It is thought that the radio emissions from pulsar magnetospheres are ruled by plasma electrodynamics in a rotating system where the magnetic field is strong enough for quantum effects to matter and the induced electric field is strong enough to accelerate charges to high Lorentz factors. Yet theoretical models of the physical conditions and details of the emission mechanism have gone largely unchallenged because of the difficulty testing them against traditional pulsar observations. However, because models diverge in their predictions for short timescales, the PIs have been pursuing high time resolution observations of the Crab Nebula pulsar. New data acquisition systems developed for this purpose have detected nanosecond long radio bursts from the Crab's Main Pulse region and the fundamental entities creating the coherent radio emission. The time and frequency characteristics of these "nanoshots" are consistent with a strong plasma turbulence model. However, subsequent observations of a second emitting region, the Interpulse, revealed dramatically different time and frequency signatures indicating substantially different physical conditions which are difficult to explain. As the Crab pulsar is unusual because of its young age, a similar study of a small set (five) of bright pulsars will be undertaken. These pulsars have been chosen to represent the range of likely conditions in other pulsars and the observations will reveal whether the type of emission from the Crab is typical of the general pulsar population. For the Crab itself, intensity and polarization fluctuations on microsecond timescales, as well as time averaged polarization signatures, will be connected to the physical conditions in the emission region by additional theoretical modeling performed by the PIs. Theoretical models of the Interpulse emission will also be critically studied to determine which, if any, existing model can explain these observations. Graduate and undergraduate students will be directly involved in all aspects of this work - from constructing and maintaining the data collection systems to developing the numerical codes for modeling and analysis. Beyond the laboratory, some of the research tools used here will be made available for teaching in local classes and the scientific results incorporated into web-based teaching materials (in addition to dissemination in the professional literature). The state-of-the-art acquisition systems, which will be improved as part of this work, will be made available to the radio astronomy community on a collaborative basis. The data acquisition and control software developed by the PIs is directly applicable to, and available for use in lightning research by the Atmospheric Physics group at New Mexico Tech.
