This plot shows the statistical uncertainty versus wire number for the n-3He Helium-3 active target leading to an overall statistical uncertainty of ten parts-per-billion.
This experiment, being carried out by an international collaboration, is measuring parity-violating (PV) neutron capture in Helium-3. Together with other PV experiments (including the NPDGamma measurement at the SNS), it will provide a complete set of such measurements in simple nuclear systems, and thus determine the strength of the fundamental forces between protons and neutrons. The experiment performed well, collecting sufficient data to allow for the desired 10 ppb precision.