Measurement of heating laser injection time to imploded core plasma by using x-ray framing camera.

A simultaneous measurement of imploded core plasma and injection time of heating laser is conducted by using an x-ray framing camera (XFC). The experiments are performed using Gekko XII laser system for implosion of the deuterated polystyrene (CD) plastic shell target and Peta Watt (PW) laser system for heating. The time of PW laser injection is observed as the bright zone in the XFC image. The measured x-ray intensity profiles fit the Gaussian profiles well. The calculations of microchannel plate by using dynode model explain these broadened temporal profiles qualitatively. The peak position of fitted x-ray intensity profile is almost in agreement with the time when the high energy x ray is observed by x-ray streak camera. Moreover, the peak position is delayed corresponding to the delayed setting of PW laser injection time. From these results, it is concluded that we can estimate the heating laser injection time with resolution of the order of 10 ps by using XFC.