One method to realize significant gains in neutron coincidence detection efficiency is to develop neutron double scatter detectors which employ monolithic blocks of organic scintillator, instrumented with photosensor arrays on multiple faces to enable 3D position and multi-interaction time pickoff. Due to the relatively low coincidence detection efficiency of fast neutrons in organic scintillator arrays, imaging efficiency for double scatter cameras can also be low. Neutron double scatter imaging exploits the kinematics of neutron elastic scattering to enable emission imaging of neutron sources. When combined with other demonstrated improvements, we project over an order of magnitude improvement in statistical sensitivity for the next generation ACME electron EDM search. We also demonstrate an upgraded rotational cooling scheme that increases the ground state population by 3.5 times compared to no cooling, consistent with expectations and a factor of 1.4 larger than previously in ACME. This results in a factor of 16 enhancement in the molecular flux detectable downstream, in a beamline similar to that built for the next generation of ACME. Here, we demonstrate electrostatic focusing of the ThO beam with a hexapole lens. An improvement in statistical uncertainty would be possible with more efficient use of molecules from the cryogenic buffer gas beam source.
The ACME experiment uses a spin-precession measurement in a cold beam of ThO molecules to detect d e. cm (90% confidence), was set by the ACME collaboration in 2018.The current best upper limit for electron electric dipole moment (EDM), |d e |<1.1×10 ⁻²⁹ e
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