ALPS Input

This is a reference for the key input parameters used by ALPS.

Namelists in input files.

The following namelists and associated input parameters are read in by ALPS from the input file.

&system

General system parameters.

kperp
Initial perpendicular wavevector $k_{\perp} d_{p}$.

kpar
Initial parallel wavevector $k_{\parallel} d_{p}$.

nspec
Number of plasma species.

nroots
Number of dispersion solutions to find and follow.

use_map
Choice of:

• True: Searching for roots over a map in complex frequency space (see &maps_1 namelist).
• False: Input nroots guesses for solutions (see &guess_1 namelist).

writeOut
Write or suppress output to screen.

nperp
Perpendicular momentum space resolution, $N_{\perp}$. The input file must have $N_{\perp}+1$ values spanning parallel momentum space.

npar
Parallel momentum space resolution, $N_{\parallel}$. The input file must have $N_{\parallel}+1$ values spanning parallel momentum space.

ngamma
Relativistic momentum space resolution, $N_{\Gamma}$.

npparbar
Relativistic parallel momentum space resolution, $N_{\bar{p}_{\parallel}}$.

vA
Reference Alfven velocity, normalized to the speed of light, $v_{A}/c$.

arrayName
Name of input array, located in 'distribution' folder.

Bessel_zero
Maximum amplitude of Bessel function to determine nmax.

secant_method
Selection for root finding method. 0: secant method from NHDS 1: rtsec method from PLUME 2: Improved secant method to reduce oscillations around solutions.

numiter
Maximum number of iterations in secant method.

D_threshold
Minimum threshold for secant method.

D_prec
Size of bounding region for secant method.

D_gap
Size of allowable difference between roots.

positions_principal
Number of parallel momentum steps distant from the resonant momentum included in the numerical calculation of Eqn 3.5, $M_{I}$.

n_resonance_interval
How many steps should be used to integrate around the resonance, $M_{P}$, used for integrating near poles (see section 3.1).

Tlim
Threshold for analytical principal-value integration, $t_{\mathrm{lim}}$.

maxsteps_fit=500
Maximum number of fitting iterations.

lambda_initial_fit
Inital Levenberg-Marquardt damping parameter.

lambdafac_fit
Adjustment factor for Levenberg-Marquardt damping parameter.

epsilon_fit
Convergence for Levenberg-Marquardt fit.

fit_check
If true, output fitted functions for each species to file in distribution directory.

determine_minima
If true, after map search, determine minima and refine solutions.

scan_option
Select case for wavevector scans:

• 1: Consecutive scans along input paths in wavevector space,
• 2: Double scan over wavevector plane.

n_scan
Number of wavevector scans.
0 turns off wavevector scans.
Must be 1 or larger for scan_option=1.
Must be set to 2 for scan_option=2.

&guess_m

Initial guess of complex frequency for $m$th solution.
Only used when use_map=.false.
Need to have number of name lists equal to nroots.

g_om
Guess for real solution $\omega_{r}/\Omega_{p} $.

g_gam
Guess for imaginary solution $\gamma/\Omega_{p} $.

&maps_1

Range of complex frequencies for map_scan subroutine.
Only used when use_map=.true.

loggridw
Linear (F) or Log (T) spacing for $\omega_{r}/\Omega_{p}$ map search. Spacing automatically calculated between omi and omf.

loggridg
Linear (F) or Log (T) spacing for $\gamma/\Omega_{p}$ map search. Spacing automatically calculated between gami and gamf

omi
Smallest $\omega_{r}/\Omega_{p}$ value for complex map search.

omf
Largest $\omega_{r}/\Omega_{p}$ value for complex map search.

gami
Smallest $\gamma/\Omega_{p}$ value for complex map search.

gamf
Largest $\gamma/\Omega_{p}$ value for complex map search.

ni
Number of $\gamma/\Omega_{p}$ points in frequency grid.

nr
Number of $\omega_{r}/\Omega_{p}$ points in frequency grid.

&spec_j

Species parameters list for distribution $f_{j}$.

nn
Relative density $n_{j}/n_{p}$.

qq
Relative charge $q_{j}/q_{p}$.

mm
Relative mass $m_{j}/m_{p}$.

ff
Number of fitted functions for analytical continuation calculation.

relat
Treat $f_{j}$ as non-relativistic or relativistic.

log_fit
Use linear or $\log_{10}$ fitting routine.

use_bM
Use actual numerical integration (F) or bi-Maxwellian/cold-plasma proxy via NHDS routines, with parameters read in from &bM_spec_j namelist.

AC_method
Choose the method for the evaluation of the analytic continuation:

• 0: Use the function that is defined analytically in distribution/distribution_analyt.f90
• 1: Use the fit routine as defined in the &ffit_j_k namelist.
• 2: Use a polynomial basis representation as defined in the &poly_spec_j namelist. This method should only be used if $|\gamma|\ll |\omega_{r}|$.

&ffit_j_k

Initial Fit Values for species $j$, function $k$.

fit_type_in
Kind of fit function:

• 1: Maxwellian,

$$F_M(\hat{p}\_{\parallel})=u_{1}\mathrm{exp}[-y{\hat{p}}^2\_{\perp}-u_{2}(\hat{p}\_{\parallel}-u_{3})^2]$$

• 2: Kappa,

$$F_{\kappa}(\hat{p}\_{\parallel})=u_{1}[1+u_2({\hat{p}}\_{\parallel}-u_{3})^2+yu_{5} {\hat{p}}^2\_{\perp}]^{u_{4}}.$$

• 3: Juettner with $p_{\perp},p_{\parallel}$,

$$F_{J}(\hat{p}\_{\perp},\hat{p}\_{\parallel})= u_{1}\mathrm{exp}\left[-u_{2}\sqrt{1+\frac{\hat{p}^2\_{\perp}+(\hat{p}^2\_{\parallel}-u_3)^2 v_A^2}{m_{j}^2 c^2}}\right].$$

• 4: Juettner with variable $\Gamma$, constant $\bar{p}_{\parallel}$,

$$F_{J}(\Gamma)= u_{1} \mathrm{exp}[-y \Gamma].$$

• 5: Juettner with $p_{\perp},p_{\parallel}$; variable $\bar{p}_{\parallel}$,

$$F_{\kappa}(\hat{p}\_{\perp},\hat{p}\_{\parallel})=u_{1}\mathrm{exp}[-y \hat{p}\_{\perp}]\mathrm{exp}[-u_{2}*(\hat{p}\_{\parallel}+u_{3})^2].$$

• 6: Bi-Moyal distribution

$$F_{bMo}(\hat{p}\_{\perp},\hat{p}\_{\parallel})= u_{1} \mathrm{exp}[0.5 (y u_4 \hat{p}^2\_{\perp} + u_{2} (\hat{p}\_{\parallel} -u_{3})^2 -\mathrm{exp}(y u_{4} \hat{p}^2\_{\perp} + u_{2} (\hat{p}\_{\parallel}-u_{3})^2) )].$$

fit_1-fit_5
Fit parameters, $u_{1}$ - $u_{5}$, defined in the above equations for each of the types of fit functions. Not all parameters will be used for all functions.
Suggested values for parameters generated by generate_distribution.

perpcorr
This parameter, $y$ in Eqn. B1, compensates for the strong $p_{\perp}$ dependence of $u_1$, making the fit more reliable.

&bM_spec_j

Bi-Maxwellian/cold-plasma parameters; for species j. Only used if use_bM=T.

bM_nmaxs
Maximum number of resonances to consider.

bM_Bessel
Precision threshold for $I_n$.

bM_betas
$\beta_{\parallel,j}$ of bi-Maxwellian distribution $f_{j}$. If this variable is set to 0.d0, then the code will treat the given species with the susceptibility from cold-plasma theory.

bM_alphas
$T_{\perp,j}/T_{\parallel,j}$ of bi-Maxwellian distribution $f_{j}$.

bM_pdrifts
Relative drift of bi-Maxwellian distribution $f_{j}$ or the cold plasma species in units of $m_{p} v_{A,p}$.

&poly_spec_j

Input for the polynomial representation of the input distribution for the analytical continuation. Only used if AC_method=2.

kind
Type of the basis polynomial:

• 1: Chebychev

order
Maximum order of the basis polynomial.

log_max
When using logfit for the polynomial representation, set all output values to zero if the log(fit_function_poly) is greater than this variable.

&scan_input_l

Inputs for scanning parameter space for $l$th scan.

scan_type
Type of parameter scan:

• 0: Current value of $\textbf{k}$ to $k_{\perp}$=swi and $k_{\parallel}$ =swf.
• 1: $\theta_0 \rightarrow \theta_1$ at fixed $|k|$ from current value of $\theta=\mathrm{atan}(k_{\perp}/k_{\parallel})$ to swf.
• 2: Wavevector scan at fixed angle $\theta_{k,B}$ to $|k|$ =swf.
• 3: $k_{\perp}$ scan with constant $k_{\parallel}$ to $k_{\perp}$=swf.
• 4: $k_{\parallel}$ scan with constant $k_{\perp}$ to $k_{\parallel}$=swf.

swi
Scan variable to define end of scan through wavevector space (only for scan_type=1).

swf
Scan variable to define end of scan through wavevector space.

swlog
Use $\log_{10}$ (T) or linear (F) spacing.

ns
Number of output scan values.

nres
Resolution between output scan values.

heating
Calculates heating rates if true.

eigen
Calculates eigenfunctions if true.