  We report on a first-principles numerical and theoretical study of plasma
dynamo in a fully kinetic framework. By applying an external mechanical force
to an initially unmagnetized plasma, we develop a self-consistent treatment of
the generation of ``seed'' magnetic fields, the formation of turbulence, and
the inductive amplification of fields by the fluctuation dynamo. Driven
large-scale motions in an unmagnetized, weakly collisional plasma are subject
to strong phase mixing, which leads to the development of thermal pressure
anisotropy. This anisotropy triggers the Weibel instability, which produces
filamentary ``seed'' magnetic fields on plasma-kinetic scales. The plasma is
thereby magnetized, enabling efficient stretching and folding of the fields by
the plasma motions and the development of Larmor-scale kinetic instabilities
such as the firehose and mirror. The scattering of particles off the associated
microscale magnetic fluctuations provides an effective viscosity, regulating
the field morphology and turbulence. During this process, the seed field is
further amplified by the fluctuation dynamo until they reach energy
equipartition with the turbulent flow. By demonstrating that equipartition
magnetic fields can be generated from an initially unmagnetized plasma through
large-scale turbulent flows, this work has important implications for the
origin and amplification of magnetic fields in the intracluster and
intergalactic mediums.
