Abstract
This Letter reports the first measurement of the energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed -induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to . Despite broad agreement, comparison of the Huber model to the measured spectrum produces a , driven primarily by deviations in two localized energy regions. The measured spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the energy region of 5–7 MeV.
- Received 31 December 2018
- Revised 22 March 2019
DOI:https://doi.org/10.1103/PhysRevLett.122.251801
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