| Abstract: | A directional neutron detector has an ion chamber formed in a dielectric
material; a signal electrode and a ground electrode formed in the ion
chamber; a neutron absorbing material filling the ion chamber; readout
circuitry which is electrically coupled to the signal and ground
electrodes; and a signal processor electrically coupled to the readout
circuitry. The ion chamber has a pair of substantially planar electrode
surfaces. The chamber pressure of the neutron absorbing material is
selected such that the reaction particle ion trail length for neutrons
absorbed by the neutron absorbing material is equal to or less than the
distance between the electrode surfaces. The signal processor is adapted
to determine a path angle for each absorbed neutron based on the rise
time of the corresponding pulse in a time-varying detector signal. |