Laser Generated Plasmas for Nuclear Astrophysical Applications

In this paper a review of the experimental and numerical results obtained from the investigation of the dynamic of a laser produced plasma in the nanosecond pulse regime is presented. The aim of the work is to use laser plasmas as a tool for fusions reaction rates measurements in low energy domain. These studies include the investigation of the electron screening effect on the total number of fusions. In a laser irradiance regime of 1012W/cm2, the produced plasma ion temperatures are high enough to ensure a not negligible number of fusion events (> 100eV ) while clouds of cold electrons with temperatures on the order of few eV’s could provide to a not negligible influence of the screening. This confers to laser plasmas the unique peculiarity to be employed for fusion reaction rates measurements in a low energy domain. For the same purposes also multiple counter-propagating colliding laser plasmas can be employed. The dynamic of a single expanding plasma was investigated with Langmuir Probe measurements. Other than the classical hydrodynamic expansion, at the early stage of the plasma expansion, the formation of Double and Multi-layers was observed. The measurements on colliding plasmas were carried out by combining time resolved imaging and spectroscopy. Fast imaging and emission spectroscopy data revealed detailed information about the dynamic of spectral emission of the atomic species which compose the colliding region of the two plumes. The overall experimental results are promising for the design of experiments devoted to fusion reaction rate measurements by including the effect of the electron screening. Numerical fusion reaction rate calculations were also carried out, in order to determine the influence of the screening on the total number of fusions.