Cavallo’s Multiplier for High Voltage Generation in the SNS nEDM Experiment

For the SNS nEDM Collaboration

With a targeted sensitivity of order 10^-28 e-cm, the neutron electric dipole moment (nEDM) experiment to be conducted at the Oak Ridge National Laboratory’s Spallation Neutron Source (SNS) requires 650 kV in the sub-1-Kelvin central detector volume to produce 75 kV/cm within the measurement cells. Cryostat design constraints -- heat budget and cryostat space -- make bringing in 650 kV from a room temperature high voltage source extremely challenging. We suggest bringing a much smaller voltage, 50 kV, into the central detector and using an 18^th century electrostatic induction machine, known as the Cavallo multiplier, operating inside the central detector volume to produce the 650 kV. We expand Cavallo’s original work by predicting the output voltage created as a function of initial voltage and machine cycles in a room-temperature demonstration apparatus, as well as maximizing the gain of the multiplier within our nEDM apparatus design constraints in an electrostatic COMSOL simulation by manipulating electrode geometries. Progress on a cryogenic test apparatus will also be discussed.