Esp solar flare model
This presentation is the property of its rightful owner.
Sponsored Links
1 / 9

ESP Solar Flare Model PowerPoint PPT Presentation


  • 96 Views
  • Uploaded on
  • Presentation posted in: General

ESP Solar Flare Model. The Problem The ESP Model of Solar Protons 11 Year Average Proton Flux. Tom Diehl 06/30/2004. Solar Cycle Projection. NGST Radiation Environmrnt: Barth, Isaacs, Poivey http://www.ngst.nasa.gov/public/unconfigured/doc_0570/rev_04/ngstradenv2.pdf.

Download Presentation

ESP Solar Flare Model

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Esp solar flare model

ESP Solar Flare Model

  • The Problem

  • The ESP Model of Solar Protons

  • 11 Year Average Proton Flux

Tom Diehl

06/30/2004


Solar cycle projection

Solar Cycle Projection

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

  • Solar flares and coronal mass ejections originate with the “sunspots”

  • Plot on left is projected sunspot count.

  • See large variation in solar activity.

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


The problem

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 to 200 rad/day.

  • We need a better model if we are to provide a spec. for radiation dose.


Emission of solar protons model

“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.pdf has the write-up and http://see.msfc.nasa.gov/ire/model_esp.html provides a link to software distribution.


Esp model results

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.


Esp model results1

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.)

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

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 1988xx to 2020 and 50% or higher c.l. flux.


Esp model plan

ESP Model - Plan

  • Incorporporate this flux into MARS

  • Get an update of the model from Mike Xapsos that goes to higher energy

    • Overnighter to IEEE conference in Atlanta; I’ve arranged to meet M.X.


Summary

Summary

  • Obtained “ESP Model” used by experts to simulate proton fluences from solar events in radiation damage simulations for satellites at L2.

  • It solves the extrema problem and will allow us to make reasonable estimates of the doses.

  • I plan to obtain an extension to the model from the authors.


  • Login