On LiF:Mg,Cu,P and LiF:Mg,Ti phosphors high & ultra-high dose features

Abstract

HIGHLIGHTS• TL peak 'B' occurs for LiF:Mg,Cu,P after high doses of all radiation types.• Highly irradiated LiF:Mg,Ti glow-curve shape depends on the radiation quality.• High dose features of both phosphors are significantly different in many aspects.• Associated PL/TL high-dose measurements are possible using LiF:Mg,Cu,P.• Dopants role is crucial for high-dose features of lithium fluoride based phosphors. AbstractLiF:Mg,Ti and LiF:Mg,Cu,P are well known thermoluminescence (TL) dosimetry materials since many years. A few years ago their properties seemed well known and it was widely believed that they are not suitable for the measurement of doses above the saturation level of the TL signal, which for both materials occur at about 1 kGy.The high-dose high-temperature TL emission of LiF:Mg,Cu,P observed at the IFJ in 2006, which above 30 kGy takes the form of the so-called TL peak 'B', opened the way to use this material for measuring the dose in the high and ultra-high range, in particular for the monitoring of ionizing radiation around the essential electronic elements of high-energy accelerators, also fission and fusion facilities, as well as for emergency dosimetry. This discovery initiated studies of high and ultra-high dose characteristics of both these phosphors, which turned out to be significantly different in many aspects. These studies not only strive to refine the method for measuring high doses based on the observed phenomenon, but also, and perhaps above all, bring us closer to understanding its origin and essence. This manuscript aims to review existing research data on the high and ultra-high dose features of both LiF based phosphors.

Thermally stimulated processes in Li and Cu doped alkali fluorides irradiated with electron beams of ultra-high dose

“…Kinetics parameters obtained for TSEE glow curves of NaF:Li and NaF:Li,Cu crystals that include peak maxima (T m ), activation energies (E a ), and frequency factor (S) are gathered in table 1 along with the data obtained for LiF:Cu and NaF:Cu considered below. o C. We note that the appearance of high-temperature TL features is typical of alkali fluorides irradiated with high and ultra-high dose of ionizing radiation (see [18] and references therein). Kinetics parameters obtained for TSEE and TL glow curves of NaF:Li and NaF:Li,Cu crystals can be found in table 1.…”

“…Some of them are based on using electron and ion beam facilities as irradiation sources. It was recently shown that LiF based TLD may be prospective for application in extremely wide dose range of up to twelve orders of magnitude (see [18] and references therein). This inspired us to test thermally stimulated processes of NaF and LiF doped with Li and Cu irradiated with ultra-high dose of electron beam.…”

State of the art on nuclear heating measurement methods and expected improvements in zero power research reactors

“…In practice, the z max thickness is calculated thanks to Monte Carlo transport codes (MCNP, TRIPOLI) and the associated nuclear data libraries (ENDF, JEFF). An example is given in Figure 5, showing the calculated dose and Kerma in different types of dosimeters irradiated nearby a 60 Co source (Fig. 5a, calibration in g field) and in the center-core of MINERVE reactor (Fig.…”

“…In order to establish the relationship shown in equation (6) between the luminescent signal emitted by the dosimeters and a reference quantity representative of the absorbed dose in the pillboxes, TLDs and OSLDs are calibrated in a pure g field nearby a 60 Co source, whose b À decay into 60 Ni with a period of about 5.27 years leads to the emission of two gamma rays at 1.17 and 1.33 MeV. This provides the best representativeness conditions with respect to reactor prompt photon spectra illustrated in Figure 7, ranging from 100 keV to 7 MeV with a major contribution to Kerma gamma in air between 1 and 3 MeV, and a mean energy around 1.7 MeV.…”

Síntesis y Caracterización de LiF Dopado con Europio para Dosimetría Termoluminiscente por Método de Precipitación

“…Las propiedades ópticas del LiF pueden ser modificadas utilizando diferentes dopantes como tierras raras, por ello en las últimas décadas ha crecido el interés por estudiar el efecto de diferentes dopantes y distintos métodos de síntesis [2,3]. Entre las tierras raras, los iones de europio (Eu 3+ ) han atraído especial interés debido a sus propiedades ópticas [7,8]; sin embargo aunque las propiedades del LiF han sido extensamente estudiadas [3,4,5], pocos trabajos se han reportado sobre el LiF dopado con Eu.…”