首页|Multivariate analysis of Compton-imaging detector response for neutron capture cross-section measurements
Multivariate analysis of Compton-imaging detector response for neutron capture cross-section measurements
luo, Mr. zhongxian Ren, Dr. Jie Wang, Dr. jincheng Ruan, Dr. Xichao Xue, Ms. Jieming Yang, Miss Haolan Bao, Dr. Jie Jiang, Dr. Wei Fan, Dr. Ruirui Huang, Dr. Hanxiong Luan, Dr. Guangyuan Zhang, Dr. Qiwei
Multivariate analysis of Compton-imaging detector response for neutron capture cross-section measurements
Multivariate analysis of Compton-imaging detector response for neutron capture cross-section measurements
摘要
The imaging total-energy detector (i-TED) uses Compton imaging to suppress background in radiative neutron capture measurements, but stringent geometric selection often entails substantial losses in event statistics. This work investigates a TabM-based multivariate event-selection method using measurements at the back-streaming white neutron beamline (Back-n) of the China Spallation Neutron Source (CSNS). Capture-cascade, particle-transport and detector-response simulations are combined with $^{197}$Au sample measurements to evaluate background suppression and event retention. Experimental results show that TabM retains more coincidences than geometric selection at the same effect-to-background ratio. At equal selected counts, it achieves a higher ratio. Pulse-height weighting and selection-specific response calibration are combined with the corresponding experimental corrections to reconstruct the $^{197}$Au(n,$\gamma$) cross section. Both reconstructions retain the main Au resonance structures, and uncertainty propagation shows improved precision for TabM with response calibration and selection thresholds held fixed. In a separate weak-signal $^{209}$Bi simulation, multivariate selection retains more true capture events at equal selected counts, making resonance structures that are weak under geometric selection more distinct. The method improves the statistical efficiency of i-TED capture measurements and provides a basis for measurements of weak capture signals and mass-limited samples.