US scientists successfully replicate fusion power achievement

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A significant breakthrough has been achieved by US government scientists in a fusion reaction, marking the second time they have achieved net energy gain. This achievement has provided a new ray of hope in the pursuit of unlimited, zero-carbon power.

Scientists have been striving to harness the power of fusion reactions, which is the same reaction that fuels the sun, since the 1950s. However, until recently, no group had successfully produced more energy from the reaction than it consumes, a condition known as ignition.

The Lawrence Livermore National Laboratory in California, having achieved ignition for the first time last year, replicated this breakthrough in an experiment on July 30. The results of this experiment showed an even higher energy output than in the previous December experiment. The laboratory has confirmed the achievement of energy gain at its laser facility and is currently analyzing the results.

The laboratory stated, “Since demonstrating fusion ignition for the first time at the National Ignition Facility in December 2022, we have continued to perform experiments to study this exciting new scientific regime. In an experiment conducted on July 30, we repeated ignition at NIF. As is our standard practice, we plan on reporting those results at upcoming scientific conferences and in peer-reviewed publications.”

Fusion occurs by heating two hydrogen isotopes, typically deuterium and tritium, to extreme temperatures, causing the atomic nuclei to fuse. This fusion releases helium and a substantial amount of energy in the form of neutrons.

While the development of fusion power stations may still be several decades away, the potential of this technology cannot be overlooked. Fusion reactions emit no carbon and produce no long-lived radioactive waste. In fact, a small cup of hydrogen fuel could theoretically power a house for hundreds of years.

The most extensively studied approach, known as magnetic confinement, utilizes large magnets to hold the fuel in place while it is heated to temperatures hotter than the sun. On the other hand, the National Ignition Facility employs a different process called inertial confinement. It uses the world’s largest laser to trigger an implosion in a tiny capsule of the fuel.

In December, US Energy Secretary Jennifer Granholm hailed the achievement of ignition as “one of the most impressive science feats of the 21st century.” The reaction in that experiment produced approximately 3.15 megajoules, which was approximately 150% of the energy in the lasers.

Preliminary data from the July experiment indicated an energy output exceeding 3.5 megajoules. This energy output would be roughly sufficient to power a household iron for an hour.

Net energy gain has long been considered a critical milestone in proving the feasibility of commercial fusion power stations. However, there are still several challenges to overcome.

It’s important to note that energy gain in this context only compares the energy generated to the energy in the lasers, not the total energy consumed by the system from the grid, which is significantly higher. Scientists estimate that commercial fusion will require reactions that generate between 30 and 100 times the energy in the lasers.

Furthermore, the National Ignition Facility currently only conducts a maximum of one shot per day, whereas an internal confinement power plant would likely need to complete several shots per second.

Nevertheless, the improved results at the National Ignition Facility, achieved in just eight months after the initial breakthrough, indicate an accelerating pace of progress according to one of the sources.