Characterisation of Liquid Solution Sheets from Various Nozzle Diameters for Laser Ion Acceleration

Ultrathin liquid sheets produced by colliding microjets have been proven an appropriate target for high repetition rate laser ion acceleration [1], [2]. The ion yield depends strongly on the thickness of the sheets and the physical properties of the liquid. According to the Hasson-Peck (HP) model [3], the thickness is inversely proportional to the distance from the collision point of the two jets and it does not depend on the parameters that characterise the material quality of the liquid (e.g. density, viscosity, surface tension). So far, thickness measurements were carried out only for single liquids as water, heavy water and glycol. Recently, good agreement was found between the measured and theoretical values [4]. From scientific and technological viewpoints, it seems promising to use a solution of two or more liquids to achieve better sheet stability and ion yield [5], [6]. Here we report on a series of systematic measurements of liquid sheets thickness for various nozzle diameters and mixtures of water, heavy water and glycol.