Back in January, we were part of a facility lead experiment using the Gemini laser at the Central Laser Facility. The aim of this experiment was to demonstrate the spacial and temporal resolution of x-rays generated by laser wakefield accelerated electrons. X-rays were created via two mechanisms: betatron oscillations inside the plasma accelerator (plasma wiggler) and Bremsstrahlung radiation from the interaction of electrons with a solid converter. Images from the experiment demonstrating the spatial resolution of these sources are shown below. The first shows a resolution grid imaged using the plasma wiggler. The smallest features which can be resolved are around 3 μm – comparable to micro-focus tube source resolution – and we suspect that limit is imposed by the detector, not the source.
A composite image of several shots using the bremsstrahlung source is shown here too. The smallest feature resolved in this image is 200 μm thick, although again the resolution seemed to be limited by the detector. This is still very good when compared against other sources with similar photon energy.