A Statistical Study of Solar Particle Events in Flux and DoseThe high-energy protons from solar energetic particle (SEP) events present a hazard to space systems: damage to science instruments/electronics/materials or to astronauts. A reliable estimate of the high-energy proton environment is critical to assure mission success. Important characteristics of an SEP event are fluence, peak flux, energy spectrum, time to reach the peak flux, time to reach peak dose, and properties of the cumulative dose profile after an event starts. All of these characteristics are important to understand in order to design space missions properly for both robotic and human missions. Because of the unpredictable and sporadic nature of SEP events, statistical models are often used to represent the SEP parameters described above. In a study by Jun et al. (2007), the statistics of event fluences, durations, and time intervals between events were investigated using the then available historical SEP dataset obtained from the instruments onboard the IMP-8 spacecraft. Since then, a more comprehensive SEP dataset based off of IMP-8 and GOES called Reference Data Set Version 2.0 (RDSv2.0) has become available covering the SEP events up to Year 2015 under a framework of the European Space Agency's (ESA's) Solar Energetic Particle Environment Modelling (SEPEM) project (Jiggens et al., 2018). The main objectives of this statistical study of SEP events are two-fold: First, the statistics of peak fluxes, event fluences, durations, and time intervals will be re-visited by using RDSv2.0; Second, the statistical analyses of flux and dose timing will be performed using the same dataset RDSv2.0. The results of this study will address the statistical properties of all key parameters for designing a spacecraft or a human mission where the SEP environment is an important consideration.
Document ID
20180006658
Acquisition Source
Johnson Space Center
Document Type
Presentation
Authors
Whitman, K. (Wyle Labs., Inc. Houston, TX, United States)
Hu, S. (Wyle Labs., Inc. Houston, TX, United States)
Allen, J. (NASA Headquarters Washington, DC United States)
Fry, D. (NASA Johnson Space Center Houston, TX, United States)
Heynderickx, D. (DH Consultancy BVBA Leuven, Belgium)
Hock, R. (Air Force Research Lab. Wright-Patterson AFB, OH, United States)
Jiggens, P. (European Space Agency. European Space Research and Technology Center, ESTEC Noordwijk, Netherlands)
Jun, I. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Mertens, C. (NASA Langley Research Center Hampton, VA, United States)
Minow, J. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Onsager, T. (National Oceanic and Atmospheric Administration Boulder, CO, United States)
Parker, L. (Universities Space Research Association (USRA) Huntsville, AL, United States)
Pulkkinen, A. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Semones, E. (NASA Johnson Space Center Houston, TX, United States)
St Cyr, C. (NASA Goddard Space Flight Center Greenbelt, MD, United States)