Properties of the neutron detector based on ionisation chamber with 6Li converters

The ICC neutron detector is an ionisation chamber with three neutron absorbing converter electrodes of ⁶Li metal foils. On both sides the foils face collector electrodes that are positively biased. The neutron detection was investigated at the pulsed neutron source of the Argonne National Laboratory. The induced charge due to drifting electrons that are generated by the energetic ³H recoil nucleus in the C₂F₆ gas between the electrodes was measured as function of gas pressure, gas contamination, and applied drift voltage. The neutron detection efficiency was determined and the gamma insensitivity was estimated. The pulse heights were calibrated by the induced charge from test pulses. The timing characteristics of the detector pulses were assessed, and TOF measurements demonstrated the usefulness of the detector. First neutron diffraction experiments were made with structured collection electrodes for position-sensitive detection and for estimating the achievable spatial resolution.