Precipitation-induced photostimulated luminescence in CsBr:Eu2+

Hackenschmied, P.; Schierning, Gabi; Batentschuk, Miroslaw; Winnacker, A.

doi:10.1063/1.1563303

Cited by 49 publications

(48 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, postannealing treatments of the plates at 170-180°C in wet air increase both the sensitivity and the AA-EPR intensity of the NIP. 6,26,27 Identification of the stabilizing impurity near Eu 2+ as H 2 O or a related molecular ion, e.g., OH − , thus seems plausible. Our aforementioned ENDOR results seem to affirm this possibility.…”

Section: B Eu 2+ -Nv Cs + Modelsmentioning

confidence: 99%

Temperature dependence of Eu-related EPR spectra in CsBr:Eu needle image plates

et al. 2009

View full text Add to dashboard Cite

Vacuum-deposited CsBr needle plates doped with Eu2+ have been investigated with Q ͑ϳ34 GHz͒ and W ͑ϳ95 GHz͒ band electron paramagnetic resonance in a large temperature interval ͑4 K: room temperature͒. At low temperatures ͑Ͻ35 K͒, two Eu-related centers were found with different symmetry ͑tetragonal and orthorhombic͒, while in earlier studies at room temperature only one center was found with tetragonal symmetry. Possible models for the three defects are investigated, taking into account their temperature behavior, their symmetry, and the atypical values of their zero-field splitting parameters.

show abstract

Section: B Eu 2+ -Nv Cs + Modelsmentioning

confidence: 99%

Temperature dependence of Eu-related EPR spectra in CsBr:Eu needle image plates

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Therefore, the impact of possible secondary phases can be excluded. 21,22 Collectively, the data support that similar to undoped KCl, V k centers can serve as hole-storage centers in KCl:Eu 2+ at room temperature; thus could be responsible for the fading due to increased mobility at room temperature. Moreover, the V k centers' temperature-dependent mobility (Fig.…”

Section: Resultsmentioning

confidence: 55%

Temporal signal stability of KCl:Eu²⁺ storage phosphor dosimeters

et al. 2013

View full text Add to dashboard Cite

Purpose: Current KCl:Eu 2+ prototype dosimeters require a wait time of 12 h between irradiation and dosimetric readout. Although irradiating the dosimeters in the evening and reading on the following day works well in the clinical schedule, reducing the wait time to few hours is desirable. The purposes of this work are to determine the origin of the unstable charge-storage centers and to determine if these centers respond to optical or thermal excitation prior to dosimetric readout. Methods: Pellet-style KCl:Eu 2+ dosimeters were fabricated in-house for this study. A 6 MV photon beam was used to irradiate the dosimeters. After x ray irradiation, dosimeters were subjected to external excitation with near-infrared (NIR) light, ultraviolet (UV) light, or thermal treatment. Photostimulated luminescence (PSL) signal's temporal stability was subsequently measured at room temperature over a few hours using a laboratory PSL readout system. The dosimeters were also placed in a cryostat to measure the temperature dependence of the temporal stability down to 10 K. Results: Strong F-band was present in the PSL stimulation spectrum, indicating that F-centers were the electron-storage centers in KCl:Eu 2+ where an electron was stored at a chlorine anion vacancy. Due to deep energy-depth (2.2 eV), F-centers were probably not responsible for the fast fading in the first a few hours post x ray irradiation. In addition, weak NIR bands were present. However, there was no change in PSL stabilization rate with intense NIR excitation, suggesting that the NIR bands played no role in the PSL fading. At temperatures lower than 77 K there was almost no signal fading with time. Noticeable PSL was observed for undoped KCl samples at room temperature, suggesting that Cl 2 − V k centers served as hole-storage centers for both undoped and doped KCl where a hole was trapped by a chlorine molecular ion. V k centers were stable at low temperature and became mobile at room temperature, probably causing the observed PSL fading with time. On the other hand, V k center could be stabilized by Eu 2+ activator or oxygen in the lattice, leading to the stable component in the PSL. A thermal process at elevated temperatures (60• C or higher) was able to significantly accelerate the migration process resulting in a fast stabilization of PSL. However, this could not be accomplished using intense UV excitation. Conclusions: Thermal treatment enables KCl:Eu 2+ prototypes to be ready for readout in 1 h without the need of applying a large time-dependent correction factor. However, this cannot be achieved using optical preexcitation.

show abstract

“…Hackenschmied et al [4] reported a thermally activated increase in PSL yield in CsBr:Eu 2+ . This increase was reported to be related to the formation of new Eu 2+ -precipitations in the CsBr matrix such as CsEuBr 3 and Cs 4 EuBr 6 observed after an annealing process [5].…”

Section: Introductionmentioning

confidence: 84%