Detection of vapors of explosives by field asymmetric ion mobility spectrometry method with laser ionization

The features of laser ionization of trinitrotoluene and hexogen at registration of ionization products by field asymmetric ion mobility spectrometer were investigated in this paper. The optimal range of intensity to obtain the maximum ion current was determined, and it was shown that composition of ions of explosives is changed with the change of intensity. The values of intensity and radiation at which it is possible to obtain spectra of nonlinear ion mobility with different composition of RDX and TNT ions were determined, which is promising for increasing the selectivity of registration. It was shown that ion peaks of TNT and RDX at laser ionization are characterized by low nonlinear mobility coefficients in comparison with a radioactive source based on Ni63, which indicates a more selective mechanism of laser ionization of these explosives at atmospheric pressure.