Help: SOLARC

Table of Contents	ECSS	Model Page
Background Information	Spacecraft charging
	SOLARC

SOLARC simulates the current collection, voltage distributions and material erosions on solar arrays and spacecraft structures in a space environment.

Two sets of input parameters are required for SOLARC, to define the plasma environment and the spacecraft configuration, respectively.

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

Model parameters

Plasma environment

The space plasma environment surrounding the solar array and spacecraft is specified by a thermal ion and electron distribution and an energetic ion and electron population. The environment parameters can be obtained with LEOPOLD. All particles can be included or excluded in the calculation to simulate different environments, e.g. wake or ram conditions.

Thermal distributions

A thermal ion distribution is characterised by a temperature, a number density, and an ion type for ions. The temperatures and densities of one ion and one electron distribution can be specified.

Energetic particles

The energetic particle population is characterised by an energy, a particle flux, and an ion type for ions. The energies and fluxes of one ion and one electron distribution can be specified.

Spacecraft configuration

Array/structure configuration

The solar array and structure configuration is specified by means of six parameters:

solar array voltage;
number of basic building blocks of which the array is composed. This may be the number of solar cells in the array or some other suitable sub-unit.
area of the individual blocks or solar cells;
fractional area of interconnects: the area of the solar cell interconnects in terms of the fraction of the block or solar cell area. Since the interconnects are the metallic surfaces on the solar array that actually collect the current from the surrounding plasma, this parameter defines the effective geometric collecting area of the solar array.
spacecraft structure surface area;
spacecraft structure/array attachment fraction: the fractional distance that the structure attachment point lies from the lower (i.e. negative) end of the solar array (0 corresponds to the negative end, 1 to the positive end).
The spacecraft structure can be excluded from the calculation if only the solar array is of interest.

Current collection models

Current collection models must be defined for the solar array and (if present) the spacecraft structure, respectively. The user has the option to exclude the energetic particle distributions from the current collection models.

Materials for erosion rate calculations

Two materials may be selected for the array and structure each, for which erosion rates due to sputtering will be calculated. These materials are not used in the calculation of the current collection.

Results

SOLARC produces the files listed in the table below. A description of the format of the files can be brought up by clicking on their description in the table.

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

**List of output files generated by SOLARC**
File name	Description
`spenvis_sop.html`	Report file
`spenvis_soo.txt`	Erosion rates and current collection models

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.

Last update: Mon, 12 Mar 2018