Applied Physics Researches Division (APRD)

Optics and Spectroscopy (240/3) Researches

Posted on Dec 13, 2015

  1. Optical “effect of small doses” is revealed in the process of electronic irradiation in corundum with two competing mechanisms: “curing” (ordering) of crystal lattice and recharge of pre-radiation defects, which depend on the crystal history.
  2. Substantial growth of intensity of photoluminescence and luminescence excitation of R – lines in ruby after irradiation by fast electrons with subsequent heat treatment at 575-625 K is experimentally received.
  3. In corundum crystals irradiated by high-energy particles, strong increase of reflect capacity is revealed in wide energy range (5-30 eV, 70-200 eV and 530-550 eV) owing to radiation stimulated desorbtion leading to the formation of Аl  on the surface – effect  of “mirror reflection”.
  4. Features of the processes of multiplication of electronic excitations in many wide-gap crystals and their role in energy transfer to the luminescence centers are studied, as well as effect of irradiation on these processes.
  5. UV and VUV luminescence (fast and slow components) of color centers, radiation centers in crystals of corundum, ruby, garnets, phosphors with high time resolution is studied, nature of which is interpreted on the basis of power levels of energy levels of radiation centers.
  6. The effect of “radiation memory” corundum crystals irradiated by fast electrons after heating at 1000оС and irradiation by SI-quanta with energy hν~12 keV, when concentration of color centers does not reach the levels before heating.
  7. For the first time complex research of radiation-optical properties of natural Armenian zeolites, in particular, clinoptilolite was carried out. Opportunity of using the modified zeolites for deactivation of liquid radiating wastes from Armenian nuclear power plant was revealed.
  8. Characteristic features of VUV luminescence was studied, in particular, up-conversion luminescence of fluoride crystals activated by Er3+ ions. It was shown that spectra of emission and excitation of YAG: Nd3+ crystals are caused by intraconfigurational and interconfigurational transitions. Probabilities of the mixed transitions were theoretically simulated.