kt_grids_box 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?

For finite magnetic shear determines the box size in the x direction according to $L_x = L_y \textrm{jtwist}/2\pi\hat{s}$. This also affects the number of connections at each ky when linked boundary conditions are selected in the dist_fn_knobs namelist.

Sets the box size in the y direction. If set to 0 (the default) then we set ly=2*pi*y0.

If set greater than zero (the default) then this sets the toroidal mode number of the first non-zero ky by overriding the value given for y0 through y0 = 1.0/(n0*rhostar_box*drhodpsi) where drhodpsi is determined during geometry setup.

The actual number of ky modes. For nonlinear runs it is generally recommended to use ny instead. If set to 0 (the default) this will be automatically set to 1 + (ny-1)/3. If both ny and naky are set then GS2 will check that ny is sufficiently high to ensure de-aliasing. It can be larger than this minimum value. Setting both values can be useful to allow values to be selected which are performant for the FFTs and provide a good range of sweetspots.

The actual number of theta0 modes. For nonlinear runs it is generally recommended to use nx instead. If set to 0 (the default) this will be automatically set to 1 + 2*(nx-1)/3. If both nx and ntheta0 are set then GS2 will check that nx is sufficiently high to ensure de-aliasing. It can be larger than this minimum value. Setting both values can be useful to allow values to be selected which are performant for the FFTs and provide a good range of sweetspots.

The number of kx points in inputs to the fft routines, and hence the number of radial points used in real space calculations. This differs from the actual number of kx points simulated in the rest of the code due to the need to prevent aliasing. The number of kx modes actually simulated (ntheta0) is, by default, equal to 1 + 2*(nx - 1)/3.

The number of ky points in inputs to the fft routines, and hence the number of binormal points used in real space calculations. This differs from the actual number of ky points simulated in the rest of the code due to the need to prevent aliasing. The number of ky modes actually simulated (naky) is, by default, equal to 1 + (ny - 1)/3.

The rhostar (rhoref/Lref) to use. Only used if n0 also set greater than zero. If rhostar_box and n0 are greater than zero then y0=1.0/(n0*rhostar_box*drhodpsi), which effectively sets the minimum non-zero ky used in the simulation.

Expert usage only -- more documentation required.

Controls the box length in the x direction (measured in the reference Larmour radius) if the magnetic shear is small ($\< 10^{-5}$). The box size in the x direction is given by $L_x = 2\pi x_0$. See rtwist for an alternative.

Controls the box length in the y direction (measured in the reference Larmour radius). The box size in the y direction is given by $L_y = 2\pi y_0$. Note if y0 is set negative then, it is replaced with -1/y0 and Effectively sets the minimum wavelength captured by the box.

Number of $k_y \rho$ modes. See [[kt_grids_box_parameters::naky]]

Number of $\theta_0$ points. See [[kt_grids_box_parameters::ntheta0]]

Number of x points in real space. See [[kt_grids_box_parameters::nx]]

Number of y points in real space. See [[kt_grids_box_parameters::ny]]

The $k_y \rho$ grid

The $\theta_0(k_x, k_y)$ grid

The $k_x \rho$ grid

Discrete kx wavenumber grid indices