Solar Storm Radiation Model SStoRM

1
Solar Storm Radiation Model SStoRM
http//hesperia.gsfc.nasa.gov/sspvse/posters/Rona
ld_Turner/October 2005Prepared by Joshua
Lande1Ron Turner2
1 Model developed while at ANSER Currently at
Marlboro College, VT.2 ANSER Suite 800 2900
South Quincy St Arlington, Virginia, 22206
2
SStoRM

• SStoRM will be useful as a teaching and
  illustration aid in understanding the severity of
  SPEs as our nation embarks on future missions to
  the Moon, Mars and beyond
• It provides an accessible Graphical User
  Interface, allowing the user to specify
• The character of the SPE (fluence and energy
  spectrum)
• The time evolution of the SPE
• It produces a radiation exposure estimates
• Absorbed Dose and Dose Equivalent
• Skin, Eye, BFO
• In free space and on a simplified lunar surface
• There is an Exercise Mode of a simulation of an
  astronaut on EVA on the lunar surface

3
SStoRM
Input to SStoRM 8,500 BRYNTRN-3 runs, each
with six products Dose Equivalent (Skin, Eye,
BFO) Absorbed Dose (Skin, Eye, BFO) Human
represented by CAM to account for body
self-shielding Five Aluminum shielding
configurations 0.3 g/cm2 (spacesuit) 1.0
g/cm2 (nominal rover) 5.0 g/cm2 (heavy
rover/light spacecraft) 10.0 g/cm2 (nominal
spacecraft) 30.0 g/cm2 (nominal shelter) Solar
Energetic Particle spectra represented by
4
Choose the Energy Spectrum

• SStoRM allows the user to specify the K, ?, and
  Eo parameters of the event
• They also get to specify Emin, or the minimum
  energy value to integrate from when finding the
  integral flux
• When the calculate button is pressed, the flux is
  graphed along with the spectral curve of several
  historical SPEs
• The integral flux for all the graphed curves is
  compared in the chart to the right

5
Choose the Time Evolution

• Here, the user can select A, B1, and B2, the
  parameters of the time evolution curve
• C is calculated automatically to ensure that the
  integral flux of the time evolution of the event
  is the same as the integral flux of the energy
  spectrum of the event
• Once the calculate button is pressed, the C
  factor and the graph of the time evolution of the
  event are displayed

6
The Estimated Dose(or How Bad is Your SPE)

• SStoRM gives total event dose to the Skin, Eye,
  and BFO
• It does so for thicknesses .3, 1, 5, 10, and 30
  g/cm2
• The radio buttons let the user select absorbed
  dose or dose equivalent
• Also, exposure is either for free space or on the
  lunar surface
• The difference is that the dose on the lunar
  surface is half of the dose in free space

7
Lunar EVA Exercise

• This exercise allows the user to simulate an
  astronaut working on the moon during an SPE
• The user can select a warning time that an
  astronaut would receive prior to the onset of the
  event
• A negative value means that they are warned about
  the SPE that many hours after the event has
  started
• They then take a given time to pack up and enter
  the rover
• They then drive back to the base
• Once at base, they stay under a heavy shielding
  for the remainder of the event
• Shielding for spacesuit, rover, and base can be
  varied