Research Interests

My interests include spacecraft measurement of electric fields and particle acceleration in space plasmas. Some of the topics we investigate are the structure and dynamics of collisionless shocks and nonlinear wave modes, auroral acceleration mechanisms, energy release due to magnetic reconnection, energetic particle acceleration and radiation belts, and the large scale convection of magnetospheric plasmas.

Radiation Belt Storm Probe Mission

I am currently the Principal Investigator on the Electric Fields and Waves Instrument on NASA's Radiation Belt Storm Probes. Other institutions involved in the hardware development phase of this instrument are the Space Sciences Lab at the University of California, Berkeley and Laboratory for Atmospheric and Space Physics at the University of Colorado. The purpose of this two spacecraft mission is to understand the mechanisms responsible for the acceleration of relativistic particles in the inner magnetosphere of the Earth. Some of the mechanisms we shall study are the effects of interplanetary shocks on relativistic particles, injection fronts propagating inward from the geomagnetic tail; Ultra-Low Frequency Waves in which the magnetic field lines of the Earth vibrate like violin strings; and, small scale large amplitude plasma waves propagating along magnetic field lines.The flight instrument has been fabricated, tested, and integrated to the spacecraft. The spacecraft were delivered to Cap Canaveral in May 2012 and launched in Fall of 2012. The spacecraft are currently on-orbit and taking data.

Solar Probe Plus Mission to the Sun

I am also involved NASA's Solar Probe Plus mission which is scheduled for launch in 2018. This mission will carry an electric and magnetic field detector, plasma and energetic particle instruments, and a white light coronagraph imager. Its closest approach to the sun will be 9.5 solar radii (the earth is at 215 solar radii). I am interested in the plasma physics of the "near sun" environment and what powers the supersonic solar wind acceleration.

Research Group

NASA's Radiation Belt Storm Probes
NASA's Solar Probe Plus