Characterisation of new inorganic fibers made of LuAG:Ce and LYSO:Ce

The development of the technology for the growth of inorganic scintillating fibers has initiated a significant progress in the production of compact inorganic scintillators during the last years. Triggered by the traditional applications of fibers based on plastic scintillators, there are strong arguments for replacing those fibers by inorganic crystals. One can rely on a significantly higher light yield, an efficient interaction with electromagnetic probes due to the content of high-Z elements, a wider range of emission wavelength to adapt to the appropriate photo sensors and remain more resistant to radiation damage for long-term applications in a highly ionizing environment. The HP3-WP22 collaboration has focused on the optimization of the micro-pulling down technique and the quality inspection of fibres based on LuAG:Ce and LYSO:Ce. There has been first progress in the variation of the geometry, pulling several fibres in parallel, the optimization of the crucibles and the requirements for an increased efficiency being mandatory for future mass production. In spite of the more challenging growing conditions the final goal of the R&D program has been directed towards fibers made of LYSO:Ce. The very radiation hard and bright scintillator material appears to be very attractive for many applications in particular due to its very short radiation length and high light yield. Fibers up to 1 mm diameter and more than 100 mm length have been successfully produced and show a very promising performance. The paper will discuss in detail measurements of the achieved light output and light attenuation in the fiber, as well as the homogeneity of the produced samples. In addition, the studies are performed and compared to the achievements manufacturing fibers based on LuAG:Ce.