONSTRAINTS USING ALL AVAILABLE DATA. TO COMPLEMENT THESE NEW LIMITS ON DARK MATTER PROPERTIES, WE WILL ALSO DEVELOP AND APPLY TRIAXIAL HYDROSTATIC MODELS TO THE RELAXED CLUSTERS IN OUR SAMPLE, AND MEASURE THE CONNECTION BETWEEN THE LEVEL SUBSTRUCTURE AND DEVIATIONS FROM SELF-SIMILARITY. THE PHYSICS CODE USED FOR THIS PROJECT WILL BE MADE PUBLICLY AVAILABLE TO THE BROADER SCIENTIFIC COMMUNITY FOR FREE USE. THIS WILL PROVE TO BE AN INVALUABLE TOOL FOR THE ANALYSIS OF UPCOMING SPACE-BASED (CLASH) AND GROUND-BASED WEAK GRAVITATIONAL LENSING SURVEYS. THE GROUND BASED SURVEYS WILL PRODUCE CATALOGS OF 10^5 CLUSTERS OF GALAXIES, AND A UNIFORM TOOL IS REQUIRED FOR ANALYZING SUCH DATA IN CONJUNCTION WITH COMPLEMENTARY MULTIWAVELENGTH OBSERVATIONS.