Ion acceleration at the front and rear surfaces of thin foils with high intensity 40 fs laser pulses

Ion acceleration from the front and rear sides of a foil target is observed by measurements of the ions' spectral and spatial emission characteristics when irradiating the targets with ultra-short (40 fs) high-intensity laser pulses. The experimental results show that the origin of accelerated ions, both from the front and rear surfaces of the target, strongly depend on the laser energy absorption mechanism. In particular, laser pulse parameters, such as pulse duration and contrast, are crucial and determine the entire acceleration scenario. Thus the experimental outcome can be controlled by selection of the irradiation conditions.