(gaussian)¶

This module provides a Gaussian shaped radial profile. The radial profile is defined according to

\[f_r(r) = a \exp\left[ -\left(\frac{\rho-b}{c}\right)^2 \right]\]

This radial profile has been observed to match well with hollow runaway beams.

Note

This module was kindly contributed by Giorgio Ghillardi.

Summary of options¶

The following parameters can be set on a gaussian radial profile.

Option	Description
`radprof-gaussian amax`	Normalized minor radius of the outer edge of the electron beam.
`radprof-gaussian amin`	Normalized minor radius of the inner edge of the electron beam.
`radprof-gaussian rhomax`	Major radius of the outer edge of the electron beam.
`radprof-gaussian rhomin`	Major radius of the inner edge of the electron beam.
`radprof-gaussian rmax`	Minor radius of the outer edge of the electron beam.
`radprof-gaussian rmin`	Minor radius of the inner edge of the electron beam.
`radprof-gaussian gau_a`	Gaussian scale factor.
`radprof-gaussian gau_b`	Gaussian shift parameter.
`radprof-gaussian gau_c`	Gaussian width parameter.

Example configuration¶

This example illustrates how a gaussian radial profile can be defined and used together with the (avalanche) distribution function in SOFT2 simulations:

# Global parameter specifying which distribution function to use
distribution_function = analytical_avalanche;

@DistributionFunction analytical_avalanche (avalanche) {
    EHat     = 10;            # Electric field strength (normalized to
                              # the Connor-Hastie critical electric field)
    lnLambda = 17;            # Coulomb logarithm
    Zeff      = 4;             # Effective plasma charge

    # Set the radial profile
    radprof   = ourradprof;
}

@RadialProfile ourradprof (gaussian) {
    # Set normalized minor radius
    # These settings creates a beam with radius
    # 2/3 of the device minor radius.
    amin = 0;
    amax = 0.99;

    # Create gaussian profile f(r) = a * exp(-(r-b)^2/c^2)
    gau_a = 0.05;
    gau_b = 1.80;
    gau_c = 0.04;
}

All options¶

amax¶

amin¶

rhomax¶

rhomin¶

rmax¶

rmin¶

Default value:	`amin = 0` and `amax = 1`.
Allowed values:	Any radial position that is inside the plasma and on the outboard side.

Specifies the inner and outer edges of the electron beam. The prefix (a*, r*, rho*) specifies whether the edge is given in normalized minor radius, regular minor radius or major radius coordinates.

gau_a¶

Default value:	Nothing
Allowed values:	Any real number.

Scale factor in front of radial profile.

gau_b¶

Default value:	Nothing
Allowed values:	Any real number.

Shift of the peak in radius of the Gaussian profile.

gau_c¶

Default value:	Nothing
Allowed values:	Any real number.

Width of the Gaussian profile.