Laser spark initiated microwave discharge

Microwave discharge initiated by double laser spark in a supersonic airflow

“…As noted earlier (Azarova et al 2011;Golbabaei Asl and Knight 2014;Polianskij et al 2013), the long and narrow plasma heated area is more efficient for supersonic applications since it provides better aerodynamic characteristics. In Afanasev et al (2010), a longer (4μs) MW pulse was used and generated MW discharge is not limited by the laser spark shock wave. However, the discharge obtained in Afanasev et al (2010) is spontaneous.…”

“…In Afanasev et al (2010), a longer (4μs) MW pulse was used and generated MW discharge is not limited by the laser spark shock wave. However, the discharge obtained in Afanasev et al (2010) is spontaneous. Our discharge is shorter but it is controllable.…”

“…Practically, both problems can be solved by laser initiation of MW discharge. Now, several types of laser initiation of discharges in quiescent air are investigated, among them resonant excitation (for example, Golbabaei Asl and ), non-resonant excitation (effect of MW discharge stabilization in quiescent air by laser radiation (Bityurin et al 2012)) and initiation by laser spark (Mashek et al 2004;Kolesnichenko et al 2006;Afanasev et al 2010). In the present work, we continue the investigation of the latter method, i.e.…”

“…Thus, the heated low density air area leave the laser focus area in a time about 10 μs. It is shown in Afanasev et al (2010) that the effect of MW breakdown threshold started decreasing after the laser spark is observed in the time delay range of about 6-120 μs. Based on this discussion, we choose for our experiments the time delay between laser sparks in the range 10-100 μs which corresponds to 4.3-43 mm between heated air areas.…”