In 1989, researchers in the United States and Great Britain claimed to have made a fusion reactor at room temperature without confining high-temperature plasmas. They made an electrode of palladium, placed it in a thermos of heavy water (deuterium oxide) and passed an electrical current through the water. They claimed that the palladium catalyzed fusion by allowing deuterium atoms to get close enough for fusion to occur. However, several scientists in many countries failed to get the same result.
But in April 2005, cold fusion got a major boost. Scientists at UCLA initiated fusion using a pyroelectric crystal. They put the crystal into a small container filled with hydrogen, warmed the crystal to produce an electric field and inserted a metal wire into the container to focus the charge. The focused electric field powerfully repelled the positively charged hydrogen nuclei, and in the rush away from the wire, the nuclei smashed into eachother with enough force to fuse. The reaction took place at room temperature. See Coming in out of the cold: Cold fusion, for real (csmonitor.com) to learn more.
Applications of Fusion
The main application for fusion is in making electricity. Nuclear fusion can provide a safe, clean energy source for future generations with several advantages over current fission reactors:
- Abundant fuel supply - Deuterium can be readily extracted from seawater, and excess tritium can be made in the fusion reactor itself from lithium, which is readily available in the Earth's crust. Uranium for fission is rare, and it must be mined and then enriched for use in reactors.
- Safe - The amounts of fuel used for fusion are small compared to fission reactors. This is so that uncontrolled releases of energy do not occur. Most fusion reactors make less radiation than the natural background radiation we live with in our daily lives.
- Clean - No combustion occurs in nuclear power (fission or fusion), so there is no air pollution.
- Less nuclear waste - Fusion reactors will not produce high-level nuclear wastes like their fission counterparts, so disposal will be less of a problem. In addition, the wastes will not be of weapons-grade nuclear materials as is the case in fission reactors.
NASA is currently looking into developing small-scale fusion reactors for powering deep-space rockets. Fusion propulsion would boast an unlimited fuel supply (hydrogen), would be more efficient and would ultimately lead to faster rockets.
For more information on nuclear fusion reactors and related topics, check out the links on the next page.