Abstract: The existence of a permanent electric dipole moment (EDM) in any non-degenerate system is an affirmation of Time and (Charge-)Parity Violation in fundamental interactions. The revelation of a non-zero EDM in next generation experiments on atoms, molecules, or nucleons would yield important information on physics beyond the Standard Model. New sources of CP violation may make it possible to understand the numerical size of the baryon asymmetry of the Universe and the discovery potential of an EDM is strongly coupled to the detection potential of (future) high energy accelerators.

The experimental sensitivity to the neutron EDM has been improved by eight orders of magnitude over the last seven decades.  At present, the best limit of 1.8x10^-26 e cm (90% C.L.) was achieved at the Paul Scherrer Institute (Switzerland) using ultra-cold neutrons in a magnetic trap.  A new experiment with the goal to improve this limit by possibly two orders of magnitude is under construction at the Spallation Neutron Source (SNS) in Oak Ridge. A dense target of ultra-cold neutrons, ​“stored in a box”, in combination with a novel detection technique will be used to accomplish this goal. An update on the status of the experiment and the technology to achieve these objectives will be discussed.