Research Needs for Magnetic Fusion Energy Sciences - US Burning ...

ate. simplified stabilization conditions are that the average toroidal rotation frequency of the
beam ions be larger than their axial betatron frequency and the fast ion current be sufficient to
balance the instability drive.
code development for RmF should be extended to include wave physics that may become important
as the plasma dimensions increase and should be coupled to other codes to obtain a more
consistent calculation, including as much physics as possible.
FaSt PaRtiCLES: unDERStanD EFFECtS OF FaSt PaRtiCLES On CuRREnt DRiVE,
StabiLity anD COnFinEMEnt.
Fast particles, e.g., due to neutral beam injection, are needed to stabilize the FRc in the mhd regime,
but are likely to have other effects on the plasma. a start on this issue will be made during
study of higher priority issues.
research requirements
There are significant effects that will require additional study by theory and experiment, including
the coupling of the energetic ions to plasma magnetosonic and other modes, plasma potential
due to first orbit losses and plasma rotation, and effects of non-maxwellian distributions on stability.
Facilities capable of research on current drive, sustainment, transport and stability are expected
to be capable of addressing the effects of fast particles. appropriate diagnostics will be needed.
HEating: DEMOnStRatE EFFiCiEnt HEating MEtHODS (E.g., ROtating
MagnEtiC FiELDS, nEutRaL bEaM injECtiOn, anD COMPRESSiOn) tO inCREaSE
tHE tEMPERatuRE tO nEaR buRning-PLaSMa VaLuES
experiments to date have focused on formation and sustainment, and not on heating the plasma,
but ion heating will be required to reach fusion temperatures.
research requirements
experiments and simulations that research heating by these methods are needed. a facility capable
of current drive, transport, stability and sustainment research should also be able to address
plasma heating in FRcs, although upgrades may be required.
SPHEROMAK
SuStainMEnt: DEVELOP anD DEMOnStRatE MEtHODS FOR SuStaining a
SPHEROMaK WHiLE aCHiEVing gOOD EnERgy COnFinEMEnt
several formation and steady-state sustainment techniques have been and are being used, including
injection of helicity (linked toroidal and poloidal magnetic fluxes) from an electrostatic gun;
helicity injection from crossed, inductively driven injectors; and induction using magnetic coils.
however, the efficiencies of current drive are too low for steady-state spheromak experiments.
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