Accessing Non-Thermal Fusion Burning Processes

In the kinds of fusion burning plasmas that can be confined by (non extreme) magnetic fields collective modes and self organization processes are expected to have a dominant role. The physical regimes of greater interest are close to ignition conditions [1] where the rate of energy deposited by the reaction products overwhelms all other forms of heating. The possibility to approach these conditions by the excitation of a novel class of ballooning modes [2] with frequencies close to the D cyclotron frequency in the case of a D-T plasma has been demonstrated theoretically. These modes are radially localized around a magnetic surface that depends on the plasma density profile. Instead, the radial distribution of the generated α-particles depends on the toroidal plasma current for an axisymmetric confinement configuration. One of the means to control the plasma density profiles is that of injection of higher mass nuclei [3,4]. Multiple machines [5] and combined interdisciplinary experiments on meaningful fusion burning plasmas are required to master the physics leading to fusion as an attractive source of energy.

[1] B. Coppi, Comments Plasma Phys. Cont. Fusion, 3, 47 (1977).

[2] B. Coppi and B. Basu, Nucl. Fusion 64, 126037 (2024).

[3] C. Mazzotta, et. al., Paper IAEA-CN-899 MFE. FEC (IAEA, Vienna, 2021).

[4] B. Coppi, H. Furth, M. Rosenbluth and R. Sagdeev, Phys. Rev. Lett. 17, 377 (1966).