Acquiring accurate neutron energy spectrum information is of vital importance to national security as well as personal safety. Unfolding neutron energy spectra from detector responses is a heavily researched area due to the importance of neutron energy for determining radiation dose received. We investigate a new detection system developed by Lawrence Livermore National Laboratory (LLNL), the passive neutron spectrometer (PNS), for use in energy spectrum unfolding techniques primarily in the event of a criticality accident. The unfolded energy spectrum is used to calculate the dose a person would receive in the presence of that neutron field. This detector provides a passive neutron detection method through the use of 55 thermoluminescent dosimeters or gold foils contained within a single polyethylene sphere. Three unfolding algorithms were employed in this research, including our own neural network.