Il primo grande passo verso la fusione nucleare 13.02.142014-02-22:11:39
ArsTechnica racconta quale sono le implicazioni dopo che per la prima volta al Lawrence Livermore National Laboratory i ricercatori sono riusciti a produrre una quantità di energia superiore a quella necessaria a innescare la reazione, dimostrando che ottenere energia dalla fusione nucleare (lo stesso processo che avviene all'interno delle stelle) è un obiettivo realistico e raggiungibile.
Nuclear fusion is the process that powers the Sun and billions of other stars in the Universe. If mastered, it could provide an unlimited source of clean energy because the raw materials are plentiful and the operation produces no carbon emissions.
During the fusion process, smaller atoms fuse into larger ones, releasing huge amounts of energy. To achieve this on Earth, scientists have to create conditions similar to those at the center of the Sun, which involves creating very high pressures and temperatures.
There are two ways to achieve this: one uses lasers and is called inertial confinement fusion (ICF), another deploys magnets and is called magnetic confinement fusion (MCF). Omar Hurricane and colleagues at the Lawrence Livermore National Laboratory opted for ICF, with the help of 192 high-energy lasers at the National Ignition Facility in the US, which was designed specifically to boost fusion research.
A typical fusion reaction at the facility takes weeks of preparation. But the reaction is completed in an instant (150 picoseconds, to be precise, which is less than a billionth of a second). In that moment, at the core of the reaction, the pressure is 150 billion times atmospheric pressure. The density and temperature of the plasma created is nearly three times that at the center of the Sun.