theta_grid_params Module

Does the related namelist exist in the target input file?

Used to hold the specific index of numbered namelists

Do we want to skip the read step in init?

Do we want to skip the broadcast step in init?

The flux surface elongation (only used when geoType=0, which selects the Generalised Miller analytic geometry specification).

The radial gradient flux surface elongation (only used when geoType=0, which selects the Generalised Miller analytic geometry specification). akappri = $d\kappa/d\rho$

Used in conjunction with alpmhdfac to override shift, set as shift=-alpmhd*alpmhdfac. Do not use unless you know what you are doing.

Minor radius of the flux surface that receives the specified shaping (only used when geoType=1, which selects the Global MHD analytic geometry specification). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.

In the slab limit, determines the angle between the field and the background flow (which flows in an imaginary toroidal direction). It is effectively equal to $\frac{B_t}{B}=\frac{u_{\parallel}}{u}$. btor_slab = btor/bpol defines direction of a flow relative to B in slab geometry, where flow is by definition in the toroidal direction.

Zeroth cosine moment for the MXH local equilibrum. See geoType and local_eq

Cosine moments for the MXH local equilibrum. See geoType and local_eq

Radial derivatives of cosine moments for the MXH local equilibrum. See geoType and local_eq

The elongation of the flux surface labeled by aSurf (only used when geoType=1, which selects the Global MHD analytic geometry specifications). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.

The triangularity of the flux surface labeled by aSurf (only used when geoType=1, which selects the Global MHD analytic geometry specifications). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.

The magnitude of the mMode shaping effect (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

Radial derivative of the magnitude of the mMode shaping effect (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

The magnitude of the nMode shaping effect (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

Radial derivative of the magnitude of the nMode shaping effect (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

Controls particle trapping (among other things) in simple geometric models. $\epsilon = r/R$

$\epsilon_\ell = \frac{2 L_\textrm{ref}}{ R}$ Sets curvature drift in s-alpha model, where $L_\textrm{ref}$ is the GS2 equilibrium reference normalisation length and $R$ is the major radius at the centre of the flux surface.

Selects between different analytic geometry specifications (only used when local_eq = T):

kp sets parallel wavenumber and box length in slab geometry. $k_p = \frac{2 \pi L_\textrm{ref}}{L_z}$.

First flux surface shaping mode number (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

Second flux surface shaping mode number (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

Number of moments for the MXH local equilibrum. Maximum value is mxh_max_moments. See geoType and local_eq for more details.

Sets the number of $2\pi$ segments along equilibrium magnetic field to include in simulation domain. $N_\textrm{segments} = (2n_\textrm{period} - 1)$. Ignored in some cases

Rough number of grid points along equilibrium magnetic field between $\theta=[-\pi,\pi]$. Actual number of grid points determined as follows:

$p_k = \frac{\textrm{epsl}}{q} = \frac{2 L_\textrm{ref}}{ q R}$ Sets $q$, the magnetic safety factor, and therefore also sets the connection length, i.e. the length of the box in the parallel direction, in terms of $L_\textrm{ref}$. Used only in high aspect ratio $\hat{s}-\alpha$ equilibrium model.

Sets value of the safety factor when using local toroidal equilibrium model.

When not local_eq: Centerpoint of LCFS (normalized to $L_\textrm{ref}$) - When local_eq: Major radius of magnetic field reference point (normalized to $L_\textrm{ref}$). Specifically, the reference magnetic field is defined to be the value of the toroidal magnetic field at R=r_geo on the flux surface labeled by rhoc.

Major radial location of the magnetic axis (only used when geoType=1, which selects the Global MHD analytic geometry specification). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.

rhoc is the flux surface label (0< rhoc< 1). Its exact meaning depends on irho. Usually rho = midplane diameter/midplane diameter of LCFS (here, "LCFS" refers to the flux surface at a radius of $L_\textrm{ref}$. If using Miller geometry with $L_\textrm{ref} \neq a$, this is not the physical last closed flux surface.

When not local_eq: Position of magnetic axis (normalized to $L_\textrm{ref}$). When local_eq: Major radius of the centre of the flux surface of interest (normalized to $L_\textrm{ref}$)

Sine moments for the MXH local equilibrum. See geoType and local_eq

Radial derivatives of sine moments for the MXH local equilibrum. See geoType and local_eq

Sets value of magnetic shear in simple geometric models. Over-ridden by s_hat_input in theta_grid_eik_knobs for most values of bishop.

shift is related to minor radial derivatives of the major radial location of the flux surface centers (i.e. the Shafranov shift), but this input variable has different physical definitions in s-alpha and other analytic equilbrium models:

Minor radial derivative of the axial location of the flux surface centers (i.e. the vertical Shafranov shift). It is only used when equilibrium_option='eik' and geoType=0, 2, or 3 (which selects the Generalised Miller, Generalised Elongation, or Fourier analytic geometry specifications). See Sections 2.1.1, 2.1.3, and 2.1.4 of the Analytic Geometry Specification documentation for more details.

The tilt angle of the elongation of the flux surface labeled by aSurf (only used when geoType=1, which selects the Global MHD analytic geometry specification). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.

The tilt angle of the triangularity of the flux surface labeled by aSurf (only used when geoType=1, which selects the Global MHD analytic geometry specification). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.

The tilt angle of the triangularity (only used when geoType=0, which selects the Generalised Miller specification). See Section 2.1.1 of the Analytic Geometry Specification documentation for more details.

The tilt angle of the elongation (only used when geoType=0, which selects the Generalised Miller specification). See Section 2.1.1 of the Analytic Geometry Specification documentation for more details.

The tilt angle of the mMode shaping effect (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

The tilt angle of the nMode shaping effect (only used when geoType=2 or 3, which selects the Generalised Elongation or Fourier analytic geometry specifications). See Sections 2.1.3 and 2.1.4 of the Analytic Geometry Specification documentation for more details.

The flux surface triangularity (only used when geoType=0, which selects the Generalised Miller analytic geometry specification). triangularity is tri = arcsin[(R(max(Z))-R_major)/r_mid]

The radial gradient of the flux surface triangularity (only used when geoType=0, which selects the Generalised Miller analytic geometry specification). tripri = dtri/drho

Axial location of the magnetic axis (only used when geoType=1, which selects the Global MHD analytic geometry specification). See Section 2.1.2 of the Analytic Geometry Specification documentation for more details.