S.Baccaro, A.Cecilia INFN Rome DPG 6/9/05 July 2005 irradiation test results of SIC & BTCP crystals I.Dafinei, M.Diemoz ENEA-Casaccia & INFN Rome

10 EB crystals made in Russia and 10 EB crystals produced in China (crystals) were irradiated in identical Gy/h dose rate: Gy Gy LTO and TT 3, 9, 15, 21 cm ( distance from FF ) Damage 18 °C followed for 22 days. Standard and Full Saturation tests on BTCP & SIC crystals

Barcode LT360 (%) LT420 (%) LT620 (%) Infl. (nm) S. Infl. (%/nm) TT sp. (nm) TT grad (nm/cm) LY (pe/MeV) FNUF (%/X0) Mean  Qualification parameters of Russian Crystals

Barcode LT360 (%) LT420 (%) LT620 (%) Infl. (nm) S. Infl. (%/nm) TT sp. (nm) TT grad (nm/cm) LY (pe/MeV) FNUF (%/X0) Mean  Qualification parameters of Chinese Crystals

Comparison of Qualification Parameters mean values Barcode LT360 (%) LT420 (%) LT620 (%) Infl. (nm) S. Infl. (%/nm ) TT sp. (nm) TT grad (nm/cm) LY (pe/MeV) FNUF (%/X0) Mean  Barcode LT360 (%) LT420 (%) LT620 (%) Infl. (nm) S. Infl. (%/nm) TT sp. (nm) TT grad (nm/cm) LY (pe/MeV) FNUF (%/X0) Mean  BTCP SIC

 ( ) of all analysed crystals after Gy BTCP SIC

 (420nm) of BTCP & SIC crystals after Gy At Gy radiation hardness parameters are within specifications for 100 % of Russian crystals and 80% for Chinese. BTCP SIC

 ( ) of all analysed crystals after Gy BTCP SIC

 (420nm) of BTCP & SIC crystals after Gy At Gy radiation hardness parameters are within specifications for 50 % of Russian crystals and 70% for Chinese. SIC BTCP

SIC Comparison of Light Yield before and after irradiation

BTCP SIC Fraction of Light Yield lost after irradiation

Comparison of FNUF before and after irradiation BTCP SIC

r = μ SFS / μ FS Saturation level reached in SFS conditions with respect to FS

q = (μ FS - μ Recov )/ μ FS Fraction of recovered colour centres after 22 days from the stop of irradiation

BarcodeLT360LT420LT620SLTODTTOLY8X0FNUF Mean StdDev Min Max IRRADIATION TESTS ON SIC PRODUCTION EB CRYSTALS

Irradiation tests on sic production EB crystals 1h Gy/h

Distribution of radiation 420 nm (1h Gy/h)

Distribution of radiation 420 nm (1h Gy/h) 1.15       0.65 DPG-June05

Some China made crystals (#02, #18) have a remarkably high radiation hardness and fast saturation of the damage. Nevertheless, their overall behaviour is quite non-uniform (possible consequence of large spread of their optical parameters). Russian crystals have a uniform behaviour under irradiation exposure. If SFS conditions are considered, radiation hardness qualification parameters are reliable for 100% of Russian crystals and 80% of Chinese. For FS conditions the reliability drops to 50% in the case of Russian crystals and 70% for Chinese. CONCLUSIONS