TY - JOUR
T1 - The role of oxygen in the photostimulated luminescence process of europium doped potassium chloride
AU - Xiao, Zhiyan
AU - Mazur, Thomas R.
AU - Driewer, Joseph P.
AU - Li, H. Harold
N1 - Funding Information:
This work was supported in part by NIH Grant No. R01CA148853 entitled storage phosphor film for radiation therapy dosimetry.
Publisher Copyright:
© 2015 Elsevier Ltd. All rights reserved.
PY - 2015/5
Y1 - 2015/5
N2 - Abstract A recent suggestion that europium doped potassium chloride (KCl:Eu2+) has the potential to significantly advance the state-of-the-art in radiation therapy dosimetry has generated a renewed interest in a classic storage phosphor material. The purposes of this work are to investigate the role of oxygen in the photostimulated luminescence (PSL) process and to determine if both increased PSL yield and improved temporal stability could be realized in KCl:Eu2+ by incorporating oxygen in the material fabrication process. Regardless of synthesis atmosphere, air or pure nitrogen, PSL amplitude shows a maximum at 1.0 mol % Eu. Depending on europium concentration, dosimeters fabricated in air exhibit stronger PSL by a factor of 2-4 compared to those made in N2. There is no change in PSL stimulation spectrum while noticeable shifts in both photoluminescence and PSL emission spectra are observed for air vs. nitrogen. Almost all charge-storage centers are spatially correlated, suggesting oxygen's stabilization role in the PSL process. However, oxygen alone does not improve material's temporal stability in the first few hours post irradiation at room temperature, probably because a significant portion of radiation-induced holes are stored in the Vk centers which are mobile.
AB - Abstract A recent suggestion that europium doped potassium chloride (KCl:Eu2+) has the potential to significantly advance the state-of-the-art in radiation therapy dosimetry has generated a renewed interest in a classic storage phosphor material. The purposes of this work are to investigate the role of oxygen in the photostimulated luminescence (PSL) process and to determine if both increased PSL yield and improved temporal stability could be realized in KCl:Eu2+ by incorporating oxygen in the material fabrication process. Regardless of synthesis atmosphere, air or pure nitrogen, PSL amplitude shows a maximum at 1.0 mol % Eu. Depending on europium concentration, dosimeters fabricated in air exhibit stronger PSL by a factor of 2-4 compared to those made in N2. There is no change in PSL stimulation spectrum while noticeable shifts in both photoluminescence and PSL emission spectra are observed for air vs. nitrogen. Almost all charge-storage centers are spatially correlated, suggesting oxygen's stabilization role in the PSL process. However, oxygen alone does not improve material's temporal stability in the first few hours post irradiation at room temperature, probably because a significant portion of radiation-induced holes are stored in the Vk centers which are mobile.
KW - Photostimulated luminescence
KW - Radiation therapy dosimetry
KW - Storage phosphor
UR - http://www.scopus.com/inward/record.url?scp=84926346459&partnerID=8YFLogxK
U2 - 10.1016/j.radmeas.2015.03.013
DO - 10.1016/j.radmeas.2015.03.013
M3 - Article
C2 - 25897274
AN - SCOPUS:84926346459
SN - 1350-4487
VL - 76
SP - 23
EP - 28
JO - Radiation Measurements
JF - Radiation Measurements
M1 - 5399
ER -