  The nuclear fission process that occurs in the core of nuclear reactors
results in unstable, neutron rich fission products that subsequently beta decay
and emit electron anti-neutrinos. These reactor neutrinos have served neutrino
physics research from the initial discovery of the neutrino to current
precision measurements of neutrino mixing angles. The prediction of the
absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon
a series of seminal papers based on measurements performed in the 1970s and
1980s. The steadily improving reactor neutrino measurement techniques and
recent re-considerations of the agreement between the predicted and observed
reactor neutrino flux motivates revisiting the underlying beta spectra
measurements. A method is proposed to use an accelerator proton beam delivered
to an engineered target to yield a neutron field tailored to reproduce the
neutron energy spectrum present in the core of an operating nuclear reactor.
Foils of the primary reactor fissionable isotopes placed in this tailored
neutron flux will ultimately emit beta particles from the resultant fission
products. Measurement of these beta particles in a time projection chamber with
a perpendicular magnetic field provides a distinctive set of systematic
considerations for comparison to the original seminal beta spectra
measurements. Ancillary measurements such as gamma-ray emission and
post-irradiation radiochemical analysis will further constrain the absolute
normalization of beta emissions per fission. The requirements for unfolding the
beta spectra measured with this method into a predicted reactor neutrino
spectrum are explored.
