GEANT-4/Spenvis User Meeting November 2006 Solar Energetic Particle Modelling Activities at ESA A.Glover 1, E. Daly 1,A. Hilgers 1, SEPEM Consortium 2 1.Space Environments and Effects Section ESA/ESTEC, Noordwijk, The Netherlands, 2.BIRA-IASB, Univ Barcelona, Spain, UCL, Leuven, Belgium, Univ Southampton, UK QinetiQ, UK

GEANT-4/Spenvis User Meeting November 2006 Contents Background –SEP Events –Effects –Existing Models The SEPEM Project –Databases –Tools based on existing models –New model development –Helioradial variation Planning Conclusions & future

GEANT-4/Spenvis User Meeting November 2006 SEP Events ● Impulsive: Solar flare accelerated particles (no shock) ● Mixed: Flare + Coronal/interplanetary shock accelerated particles ● Gradual: (Coronal and interplanetary) shock-accelerated particles Impulsive (left) and Gradual (right) SEP event measured by ACE/EPAM (2x low energy channels) and IMP-8/CPME (2x high energy channels).

GEANT-4/Spenvis User Meeting November 2006 Example SEP Effects Cumulated damage (ionisation, displacement, etc…) e.g., on electronic and optical components.Cumulated damage (ionisation, displacement, etc…) e.g., on electronic and optical components. Single Event Upsets.Single Event Upsets. Background in detectors.Background in detectors.

GEANT-4/Spenvis User Meeting November 2006 Engineering requirements Integrated proton fluence over time period (months to years) at given energy (direct effect would be even better). Frequency of occurrence of particle flux above given value over time period (seconds to years) at given energy, given ion mass. Function of location (geo- and interplanetary space) Function of time (minutes to years).

GEANT-4/Spenvis User Meeting November 2006 Available Models and Standards Work JPL-91: “de-facto” & ECSS-E standard –Suitable for fluence assessment –Re-evaluations by Rosenqvist et al. & Glover et al. ESP (Xapsos): gaining rapid acceptance –Fluence and peak flux, extreme value approach CREME-96 –Based on October 89 “worst case” ; suited to SEE –Not worst case; no indication of statistical “rank” “Nymmik/ISO –Correlation of event rate with SSN –Reevaluation of data sets

GEANT-4/Spenvis User Meeting November 2006 SEPEM Study New 2 year study Consortium led by BIRA-IASB & including Univ. Barcelona, U C Leuven, Univ. Southampton and QinetiQ Wide ranging study geared towards updating existing models and developing new models and tools Started September 2006

GEANT-4/Spenvis User Meeting November 2006 Goals of the SEPEM Study Create new engineering models to address ESA’s future needs including: –Ingestion of new data –Enable automated model update –Go beyond mission integrated fluences for given confidence level: new products e.g. peak flux stats, duration of high flux periods… –Incorporate databases of ion species –Include new understanding of generation mechanisms –Investigate helio-radial variation using physics based shock—acceleration models

GEANT-4/Spenvis User Meeting November 2006 Requirements Phase Review of engineering requirements currently underway Requirements will be input to roundtable meeting on SEP Modelling th Feb, Southampton, UK E.g. requirements… –Estimate dose over timescale mths/yrs as function of heliocentric distance –Estimate maximum differential flux at given energy –Estimate frequency of occurrence of differential flux above given threshold –…

GEANT-4/Spenvis User Meeting November 2006 Basic ingredients for modeling a SEP event shock propagation  A good description of the shock propagation  A realistic simulation of particle transport the particle transport  A continuous survey of the shock-acceleration injection mechanisms and injection of energetic particles of energetic particles, as the shock expands. Interplanetary Magnetic Field COBPOINT Observer Energetic particles Cobpoint displacement A key concept: Connecting with the Observer Point Propagating front of the interplanetary MHD shock 0.8 AU Observer Helioradial Dependence: Shock-plus-particle model 1 AU

GEANT-4/Spenvis User Meeting November 2006 SOLPENCO Solar particle engineering code –Step towards an operational tool aiming to predict flux & fluence profiles of SEP events –Database of 448 scenarios at 1AU & 0.4AU for p + energies MeV –User interface allowing rapid acquisition by interpolation of flux & fluence profiles of upstream part of SPE event for given interplanetary scenario –Estimates transit time & speed of IP shock

GEANT-4/Spenvis User Meeting November 2006 E W10 [l08TN] 2 MeV W W10 [l02TN] 2 MeV Flux Fluence Shock arrival SOLPENCO: Example Outputs

GEANT-4/Spenvis User Meeting November 2006 Updating SOLPENCO Original shock-plus-particle model: –MHD shock propagation model (Wu et al.: Solar Phys. 84, 395, 1983 –Particle propagation model (Lario et al.: ApJ 509, 415, 1998) Update to include: –Improved wind model: inner boundary closer to Sun, different wind velocities, extend results out to 2AU

GEANT-4/Spenvis User Meeting November 2006 Upcoming Activities SPE modelling review – identify other candidate models Review of available datasets – generate comprehensive database of available SEP data Development and validation of effects model at 1AU Development and validation of heliocentric dependence of effects Produce guidelines for use and update Propose suitable outputs as potential standard

GEANT-4/Spenvis User Meeting November 2006 Last Word… Need for community involvement in ISO standards process to propose a consensus approach; –Example first steps might be: Standardize data sets to employ ( GOES (which ones?); IMP (which instruments?) ) Standardize event selection methods