When the input form has been completed, pressing the button will start the calculation and bring up the "Results" page.

The version of DICTAT implemented in SPENVIS is 3.1.

Important note: With the release of SPENVIS 4.6.11 (August 26, 2022) DICTAT was updated to version 3.1 which includes a bug correction (related to missing unit conversions) that produces results that may differ a factor of ten (for cylindrical geometries only) compared to the previous version 3.0. Therefore it is highly recommended to redo past runs (with SPENVIS 4.6.10 and earlier) for cylindrical geometries.

Electron environment

• use the orbit parameters defined for the orbit generator: DICTAT will evaluate the FLUMIC spectrum for a number of points on the orbit defined for the first mission segment;
• the FLUMIC spectrum is generated for one pair of (B/B₀,L) values. Additional inputs are the fraction of the solar cycle and the fraction of the year.
• directly input an integral electron spectrum: this requires a label for the spectrum, the number of energies, the energies and the fluxes, and the exposure duration (the time during which the satellite is exposed to these fluxes). Energies should be monotonically increasing. The spectrum can be isotropic or monodirectional, to simulate laboratory conditions.

Geometry of the structure

The field of view parameter restricts the angle range over which trapped electrons can strike the structure to between 0° and the angle specified by the user. This feature enables the user to simulate cases where the environment is obscured away from the normal by a dense structure. For planar geometry, this reduces the visible environment to a cone. For cylindrical geometry, the visible environment is reduced to a segment centred on the equator, as cylindrical symmetry is assumed. This option is not available when a unidirectional electron spectrum is uploaded.

The number of grounds for the dielectric (one or two) specifies whether the dielectric is grounded at just one surface or at both. A completely isolated dielectric is not simulated. When a singly grounded dielectric is selected, the user has to specify which surface is grounded: the inner surface furthest from the environment, or the outer surface nearest the environment. The combination of a grounded core with zero radius is not allowed and will cause an error.

The user has to specify the thickness of the dielectric and the shield (zero shield thickness is allowed), and of the core material of a cylindrical structure. The dielectric temperature is linked to the activation energy (E_A) of the dielectric material: if E_A=0, then no temperature changes result.

Material parameters

For the conductive shield and core, only the density has to be specified. For the dielectric, additional parameters are required:

• conductivity
• dielectric constant
• breakdown electric field
• k_p and Delta for radiation induced conductivity
• activation energy

In addition, the user can define new materials.

Results

The report file spenvis_dip.html is a printable file containing the input parameters and summary tables. The spenvis_dio.txt file is used by the plotting routines to produce graphical output.

To generate plots, click the appropriate check boxes, select the plot options and graphics format, and click the button. The current page will be updated with the newly generated plot files.