A Hybrid Technique for Neutron Spectroscopy Using Deuterated Scintillators and Spectrum Unfolding for FRIB.

As the field of nuclear physics looks towards the next-generation of radioactive beam facilities, such as FRIB, it is vital that the appropriate infrastructure is in place so the full capabilities of these facilities can be exploited. Neutron spectroscopy is an example of an important area where efforts should be focused to be fully prepared for first beam at FRIB. Traditionally, neutron spectroscopy measurements are performed using the time-of-flight (ToF) method. However, to achieve reasonable energy resolution the detector must be placed a significant distance from the target, which reduces solid angle efficiency. An alternative to this is a hybrid method developed at ORNL which combines the neutron spectroscopy method of spectrum unfolding with the traditional ToF method to maximize the solid angle efficiency without sacrificing the energy resolution. An array of deuterated organic liquid scintillators has been designed and built at ORNL and characterized using the ToF tunnel at Ohio University. The light response and pulse shape discrimination capabilities of this array will be presented, and the spectrum unfolding method will be discussed.