Materials for Vacuum Ultraviolet Emitters
New VUV Inorganic Media for High Technologies in Laser, Scintillation and Phosphor Techniques
Tech Area / Field
- MAT-ELE/Organic and Electronics Materials/Materials
- PHY-OPL/Optics and Lasers/Physics
- PHY-SSP/Solid State Physics/Physics
3 Approved without Funding
VNIIKhT (Chemical Technology), Russia, Moscow
- Institute of General Physics named after A.M. Prokhorov RAS, Russia, Moscow\nFIAN Lebedev, Russia, Moscow
- Texas A&M University / Department of Physics, USA, TX, College Station\nUtrecht University, The Netherlands, Utrecht\nCNRS / Institut de Physique Nucléaire - Orsay, France, Orsay
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 ultraviolet (UV) and vacuum ultraviolet (VUV) wavelength regions and for high-efficient phosphors excited by VUV radiation.
There is currently an urgency 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 extended range of the generated wavelengths in UV and VUV spectral regions could solve a range of technological problems, for example, in the VUV micro-lithography, isotope separation, ecology of oil product refining, production of protein based medicines, treatment of tuberculosis, sanitation, etc.
The search of new VUV scintillators possessing high light yield, short decay time, high efficiency of annihilation photon absorption, good mechanical stability, chemically inactive and relatively cheep is mostly topical at present.
The elaboration of new phosphors with high conversion efficiency of VUV radiation into visible light is a key aspect in promotion of mercury-free fluorescent lamps and flat color plasma displays. The phosphors, emitting more than one visible photon per each absorbed VUV quantum (i.e. with quantum efficiency more than 100%), can be created in complex fluoride systems, containing two and more various RE ions, using the mechanisms of cascade luminescence and down-conversion.
Highly qualified experts in chemistry, technology and physics, engaged in the nuclear arms production are to be involved in the Project as well as scientists of the Russian Academy of sciences, with previous activity in the Project’s problems. The experts of ARICT to be involved in the Project, have performed investigations on the synthesis and analysis of high purity fluorides for nuclear technologies, production of fluoride optical glasses and fibres, operating in aggressive media and high radiation environment.
The experts of LPI have more than 20 years of experience in the study of scintillation crystals, their application in the detectors of gamma and charged radiation. The experts of IGP possess rich experience in the field of optics and spectroscopy of luminescent materials, as well as in growing of fluoride crystals using different growth techniques. There is more than 150 scientific publication, related to synthesis, physical and chemical, spectroscopic, scintillation and laser properties of fluorides, doped with rare earth elements and four patents 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 positron emission tomography (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 weapon scientists and engineers in Russia the opportunities to redirect their talents to peaceful activities; will promote integration of Russian scientists into the international scientific community; will support basic research and technology development for peaceful purposes.
In the framework of the project there are the following objectives: development and optimization of growing methods of 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 the effect of interaction of various types of radiation with grown fluoride single crystals of complex fluoride compounds doped with 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 amplified spontaneous emission (ASE) mode: evaluation of the media resistance against pumping radiation, measurements of the re-tuning wavelength bands and gain coefficients; test of the efficiency and radiation stability of the grown crystals emitting in the UV and VUV from the viewpoint of their applications in detectors of ionizing radiation and elementary particles; development and test 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 Project’s frame; evaluation of technical reports (annual, final), presented by the Project’s participants to ISTC; joint use of equipment and performing of tests of produced material samples; participation in evaluation of the results, obtained during implementation of the Project; assistance in participation in international meetings; organization of joint seminars and meetings.
The following techniques to be applied during the project execution: crystals of various compositions will be grown from a melt using Bridgeman method in the temperature range up to 1500 °C. The crystals can be grown in gaseous atmosphere as well as in vacuum (maximum size of a crystal is Ø10×30 mm). Equipment is available for optical and luminescence spectroscopy (in VUV range) of solid state materials using compact (laboratory) sources and of the synchrotron radiation of C-60 accelerator, including high time resolution equipment.
Equipment is available for investigation of scintillation kinetics (single photon counting method), light yield and radiation hardness (spectrometer for crystal absorption spectra measurements before and after gamma irradiation).
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.