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The deadline arrives: Checking in on the Reactor Pilot Program
On May 23, 2025, President Trump signed Executive Order 14301, “Reforming Nuclear Reactor Testing at the DOE,” which instructed the Department of Energy to create a Reactor Pilot Program (RPP)—a new system in which companies could pursue DOE authorization to build and test their first-of-a-kind nuclear technologies. EO 14301 set an ambitious goal for that program: three reactors achieving criticality by July 4, 2026.
F. Carvalho
Nuclear Science and Engineering | Volume 34 | Number 3 | December 1968 | Pages 224-236
Technical Paper | doi.org/10.13182/NSE68-A21088
Articles are hosted by Taylor and Francis Online.
The Karlsruhe rotating crystal time-of-flight spectrometer was used to measure the slow neutron scattering law of graphite in a range of energy transfer of 7 to 180 meV and momentum transfer of 1.5 to 16 Å−1. The graphite samples were heated to a temperature of 533°K, thereby increasing the probability of scattering with high energy transfer. The experimental data are corrected for multiple scattering in the sample using the incoherent approximation. The corrected data are in good agreement with calculated scattering law values. Large discrepancies between theory and previous experimental results are thus satisfactorily explained. The coherent nature of inelastic scattering in graphite is apparent in the data, especially in the region of lower energy and momentum transfers. The possibility of using the experimental results in this region directly to test and eventually to correct lattice model parameters is discussed. It is suggested that further measurements in this region with higher energy resolution might yield useful information. A phonon frequency distribution is extrapolated from the data and used to calculate several integral quantities. The values obtained are compared with previous results, both theoretical and experimental.