EUV induced, low temperature plasmas, produced in an aerosol target

Abstract

In this work spectral investigations of low temperature plasmas, created by photoionization of aerosol targets, were performed. A laser produced plasma (LPP) source of extreme ultraviolet (EUV) was used as a source of ionizing radiation. The source was driven by a 10 Hz Nd:YAG laser system, delivering pulses of energy up to 10 J with a time duration of approximately 10 ns. The aerosol target was formed using a specially prepared system composed a mist ultrasonic generator and a solenoid valve. The mist was created inside a small cell containing a small portion of methanol and filled with a He gas. The valve coupled to this cell allowed to inject the aerosol into a vacuum chamber synchronously with the EUV pulse. Low temperature plasmas created by the EUV irradiation of the aerosol target were investigated mainly by spectral measurements. The spectra, acquired in the UV/VIS range, were composed of lines corresponding to radiative transitions in atoms and singly charged ions originating from the He gas and dissociation products of the methanol. Spectral measurements were performed also for aerosol targets created from solutions of various inorganic salts in the methanol. In this case, additional lines corresponding to decomposition products of these salts were detected.