Fusion products

TRANSP can follow the fusion products using the NUBEAM MonteCarlo.

NPTCLF

Number of particles to be tracked in the MonteCarlo code. The default is 1000

NLFST

Set equal to TRUE to calculate products from D(D,T)p reactions [Eq.1].

NLFSP

Set equal to TRUE to follow protons from D(D,T)p reactions [Eq.1].

NLFHE3

Set equal to TRUE to calculate products from D(D,He3)n reactions [Eq.2].

NLFHE4

Set equal to TRUE to calculate alpha products from D(T,He4)n reactions {Eq.3}.

NLFATOM

Set equal to TRUE to compute atomic physics effects on fusion products fast ions slowing down.

The T(T,He4)2n reactions [Eq.4], as a by-product of D(D,T)p reactions, are also calculated in TRANSP.

New fitting for T-T reactivities

With version 18.2 new fittings over DPC have been implemented for T(T,2n)4He fusion reactions, based on the work by David Coster [IPP, Garching].
The input data are available on the SVN repository

https://gforge6.eufus.eu/svn/amnsproto/curation/nuclear [password-protected page]. Please check for Revision 642.

Set:

LEV_TTNUK = 1

To use the new fittings by David Coster. The figure below shows a comparison between the old fitting in TRANSP and the new fit by D. Coster.

Power threshold

It is possible to set a power threshold above which the number of particles NPTCLF in the MonteCarlo calculations is maintained. If the actual source power is lower than the set power threshold, then a population of f*NPTCLF MonteCarlo particles is maintained, where f=[actual source power]/threshold power. The default values for the various fusion reactions are as follow:

PLFST [=100.0 W]

power threshold for D(D,T)p reactions

PLFSP [=100.0 W]

power threshold for D(D,T)p reactions

PLFHE3 [=100.0 W]

power threshold for D(D,He3)n reactions

PLFHE4 [=10.0 kW]

power threshold for D(T,He4)n reactions

Model Options for alphas

NALPHA=0

This is the default value, to calculate the alphas from the MonteCarlo model.

NALPHA=1

Fast, non-Monte Carlo model by D. Mikkelsen. This model has no orbit effects and assumes instant equilibration of the alpha slowing down distribution on the background plasma.

Renormalisation

It is possible to use 1D input Ufile data for the total production rates of the various fast ion populations as a function of time to renormalise the profiles determined from simulation. This is done using the following switches:

NLUSFA

Set this flag to TRUE to read in He⁴ data from UFILES PRESFA/EXTSFA.

NLUSF3

Set this flag to TRUE to read in He³ data from UFILES PRESF3/EXTSF3.

NLUSFT

Set this flag to TRUE to read in He³ data from UFILES PRESFT/EXTSFT.

NLUSFP

Set this flag to TRUE to read in He³ data from UFILES PRESFP/EXTSFP.