A British teenager built the world’s first school thermonuclear reactor and produced plasma in it.

A senior student at Cardiff College in the UK created the world’s first school fusion reactor, which was able to produce plasma. The most difficult thing was to convince teachers of the safety of the project when he came to them with this proposal. After a year and a half of work and with a cost of just over $10 thousand, the project was implemented in hardware and produced the first plasma.

School inertial electrostatic thermonuclear reactor. Image source: Cesare Mencarini

The development of a desktop fusion reactor was proposed by 17-year-old Cesare Mencarini. The work was carried out within the framework of a two-year A-Levels educational program, which provides an opportunity to prepare for admission to higher educational institutions in the country or abroad. The teachers’ first reaction to the proposal to build a thermonuclear reactor at school was concern about the consequences of its launch. The student also requested a significant amount of expenses – £20 thousand. As a result, he received permission and only £8 thousand, which forced him to seriously work on optimizing the design of the reactor.

Sources and the designer himself do not report the parameters of the plasma achieved in the reactor (it was obtained in June 2024). The only claims are to achieve a vacuum in the working chamber of 0.008 mm Hg using a TRIVAC D 2.5 E vacuum pump and to supply 30 kV power from a 5 kV Unilab power supply. Since the currents there are extremely weak, there was no risk of damage to the school electrical wiring.

Plasma in the working chamber of a school reactor

The reactor created by the schoolboy was shown at the Cambridge Science Festival, where it received high praise and well-deserved interest from visitors. In a world where everyone is starting to boast about digital achievements, it’s worth a lot to imagine something tangible and out of the ordinary.

On the other hand, the reactor created by Cesare is not something exceptional. This is the so-called fusor. The Guinness Book of Records has its own record holder for the creation of thermonuclear reactors (fusors) – this is the American schoolboy Jackson Oswalt, who received the first plasma at the age of 12.