Title: УДК 124
Author: alex
Last saved by: max
Company: HOME

Specialization: 010712  Physics of optical phenomena
The program: 08 Coherent optics 
The head of the program: prof. I.Ch.Mashek
Chair of the general physics 1
The supervisor of studies: doc. V.Yu.Venediktov
The reviewer: doc. S.A.Pulkin

Efficient generation of quasi-monochromatic X-rays using superpower femtosecond laser pulses. M.V.Sedov

The advanced technology of short-pulse lasers now provides the opportunity of building  sufficiently compact lasers with moderate and high repetition rates. The pulses generated by these lasers can be focused to reach high intensities on a solid target, and the absorbed laser energy can be partially converted into X-ray radiation. More specifically, such laser pulses can be used to realize high power X-ray pulses of short duration. During the interaction between a high-intensity, ultra-short laser pulse and a solid target, fast electrons are created at the target surface that then penetrate the target where they generate Kα radiation and Bremsstrahlung. The generated X-ray pulses offer the prospect of creating a cheap and compact X-ray source, and thus provide a promising alternative to synchrotron radiation, e.g. for material science and medical applications. Solid matter irradiated by an intense short-pulse laser constitutes a high brightness line source and particularly Kα emission. With an increase in laser intensity, we can expect efficient X-ray emission in the 1–100-keV range with a pulse duration shorter than a few picoseconds. This short incoherent but monochromatic X-ray emission synchronized with laser pulses may be used for time-resolved measurements in various medical and material processing applications.
The aim of the present work is to obtain monochromatic X-ray source based on laser plasma and to study the possibility of increasing the conversion rate of the laser pulse into  X-rays through the use of nano-sized and shaped targets. 
The significant progress in the present research has been achieved. Experimental setup for investigations of femtosecond laser plasmas was created, with energy in 50-fs-pulse up to 10 mJ and with vacuum target chamber. Laser radiation intensity in experiment is from 10^15 to 2x10^17 W/cm^2 depending on the focal diameter. Satisfactory agreement was demonstrated between experimental and theoretical data on generation of quasi-monochromatic X-rays by laser pulses.

The list of the publications
1.	 “New fs Plasma Laser Facility at St.  Petersburg State University: Status and Prospects”  poster presentation //  ISTC-GSI young scientist school “Ultra-High Intensity Light Science and Applications” , Darmstadt,  2011
2.	Efficient generation of quasi-monochromatic X-rays using superpower Femtosecond laser pulses.  poster presentation // International Student Conference “Science and Progress”, Saint-Petersburg, 2012
3.	“Efficient generation of X-rays using superpower laser pulses” poster presentation // 15^th international conference “laser optics 2012”, Saint-Petersburg, 2012