Alphabetical list for input.cgyro

AMP

Definition

Initial amplitude of finite-$n$ modes.

Comments

• DEFAULT = 0.1

• For linear simulations, the value is unimportant

• For nonlinear runs, this will usually need to be reduced to a smaller value.

---

AMP0

Definition

Initial amplitude of $n=0$ modes.

Comments

• DEFAULT = 0.0

---

BETAE_UNIT

Comments

• DEFAULT = 0.0

Definition

The electron beta with reference to $B_{\mathrm{unit}}$:

$${\beta }_{e,\mathrm{unit}}\doteq \frac{8\pi n_e{T}_e}{B_{\mathrm{unit}}^2}$$

Comments

• DEFAULT = 0.0

---

BETAE_UNIT_SCALE

Definition

Scale factor for BETAE_UNIT.

Comments

• DEFAULT = 1.0

---

BETA_STAR_SCALE

Definition

Pressure gradient scaling factor. Here, the pressure gradient factor is defined as

$${\beta }_{\ast }=-\frac{8\pi }{B_{\mathrm{unit}}^2}\frac{dp}{dr}$$

Comments

• DEFAULT = 1.0

• In the absence of scaling, the value of ${\beta }_{\ast }$ will be computed self-consistently given the value of ${\beta }_{e,\mathrm{unit}}$ set in BETAE_UNIT.

• Often it is desired to reduce ${\beta }_{e,\mathrm{unit}}$ but leave the effective ${\beta }_{\ast }$ unchanged. In this case, one should divide BETAE_UNIT by 2, then set BETA_STAR_SCALE=2.

---

BTCCW

Definition

Parameter which selects the orientation of the toroidal magnetic field $B_t$ relative to the toroidal angle $\phi$.

Choices

• BTCCW = 1: Counter-clockwise when viewed from above the torus - negative ${\mathbf{e}}_{\phi }$ for the right-handed coordinate system $(r,\theta ,\phi )$. Thus, $B_t$ is oriented along the negative ${\mathbf{e}}_{\phi }$ direction.

• BTCCW = -1: Clockwise when viewed from above the torus - positive ${\mathbf{e}}_{\phi }$ for the right-handed coordinate system $(r,\theta ,\phi )$. Thus, $B_t$ is oriented along the positive ${\mathbf{e}}_{\phi }$ direction.

Comments

• DEFAULT = -1

• In DIII-D, typically BTCCW = 1.

• When experimental profiles are used (PROFILE_MODEL = 2), the orientiation of $B_t$ is inferred from input.gacode.

---

BOX_SIZE

Definition

Integer multiplier to determine the radial box length, $L_x$, as a multiple of the distance between reference singular surfaces, $L_0=r/(qs)$.

$$\frac{L_x}{a}=\mathrm{BOX}\mathrm{\_}\mathrm{SIZE}\left(\frac{r}{qs}\right)$$

Comments

• DEFAULT = 1 (integer)

• Note that the reference singular surface spacing refers to $n=1$ which is always the lowest non-zero mode in CGYRO.

• Also, $r\to$ RMIN, $s\to$ S, $q\to$ Q.

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COLLISION_MODEL

Definition

Collision operator selection.

Choices

• COLLISION_MODEL = 1: Lorentz ee+ei

• COLLISION_MODEL = 2: Connor

• COLLISION_MODEL = 4: Sugama (maximal accuracy)

• COLLISION_MODEL = 5: Simple Lorentz ee+ei (fastest)

Comments

• DEFAULT = 4

• To control conservation and other properties, the following parameters can be set: COLLISION_FIELD_MODEL, COLLISION_MOM_RESTORE, COLLISION_ENE_RESTORE, COLLISION_ENE_DIFFUSION, COLLISION_KPERP

• Memory usage can be reduced by setting COLLISION_PRECISION_MODE.

• On GPU systems, GPU offload is controlled by GPU_BIGMEM_FLAG. When that is not enabled, the slower but less GPU memory demanding CPU-only Sugama operator is used.

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COLLISION_FIELD_MODEL

Definition

Flag to toggle self-consistent field update during collisions.

Choices

• COLLISION_FIELD_MODEL = 0: Field update OFF

• COLLISION_FIELD_MODEL = 1: Field update ON

Comments

• DEFAULT = 1

---

COLLISION_MOM_RESTORE

Definition

Flag to toggle collisional momentum conservation.

Choices

• COLLISION_MOM_RESTORE = 0: Momentum conservation OFF

• COLLISION_MOM_RESTORE = 1: Momentum conservation ON

Comments

• DEFAULT = 1

• For test purposes only.

---

COLLISION_ENE_RESTORE

Definition

Flag to toggle collisional energy conservation.

Choices

• COLLISION_ENE_RESTORE = 0: Energy conservation OFF

• COLLISION_ENE_RESTORE = 1: Energy conservation ON

Comments

• DEFAULT = 1

• For test purposes only.

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COLLISION_ENE_DIFFUSION

Definition

Flag to toggle collisional energy diffusion.

Choices

• COLLISION_ENE_DIFFUSION = 0: Energy diffusion OFF

• COLLISION_ENE_DIFFUSION = 1: Energy diffusion ON

Comments

• DEFAULT = 1

• For test purposes only.

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COLLISION_KPERP

Definition

Flag to toggle $k_{\perp }^2$ terms in collision operator.

Choices

• COLLISION_KPERP = 0: Terms OFF

• COLLISION_KPERP = 1: Terms ON

Comments

• DEFAULT = 1

• For test purposes only.

---

COLLISION_PRECISION_MODE

Definition

Control the precision of the cmat constants.

Choices

• COLLISION_PRECISION_MODE = 0: Full 64-bit precision.

• COLLISION_PRECISION_MODE = 1: Heuristics-based lower-precision setup, slightly better than 32-bit precision.

• COLLISION_PRECISION_MODE = 32: Reduced 32-bit precision.

• COLLISION_PRECISION_MODE = 64: Full 64-bit precision. (Same as 0)

Comments

• DEFAULT = 0

• Selecting COLLISION_PRECISION_MODE 1 and 32 results in significant memory saving and negligible precision loss in most use-cases.

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DELTA

Definition

Triangularity, $\delta$, of the flux surface:

Comments

• DEFAULT = 0.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the triangularity as a function of radius is read from input.gacode.

---

DELTA_T

Definition

Simulation timestep $(c_s/a)\mathrm{\Delta }t$.

Comments

• DEFAULT = 0.01

• Because CGYRO uses an explicit time-integration scheme for collisionless terms, the timestep must typically be smaller than for long-wavelength GYRO simulations.

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DELTA_T_METHOD

Definition

Control for adaptive or fixed time-stepping.

Choices

• DELTA_T_METHOD = 0: RK4 4:4(3) [non-adaptive]

• DELTA_T_METHOD = 1: Cash-Karp 6:5(4)

• DELTA_T_METHOD = 2: Bogacki-Shampine 7:5(4)

• DELTA_T_METHOD = 3: Verner 10:7(6)

Comments

• DEFAULT = 0

• Notation is s:o(e) where s=stages,o=order,e=order of error estimate.

---

DENS_*

Definition

The normalized equilibrium-scale density. First species density is DENS_1, and so on.

$$\mathrm{DENS}\ast =\frac{n_{\ast }}{n_e}$$

Commments

• DEFAULT = $[1,0,0,\dots ]$

• The user should set DENS=1 for electrons.

• When experimental profiles are used (PROFILE_MODEL = 2), the densities are automatically normalized to $n_e$.

• When rotation effects are included (ROTATION_MODEL = 2), this parameter is the density at the outboard midplane ($\theta =0$).

---

DLNNDR_*

Definition

The normalized equilibrium-scale density gradient scale length:

$$\mathrm{DLNNDR}\mathrm{\_}\ast =-a\frac{\partial \mathrm{l}\mathrm{n}{n}_{\ast }}{\partial r}$$

Commments

• DEFAULT = $[1,1,1,\dots ]$

• When experimental profiles are used (PROFILE_MODEL = 2), the density as a function of radius is read from input.gacode and the gradient is computed internally. The normalizing length is the plasma minor radius.

• When rotation effects are included (ROTATION_MODEL = 2), this parameter is the value at the outboard midplane ($\theta =0$).

---

DLNTDR_*

Definition

The normalized equilibrium-scale temperature gradient scale length:

$$\mathrm{DLNTDR}\mathrm{\_}\ast =-a\frac{\partial \mathrm{l}\mathrm{n}{T}_{\ast }}{\partial r}.$$

Commments

• DEFAULT = $[1,1,1,\dots ]$

• When experimental profiles are used (PROFILE_MODEL = 2), the temperature as a function of radius is read from input.gacode and the gradient is computed internally. The normalizing length is the plasma minor radius.

• When rotation effects are included (ROTATION_MODEL = 2), this parameter is the value at the outboard midplane ($\theta =0$).

---

DZMAG

Definition

The derivative of the elevation:

$$\frac{\partial Z_0(r)}{\partial r}.$$

Comments

• DEFAULT = 0.0

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E_MAX

Definition

Maximum value of (pseudospectral) dimensionless energy, ${\epsilon }_{\max }$

Comments

• DEFAULT = 8.0

• Corresponds to Maxwellian factor ${\displaystyle e^{-{\epsilon }_{\max }}}$

---

ERROR_TOL

Definition

Error tolerance for adaptive time-stepping.

Comments

• DEFAULT = 1e-4

• Decrease this slightly for very-high-transport cases

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EQUILIBRIUM_MODEL

Definition

Flux-surface shape specification parameter.

Choices

• EQUILIBRIUM_MODEL = 1: $s$ - $\alpha$

• EQUILIBRIUM_MODEL = 2: Miller parameterization

• EQUILIBRIUM_MODEL = 3: General (Fourier) parameterization

Comments

• DEFAULT = 2

• EQUILIBRIUM_MODEL=1 is not available for experimental profiles (PROFILE_MODEL =2).

---

FIELD_PRINT_FLAG

Definition

Toggle printing of $\delta A_{\parallel }(k_x^0,k_y,t)$ and $\delta B_{\parallel }(k_x^0,k_y,t)$ .

Comments

• DEFAULT = 0

• Output files are bin.cgyro.kxky_apar and bin.cgyro.kxky_bpar, respectively

• Even if this flag is set to zero, potential fluctuations $\delta \varphi (k_x^0,k_y,t)$ are written to bin.cgyro.kxky_phi

---

FREQ_TOL

Definition

Eigenvalue convergence tolerance for linear simulations.

Comments

• DEFAULT = 0.001

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GAMMA_E

Definition

Normalized $\mathbf{E}\times \mathbf{B}$ shearing rate ${\displaystyle \frac{a}{c_s}{\gamma }_E}$.

Comments

• This is the radial electric field shear and is a global term (can’t be treated in a local simulation)

• It it zeroed automatically in a linear simulation

• DEFAULT = 0.0

• See discussion on plasma rotation

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GAMMA_E_SCALE

Definition

Scaling factor applied to experimental value of ${\gamma }_E$ .

Comments

• DEFAULT = 1.0

• Only active for PROFILE_MODEL =2

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GAMMA_P

Definition

Normalized rotation shearing rate ${\displaystyle \frac{a}{c_s}{\gamma }_p}$.

Comments

• DEFAULT = 0.0

• See discussion on plasma rotation

---

GAMMA_P_SCALE

Definition

Scaling factor applied to experimental value of ${\gamma }_p$ .

Comments

• DEFAULT = 1.0

• Only active for PROFILE_MODEL =2

---

GPU_BIGMEM_FLAG

Definition

Enable (or disable) memory intensive GPU offload.

Choices

• GPU_BIGMEM_FLAG = 0: The slower but less GPU memory demanding CPU-only Sugama operator is used.

• GPU_BIGMEM_FLAG = 1: The GPU-accelerated Sugama operator is used. Large memory use due to cmat.

• GPU_BIGMEM_FLAG > 1: Less GPU memory demanding, as only 1/GPU_BIGMEM_FLAG of cmat is kept in memory at any time. Slower due to memory copies.

Comments

• DEFAULT = 1

• Only active on GPU systems for COLLISION_MODEL =4

---

H_PRINT_FLAG

Definition

Toggle printing of distribution for single-mode runs.

Comments

• DEFAULT = 0.

---

IPCCW

Definition

Parameter which selects the orientation of the plasma current (and thus the poloidal magnetic field $B_p$) relative to the toroidal angle $\phi$.

Choices

• IPCCW = 1: Counter-clockwise when viewed from above the torus - negative ${\mathbf{e}}_{\phi }$ for the right-handed coordinate system $(r,\theta ,\phi )$. Thus, $B_p$ is oriented along the negative ${\mathbf{e}}_{\phi }$ direction.

• IPCCW = -1: Clockwise when viewed from above the torus - positive ${\mathbf{e}}_{\phi }$ for the right-handed coordinate system $(r,\theta ,\phi )$. Thus, $B_p$ is oriented along the positive ${\mathbf{e}}_{\phi }$ direction.

Comments

• DEFAULT = -1

• In DIII-D, typically IPCCW = 1.

• When experimental profiles are used (PROFILE_MODEL = 2), the orientiation of IP is inferred from input.gacode.

---

KAPPA

Definition

Elongation, $\kappa$, of the flux surface.

Comments

• DEFAULT = 1.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the elongation as a function of radius is read from input.gacode.

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GFLUX_PRINT_FLAG

Definition

Toggle printing of global flux profiles.

Comments

• DEFAULT = 0

• See also N_GLOBAL

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KY

Definition

Selector for value of $k_{\theta }{\rho }_s$ .

Comments

• If N_TOROIDAL = 1, this is the simulated value of $k_{\theta }{\rho }_s$

• If N_TOROIDAL > 1, this is the lowest nonzero value of $k_{\theta }{\rho }_s$

• Use the output in out.cgyro.info to guide selection of KY

---

LAMBDA_DEBYE

Definition

---

LAMBDA_DEBYE_SCALE

Definition

---

MACH

Definition

Rotation speed (Mach number) $M$

Comments

• DEFAULT = 0.0

• See discussion in plasma rotation

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MACH_SCALE

Definition

Scaling factor applied to experimental value of $M$ .

Comments

• DEFAULT = 1.0

• Only active for PROFILE_MODEL =2

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MASS_*

Definition

The species mass normalized to deuterium mass: MASS_1, and so on.

$$\mathrm{M}\mathrm{A}\mathrm{S}\mathrm{S}\mathrm{\_}\ast =\frac{m_{\ast }}{m_D}.$$

Commments

• DEFAULT = $[1,1,1,\dots ]$

• When experimental profiles are used (PROFILE_MODEL = 2), the normalizing mass is deuterium.

• A typical case (deuterium, carbon, electrons) would be:

  MASS_1=1.0
  MASS_2=6.0
  MASS_3=2.724e-4
  

---

MAX_TIME

Definition

Maximum simulation time in units of $a/c_s$

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MOMENT_PRINT_FLAG

Definition

Toggle printing of $\delta n_a(k_x^0,k_y,t)$ and $\delta E_a(k_x^0,k_y,t)$ .

Comments

• DEFAULT = 0.

---

MPI_RANK_ORDER

Definition

Specify the relative ordering of MPI ranks.

Choices

• MPI_RANK_ORDER = 1: Depth-first mode

• MPI_RANK_ORDER = 2: Breadth-first mode

Comments

• DEFAULT = 2

• The optimal value depends on both the hardware and the problem being run.

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NONLINEAR_FLAG

Definition

Toggle inclusion of nonlinear terms.

Choices

• NONLINEAR_FLAG=0: Nonlinear terms OFF

• NONLINEAR_FLAG=1: Nonlinear terms ON

Comments

• DEFAULT = 0

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NL_SINGLE_FLAG

Definition

Toggle FP precision used by nonlinear terms compute.

Choices

• NL_SINGLE_FLAG=0: Use full FP64 (double) precision for all phases, including compute and MPI communication.

• NL_SINGLE_FLAG=1: Use FP64 (double) precision for foreard communication and compute, FP32 (single) precision for reverse communication.

• NL_SINGLE_FLAG=2: Use FP32 (single) precision for all phases, including compute and MPI communication.

Comments

• DEFAULT = 0

• Use of FP32 validated for modest sized simulations.

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N_FIELD

Definition

Selector for number of fluctuating fields

Choices

• N_FIELD=1: Retain $\delta \varphi$

• N_FIELD=2: Retain $(\delta \varphi ,\delta A_{\parallel })$

• N_FIELD=3: Retain $(\delta \varphi ,\delta A_{\parallel },\delta B_{\parallel })$

Comments

• DEFAULT = 1

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N_GLOBAL

Definition

Control number of global output harmonics

Comments

• DEFAULT = 4

• Making this larger retains shorter scales in the output

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NU_GLOBAL

Definition

Source rate

Comments

• DEFAULT = 15.0

• Making this larger increases the source rate

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NUP_RADIAL

Definition

---

UP_THETA

Definition

---

NUP_THETA

Definition

Accuracy control for the poloidal discretization scheme.

Choices

• NUP_THETA=1: 1st-order conservative upwind

• NUP_THETA=2: 3rd-order conservative upwind

• NUP_THETA=3: 5th-order conservative upwind

Comments

• DEFAULT=3 (5th order)

• The numerical scheme (conservative upwind) is modified by projecting out density and current perturbations induced by the grid-scale dissipation.

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UP_ALPHA

Definition

---

NUP_ALPHA

Definition

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NU_EE

Definition

Electron-electron collision frequency ${\nu }_{ee}$, in units of $c_s/a$.

$${\nu }_{ee}=\frac{4\pi n_e{e}^4}{(2T_e{)}^{3/2}{m}_e^{1/2}}\log \mathrm{\Lambda }.$$

Comments

• DEFAULT = 0.1

• All ion collision rates are self-consistently determined from NU_EE.

• The recommended minimum value is NU_EE = 0.01.

---

N_RADIAL

Definition

Number of radial wavenumbers (radial Fourier harmonics) to retain in simulation.

Comments

• DEFAULT = 4

• For linear simulations with BOX_SIZE =1, this can be as small as 2, but a minimium of 4 is recommended.

• For nonlinear simulations, we recommend N_RADIAL > $L_x/\rho$

• Wavenumbers span $p=-N,\dots ,N-1$ where $N$ = N_RADIAL/2

---

N_THETA

Definition

Number of poloidal gridpoints ${\theta }_i$. There is a single poloidal mesh for both the distribution function and the fields (unlike GYRO).

Comments

• DEFAULT = 24

• The order of accuracy of the poloidal discretization is controlled by NUP_THETA.

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N_XI

Definition

Number of Legendre pseudospectral meshpoints ${\xi }_i$ to retain in simulation.

Comments

• DEFAULT = 16

• This is the pitch-angle resolution

• This is equivalent to number of retained Legendre polynomials

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N_ENERGY

Definition

Number of generalized-Laguerre pseudospectral meshpoints $v_i$ to retain in simulation

Comments

• DEFAULT = 8

• This is the energy resolution

• This is equivalent to number of retained Laguerre polynomials

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N_TOROIDAL

Definition

Number of toroidal harmonics (binormal Fourier modes).

Comments

• Together with KY, this controls the toroidal resolution.

• Together with TOROIDALS_PER_PROC, this controls the number of MPI processes needed.

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N_SPECIES

Definition

Number of kinetic species (includes electrons and all ions).

Comments

• DEFAULT = 1

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PRINT_STEP

Definition

Frequency of simulation data output.

Comments

• DEFAULT = 100

• If PRINT_STEP=100, simulation data will be output after every 100 timesteps

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PROFILE_MODEL

Definition

Selector for profile data input.

Choices

• PROFILE_MODEL=1: Set local profile parameters in input.cgyro.

• PROFILE_MODEL=2: Compute local profile parameters from data in input.gacode.

Comments

• DEFAULT = 1

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PX0

Definition

The ballooning angle parameter $\mathrm{PX}0={\theta }_0/(2\pi )$.

Comments

• DEFAULT = 0.0

• This is used only for linear simulations.

• The most unstable linear mode is normally at $\mathrm{PX}0=0$.

• Choose $0\le \mathrm{PX}0<1$.

---

Q

Definition

Safety factor, $q$, of the flux surface.

Comments

• DEFAULT = 2.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the safety factor as a function of radius is read from input.gacode and the safety factor gradient is computed internally.

---

QUASINEUTRAL_FLAG

Definition

Enforce quasineutrality when using experimental profiles.

Choices

• QUASINEUTRAL_FLAG=0: Use raw density data.

• QUASINEUTRAL_FLAG=1: Reset main ion density to enforce quasineutrality.

Comments

• DEFAULT = 1

• This is only active when experimental profiles are used (PROFILE_MODEL = 2).

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RESTART_STEP

Definition

Frequency of restart file generation

Comments

• DEFAULT = 10

• If PRINT_STEP=100 and RESTART_STEP=10, simulation data will be output once every 100 timesteps and restart data will be output once every 1000 timesteps (i.e., once every 10 data outputs)

RMIN

Definition

The ratio $r/a$, where $r$ is the minor radius and $a$ is the radius of the LCFS.

Comments

• DEFAULT = 0.5

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RMAJ

Definition

The ratio $R_0/a$, where $R_0$ is the major radius and $a$ is the radius of the LCFS.

Comments

• DEFAULT = 3.0

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ROTATION_MODEL

Definition

Choices

• ROTATION_MODEL = 1: Weak rotation

• ROTATION_MODEL = 2: Sonic (Sugama) rotation

Comments

• DEFAULT = 1

---

S

Definition

Magnetic shear, $s$, of the flux surface:

$$s=\frac{r}{q}\frac{\partial q}{\partial r}.$$

Comments

• DEFAULT = 1.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the safety factor as a function of radius is read from input.gacode and the safety factor gradient is computed internally.

---

SHIFT

Definition

Shafranov shift, $\mathrm{\Delta }$, of the flux surface:

$$\mathrm{\Delta }=\frac{\partial R_0}{\partial r}.$$

Comments

• DEFAULT = 0.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the flux-surface-center major radius as a function of radius, $R_0(r)$, is read from input.gacode and its derivative is computed internally.

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SHAPE_COS0

Definition

0th antisymmetric moment.

• DEFAULT = 0.0

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SHAPE_S_COS0

Definition

0th antisymmetric moment shear.

• DEFAULT = 0.0

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SHAPE_COS1

Definition

1st antisymmetric moment.

• DEFAULT = 0.0

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SHAPE_S_COS1

Definition

1th antisymmetric moment shear.

• DEFAULT = 0.0

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SHAPE_COS2

Definition

2nd antisymmetric moment.

• DEFAULT = 0.0

---

SHAPE_S_COS2

Definition

2th antisymmetric moment shear.

• DEFAULT = 0.0

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SHAPE_COS3

Definition

3rd antisymmetric moment.

• DEFAULT = 0.0

---

SHAPE_S_COS3

Definition

3rd antisymmetric moment.

• DEFAULT = 0.0

---

SHAPE_SIN3

Definition

3rd symmetric moment.

• DEFAULT = 0.0

---

SHAPE_S_SIN3

Definition

3rd symmetric moment shear.

• DEFAULT = 0.0

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SILENT_FLAG

Definition

---

S_DELTA

Definition

Measure of the rate of change of the average triangularity of the flux surface:

$$s_{\delta }=r\frac{\partial \delta }{\partial r}.$$

Comments

• DEFAULT: 0.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the triangularity as a function of radius is read from input.gacode and the triangularity gradient is computed internally.

---

S_KAPPA

Definition

Measure of the rate of change of the elongation of the flux surface:

$$s_{\kappa }=\frac{r}{\kappa }\frac{\partial \kappa }{\partial r}.$$

Comments

• DEFAULT: 0.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the elongation as a function of radius is read from input.gacode and the elongation gradient is computed internally.

---

S_ZETA

Definition

Measure of the rate of change of the average squareness of the flux surface:

$$s_{\zeta }=r\frac{\partial \zeta }{\partial r}.$$

Comments

• DEFAULT: 0.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

---

TEMP_*

Definition

The normalized equilibrium-scale temperature. First species temperature is TEMP_1, and so on.

$$\mathrm{TEMP}\mathrm{\_}\ast =\frac{T_{\ast }}{T_e}.$$

Commments

• DEFAULT: TEMP_*= $[1,\dots ]$

• The user should set TEMP=1 for electrons.

• When experimental profiles are used (PROFILE_MODEL = 2), the temperatures are automatically normalized to $T_e$.

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THETA_PLOT

Definition

The number of poloidal points for output of large fluctuation moment arrays.

Commments

• DEFAULT: THETA_PLOT=1

• Value should be an integer divisor of N_THETA

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TOROIDALS_PER_PROC

Definition

Number of toroidal harmonics to process in a single MPI process.

Comments

• DEFAULT: 1

• Must be a divisor of N_TOROIDAL.

• A higher number typically results in faster simulation on low node count.

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UDSYMMETRY_FLAG

Definition

---

UP_RADIAL

Definition

---

UPWIND_SINGLE_FLAG

Definition

Control the precision of upwind communication.

Choices

• UPWIND_SINGLE_FLAG = 0: Full 64-bit precision

• UPWIND_SINGLE_FLAG = 1: Faster but lower 32-bit precision.

Comments

• DEFAULT = 0

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VELOCITY_ORDER

Definition

Specify the ordering inside the velocity space

Choices

• VELOCITY_ORDER = 1: species inner loop, energy outer loop

• VELOCITY_ORDER = 2: xi inner loop, species outer loop

Comments

• DEFAULT = 1

• VELOCITY_ORDER=2 drastically reduces the cost of communication, but requires MPI rank to be a multiple of both N_TOROIDAL and N_SPECIES.

• The restart file format is specific to VELOCITY_ORDER.

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Z_*

Definition

Species charge. First species charge is Z_1, and so on.

Comments

• DEFAULT = 1

• A typical case (deuterium, carbon, electrons) would be:

  Z_1=1
  Z_2=6
  Z_3=-1
  

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Z_EFF

Definition

User-specified value for $Z_{\mathrm{eff}}$.

Comments

• DEFAULT = 1.0

• Normally this is computed self-consistently by CGYRO, but can be set by the user

• Enabled by setting Z_EFF_METHOD = 1

• Only allowable with simple collision models: COLLISION_MODEL = 1 or 5

---

Z_EFF_METHOD

Definition

Control how $Z_{\mathrm{eff}}$ is computed.

Choices

• Z_EFF_METHOD=1: Use value for Z_EFF defined in input.cgyro (or input.gacode)

• Z_EFF_METHOD=2: Compute Z_EFF automatically and self-consistently based on species data (recommended)

Comments

• DEFAULT = 2

• Only allowable with simple collision models: COLLISION_MODEL = 1 or 5

---

ZETA

Definition

Squareness, $\zeta$, of the flux surface.

Comments

• DEFAULT = 0.0

• This is only active with EQUILIBRIUM_MODEL = 2 (the Miller equilibrium model).

• When experimental profiles are used (PROFILE_MODEL = 2), the squareness as a function of radius is read from input.gacode.

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ZF_TEST_MODE

Definition

Toggle test for time-evolution of a single $k_x$ mode (the classic zonal flow test).

Choices

• ZF_TEST_MODE = 0: No test (default)

• ZF_TEST_MODE = 1: Trigger test

Comments

• DEFAULT = 0

• The standard test is to evolve a single radial mode (N_RADIAL=1)

• If N_RADIAL > 1, multiple independent modes will be evolved with $k_x\rho =2\pi p/L$ where $1\le p\le$ N_RADIAL

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ZMAG

Definition

The ratio $Z_0(r)/a$, where $Z_0$ is the elevation and $a$ is the radius of the LCFS.

Comments

• DEFAULT = 0.0

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