Evaluation of the White Neutron Beam Spectrum for Single-Event Effects Testing at the RCNP Cyclotron Facility

The 30-deg white neutron beam at the Research Center for Nuclear Physics (RCNP) cyclotron facility has been characterized as a probe suitable for testing of single-event effects (SEE) in semiconductor devices in the neutron energy range from 1 to 300 MeV using the 392-MeV proton incident reaction on a 6.5-cm-thick tungsten target. The neutron spectrum obtained by time-of-flight measurements reproduced the terrestrial neutron flux distribution at sea level, and neutron intensity increased by a factor of 1.5 × 10⁸ became available. The average neutron intensity and spectrum in the energy region from 10 to 100 MeV at RCNP were almost the same as those at the Weapons Neutron Research (WNR). The calculated RCNP neutron flux using Particle and Heavy Ion Transport code System (PHITS) generally agreed with the measured RCNP data within a factor of 2. The neutron density per pulse at RCNP, which is around 500 times lower than that for WNR, has the advantage in reduction of the pileup probability of single-event transient currents and false multiple-bit upsets. Such conditions at RCNP are suitable for accelerated SEE testing to get meaningful results in a realistic time frame.