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

Figure 3. The FRC development path will benefit from an intermediate high-flux step.
2. studies of confinement and b-limits require a new experiment of sufficient size to minimize
charge-exchange losses. minimizing these losses can be achieved with major and minor radii
of 0.5 m or more, the product of plasma density and minor radius exceeding 2×10 19 m -2 ,
and extensive wall conditioning. exploring current drive will require flexible power systems
that can drive plasma current in the megampere range. current and flow profile control
may rely on neutral beam and radiofrequency technologies that are tailored for low-field
configurations. Feedback-controlled coils will allow time-dependent control of the flux
boundary conditions.
3. With better understanding of current drive and confinement from actions 1 and 2 and
from simulations, a new long-pulse (100 ms) proof-of-principle experiment will study the
integration of the physics of kev plasma with boundary and profile control. it will also
demonstrate the compatibility of RWm feedback with divertors and particle handling.
The FRc program path builds upon the recent advances made in formation, current drive, and
theoretical understanding of kinetic stability. The development path, illustrated in Figure 3, will
extend experimental research to the reactor-representative regime, where thermal ion gyro-orbits
are small relative to the minor radius, and improve understanding of stability and particle
transport, hence perpendicular current drive requirements.
1. existing experimental facilities and simulations should be upgraded to realize their full
potential. increasing trapped magnetic flux will confine particles with energy nearing
10 kev so that neutral beams can be added to validate predictions of stability based on
kinetic and kinetic-fluid hybrid simulations. simulations of Rotating magnetic Fields
(RmF) can combine energetic ion modeling with boundary conditions for time-dependent
fields from antennas. This will help in understanding RmF effects on stability and particle
confinement, and to optimize current drive.
385