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  • Meeting abstract
  • Open Access

Scintillation properties of Ca co-doped L(Y)SO:Ce between 193 K and 373 K for TOF-PET/MRI

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EJNMMI Physics20141(Suppl 1):A10

Published: 29 July 2014


  • Positron Emission Tomography
  • Decay Time
  • Timing Resolution
  • Rise Time
  • Pulse Shape

Time-of-flight Positron Emission Tomography (TOF-PET) and TOF-PET/MRI require scintillators with high light yield, short decay time, and short rise time in order to obtain high timing resolution. LSO:Ce and LYSO:Ce are commonly used. Ca co-doped LSO:Ce shows improved scintillation properties. The decay time constant of LSO:Ce,0.2%Ca (~33 ns) is shorter than standard LSO:Ce (~38-40 ns), and it has about 15% higher light yield. We measured scintillation pulse shapes and photoelectron yields of LSO:Ce, LSO:Ce,0.2%Ca, LYSO:Ce, LYSO:Ce,20ppmCa, LYSO:0.11%Ce,0.2%Mg, and LYSO:0.2%Ce,0.2%Ca at temperatures ranging from 193 K to 373 K. To study rise times we built a set-up in which samples are excited by 100 ps (FWHM) x-ray pulses.

Figure 1 shows that the scintillation rise time of LSO:Ce,0.2%Ca is constant between 273 K and 373 K, while the decay time constant decreases. Figure 2 shows that the light yield of LSO:Ce,0.2%Ca decreases with rising temperature. We noticed that the decrease in light yield is entirely caused by non-radiative decay of excited Ce3+ centres. This quenching mechanism does not worsen the timing resolution, as opposed to recombination of electron-hole pairs. It follows that the timing resolution of LSO:Ce(,0.2%Ca) is constant over the entire temperature range, in accordance with the timing model described in [1].
Figure 1
Figure 1

Scintillation pulse shape of LSO:Ce,0.2%Ca.

Figure 2
Figure 2

Normalized scintillation properties as a function of temperature.

Authors’ Affiliations

Faculty of Applied Sciences, Delft University of Technology, Delft, the Netherlands


  1. Seifert S, van Dam HT, Schaart DR: The lower bound on the timing resolution of scintillation detectors. Phys Med Biol 2012, 57: 1797–1814. 10.1088/0031-9155/57/7/1797PubMedView ArticleGoogle Scholar


© ter Weele et al; licensee Springer 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.