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In transition: Commercializing fusion power
Commercial fusion power is closer than ever. There are now around 30 U.S. fusion companies, several of which claim to be on track to connect to the grid as early as the 2030s.
Tokamak and laser inertial confinement approaches benefit from decades of research at facilities such as the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory and ITER, with alternative concepts including stellarator, magnetic mirror, and Z-pinch confinement also making notable progress as private and government funding for fusion increases.
H. Gruppelaar, G. Reffo
Nuclear Science and Engineering | Volume 62 | Number 4 | April 1977 | Pages 756-763
Technical Note | doi.org/10.13182/NSE77-A15219
Articles are hosted by Taylor and Francis Online.
In this Note the subject of width fluctuation correction to average compound-nucleus cross sections is reviewed, with special emphasis on neutron capture and scattering cross sections. Recent statistical model theories on the calculation of cross sections offer a new approach to the calculation of this correction factor. For low energies, the classical integration method gives the best description. At higher energies, the approximation of Tepel et al. with a semi-empirical relation for the elastic enhancement parameter is recommended for practical calculations. In the discussion about properties of the width fluctuation factor (WFF), the concept of a lumped channel with an effective number of degrees of freedom, veff, has proven to be helpful. A new definition of veff is given in this Note. Under certain conditions, the WFF for nonelastic processes can become larger than unity. This effect can be important in neutron capture when strong nonelastic channel competition is present. An example of this effect is given for the reaction 100Mo(n,γ) at 0.9 MeV, where, due to width fluctuation effects, the capture cross section is enhanced by ≈30%. Some other examples of width fluctuation effects are given for neutron elastic and inelastic scattering.