Thank you for using my code ALCON. By default, the vertical is the angular frequency ω normalized by v_{Ap}/R_{0}, where v_{Ap} is the on-axis Alfvén speed for protons, and R_{0} is the major radius. More details can be found in Eqs. (A.36) and (A.37) in my paper Linear properties of reversed shear Alfvén eigenmodes in the DIII-D tokamak. Please note that this scale can be changed by the `--omegascale`

option, which multiplies the normalized ω by the specified factor before output.

Best wishes,

Wenjun

Actually, from the picture above, i see that the unit is (Omega*R_0)/v_A.

Thanks again,

Sam

I just used Alcon to solve for the Alfven continuum. Can you please tell me the units of the vertical scale? Thanks very much. (please ignore my last comment. I input the wrong email address).

Sam

]]>It looks like you’re still using the old version of acdgen_sample.F90. Note that in the latest version, some of these variables are renamed: ci -> ii, ni -> deni, ti -> tti, ne -> dene, te -> tte, b -> bb, dbdt -> dbbdtheta.

As for the detailed units, firstly, rho = sqrt(psi_tor / psi_tor_wall), so it’s dimensionless, where psi_tor is toroidal flux and psi_tor_wall is toroidal flux at wall. Safty factor q is naturally dimensionless.

Secondly, in general, acdgen_sample.F90 uses CGS/Gaussian units, so b (bb) is in the unit of Gauss. dbdt (dbbdtheta) is in the unit of Gauss, because theta is in the unit of radian and is effectively dimensionless. Noting that **B** = δ ∇ψ + I ∇θ + g ∇ζ, and lengths are in cm, so g and ci (ii) are in the unit of Gauss*cm. Densities (ni, deni, ne, dene) are in the unit of cm^{-3}. Temperatures (ti, tti, te, tte) are in the unit of erg (1 eV = 1.6022e-12 erg). psi = ψ is poloidal magnetic flux so it’s in the unit of Gauss*cm^{2}, so gradpsi = |∇ψ| has the unit of Gauss*cm.

Hope this helps.

Best wishes,

Wenjun

I have more quenstions.

As I mentioned, I’m trying to load spdata so I want detailed unit for rho, q, g, ci, ni, ti, ne, te, b, dbdt, gradpsi.

Thanks in advance.

Best regards,

tn

I’m glad you’re using ALCON. 0:nfft is indeed the poloidal harmonic number m. The real part represents the cos component and the imaginary part represents the sin component. So given an array representing cos(theta), then performing fftr1d would give [0, n/2, 0, 0, …], where n is the array length. Similarly for an array representing sin(theta), then fftr1d would give [0, -i*n/2, 0, 0, …].

Best wishes,

Wenjun

I’m using alcon for frequency testing of TAE.

It is very useful because simple and fast in my system.

I’m trying to using spdata to make equilibrium to test our device measurement.

What I want to know is format of fft1d.

You use 0:nfft.

I think it may m=0~nfft.

Real is cos and imaginary is sin?

Thanks in advance.

Best wishes,

Wenjun

1.How can one plot input data ?

2. Is it possible to use EFIT eq. data as input ? Then how it should be modified ? ]]>