مشخصه‌یابی و مقایسه ضرایب پلاسمای لیزری با روش ردیاب لانگمیر در فشارهای پایین اتمسفر

In this paper, the electron temperature and ion density of laser-produced plasma in nanosecond regime in different pressure of ambient gas have been studied by using single Langmuir probe. Using the current-voltage characteristics curve of probe, the value of electron temperature in different pressure (range of 10-5×10-5 mbar) is in the range of 2-29 eV and also the ion density estimated about 1013 cm-3 in millimeter scale and 1011 cm-3 in centimeters scale from target to probe. . It is important that regardless of I-V characteristic of Langmuir probe, having time of maxim current signal of probe at certain distance from target surface, it would be possible to obtain the particles speed by time of flight method. The results show that the electrons and ions speeds are about 108 cm/s and 106cm/s respectively. Also the results of this experiment are Comparable with other techniques such as Shadowgraphy in the similar experimental conditions.