Abstract
We have made a search for doubly radiative capture . It has been suggested that this process might contribute to the total -capture cross section and thus explain the long-standing discrepancy in capture ( mb and mb). Previous -capture experiments have been insensitive to the energy distribution of the capture rays. In this experiment we searched for two-photon events by looking for rays in coincidence from a O target exposed to a beam of thermal neutrons using two 5×5-cm NaI detectors. Analysis of the coincidence spectra indicates two-photon -capture events have not been observed. An upper limit at the 3 standard deviation confidence level of mb can be placed on the doubly radiative -capture cross section. Therefore the two-photon cross section does not explain the discrepancy between the theoretical and experimental -capture cross sections.
- Received 17 May 1973
DOI:https://doi.org/10.1103/PhysRevC.8.1179
©1973 American Physical Society