Help: Magnetic shiedling

Table of Contents	ECSS	Model Page
Background Information	Radiation sources and effects
	Magnetic shielding

SPENVIS allows to apply magnetic attenuation to particle fluxes outside the planet's magnetosphere.

The user can turn the shielding on or off. When shielding is activated the following input parameter(s) with options are required, depending on the selected planet.

Arrival direction

The rigidity cut-off is either calculated by integrating over all incoming directions or only for vertical arrival.

For Earth only:

Magnetosphere

The condition of the magnetosphere can be set to quiet or stormy.

Method

Three methods are implemented in SPENVIS for computing the rigidity cut-off:

Størmer with eccentric dipole model
Smart and Shea (1967) with the IGRF model
Størmer upgrade

The Størmer upgrade uses an analytic expression that fits the average results obtained with Magnetocosmics for the following set of SM coordinates and input parameter values:

Altitudes: 400, 4000, 200000 km
Longitudes: 0°, 90°, 180°, 270°
Latitudes: -60°, -20°, 0°, 20°, 60°
Two different dates in year 2000 with 6 month interval
Internal magnetic field: IGRF 2000
External magnetic field: Tsyganenko 96
Quiet magnetosphere
Soalr activity parameter values: Dst=-30 nT, ImfBz=ImfBy=0 nT, Pdyn=3 nPa

Magnetic moment value

The user can select from the following set of values for the magnetic moment:

unchanged (= epoch value)
McIlwain
CREME-86
CREME-96

The physical background of the parameters is given here.

References

Størmer, C., Periodische Elektronenbahnen im Felde eines Elementarmagneten und ihre Anwendung auf Brüches Modellversuche und auf Eschenhagens Elementarwellen des Erdmagnetismus. Mit 32 Abbildungen., Zeitschrift für Astrophysik, Vol. 1, p.237, 1930.

Shea, M. A., and D. F. Smart, Worldwide Trajectory-Derived Vertical Cutoff Rigidities and Their Application to Experimental Measurements, J. Geophys. Res., 72(7), 2021–2027, 1967.

Last update: Wed, 25 Apr 2018