Particle Physics Seminar

Liquid argon is becoming a popular medium for particle detection, with applications ranging from low-background dark matter searches to high-energy neutrino detection. Because neutrons may represent both an important source of background and a product of signal events, a good understanding of their interactions in argon is a requirement for precision physics measurements. Despite being one of the most basic quantities needed to describe low energy neutron transport, the thermal neutron capture cross section on argon remains poorly understood, with the existing activation measurements showing significant disagreements. To resolve these disagreements, the Argon Capture Experiment at DANCE (ACED) collaboration has performed a differential measurement of the 40Ar(n, gamma)41Ar cross section using a time of flight neutron beam and the Detector for Advanced Neutron Capture Experiments (DANCE), a ∼4pi gamma spectrometer at Los Alamos National Laboratory. A fit to the differential cross section from 0.015-0.15eV, assuming a 1/v energy dependence, yields sigma(2200)=673+-26 (stat.) +- 59(sys.) mb. During this talk, I will introduce the DUNE experiment before focusing on the importance of neutrons in liquid argon detectors. I will then present the ACED experiment and the use of neutrons as a detector calibration method.