1. ESP & Psychic Solar Flare Models
The Problem
The ESP Model of Solar Protons
Psychic Model
Tom Diehl
January 5, 2005

2. The Problem Creme96 simulation provides
Galactic cosmic ray fluences at solar minimum and solar maximum
Worst 5 minutes, day, & week of solar flares
These are the extrema and the expected radiation dose varies from 7 rads/yr (from galactic protons) to 200 rad/day (from the worst solar flare).
We need a better model if we are to provide a spec. for radiation dose.

3. Solar Cycle Projection
Solar flares and coronal mass ejections originate with the “sunspots”
Plot on left is projected sunspot count.
There’s an 11Yr solar cycle.
Est. Sunspot Activity vs. Year ( )
NGST Radiation Environment: Barth, Isaacs, Poivey

4. “Emission of Solar Protons” Model
I came across it in an NASA memo “The Radiation Environment … GOES-R Series Satellites”, 417-R-RPT-0027 (March 2004) and in NGST radiation estimates, both by Janet Barth and Mike Xapsos.
They referenced their model. has the write-up and provides a link to software distribution.

5. ESP Model & Results Input Ranges 1970-2020 and 50%-99%
Results from 1970 to 1999 are based on actual observations.
Results from 2000 on are averaged over previous years in the solar cycle.
Simple Interface:

6. ESP Model & Results
Four part output: Proton Flux vs. C.L. for several C.L. and also the user C.L., same for worst case solar event.
Energy range is 1 MeV to 300 MeV (k.e.)
The 100 to 300 MeV part is an extrapolation.
2 // TYPE (1=Input,2=Output)
1998,1999,90 //INPUTS (Start Year,End Year,Confidence Level)
TOTAL PROTON FLUENCE FOR MISSION
Results for a mission of 1998 to 1999.(2 Active Years)
GENERAL CONFIDENCE LEVEL TABLE
Integral Proton Fluence(cm^-2)
Energy Levels Confidence Levels()
(>MeV)
E E E E E+011
E E E E E+011
E E E E E+011
E E E E E+008
E E E E E+008

7. Proton Flux
ESP Model provides solar proton flux estimates in energy range 1 to 300 MeV at distance averaged at 1 A.U.
Provides any combination of years from 1988 to 2020 and 50% or higher c.l. flux.
Plot is “Integral Flux”.
Integral Flux (> MeV) 99 95 90 85 80 50
C.L. (%)

8. Proton Flux
ESP Model
Differential spectrum produced from the integral plot. The units are : #/cm2/yr at 50% C.L.
Caveat: This ESP isn’t the Spenvis version. It’s the version I got from NASA.

9. Psychic Model Update to ESP from Mike Xapsos (NASA Goddard)
This guy is one of co-authors of the model. I met him at the IEEE NSREC meeting in Atlanta in July.
This update is called “Psychic” goes 327 MeV and has smoother differential spectrum.

10. Proton Flux – Psychic Model
Average for 11 year cycle with 7 years at solar max and 4 years at solar min.
# Protons above MeV is: C.L. (%) #/cm2/s
These are 2-3x higher than the ESP Model at k.e. > 50 MeV

11. ESP vs. Psychic
Comparison based on 8 solar max and 3 solar min.

12. “MARS 15” and Psychic Results
NVM inc. made a new MARS release in November.
I picked that up, incorporated the SNAP model and reproduced the previous results.
I ran 20M “Psychic protons” using the average flux from 7 yrs of solar max and 4 years of solar min.
The silicon received a dose of 0.1 Rad/yr.

13. Summary and Plan
Solar proton model from Mike X. provides solution. Dose was negligible.
Check MARS result
to Mike X. with ESP vs. Psychic comparison
Possibly this doesn’t include solar “events”.
Implement the flux from the ESP Model.
Write up results. Est. Feb 16.