# Presentation: 721831

## ESP & Psychic Solar Flare Models

- The Problem
- The ESP Model of Solar Protons
- Psychic Model

- Tom Diehl
- January 5, 2005

## 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.

## Solar Cycle Projection

- NGST Radiation Environment: Barth, Isaacs, Poivey http://www.ngst.nasa.gov/public/unconfigured/doc_0570/rev_04/ngstradenv2.pdf

- Est. Sunspot Activity vs. Year (2009-2020)

- Solar flares and coronal mass ejections originate with the “sunspots”
- Plot on left is projected sunspot count.
- There’s an 11Yr solar cycle.

## “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. _[http://trs.nis.nasa.gov/archive/00000505/01/tp209763.](http://trs.nis.nasa.gov/archive/00000505/01/tp209763.pdf)__[pdf](http://trs.nis.nasa.gov/archive/00000505/01/tp209763.pdf)_  has the write-up and _[http://see.msfc.nasa.gov/ire/model_esp.html](http://see.msfc.nasa.gov/ire/model_esp.html)_ provides a link to software distribution.

## 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:

## 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)             80         85         90         95         99
- -------------      ---------  ---------  ---------  ---------  ---------
-        1           2.44E+011  2.89E+011  3.56E+011  4.85E+011  8.68E+011
-        3           8.62E+010  1.02E+011  1.27E+011  1.74E+011  3.17E+011
-        5           5.09E+010  6.16E+010  7.82E+010  1.11E+011  2.16E+011
- .                .         .          .          .          .
- .                .         .          .          .          .
- .                .         .          .          .          .
-      275           2.03E+007  3.02E+007  4.97E+007  1.04E+008  4.19E+008
-      300           1.59E+007  2.37E+007  3.91E+007  8.20E+007  3.29E+008

## Proton Flux 2004-2015

- 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”.

- 99
- 95
- 90
- 85
- 80
- 50
- C.L. (%)

- Integral Flux (> MeV)

## Proton Flux 2004-2015

- 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.

## 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.

## Proton Flux – Psychic Model

- Average for 11 year cycle with 7 years at solar max and 4 years at solar min.
- # Protons above         11 51 100 MeV is:            C.L. (%)    #/cm2/s   50   93.9  7.8  1.3
- These are 2-3x higher than the ESP Model at k.e. > 50 MeV

## ESP vs. Psychic

- Comparison based on 8 y @ solar max and 3 y @ solar min.

## “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.

## Summary and Plan

- Solar proton model from Mike X. provides solution. Dose was negligible.
- Check MARS result
- Email 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.