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Solar radio spikes are short duration and narrow bandwidth fine structures indynamic spectra observed from GHz to tens of MHz range. Their very shortduration and narrow frequency bandwidth are indicative of sub-secondsmall-scale energy release in the solar corona, yet their origin is notunderstood. Using the LOw Frequency ARray (LOFAR), we present spatially,frequency and time resolved observations of individual radio spikes associatedwith a coronal mass ejection (CME). Individual radio spike imaging demonstratesthat the observed area is increasing in time and the centroid positions of theindividual spikes move superluminally parallel to the solar limb. Comparison ofspike characteristics with that of individual Type IIIb striae observed in thesame event show similarities in duration, bandwidth, drift rate, polarizationand observed area, as well the spike and striae motion in the image planesuggesting fundamental plasma emission with the spike emission region on theorder of ${\sim}\:10^8$ cm, with brightness temperature as high as $10^{13}$ K.The observed spatial, spectral, and temporal properties of the individual spikebursts are also suggesting the radiation responsible for spikes escapes throughanisotropic density turbulence in closed loop structures with scatteringpreferentially along the guiding magnetic field oriented parallel to the limbin the scattering region. The dominance of scattering on the observed timeprofile suggests the energy release time is likely to be shorter than what isoften assumed. The observations also imply that the density turbulenceanisotropy along closed magnetic field lines is higher than along open fieldlines.

First Frequency-Time-Resolved Imaging Spectroscopy Observations of Solar Radio Spikes