Fusion startups have struggled to raise funding of late, but young startup Acceleron Fusion has joined the pack, raising $15 million of its targeted $23.7 million round, according to an SEC filing. That's what it means.
The fusion sector has recently received a lot of interest from investors, who are no doubt encouraged by the groundbreaking experiment at the National Ignition Facility two years ago, in which a controlled fusion reaction is about to begin. It has been proven that more power can be generated than is needed.
The first companies to build power plants capable of producing electricity that can be sold in bulk to the grid could begin chipping away at the multitrillion-dollar global energy market. Tech companies, in particular, are eyeing fusion and nuclear startups as potential pollution-free solutions to AI-powered electricity needs.
Acceleron did not immediately respond to questions.
While most startups aim to recreate the superheated, ultra-high pressure conditions inside stars, Acceleron takes a different approach, using subatomic particles known as muons to generate fusion reactions. Reduce the heat and pressure required.
In nature, atoms tend to resist fusion, primarily because the atoms' orbiting electrons repel other atoms. To avoid this, most approaches to fusion follow nature's approach. That is, make the atom hot enough to release its electrons from their orbits and lower the inhibition of normal atoms. When atomic nuclei fly around without electrons, some of them collide with each other and fuse into new nuclei, releasing huge amounts of energy. That's what's happening inside the star.
Muon-catalyzed fusion takes a different direction. Instead of heating and compressing hydrogen isotopes, muons are injected into the mixture. A muon is an elementary particle similar to an electron, both of which have a negative charge, but with a mass 207 times greater. When a muon collides with a hydrogen isotope, some atoms' electrons are replaced. Muons orbit much closer to the nucleus than electrons, lowering the barrier required for atomic fusion.
In muon-catalyzed fusion, the barrier is sufficiently low that fusion can occur at room temperature and atmospheric pressure. Therefore, it is also called cold fusion. Although muon catalysis has been demonstrated in laboratory conditions, the energy required to produce muons has so far exceeded the amount of energy produced by nuclear fusion reactions.
There are several reasons why muon-catalyzed fusion has not yet worked. First, each muon only lasts about 2.2 microseconds before decaying into less useful subatomic particles. This is long enough to power about 100 fusion reactions, but still too short for commercial power. Another problem is that about 0.8% of the time, a muon gets attached to another particle (an alpha particle) and no longer participates in the fusion reaction. This may not seem like a big deal, but again, it's high enough to doom commercial plans.
Acceleron, a Cambridge, Mass.-based company spun out of NK Laboratories, hopes that by increasing the pressure and perhaps the temperature of the hydrogen isotope mixture, it might be able to reduce the rate at which muons attach to alpha particles. I am doing it. The hope is to keep enough muons in the mixture to catalyze more fusion reactions, and ideally enough muons to offset the amount of power required to produce muons. It is to maintain.
In 2020, the NK Institute won a three-year, $2 million ARPA-E grant to investigate whether higher pressures improve prospects for muon-catalyzed fusion. Although the full results have not been made public at this time, it appears to have piqued the interest of investors.