Successful demonstration of a compact laser-pumped vector helium magnetometer on the Daytime Dynamo sounding rockets

The Daytime Dynamo sounding rocket mission is a Goddard Space Flight Center led experiment (PI, Rob Pfaff) to study the dayside ionospheric dynamo with a suite of instruments that measure electromagnetic fields, upper atmospheric winds, and the ambient charged and neutral particle populations. Two Dynamo launches have taken place, the first on July 10th, 2011, the second on July 4th 2013. The primary objective of the mission is to determine the constituents of the dynamo current equation and to determine the degree to which the dynamo current is sustained via neutral winds, DC electric fields, or both. Dynamo carries a magnetometer developed by a JPL/UCLA collaboration that measures the vector magnetic field, and from its variation with altitude, allows us to deduce the horizontal current density. The low-mass instrument uses a laser pumped helium sensor developed at JPL, combined with digital electronics based on recent developments in fluxgate magnetometer electronics at UCLA. We will present an overview of the magnetometer design and the instrument performance.