Measurement of heating laser injection time in a fast-ignition experiment

The ability to measure the injection time of a heating laser synchronized to the imploded core plasma is very important in fast-ignition experiments. In this research, we demonstrate the successful measurement of the injection time using a new x-ray framing camera design. Thermal x-rays for imploded core measurement and hard x-rays for measurement of the heating laser injection time were discriminated using x-ray reflectors made of platinum. The measured hard x-ray signal was evaluated with numerical calculations and found to agree well with the calculated values. We have established a technique for estimating the heating laser injection time from the position of the peak intensity of the hard x-ray signal.