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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Fusion Science and Technology
Latest News
The RAIN scale: A good intention that falls short
Radiation protection specialists agree that clear communication of radiation risks remains a vexing challenge that cannot be solved solely by finding new ways to convey technical information.
Earlier this year, an article in Nuclear News described a new radiation risk communication tool, known as the Radiation Index, or, RAIN (“Let it RAIN: A new approach to radiation communication,” NN, Jan. 2025, p. 36). The authors of the article created the RAIN scale to improve radiation risk communication to the general public who are not well-versed in important aspects of radiation exposures, including radiation dose quantities, units, and values; associated health consequences; and the benefits derived from radiation exposures.
G. H. Miley, H. Hora, B. Malekynia, M. Ghoranneviss
Fusion Science and Technology | Volume 56 | Number 1 | July 2009 | Pages 384-390
IFE Target Design | Eighteenth Topical Meeting on the Technology of Fusion Energy (Part 1) | doi.org/10.13182/FST09-A8931
Articles are hosted by Taylor and Francis Online.
Block ignition was proposed recently as a possible alternate approach to fast ignition for ICF fusion. This approach uses a modified petawatt-picosecond (PW-ps) laser pulse shape where the prepulse is strongly suppressed. This results in highly directed plasma blocks due to nonlinear (ponderomotive) force acceleration with space charge neutral ion current densities above 1011 Amp/cm2. This allows ignition of deuterium-tritium targets at densities somewhat above solid state density. However, a key issue has been the need to reduce the extremely high thresholds for the high energy flux densities of the blocks as pointed out in a related theory by Bobin and Chu in 1972. Here we show how the threshold can be reduced by a factor up to 20 by two effects. An important contribution comes from the inhibition factor for thermal conductivity due to electric double layers created in the block process. The second effect is the reduction to the stopping length, giving increased heating by the fusion product alpha due to collective interactions in the blocks. Results from including these effects in a hydrodynamic analysis are presented. The advantage of this approach for an ICF fusion reactor is the relaxed pre-compression requirement for high gain.