A sensitive multi-detector neutron counter used to monitor `cold fusion´ experiments in an underground laboratory; negative results and positive artifacts

A description is given of the neutron counter system used in a search for neutrons at high-sensitivity, the negative results obtained, and the identification of some potentially misleading artifacts of neutron detection. More than 30 different test cell configurations were tested to cover the full range of the pertinent experimental variables. The design and characteristics of the neutron counter are discussed. The significant features of this neutron search technique are: (1) three independent neutron detectors of relatively high efficiency were used to simultaneously monitor the test cells; (2) the detectors were calibrated using a ²⁵²Cf neutron source in place of the test cells; and (3) the experiments were performed in an underground laboratory to reduce the neutron background induced by cosmic rays. The overall efficiency of the counter for ²⁵²Cf neutrons was 9.2 to 15%, depending on the experimental arrangement. No evidence was observed for significant neutron emission from any of the more than 30 test cell configurations that were monitored for a total of 339 h in the underground laboratory