They claimed a liquid scintillation detector measured neutron levels at 8 standard deviations above the background level, while plastic detectors measured levels at 3.8 standard deviations above the background. When the same experiment was performed with non-deuterated control liquid, the measurements were within one standard deviation of background, indicating that the neutron production had only occurred during cavitation of the deuterated liquid.[20][21][22][23] William M. Bugg, emeritus physics professor at the University of Tennessee also traveled to Taleyarkhan's lab to repeat the experiment with his equipment. He also reported neutron emission, using plastic neutron detectors.[23] Taleyarkhan claimed these visits counted as independent replications by experts, but Forringer later recognized that he was not an expert, and Bugg later said that Taleyarkhan performed the experiments and he had only watched.[24]