CRad

CRad is a tool to predict Single Event Effects (SEE) rate, Total Displacement Dose (TDD) and Total Ionizing Dose (TID) of semiconductor devices on orbits in space. It's the professional version of ForeCAST. Their differences are at the bottom of this page.

The workflow, and also the GUI of CRad:
crad

Radiation Environment on Certain Orbits

Models for radiation environment:

  • Orbit description：
    • Orbital elements (Keplerian elements)
  • Geomagnetic model：
    • mimic ISO
  • Radiation models：
    • Galaxy cosmic rays
    • CREME86
    • ISO15390
    • Solar cosmic rays
    • CREME86
    • CREME96
    • Anomalous cosmic rays
    • CREME86
    • CREME96
    • Trapped radiation by geomagnetic field (Van Allen Belt)
    • AP8/AE8 model
  • Shielding by geomagnetic field

The flux of particles：

crad_rslt

The trapped radiation can also be shown on 2D-orbit：

orbit_m

SEE Rate Prediction

The methods of SEE rate prediction are explained here. What CRad do includes：

  • Ground Test Based
    • For heavy ions
    • IRPP model
    • For proton
    • Bendel model with two parameters
    • PROFIT model
    • J.Barak2006 model
  • Device Structure Based
    • NRED
    • NRED-MC

Shielding of the Space Craft

For SEE Rate

The shielding effect of a space craft can be simplified as a thickness distribution of equivalent aluminum layers. To calculate the thickness distribution of a certain space craft, SSAT (developed by ESA) is employed. Due to different physics and geometry requirements, SSAT is not a part of CRad, but implemented in VisualParticle.

For TDD and TID

When predicting TDD and TID of devices in space orbits, Shieldose2 code, developed by NASA, is used for simulating the shielding of space craft shell. Three kinds of geometry model are supported by Shieldose2, including infinite-thickness slab, finite-thickness slab, and finite sphere.

ForeCAST vs. CRad

ForeCAST is the on-line version of CRad.

ForeCAST CRad
Running on On-line GNU Linux(R) 或 MS Windows(R)
Function Modules Standard Customizable
Spacecraft Shielding 1-Dimension 3-Dimension
SEE Prediction Standard Fancier Methods
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