ITER Neutral Beam Model | iternb()
iefrf/iefrffix
= 5
Output | Description |
---|---|
\mathtt{effnbss} | Neutral beam current drive efficiency in \text{A/W} |
\mathtt{fpion} | Fraction of NB power given to ions |
\mathtt{fshine} | Shine-through fraction of the beam |
This model calculates the current drive parameters for a neutral beam system, based on the 1990 ITER model.1
Firstly the beam access is checked for such that $$ \bigg(1+ \frac{1}{A}\bigg) > (R_{\text{tangential}}/R_0) $$
The beam path length to centre is calculated:
Beam stopping cross-section (\sigma_{\text{beam}}) is calculated using the sigbeam
method described here :
Calculate number of electron decay lengths to centre
Shine-through fraction of beam: $$ f_{\text{shine}} = e^{(-2.0 \times \mathtt{dpath} \times n_e \sigma_{\text{beam}})} \ $$
Deuterium and tritium beam densities: $$ n_D = n_i * (1.0 - \mathtt{ftritbm}) $$
Power split to ions / electrons is calculated via the the cfnbi
method described here
Current drive efficiency | etanb()
This routine calculates the current drive efficiency of a neutral beam system, based on the 1990 ITER model. AEA FUS 251: A User's Guide to the PROCESS Systems Code ITER Physics Design Guidelines: 1989 IPDG89, N. A. Uckan et al, ITER Documentation Series No.10, IAEA/ITER/DS/10, IAEA, Vienna, 1990
Input | Description |
---|---|
\mathtt{abeam}, m_{\text{u,ion}} | Beam ion mass (\text{amu}) |
\mathtt{alphan} | Density profile factor |
\mathtt{alphat} | Temperature profile factor |
\mathtt{aspect}, A | Aspect ratio |
\mathtt{dene20}, n_{\text{e,20}} | Volume averaged electron density (10^{20} \text{m}^{-3}) |
\mathtt{ebeam} | Neutral beam energy (\text{keV}) |
\mathtt{rmajor}, R | Plasma major radius (\text{m}) |
\mathtt{ten} | Density weighted average electron temperature (\text{keV}) |
\mathtt{zeff}, Z_{\text{eff}} | Plasma effective charge |
Output | Description |
---|---|
\mathtt{etanb} | Neutral beam current drive efficiency in \text{A/W} |
Ratio of E_beam/E_crit
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N. A. Uckan and ITER Physics Group, "ITER Physics Design Guidelines: 1989", ITER Documentation Series, No. 10, IAEA/ITER/DS/10 (1990) ↩