1. Scintillation properties of selected oxide monocrystals activated with Ce and Pr A.J. Wojtowicz 1), W. Drozdowski 1), and D. Wisniewski 1) J.L. Lefaucheur 2), Z. Galazka 2), and Zhenhui Gou 2) T. Lukasiewicz 3), and J. Kisielewski 3) 1) Institute of Physics, N. Copernicus University, Torun, Poland 2) Photonic Materials, Ltd, Bellshill, Scotland 3) Institute of Electronic Materials Technology, Warszawa, Poland Polish-French-Israeli Symposium „Spectroscopy of Modern Materials in Physics and Biology” Bedlewo, Poland, Sept. 27-30, 2004

2. A.J. Wojtowicz, Bedlewo, Sept. 20042 OUTLINE Institutions, projects, crystals Ce and Pr in solid state matrix Ce and Pr - energy structure Experimental results and discussion: Radioluminescence VUV spectroscopy Scintillation light yield Scintillation time profiles radio- and thermoluminescence Summary

3. A.J. Wojtowicz, Bedlewo, Sept. 20043 Institutions and R&D projects: Photonic Materials Ltd (PML) R&D on LYSO:Ce, LuAP:Ce, LuYAP:Ce PML manufactures LYSO and is the only company supplying large LuAP and LuYAP crystals on commercial scale Institute of Electronic Materials Technology (ITME) development of LuAP:Ce, LuAP:Pr, YAP:Ce, YAP:Pr, YAG:Pr Institute of Physics, N. Copernicus University (UMK) Research, characterization of scintillator materials FUNDING: PML, Polish government (KBN) grants

4. A.J. Wojtowicz, Bedlewo, Sept. 20044 CRYSTALS oxyorthosilicates (Re 2 SiO 5 ): LSO, LYSO Al perovskites (ReAlO 3 ): YAP, LuAP, LuYAP Al garnets (Re 3 Al 5 O 12 ): YAG Activators Ce 3+ [Xe] 4f 1, [Xe] 5d 1 Pr 3+ [Xe] 4f 2, [Xe] 4f 1 5d 1 2+ ion level pinned to cb 3+ ion ground level (g) above vb 3+ ion excited level (e) below cb f and d levels

5. A.J. Wojtowicz, Bedlewo, Sept. 20045 ENERGY STRUCTURE of Ce 3+ and Pr 3+ ions Ce 3+ - broad band parity allowed emission from 5d to 4f, 360 nm, YAP, LuAP 17 ns, LSO 40 ns; no nonradiative d-f relaxation Pr 3+ - broad band, parity allowed emission from 5d to 4f: YAP, LuAP 250 nm, 8 ns, YAG, 320 nm, 10 ns; sharp line, parity forbidden f-f emissions at 500 and 620 nm; nonradiative d-f relaxation; collective Pr-Pr interactions

6. A.J. Wojtowicz, Bedlewo, Sept. 20046 Radioluminescence spectra LuAP:Pr (ITME) various Pr concentrations for higher Pr concentrations less host and more f-f emissions

7. A.J. Wojtowicz, Bedlewo, Sept. 20047 Radioluminescence spectra YAG:Pr (ITME) various Pr concentrations for higher Pr concentrations less host emission no change in f-f emissions

8. A.J. Wojtowicz, Bedlewo, Sept. 20048 Excitation spectra LYSO:Ce (PML) 11 K em. 400 nm (Ce1) two time gates, prompt and delayed slow emission excited at the bandgap peak VUV spectroscopy

9. A.J. Wojtowicz, Bedlewo, Sept. 20049 Excitation spectra LYSO:Ce (PML) 11 K em. 480 nm (Ce2) thick line em. 320 nm (host) thin line host emission excitonic origin VUV spectroscopy

10. A.J. Wojtowicz, Bedlewo, Sept. 200410 Luminescence spectra LYSO:Ce (PML) RT VUV excitation solid line UV excitation (Ce2 band), dashed line VUV spectroscopy

11. A.J. Wojtowicz, Bedlewo, Sept. 200411 Luminescence spectra LYSO:Ce (PML) 11 K VUV excitation thick solid line UV excitation (Ce2 band), dashed line VUV spectroscopy

12. A.J. Wojtowicz, Bedlewo, Sept. 200412 Luminescence time profiles LYSO:Ce (PML) 11 K At 390 nm excited by 109 nm thick line At 390 nm, excited by 293 nm (Ce1) thin solid line At 500 nm, excited by 317 nm (Ce2) thin dashed line VUV spectroscopy

13. A.J. Wojtowicz, Bedlewo, Sept. 200413 Energy spectra YAG:Pr, LuYAP:Ce, LuAP:Ce, LYSO:Ce, LSO:Ce, and BGO amount of light (x axis) vs no of scintillations (y axis) Photopeak and Compton edge, backscatter peak Na22 (511 and 1274 keV) 1500 V, gain 3 or 9 Hamamatsu R2059

14. A.J. Wojtowicz, Bedlewo, Sept. 200414 Scintillation time profiles at RT LuAP:Pr, 9.4 ns YAG:Pr, 17.6 ns LuYAP:Ce, 16.9 ns LuAP:Ce, 15.9 ns LYSO:Ce, 29.1 and 57.1 ns LSO:Ce, 38.6 ns BGO, 10.9 ns and 274 ns LuYAP:Ce, LuAP:Ce, LYSO:Ce, LSO:Ce, and BGO

15. A.J. Wojtowicz, Bedlewo, Sept. 200415 Steady state radioluminescence (flat) and thermoluminescence (starting at 0 time) Irradiation by X-rays at 10 K TL runs from 10 to 300 K FRACTIONS: YAG:Pr, 0.28 LuYAP:Ce, 0.41 LuAP:Ce 0.17 LYSO:Ce, 0.001 LYSO – no loss to traps!

16. A.J. Wojtowicz, Bedlewo, Sept. 200416 Summary Ce 3+ and Pr 3+ are good recombination centers LuAP:Pr is the fastest, LYSO the most efficient new scintillator material LY of LYSO from PML is about 20% higher than LY of LSO Pr-Pr interaction degrades scintillator performance of LuAP:Pr YAG:Pr is a new potentially interesting addition to scintillators Traps are responsible for loss of efficiency and slow components in LuAP, LuYAP and YAG, no loss to traps in LYSO