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Mineral Color Modification with Proton Beams

#1383


Directed Modification of Mineral Coloring with Intensive Proton Beams

Tech Area / Field

  • PHY-PFA/Particles, Fields and Accelerator Physics/Physics
  • MAT-SYN/Materials Synthesis and Processing/Materials

Status
3 Approved without Funding

Registration date
28.10.1998

Leading Institute
Institute for High Energy Physics (IHEP), Russia, Moscow reg., Protvino

Supporting institutes

  • Institute of Geology of Komi Scientific Center, Russia, Komi, Syktyvkar\nResearch Testing Center for Radiation Safety of Space Objects, Russia, Moscow

Project summary

Modification of mineral coloring by ionizing radiation is widely used for ennobling of natural gems. The output of high-quality gems from the majority of natural deposits does not exceed 3-5 per cent. Applying methods of ennobling allows increasing this quantity significantly. Conventional methods of mineral coloring modification involve natural sources of g- or b-radiation of low intensity and require very long exposure time. An application of modern particle accelerators allows solving the problem at a new level. Beams of charged particles in modern accelerators have high intensity and are easily controllable, resulting in exposure time several orders of magnitude shorter and permitting to develop a unique technique of local coloring of minerals.

The study of directed modification of optical properties of minerals with intensive proton beams has been started by the authors of the project in 1990. The first experiments have shown that the IHEP linear accelerator I-100 with proton energy of 100 MeV and impulse current of 100 mA is a unique physical device for such research. Drastic modification of the color of quartz-group minerals has been observed to occur with exposure time of about several minutes.

The work was stopped in 1991 due to lacking of the financial support.

The project is essentially aimed at working out the technique of directed modification of mineral coloring with intensive proton beams with energy of 30-100 MeV. Investigating a number of various minerals and using various irradiation regimes will allow studying the mechanism of formation and stabilization of lattice defects responsible for the color modification. An elaboration of database on modification of optical properties of minerals by ionizing radiation is also supposed. Such database will permit to predict the quality of outcoming products by the properties of input materials.

Since the basic objects of research are weakly-colored gems, practical meaning of the work consists in elaborating a new method of ennobling of precious and semiprecious stones. The project is supposed to be realized by Institute for High Energy Physics (Project Manager: Dr. V.E. Rochev) in collaboration with Institute of Geology of Komi Scientific Center, Ural pision of Russian Academy of Sciences, Syktyvkar, Russia (Project Leader: Dr. B.A. Ostashenko), and Scientific-Research Test Center of Radiation Safety of Space Objects, Moscow (Project Leader: Dr. V.G. Semenov).


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