INFLPR Seminar, Tuesday, 7 February 2023, 10:00 am, PPNF Laboratory, Dr. Florin Spineanu: The "Bootstrap Current" and its absence
Tuesday, 7 February 2023, 10:00 am
Title: The "Bootstrap Current" and its absence
Lecturer: Dr. Florin Spineanu
Work Sessions of Plasma Theory
Abstract: The “bootstrap” electric current is specific to the toroidal geometry and is highly precious for Tokamak plasma. It exists due to the collisional momentum exchange between the population of trapped particles (on banana orbits) and the circulating particles. We will show that a popular physical picture is not satisfactory and that a detailed presence of collisionality must be preserved even in the simplest descriptions. Since the inductive current has finite-time existence the bootstrap current (being an intrinsic effect) will take the charge of maintaining the magnetic field that supports the confinement. However the reactor with its very high temperature will have very low collisionality, which reduces the bootstrap current and sends the message that we must look for other sources of currents, if any.