Initial years’ neutron-induced cross-section measurements at the CSNS Back-n white neutron source *

Abstract

The Back-n white neutron source (known as Back-n) is based on back-streaming neutrons from the spallation target at the China Spallation Neutron Source (CSNS). With its excellent beam properties, e.g., a neutron flux of approximately 1.8×107 n/cm2/s at 55 m from the spallation target, energy range spanning from 0.5 eV to 200 MeV, and time-of-flight resolution of a few per thousand, along with the equipped physical spectrometers, Back-n is considered to be among the best facilities in the world for carrying out nuclear data measurements. Since its completion and commencement of operation in May 2018, five types of cross-section measurements concerning neutron capture cross-sections, fission cross-sections, total cross-sections, light charged particle emissions, in-beam gamma spectra, and more than forty nuclides have been measured. This article presents an overview of the experimental setup and result analysis on the neutron-induced cross-section measurements and gamma spectroscopy at Back-n in the initial years.

Measurement and analysis of the neutron-induced total cross-sections of 209Bi from 0.3 eV to 20 MeV on the Back-n at CSNS*

“…In the future, a 6 Li-containing scintillator-based detector will be developed and applied for neutron total cross-sections measurement as an update to the NTOX spectrometer. A fast scintillator-based neutron total crosssection (FAST) spectrometer is under construction, and…”

“…The neutron transmission ( ) was then obtained after considering the background counts ( ) subtraction and proton beam normalization in Eq. (6).…”

“…This paper reports a new measurement of the neutron total cross-sections of 209 Bi in the energy range from 0.3 eV to 20 MeV on the back-streaming neutron beamline (Back-n [6]) at the China Spallation Neutron Source (CSNS). Neutron energy was determined by the neutron total cross-section spectrometer (NTOX) using the timeof-flight (TOF) technique.…”

“…the physical design has been completed [21,22]. With the FAST spectrometer, the experimental uncertainty of the neutron-induced total cross-sections in the energy region of eV to keV will be improved due to the smooth reaction cross-section of 6 Li(n, α)T, and the statistical uncertainty will also be improved for the high detection effi-ciency of the FAST spectrometer.…”

Evaluation of Single Event Upset on a Relay Protection Device

“…The spallation neutron source is an excellent candidate for conducting atmospheric neutron induced SEE evaluation [26]. With the operation of the China Spallation Neutron Source (CSNS), it has become feasible to study atmospheric neutron SEE in China [27,28]. Due to factors such as uncertainty in irradiation tests, irradiation hours, and cost, the current study primarily focuses on using spallation neutron irradiation to confirm whether SEE can affect the target relay protection device, specifically the Loongson 2K1000 systemon-chip based development kit.…”