1. WP 22 – SciFi Development and Characterisation of Inorganic Scintillating Fibers Made of LuAG:Ce and LYSO:Ce S. Diehl 1, R. Novotny 1, Aubry Nicolas 2 1) 2nd Physics Institute, University Giessen, Germany 2) Société Fibercryst, Villeurbanne, France and for the HP 3 – WP 22 collaboration 16. 02. 2013 - Wien Workshop on Silicon Multiplier and Associated Electronics

2. Outline and Motivation Significantly higher light yield More effective interaction with electromagnetic probes Higher resistance to radiation damage Advantages compared to organic fibers: 1. Production Technology 2. Investigated Scintillators LuAG:Ce ( fibers ) LYSO:Ce ( rods / fibers ) Envisaged applications: 2 D beam monitor PET device start detector S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20132

3. Fiber Growth and Investigated Scintillators Micro-Pulling-Down Method: Investigated Scintillators Investigated Scintillators: S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20133

4. Response Test Used Radioactive Sources: 241 Am (E α ≈ 5.5 MeV) 137 Cs (E γ = 0.66 MeV) 60 Co (E γ = 1.17 MeV, 1.33 MeV) Experimental Setup: single sided or coincidence readout S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20134

5. LuAG:Ce fiber (Ø = 1.0 mm and 0.3 mm, L = 100 mm) Response to 241 Am - single sided readout A additional wrapping with teflon increases the light yield by ≈ 70 % Ø 1.0 mm fiber S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20135

6. GEANT 4 and LITRANI simulations for α- and γ - sources can not reproduce the experimental results. Comparison of a 1.0 mm and a 0.3 mm fiber average attenuation coefficient for Ø = 1.0 mm fibers: μ ≈ (1.56 ± 0.32) cm -1 Ø = 0.3 mm fibers: μ ≈ (0.85 ± 0.06) cm -1 Ø = 0.3 mm fibers: μ ≈ (0.85 ± 0.06) cm -1 Ø Ø μ ≈ (1.56 ± 0.32) cm -1 μ ≈ (0.85 ± 0.06) cm -1 S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20136

7. average attenuation coefficient for Ø = 1.0 mm fibers: μ ≈ (1.56 ± 0.32) cm -1 Ø = 0.3 mm fibers: μ ≈ (0.85 ± 0.06) cm -1 Ø = 0.3 mm fibers: μ ≈ (0.85 ± 0.06) cm -1 Comparison of a 1.0 mm and a 0.3 mm fiber 1 mm Ø = 1.0 mm fiber The large absorption coefficient for 1.0 mm fibers is an effect of the fiber quality! S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20137

8. Response to 241 Am - coincidence readout fiberlength between 2.5 cm and 4.5 cm time resolution of a single PMT: (deduced from left - right coincidence) S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20138

9. LYSO:Ce rectangular rod LYSO:Ce rectangular rod (2.5 × 5.0 × 100 mm³) intrinsic activity due to 176 Lu - decay for a typical 2.5 × 5.0 × 100 mm 3 rod ≈ 100 counts / s (E < 400 keV) Response to 137 Cs and 60 Co γ - sources S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 20139

10. Light yield at one end of the rod without wrapping: rod 1 wrapped with teflon and aluminum foil: S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 201310

11. Response to 241 Am - single sided readout LYSO:Ce fiber LYSO:Ce fiber (Ø = 0.3 mm, L = 100 mm) Average attenuation coefficient: Average attenuation coefficient: μ ≈ (0.68 ± 0.02) cm -1 μ ≈ (0.68 ± 0.02) cm -1 good homogeneity of all investigated fibers LuAG:Ce (0.3 mm): μ ≈ (0.85 ± 0.06) cm -1 LuAG:Ce ( Ø 0.3 mm): μ ≈ (0.85 ± 0.06) cm -1 S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 201311

12. Response to 241 Am Fiber Readout with SiPM S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 2013 Ø 1 mm LuAG:Ce fiber Ø 1 mm LYSO:Ce fiber Setup photons seen by SiPM counts counts 241 Am-source dist. = 0.5 cm 241 Am-source dist. = 0.5 cm avg. ~ 50 photons max. ~ 160 photons seen on 0.8 mm 2 12 SiPM : S10362-33-025C (14400 pixels, fill factor: 30.8)

13. Conclusion Comparison of fibers and rectangular rods made of LYSO:Ce + promising performance of first prototypes - but: significant improvement necessary reduction of cracks reduction of cracks homogeneity of Ce doping homogeneity of Ce doping Response test with low energy γ - sources not yet feasible Response test with low energy γ - sources not yet feasible S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 201313

14. Outlook S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 2013 Systematic fiber development in cooperation with fibercryst will go on Production of LYSO:Ce fiber bundles by fibercryst Double sided SiPM readout of small fibers pieces Noise rejection Determination of time resolution Data aquisition with a sampling ADC Offline analysis and optimization of signal shaping … 14

15. S. Diehl, JLU GießenSiPM workshop - Wien 16. Feb. 201315

16. Response to γ - sources - single sided readout S. Diehl, JLU Gießen Crystal Clear Collaboration Meeting - CERN24 - 25 Nov. 2011 LuAG:Ce fiber LuAG:Ce fiber (Ø = 1.0 mm, L = 100 mm) signal amplitude /a.u. counts 16 backup slides