Abstract
A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Ti:sapphire laser. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of ∼10 µm, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.