Fluoride Materials for VUV Lasers
New Complex Fluoride Compounds as Promising Materials for Solid State Lasers, Fast Scintillators and Luminophors of UV and VUV Wavelength Regions
Tech Area / Field
- MAT-ELE/Organic and Electronics Materials/Materials
- PHY-SSP/Solid State Physics/Physics
3 Approved without Funding
VNIIKhT (Chemical Technology), Russia, Moscow
- FIAN Lebedev, Russia, Moscow\nInstitute of General Physics named after A.M. Prokhorov RAS, Russia, Moscow
- Spectragen, Inc., USA, IL, Des Plaines\nInstitute for Advanced Studies, Japan, Tokyo
Project summaryThe current Project is aimed at the search, design and study of crystalline materials for new high-efficient solid state lasers and scintillators emitting in the ultra violet (UV) and vacuum ultraviolet (VUV) wavelength regions and for high-efficient phosphors.
There is now an urgent need to produce efficient, compact and simple UV and VUV emitters (lasers, scintillators, and phosphors), since many contemporary problems of chemical technology, physics, biology, medicine and environmental monitoring could be easily solved with the help of such devices. The present Project is aimed at development of efficient media based on new complex fluoride compounds for emitters in UV and VUV regions.
Solid state lasers with an extended range of generated wavelengths in UV and VUV spectral regions could solve a range of technological problems, including VUV micro-lithography, isotope separation, ecology of oil product refining, production of protein based medicines, treatment of tuberculosis, sanitation, etc.
The search for new VUV scintillators with high light yield, short decay time, high efficiency of annihilation photon absorption, good mechanical stability, and which are chemically inactive and relatively cheap, is now most topical.
The elaboration of new VUV phosphors with high conversion efficiency is a key aspect in the promotion of plasma displays. Phosphors which emit more than one photon in interaction with one VUV photon (with quantum efficiency of more than 100%) can be created in complex fluoride systems, containing two and more various RE ions, using the mechanism of down-conversion.
Highly qualified experts in chemistry, technology and physics, engaged in nuclear arms production, are to be involved in the Project, alongside scientists from the Russian Academy of Sciences, with previous activity in the Project subject area. ARICT experts are to be involved in the Project; thay have performed investigations on the synthesis and analysis of high purity fluorides for nuclear technologies, and the production of fluoride optical glasses and fibers, operating in aggressive and high radiation mediums.
LPI experts have more than 20 years of experience in the study of scintillation crystals, and their application in gamma and charged radiation detectors. GPI experts possess rich experience in the field of optics and spectroscopy of luminescent materials, and in the cultivation of fluoride crystals using different growth techniques. There are more than 150 scientific publications, related to synthesis, physical and chemical, spectroscopic, scintillation and laser properties of fluorides, doped with rare earth elements, and four patents have been awarded in the field of new phosphors based on fluoride compounds with rare earth elements.
As the final result of the project several classes of laser crystals generating in the VUV spectral region will be recommended for further detailed studies and most optimal schemes of pumping such types of lasers will be developed. Some VUV emitting crystals will be recommended for application in different detectors, in particular, in annihilation gamma-quanta detectors for PET and in detectors suitable for neutron/gamma discrimination. A number of efficient phosphors of high quantum efficiency (higher than 100%), fast decay times of emission (less than 10 ms) and good absorption (higher than 90%) in the VUV will be proposed for applications in mercury free fluorescent lamps and color plasma display panels.
The proposed project will provide weapons scientists and engineers in Russia the opportunities to redirect their talents to peaceful activities. It will promote the integration of Russian scientists into the international scientific community and it will support basic research and technology development for peaceful purposes.
The project has the following objectives: development and optimization of methods for growing novel complex fluoride compounds doped with rare earth ions in the melt; study of spectroscopic characteristics (absorption, luminescence, excitation spectra, decay kinetics) of the obtained single-crystals of complex fluoride compounds doped with rare earth ions, study of their emission and excitation in the UV and VUV; to study the effect of the interaction of various types of radiation with grown fluoride single crystals of complex fluoride compounds doped by rare earth elements, and mechanisms of the energy transfer in these single-crystals; selection of optimal compositions of media for use in lasers, scintillators and phosphors in UV and VUV regions, and preparation of samples for each of these applications; tests of developed laser media in the generation mode: evaluation of the media resistance to pumping radiation, measurements of the re-tuning wavelength bands and generation efficiency; testing of the efficiency and radiation stability of the grown crystals emitting in the UV and VUV from the viewpoint of their applications in ionizing radiation and elementary particle detectors; development and testing of new high-efficiency phosphors, based on complex fluorides with simultaneous doping by several rare earth elements.
The following forms of co-operation are planned in the framework of the Project: exchange of information, obtained during the activities within the framework of the Project; evaluation of technical reports (annual, final), presented by the Project participants to the ISTC; joint use of equipment and performance of tests of produced material samples; participation in evaluation of the results, obtained during Project implementation; assistance in participation in international meetings; organization of joint seminars and meetings.
Crystals of various compositions will be grown from a melt using the Bridgeman method, in the temperature range up to 1500oC. The crystals can be grown in a gaseous atmosphere and in a vacuum (maximum size of a crystal is Ш10x30mm). Equipment is available for optical and luminescence spectroscopy (in VUV range) of solid state materials using compact (laboratory) sources and of synchrotron radiation of a C-60 accelerator, including high time resolution equipment.
Equipment is available to investigate scintillation kinetics (single photon counting method), light yield and radiation hardness (spectrometer for crystal absorption spectra measurements before and after gamma irradiation).
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