Andryushchenko L. Development of optical protective coatings for scintillation crystals based on CsI and NaI

Research subject: organic-silicon coatings and physics and chemical processes of their interactions with surface of CsI and NaI crystals. Research goal: development of optical coupling (OCC) and protective (PC) coatings for scintillation crystals and methods of crystal surface treatment taking into account a sequence of operations such as gluing or coating by vanish film. Research methods and devices: optical, luminescence and spectrometrical methods using a standard devices. Theoretical and practical results, novelty. A new organic-silicon OCC and PC have been developed as well as new methods of crystal surface treatment taking into account an application of coatings. Thus a significant improvement of detector scintillation characteristics and their stability during exploitation have been realized. The optimum composition have been found for wavelength shifting (WLS) coatings on a base of KO-08 vanish and organic luminescence dopands. WLS coatings increase a light output, improve its axial non-uniformity and energy resolution of CsI or CsI:Tl scintillators. The gel-like OCC with increased cohesion strength has been developed for optical coupling of large area NaI:Tl crystal plates to exit window of Anger cameras detectors. Such OCC provides a reliable optical coupling which not depend on scintillator orientation. Stage of implementation: the method of NaI:Tl crystal surface treatment and new materials for OCC have been introduced to the pilot plant of STC "Institute for Single Crystals". Field of application: experimental high energy physics, hi-tech nuclear and medical equipment manufacturing, and monitoring of environment.