MAGNETIC RECONNECTION IN A CURRENT SHEET IS A UNIVERSAL PLASMA PROCESS THAT CONVERTS MAGNETIC ENERGY INTO PARTICLE ENERGY. THE PROCESS IS INITIATED AT AN X-LINE. THIN CURRENT SHEETS ARE PRONE TO MULTIPLE X LINE FORMATION LEADING TO A STRING OF RECONNECTION O-LINES BETWEEN PAIRS OF X-LINES. IN THE 3D PICTURE O-LINES BECOME MAGNETIC FLUX ROPES. FLUX ROPES ARE FORMED BY TWO ACTIVE X-LINES (I.E. THE FLUX ROPE IS ACTIVE) BUT AS THE FLUX ROPE EVOLVES ONE OR BOTH OF THE X-LINES CAN BECOME INACTIVE. DESPITE THEORETICAL PREDICTIONS SHOWING O-LINES TO BE IMPORTANT IN PARTICLE ENERGIZATION THERE IS CURRENTLY A LACK OF OBSERVATIONAL STUDIES ON THIS TOPIC. THIS POINTS TO THE NEED FOR A SYSTEMATIC OBSERVATIONAL STUDY OF PARTICLE ENERGIZATION IN O-LINES/FLUX ROPES. WE PROPOSE TO SYSTEMATICALLY STUDY THERMAL AND NON-THERMAL ION AND ELECTRON HEATING/ENERGIZATION IN FLUX ROPES ASSOCIATED WITH RECONNECTION. THE GOAL OF THE PROPOSED COMPREHENSIVE STUDY IS TO ESTABLISH THE POSSIBLE ASSOCIATION OF FLUX ROPES/O-LINES WITH ION AND ELECTRON ENERGIZATION. SPECIFICALLY WE FOCUS ON THE FOLLOWING KEY QUESTIONS: (1) WHAT IS THE OCCURRENCE AND CHARACTERISTICS OF ION AND ELECTRON ENERGIZATION IN ACTIVE VS. NON-ACTIVE FLUX ROPES? (2) WHAT FACTORS CONTROL THE OCCURRENCE AND CHARACTERISTICS OF THE ENERGIZATION? TO CARRY OUT THIS STUDY WE WILL UTILIZE THEMIS OBSERVATIONS FROM THE DAYSIDE MAGNETOPAUSE. THE DATA SET WILL INCLUDE BOTH ACTIVE (I.E. FLANKED BY TWO ACTIVE X-LINES) AND INACTIVE FLUX ROPES WITH A BROAD RANGE OF GUIDE FIELD MAGNITUDES AND PLASMA BOUNDARY CONDITIONS. PARTICLE ENERGIZATION BY RECONNECTION IS OF FUNDAMENTAL IMPORTANCE IN SPACE PLASMA PHYSICS. THE PROPOSED STUDY WILL REVEAL WHAT TYPES OF FLUX ROPES ARE ASSOCIATED WITH HEATING/ENERGIZATION AND WILL PUT CONSTRAINTS ON THEORETICAL MODELS OF PARTICLE ENERGIZATION IN O-LINES/ FLUX ROPES. THE SCIENTIFIC OBJECTIVES OF THIS PROJECT ARE DIRECTLY ALIGNED WITH THREE OF THE HIGH-LEVEL SCIENCE GOALS IDENTIFIED IN THE MOST RECENT HELIOPHYSICS DECADAL SURVEY: GOAL #2 - DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS. GOAL #3 DETERMINE THE INTERACTION OF THE SUN WITH THE SOLAR SYSTEM AND THE INTERSTELLAR MEDIUM. GOAL #4 - DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE.