Ion acceleration boosted by multi-picosecond relativistic-intensity laser

This paper takes up the ion acceleration experiments using kilojoule class multi-picosecond relativistic laser that were conducted at the petawatt laser facilities LFEX (Laser for Fast Ignition Experiments) installed at the Institute of Laser Engineering, Osaka University. In the experiments at LFEX, the protons and ions such as carbon of MeV energy class are accelerated in the vertical direction at the back surface of an aluminum thin film target. It can be said that in the background of ion acceleration boost in the multi-picosecond region, a statistically new electronic heating mechanism is hidden, where plasma electron temperature greatly rises due to the elongation of time width. This paper comprehensively explains that it is possible to accelerate ions far exceeding the conventional scaling rule due to the statistical theory mechanism, by comparing experiments and simulation on a theoretical model. (A.O.)