Experimental observation of radiation heat waves

ＥｘｐｅｒｉｍｅｎｔａｌｏｂｓｅｒｖａｔｉｏｎｏｆｒａｄｉａｔｉｏｎｈｅａｔｗａｖｅｓＤｉｎｇＹａｏＮａｎ，ＹａｏＺｈｅｎＹｕ，ＭｉａｏＷｅｎＹｏｎｇ，ＬｉＷｅｎＨｏｎｇ，ＨｅＨａｉＥｎ，ＹｉＲｏｎｇＱｉｎｇ，ＳｈｕｎＫｅＸｉ，Ｚｈｅ...

Radiation heat waves play an important role in high temperature hydro dynamic phenomena which is very important for laser fusion.Therefore, the propagation of a radiation heat wave through a thin foil of solid aluminium is observed. The wave is driven by the intense soft X ray radiation in acylindrical cavity heated by the intense laser pulse. Experiments are carried out with two beams of λ=1.05μm light from the Shenguang Nd glass laser facility. The pulse energy is about 600 J and the pulse duration 0.8 ns. Evidence of radiation heat wave is obtained by observing the delayed signal of intense thermal emission from the outside of the foil. The delay is 850 ps for 1.5μm thick foil and the mass ablation rate is about 4.8×10 5 g/(cm 2 ·s)under the X ray flux of about 1×10 13 W/cm 2 . Also, the radiation driven shock waves of (2±1)TPa are observed from different shots in the experiments.