(Short Talk) Neutrons in Nuclear Fusion Reactors

by Peter Reichel (TUM)

Monday 22 Jan 2024, 14:30 → 15:30 Europe/Berlin

PH HS 3 (Physics Department)

Nuclear fusion, a process that takes place in the sun and stars, involves the combination of light elements to form heavier ones, releasing a significant amount of energy. If harnessed on Earth, this principle could address our energy crisis by providing a plentiful and clean source of base load energy.

The most promising approach for achieving controlled fusion reactions on Earth involves the fusion of the two hydrogen isotopes, deuterium and tritium, within a magnetically confined plasma. Deuterium is abundant on Earth and can be extracted from seawater. Tritium, on the other hand, is radioactive with a half-life of 12.3 years and occurs naturally only in trace amounts. However, it can be bred in a fusion reactor.

The Deuterium-Tritium (DT) fusion reaction results in the release of an alpha particle and a neutron, with the neutron carrying 80% of the energy and exiting the plasma. Lithium can interact with the neutron and decay into Tritium and Helium. The tritium can be reprocessed and introduced in the fusion reaction again. The energy imparted by the neutron is harnessed by a coolant, which subsequently drives a turbine to generate electricity.

In this talk, I will introduce the principles of fusion, discuss various strategies to breed tritium in a reactor for self-sustainability, and address the challenges that neutrons impose to a nuclear fusion power plant.