Joint European Torus (JET)
The Joint European Torus (JET) is a prominent magnetically confined plasma physics experiment that was located at the Culham Centre for Fusion Energy in Oxfordshire, United Kingdom. It was a central part of European efforts to advance research in nuclear fusion, a field that aims to replicate the energy-producing processes occurring in the sun and other stars.
Historical Background
The concept of JET emerged from collaborative European research efforts in nuclear fusion, with its funding approved on April 1, 1978, under the legal entity known as the "JET Joint Undertaking." This initiative aimed to bring together European expertise and resources to push the boundaries of fusion technology. The reactor was constructed adjacent to the Culham Centre for Fusion Energy, a hub for nuclear research established in 1965.
Construction of the Torus Hall, where the JET machine would be housed, commenced in 1978, managed by Tarmac Construction. The hall was completed in January 1982, allowing the construction of the JET machine to proceed immediately thereafter. The total cost was approximately 198.8 million European Units of Account, equivalent to 438 million US dollars in 2014.
Design and Purpose
JET is based on the tokamak design, a type of magnetic confinement fusion device that uses a powerful magnetic field to confine plasma in the shape of a torus. The primary goal of JET was to explore the feasibility of nuclear fusion as a source of grid energy, paving the way for future fusion reactors.
One of JET’s significant achievements is its use of a real deuterium-tritium fuel mix, making it one of the very few tokamak installations at the time capable of doing so. This mixture is crucial for achieving conditions similar to those required for a sustainable fusion reaction.
Achievements and Scientific Impact
JET has been instrumental in advancing the understanding of plasma physics and nuclear fusion. It was one of the first machines designed with the ambitious goal of reaching scientific breakeven, where the fusion energy gain factor, or Q, is equal to 1.0. This milestone signifies that the energy produced by the fusion reaction equals the energy invested in maintaining the reaction.
The data and findings from JET have significantly contributed to other international fusion projects, including ITER, an upcoming large-scale fusion experiment that seeks to demonstrate the feasibility of fusion power on a commercial scale.