| Born: 1957, USSR |
Academic Qualifications:M.Sc. , 1980, Moscow Institute of Physics and Technology. Moscow. USSR, Physics (with distinction)
Ph.D. , 1985, Institute of Physics /Institute of Semiconductors Academy of Sciences of the Ukrainian SSR. Kiev. USSR|, Physics
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Academic Positions:
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Research Interests:
Chemical oxygen-iodine laser, chemical lasers, gas lasers, optical resonators, nonlinear optics |
Research Projects:
i)Experimental and theoretical study of the supersonic chemical oxygen-iodine laser;
ii)Modeling of non-linear frequency conversion for non-uniform transverse intensity profiles of the pumping beam
iii) Modeling of Stimulated Raman Scattering process including thermal effects of defocusing |
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Abstracts of Current Research:- Toward understanding the dissociation of I2 in chemical oxygen-iodine lasers: combined experimental and theoretical studies: The dissociation of I2 molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied via detailed measurements and three dimensional computational fluid dynamics calculations. The measurements, briefly reported in a recent paper (Appl. Phys. Lett., 89, 021115 (2006)) and reanalyzed in detail here, revealed that the number N of consumed O2(a1Δg) molecules per dissociated I2 molecule depends on the experimental conditions: it is 4.5 ± 0.4 for typical conditions and I2 densities applied for optimal operation of the COIL, but increases at lower I2 densities. Comparing the measurements and the calculations enabled critical examination of previously proposed dissociation mechanisms and suggestion of a mechanism consistent with the experimental and theoretical results obtained in a supersonic COIL for the gain, temperature, I2 dissociation fraction and N at the optical axis. The suggested mechanism combines the recent scheme of Azyazov and Heaven (AIAA J. 44, 1593 (2006) with the "standard" chain branching mechanism of Heidner et al. (J. Phys. Chem. 87, 2348 (1983).
- Power enhancement in chemical oxygen-iodine lasers by iodine pre-dissociation via corona/glow discharge: The gain and power in a supersonic chemical oxygen-iodine laser (COIL) are enhanced by applying DC corona/glow discharge in the transonic section of the secondary flow in the supersonic nozzle, dissociating I2 prior to its mixing with O2(1Δ). The loss of O2(1Δ) consumed for dissociation is thus reduced and the consequent dissociation rate downstream of the discharge increases, resulting in up to 80% power enhancement. The implication of this method for COILs operating beyond the specific conditions reported here is assessed.
- Analysis of Lasing in Chemical Oxygen-Iodine Lasers with Unstable Resonators Using a Geometrical-Optics Model: A simple geometrical optics model is developed, describing the power extraction in chemical oxygen-iodine lasers (COILs) with unstable resonators. The positive and negative branch unstable resonators with cylindrical mirrors that were recently used in COILs are studied theoretically. The optical extraction efficiency, spatial distributions of the intracavity radiation intensity in the flow direction and the intensity in the far field are calculated for both kinds of resonators as a function of both the resonator and COIL parameters. The optimal resonator magnifications corresponding to the maximum intensity in the far field are found.
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Publications:- Barmashenko B. D.. Analysis of lasing in chemical oxygen–iodine
lasers with unstable resonators using
a geometric-optics model Applied optics 48: 2542-2550 (2009)
- Waichman, K., Rybalkin, V., Katz, A., Dahan,Z., Barmashenko,B.D. & Rosenwaks, S.. Toward understanding of the dissociation of I2 in chemical oxygen-iodine lasers: combined experimental and theoretical studies Journal of Applied Physics. 102: 013108 (2007)
- Katz, A., Dahan,Z., Rybalkin, V., Waichman, K., Barmashenko,B.D. & Rosenwaks, S.. Power enhancement in chemical oxygen-iodine lasers by iodine pre-dissociation via corona/glow discharge Applied Physics Letters 90: 161122 (2007)
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Book Chapters:- Barmashenko B. D.& Rosenwaks S., Chemical Lasers: COIL, Handbook of Laser Technology and Applications, Webb C. E., 861-880, Institute of Physics, 2003
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| Keywords:Chemical Lasers, Optical Resonators, Nonlinear Optics. |
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Phones:
- Phone: 972-8-6477127
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