Sensitivity changes of LiF:Mg,Ti and LiF:Mg,Cu,P TL detectors after proton exposures

Sądel, M.; Bilski, P.; Swakoń, Jan; Rydygier, Marzena

doi:10.1016/j.radmeas.2015.02.009

Cited by 6 publications

(2 citation statements)

References 13 publications

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“…The spectra show two distinguishable emission bands with maxima at 365 nm (27400 cm –1 ) and 460 nm (21740 cm –1 ). Usually, the emission spectra in Ce 3+ -doped samples are expected to be a doublet due to the spin-orbit splitting of the 4f 1 ground state into 2 F 5/2 and 2 F 7/2 levels, with a separation of ∼2000±250 cm –1 . The PL emissions at 365 and 460 nm for our sample have a separation of ∼5660 cm –1 , which cannot be assigned to Ce 3+ alone.…”

Section: Results and Discussionmentioning

confidence: 99%

Dynamics of Charges in Superlong Blacklight-Emitting CaB₂O₄:Ce³⁺ Persistent Phosphor

et al. 2019

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The optical and persistent luminescence properties of CaB2O4:Ce3+ phosphor are presented. The optical emission for excitation in the 250–340 nm wavelength region is dominated by two bands at 365 and 460 nm. Lifetime measurements suggested that the 365 nm emission band is due to interconfigurational Ce3+ 5d → 4f transitions. Upon excitation with a 254 nm UV lamp, a superlong persistent luminescence in the UVA1 region (340–400 nm, blacklight) was observed, lasting for at least 15 h, and with excellent reproducibility, which is perfectly suitable for phototherapy application. The initial-rise method was applied on the thermoluminescence glow curves to determine the trap distribution and trap depth. The results suggest that one distinct trap, with an activation energy of ∼0.52 eV, was solely responsible for the persistent luminescence in the CaB2O4:Ce3+ phosphor. The other traps had a quasi-continuous distribution, with activation energies between 0.56 and 1.15 eV. The proposed persistent luminescence and the thermoluminescence mechanisms are elucidated using experimental parameters obtained from the optical and thermoluminescence results and the theoretically calculated electronic structure of the Ce3+ ion in CaB2O4. The lowest Ce3+ 5d1 level was found to be ∼0.97 eV below the conduction band, and the persistent luminescence/thermoluminescence emission was dominated by the radiative transitions between Ce3+ energy levels, 5d → 2F5/2,7/2.

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Section: Results and Discussionmentioning

confidence: 99%

Dynamics of Charges in Superlong Blacklight-Emitting CaB₂O₄:Ce³⁺ Persistent Phosphor

et al. 2019

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“…Conversely, MTS-7 ( 7 LiF:Mg,Ti) detectors contain pure (99.9%) 7 Li showing a greatly reduced response to thermal neutrons (Obryk et al 2014). The dose linearity index, defined as the ratio between the luminescence signal per dose unit over the luminescence signal for a low dose lying in the linear response region of the detector (Horowitz, 2001;Olko et al 2001), is equal to unity for LiF:Mg,Ti detectors for proton doses below ~ 3 Gy; above this value this detector shows a supralinear response (Sądel et al 2015). In turn, LiF:Mg,Cu,P detectors show a linear proton dose response up to ~ 10 Gy, while above their response becomes sublinear (Sądel et al 2015).…”

Section: Dosimetry Systemmentioning

confidence: 99%

Modelling and measurements of distributions in an adult human phantom undergoing proton scanning beam radiotherapy: lung- and prostate-located tumours

Puchalska

2021

Radiat Environ Biophys

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Proton radiotherapy has been shown to offer a significant dosimetric advantage in cancer patients, in comparison to conventional radiotherapy, with a decrease in dose to healthy tissue and organs at risk, because the bulk of the beam energy is deposited in the Bragg peak to be located within a tumour. However, it should be kept in mind that radiotherapy of cancer is still accompanied by adverse side effects, and a better understanding and improvement of radiotherapy can extend the life expectancy of patients following the treatment of malignant tumours. In this study, the dose distributions measured with thermoluminescent detectors (TLDs) inside a tissue-equivalent adult human phantom exposed for lung and prostate cancer using the modern proton beam scanning radiotherapy technique were compared. Since the TLD detection efficiency depends on the ionization density of the radiation to be detected, and since this efficiency is detector specific, four different types of TLDs were used to compare their response in the mixed radiation fields. Additionally, the dose distributions from two different cancer treatment modalities were compared using the selected detectors. The measured dose values were benchmarked against Monte Carlo simulations and available literature data. The results indicate an increase in the lateral dose with an increase of the primary proton energy. However, the radiation quality factor of the mixed radiation increases by 20% in the vicinity to the target for the lower initial proton energy, due to the production of secondary charged particles of low-energy and short range. For the cases presented here the MTS-N TLD detector seems to be the most optimal tool for dose measurements within the target volume, while the MCP-N TLD detector, due to an interplay of its enhanced thermal neutron response and decreased detection efficiency to highly ionising radiation, is a better choice for the out-of-field measurements. The pairs of MTS-6 and MTS-7 TLDs used also in this study allowed for a direct measurement of the neutron dose equivalent. Before it can be concluded that they offer an alternative to the time-consuming nuclear track detectors, however, more research is needed to unambiguously confirm whether this observation was just accidental or whether it only applies to certain cases. Since there is no universal detector, which would allow the determination of the dosimetric quantities relevant for risk estimation, this work expands the knowledge necessary to improve the quality of dosimetry data and might help scientists and clinicians in choosing the right tools to measure radiation doses in mixed radiation fields.

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New perspectives on traps and radiative recombination centers for optically stimulated luminescence in LiF:Mg,Cu,P

Nyemann

Nielsen

Turtós

et al. 2023

Journal of Luminescence

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Sensitivity changes of LiF:Mg,Ti and LiF:Mg,Cu,P TL detectors after proton exposures

Cited by 6 publications

References 13 publications

Dynamics of Charges in Superlong Blacklight-Emitting CaB₂O₄:Ce³⁺ Persistent Phosphor

Dynamics of Charges in Superlong Blacklight-Emitting CaB₂O₄:Ce³⁺ Persistent Phosphor

Modelling and measurements of distributions in an adult human phantom undergoing proton scanning beam radiotherapy: lung- and prostate-located tumours

New perspectives on traps and radiative recombination centers for optically stimulated luminescence in LiF:Mg,Cu,P

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Sensitivity changes of LiF:Mg,Ti and LiF:Mg,Cu,P TL detectors after proton exposures

Cited by 6 publications

References 13 publications

Dynamics of Charges in Superlong Blacklight-Emitting CaB2O4:Ce3+ Persistent Phosphor

Dynamics of Charges in Superlong Blacklight-Emitting CaB2O4:Ce3+ Persistent Phosphor

Modelling and measurements of distributions in an adult human phantom undergoing proton scanning beam radiotherapy: lung- and prostate-located tumours

New perspectives on traps and radiative recombination centers for optically stimulated luminescence in LiF:Mg,Cu,P

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Dynamics of Charges in Superlong Blacklight-Emitting CaB₂O₄:Ce³⁺ Persistent Phosphor

Dynamics of Charges in Superlong Blacklight-Emitting CaB₂O₄:Ce³⁺ Persistent Phosphor