Performance of KCl:Eu²⁺storage phosphor dosimeters for low-dose measurements

Abstract

Recent research has demonstrated that europium doped potassium chloride (KCl:Eu2+) storage phosphor material has the potential to become the physical foundation of a novel and reusable dosimetry system using either film-like devices or devices similar to thermoluminescent dosimeter (TLD) chips. The purposes of this work are to quantify the performance of KCl:Eu2+ prototype dosimeters for low dose measurements and to demonstrate how it can be incorporated into clinical application for in vivo peripheral dose measurements. Pellet-style KCl:Eu2+ dosimeters, 6 mm in diameter, and 1 mm thick, were fabricated in-house for this study. The dosimeters were read using a laboratory photostimulated luminescence detection system. KCl:Eu2+ prototype storage phosphor dosimeter was capable of measuring a dose-to-water as low as 0.01 cGy from a 6 MV photon beam with a signal-to-noise ratio greater than 6. A pre-readout thermal annealing procedure enabled the dosimeter to be read within an hour post irradiation. After receiving large accumulated doses (~10 kGy), the dosimeters retained linear response in the low dose region with only a 20 percent loss of sensitivity comparing to a fresh sample (zero Gy history). The energy-dependence encountered during low dose peripheral measurements could be accounted for via a single point outside-field calibration per each beam quality. With further development the KCl:Eu2+− based dosimeter could become a versatile and durable dosimetry tool with large dynamic range (sub-cGy to 100 Gy).

Facile synthesis of KCl:Sm3+ nanophosphor as a new OSL dosimetric material achieved through charge transfer between the defect states

“…Sm-doped nanocrystalline KCl was synthesised by a solid state reaction at a high temperature of 200 C for 3 hours with highquality precursors KCl (M/S Merck, AR grade, 99.95% pure) and SmCl 2 $6H 2 O (M/S Alfa Aesar, 99.5% pure). 17 During the synthesis, KCl was mixed with various concentrations of dopant precursor Sm such as 0.15, 0.25, 0.45, and 0.50 mol% to investigate the role of the Sm concentration for OSL applications. A nely ground homogenous mixture of prepared powder was subjected to a thermal treatment at 353-363 K for 3 hours to obtain ne nanophosphor.…”

Two-dimensional high spatial-resolution dosimeter using europium doped potassium chloride: a feasibility study

“…KCl:Eu 2+ shows a linear response from zero to 60 Gy, and eventually saturates at about 500 Gy. Li et al (Li et al , 2013) recently reported that the same 1 mm- thick pellet sample is capable of detecting a doseto- water of 0.01 cGy, suggesting that KCl:Eu 2+ material yields a large dynamic range with comparable storage performance as traditional CR materials but superior radiation resilience.…”

Development of a storage phosphor imaging system for proton pencil beam spot profile determination

“…The CCD of the Lynx scintillation detector measures discrete pixel counts ranging from 1 to 1000 and this will impose a maximum theoretical dynamic range of 1000:1. While this dynamic range is already respectable and useful for versatile dosimetry purposes, storage phosphors can confer an even higher dynamic range as they are able to measure absorbed doses‐to‐water that are as low as 0.01 cGy and high doses of up to 60 Gy without any saturation effects 18‐20,29,30 . Having a dosimeter with a wide dynamic range is important for the expedient measurement of proton halo effects as their doses are typically on the order of 0.1% of the peak proton dose 13 .…”

“…While this dynamic range is already respectable and useful for versatile dosimetry purposes, storage phosphors can confer an even higher dynamic range as they are able to measure absorbed doses-towater that are as low as 0.01 cGy and high doses of up to 60 Gy without any saturation effects. [18][19][20]29,30 Having a dosimeter with a wide dynamic range is important for the expedient measurement of proton halo effects as their doses are typically on the order of 0.1% of the peak proton dose. 13 Often, a proton spot will have to be delivered at a high dose for proton halo signals to be above background noise levels and a detector with an insufficient dynamic range will saturate easily.…”