FEATURES OF THE TIME SHAPE OF THE PRESSURE PULSES OF 
OPTICAL AIR BREAKDOWN

A. N. Chumakov,a A. M. Petrenko,b and N. A. Bosaka 

UDC 534.222.2:621.373

The time shape and amplitude of pressure pulses initiated 
by surface laser air breakdown for different energies of laser pulses 
(1-180 mJ) has been compared to the results of numerical gasdynamic 
calculations of unsteady explosive motions with allowance for counterpressure 
at distances of 0.2 to 30 cm from the breakdown region. It has been 
established that the experimental pressure pulse has the character 
of slowly damped quasiperiodic vibrations, whereas the calculated 
pulse is a bipolar single pulse of a much shorter duration. Good agreement 
between the experimental and calculated amplitudes of a positive pressure 
phase has been found throughout the investigated range, whereas the 
agreement between the corresponding amplitudes and durations of a 
negative pressure phase is limited in character. The differences observed 
in the experimental and calculated data have been attributed to the 
transformation of the shock-wave motion to acoustic radiation.

aInstitute of Molecular and Atomic Physics, National Academy 
of Sciences of Belarus, Minsk, Belarus; 
bInstitute of Solid and Semiconductor Physics, 
National Academy of Sciences of Belarus, Minsk, Belarus. Translated 
from Inzhenerno-Fizicheskii Zhurnal, Vol. 76, No. 4, pp. 89-94, 
July-August, 2003. Original article submitted November 26, 2002.