After a series of successful tests at Caltech the nEDM@SNS magnet was shipped to ORNL. It is now being reassembled in preparation for tests in the neutron beam.  

Magnetic Shield Enclosure under construction.   Details: The nEDM@SNS experimental apparatus must be shielded from stray magnetic fields. A multi-layer Magnetic Shield Enclosure (MSE) is being assembled for this purpose by IMEDCO, a Swiss firm specializing in magnetic shielding applications. This video shows the assembly in action.

Collaborators at Caltech completed fabrication of the primary (“B0”) magnet coil. Click here to watch video

Collaborators at the University of Kentucky and Caltech carried out successful tests of the cryogenic magnetic field monitor.

The nEDM@SNS experiment uses the equivalent of an oversized travel mug to surround the large volume of liquid helium at its heart with a vacuum layer to prevent it from heating up. The so-called Outer Vacuum Chamber (OVC) was recently delivered to ORNL. nEDM@SNS Outer Vacuum Chamber arriving from GNB

For optimal performance the experiment’s SQUID magnetometers must reside in a hermetically sealed Faraday cage. The aluminum Cryovessel serves this function, but temperature sensors and other devices with wiring that penetrates the Cryovessel must terminate in a connected Faraday cage (the Radio-Frequency Screen Room, or RFSR) outside the Magnetic Shield

Large size, cooling requirements, non-metallic construction all combine to make the nEDM@SNS magnet a complicated engineering and assembly challenge. Construction of the magnet is now well underway at Caltech.

The nEDM@SNS experimental signal is a burst of scintillation light following the capture of a neutron by a Helium-3 nucleus. Processing electronics that use silicon photomultipliers to count the number of emitted photons and record their arrival time have now been completely tested.

Unusual requirements for the nEDM@SNS experimental building include a magnetic keep-out zone near the apparatus and a deep basement for access to the cryogenic interior. Final design of the building was recently completed. 3D CAD model of nEDM@SNS experimental building. Drawing of the experimental building and environs from final design