Changes in the structure of polymethyl methacrylate caused by irradiation with millisecond laser pulses

Changes in the molecular structure of polymethyl methacrylate caused by irr adiation with laser pulses of different powers were investigated by x-ray d iffractometry methods. An analysis was made of the position and halfwidth o f a halo in x-ray diffractograms. Coherent scattering regions and the distr ibutions of the moduli of the interatomic vectors were determined. Action o f laser radiation on this transparent dielectric induced molecular structur e changes associated with an increase in the molecular order in the amorpho us matrix and with the formation of clusters at certain specific laser radi ation energies.