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1

Luminescence and Transient Absorption of CdWO_{4} Crystals

100%

Millers D., Grigorjeva L., Chernov S.

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vol. 95

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issue 6

965-969

EN

Luminescence and transient absorption of the oxygen-deficient CdWO_{4} crystal were studied. The electron transitions from the excited state of the luminescence center to some higher energy state are responsible for the transient absorption observed. The scheme of luminescence center levels is proposed from the obtained experimental results.

2

Thermoluminescence and Scintillation Time Profiles of BaF_{2}:Ce

80%

Głodo J., Szupryczyński P., Wojtowicz A.

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vol. 95

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issue 2

259-268

EN

In this communication we present results of measurements of low temperature thermoluminescence, isothermal decays, steady state radioluminescence yield, and scintillation time profiles at various temperatures on two scintillator materials, BaF_{2}:Ce and undoped BaF_{2}. We find that all these results can be consistently interpreted in the frame of a model that includes several relatively shallow charge traps. We have identified and characterized one particular shallow trap that causes the decay of the dominant scintillation component of BaF_{2}:Ce to be slower than radiative, as well as a set of others that are responsible for even slower components in the scintillation time profile of this material.

3

The Model for Luminescence Center Excitation in PbWO_{4}

80%

Millers D., Grigorjeva L., Chernov S., Pankratov V.

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vol. 95

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issue 6

971-976

EN

The luminescence and transient absorption of PbWO_{4} crystals were studied. The electron beam (10 ns, E≈270 keV) was used as excitation source. The kinetics of luminescence is complicated - the prompt rise of luminescence intensity is followed by a slow (τ_{r}≈100 ns) rise. The luminescence decay at 80 K is nearly exponential with τ_{d}≈4.0- 4.5 μs. The decay kinetics of transient absorption at 3.5 eV can be described roughly by two exponents with time constants τ_{1}≈100 ns and τ_{2}≈4.0 μs. A common process responsible for absorption relaxation and luminescence rise is suggested. The luminescence center excitation occurs during recombination process via Pb^{2+} excited state formation and subsequent energy transfer to WO_{4}^{2-} group.

4

Some Aspects of Solid State Radioluminescence

80%

Wojtowicz A.

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vol. 95

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issue 1

165-178

EN

In this paper we review results of radioluminescence studies on two scintillator materials, LuAlO_{3} and YAlO_{3}, activated with Ce. The experiments include measurements of ther moluminescence, isothermal phosphorescence decays, scintillation light yield as function of temperature, and scintillation time profiles under gamma excitation. Experimental results are interpreted in the frame of a simple kinetic model that includes a number of electron traps. We have identified and characterized a number of deep and shallow traps and demonstrated that traps in LuAlO_{3}:Ce are deeper than corresponding traps in YAlO_{3}:Ce. Unlike deep traps which are responsible for some scintillation light loss but otherwise do not have any impact on generation of scintillation light, shallow traps are shown to actively interfere with the process of radiative recombination via Ce ions. We demonstrate that shallow traps are responsible for some as yet unexplained observations including a higher room temperature light yield of YAlO_{3}:Ce and its longer scintillation decay time, as well as a longer scintillation rise time in LuAlO_{3}:Ce.

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4 Acta Physica Polonica A

4 1999

2 Chernov S.

2 Grigorjeva L.

2 Millers D.

2 Wojtowicz A.

1 Głodo J.

1 Pankratov V.

1 Szupryczyński P.

Luminescence and Transient Absorption of CdWO_{4} Crystals

Thermoluminescence and Scintillation Time Profiles of BaF_{2}:Ce

The Model for Luminescence Center Excitation in PbWO_{4}

Some Aspects of Solid State Radioluminescence