Author:
Novak J.,Solomey N.,Hartsock B.,Doty B.,Folkerts J.
Abstract
Abstract
Low energy anti-neutrinos detected from reactors or other
sources have typically used the conversion of an anti-neutrino on
Hydrogen, producing a positron and a free neutron. This neutron is
subsequently captured on a secondary element with a large neutron
capture cross-section such as gadolinium or cadmium. With most
neutron captures on gadolinium, it is possible to get two or three
delayed gamma signals of known energy to occur. Modern experiments
can make measurements with timing on the order of 25 ns. Fast
electronics like these allow for the possibility of accessing the
very fast signals from the nuclear de-excitation of a heavy nucleus
following the prompt positron signal, rather than relying on
traditional IBD techniques. We have found an isotope of tungsten,
183W that produces tantalum in the ground state at 2.094 MeV
or the first excited state at 2.167 MeV. The excited state of
183Ta* emits a signature secondary gamma pulse of 73 keV
with a 106 ns half-life. This offers a new delayed coincidence
technique that can be used to identify anti-neutrinos with lower
background noise. This allows for less shielding than required for
modern inverse beta decay detectors.