Necessity of ponderomotive potentials for α-particle sequestration in pB11 fusion plasmas

Determine whether wave-based ponderomotive potentials are necessary to achieve effective α-particle sequestration (i.e., separation of α particles from protons and boron to reduce bremsstrahlung and ash poisoning) in two-region proton–boron-11 fusion plasmas, or whether alternative potential barrier configurations without ponderomotive fields can produce the same desired separation and performance outcomes.

Background

The paper demonstrates that self-consistent accumulation of fusion-born α particles in pB11 plasmas substantially increases bremsstrahlung losses and pressure, making electrical breakeven infeasible if α confinement time equals energy confinement time. It proposes either rapid α extraction or spatial separation into a fusion region accessible to fuel and an α storage region accessible only to α’s and electrons.

A specific separation mechanism is illustrated using a combination of centrifugal and ponderomotive potentials to repel/attract species selectively, enabling α’s to traverse both regions while confining protons and boron to the fusion region. However, the authors note uncertainty about whether ponderomotive potentials are strictly required, suggesting that alternative configurations involving potential barriers and manipulated diffusion might suffice, though a kinetic analysis is needed.