Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Oikos 100: 439 -- 446, 2003

time series are a good proxy for population abundance. I. M. Cattadori, Dept of Biological Sciences, Uni#. of Stirling, Scotland FK94LA ([email protected]).--D. T. Haydon, Dept of Zoology, Uni#. of Guelph, N1G 2W1 Ontario, Canada.--S. J. Thirgood and P. J. Hudson, Dept of Biological Sciences and Centre of Conser#ation Science, Uni#. of Stirling, Scotland FK94LA. Some of the most detailed and revealing long-term population studies have used data that only indirectly assessed population abundance. The majority of these data sets have been derived from harvested species such as Canadian lynx (Elton and Nicholson 1942), snowshoe hares (MacLulich 1937), dungeness crabs (Botsford et al. 1983, Hankin 1985) or red grouse (Hudson 1992). There have also been intensive long term studies that have used indirect measures of abundance such as snap trapping of small mammals (Koshkina 1966, Hanski et al. 1993, Pucek et al. 1993, Saitoh et al. 1997, Henttonen and Hanski 2000), trapping of larch bu

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin “burn propagation” into surrounding cold fuel, enabling the possibility of high energy gain. While “scientific breakeven” (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion