ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
April 2026
Nuclear Technology
February 2026
Fusion Science and Technology
Latest News
Swiss nuclear power and the case for long-term operation
Designed for 40 years but built to last far longer, Switzerland’s nuclear power plants have all entered long-term operation. Yet age alone says little about safety or performance. Through continuous upgrades, strict regulatory oversight, and extensive aging management, the country’s reactors are being prepared for decades of continued operation, in line with international practice.
S. C. Chiu, V. S. Chan
Fusion Science and Technology | Volume 18 | Number 4 | December 1990 | Pages 591-596
Alpha Particles in Fusion Research | doi.org/10.13182/FST90-A29251
Articles are hosted by Taylor and Francis Online.
Fast-wave current drive presents a promising scheme for steady-state operation of reactor tokamaks. This scheme is being studied for application in the International Thermonuclear Experimental Reactor (ITER), the Joint European Torus (JET), and the Doublet III-D reactor (DIII-D). There are two regimes that appear to be promising, the low-frequency range 0 < ω < 2ΩD and the lower hybrid frequency range ΩD ≪ ω < ωLH. In the latter scheme, the wavelength of the fast wave becomes much shorter than the alpha-particle gyroradius and alpha-particle absorption can become significant. An analytic formula for alpha-particle absorption of fast waves for the standard slowing down distribution has been derived and compared with electron absorption at ITER parameters. It has been found that at TD > 30 keV and ne ∼ 1014 cm−3, the alpha-particle absorption is large and can greatly decrease the current drive efficiency. However, without sacrificing the fusion reactivity rate, by increasing the density and decreasing the temperature 15 keV < TD < 25 keV, the alpha-particle absorption can become small at a sufficiently high frequency. It is suggested that a simulation of the alpha-particle absorption effect on fast-wave current drive can be made in DIII-D by using a lower frequency source (∼30 MHz) to create a minority tail and a high-frequency source (200 MHz) to drive the current. Results of minority absorption are presented. Effects that can improve current drive efficiency are discussed.