13 February 2014
Scientific Breakeven” at the National Ignition Facility (NIF) in California was achieved on 29th September 2013 with an output of 5.1015 neutrons using a new “high foot” design of target which gives improved hydrodynamic stability during the compression phase.
Defined as “thermonuclear energy out” > “energy absorbed by the fuel capsule”, scientific breakeven is a major milestone in the quest for fusion energy and demonstrates significant alpha particle heating of the fuel assembly.
A subsequent shot taken during November produced a 50% increase in yield by tuning the temporal profile of the laser pulse.
While the design of target that has produced the latest improvements in yield may not scale directly to ignition, these results show good agreement with the numerical codes used to predict performance and to guide the experimental programme. At the same time, enhancements to the X-ray backlighting capability at NIF are leading to better understanding of the hydrodynamic performance which is being used to drive further improvements to both the experimental campaign and the codes.
The new target design, improved predictive capability and enhanced radiographic capability, give the science community a much higher confidence in the likelihood of ignition.
Note: HiPER is following the “direct drive”, high gain route to ignition, rather than the indirect drive approach of NIF, but success at NIF builds confidence in the viability of laser driven fusion energy in general.
For more details newly published on the scientific breakeven result at NIF, visit: