Characterisation of dispersed phosphor particles for quantitative photoluminescence measurements

Fond, Benoît; Abram, Christopher; Pougin, Miriam; Beyrau, Frank

doi:10.1016/j.optmat.2019.01.011

Cited by 28 publications

(24 citation statements)

References 37 publications

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“…[20] and [1]. The second reason is that a comparison of luminescence emission intensities from powder samples may not bear any relation to the relative emission intensities measured from dispersed particles [8], which are the data relevant to fluid thermometry.…”

Section: Liquid Dispersion and Particle Countingmentioning

confidence: 99%

“…For excitation of the particles in suspension, a 2.1 mm wide and 4.3 mm high laser beam was formed in the center of the cuvette from the output of the Nd:YAG laser at either 266 or 355 nm using a single cylindrical convex lens (f=50 mm). Based on the dimensions of the probe volume, the seeding density, and the calibration of the detection system throughput, the spectrally resolved emission intensity (photons/particle/pulse/nm) was determined [8].…”

Section: Spectroscopymentioning

confidence: 99%

“…Interestingly, the difference in emission intensity between 355 nm and 266 nm excitation is far more pronounced in these measurements on dispersed particles than what the photoluminescence excitation spectrum, which is typically obtained from thick powder samples, indicates. This may be attributed to differences in optical thicknesses between the two states, which are discussed in [8].…”

Section: Emission Intensity Per Particlementioning

confidence: 99%

“…Those covered a wide range of lifetimes and temperature sensitivities. Recently, the emission of six of those phosphors were compared using dispersed particle methods, finding that the luminescence emission intensity of ZnO, BaMgAl 10 O 17 (BAM):Eu 2+ and Mg 4 FGeO 4 (MFG):Mn 4+ were similar and on the order of 10 6 photons per particle at an excitation fluence of a 20 mJ/cm 2 [8]. For Y 3 Al 5 O 12 (YAG):Pr 3+ , YAG:Dy 3+ and La 2 O 2 S:Eu 3+ , the emission intensities of the emission bands used for thermometry were found to be several orders of magnitude lower than this, even for significantly higher laser fluences.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of the tin-doped phosphor (Sr,Mg)₃(PO₄)₂:Sn²⁺ for fluid temperature measurements

Fond

Abram

Pougin

et al. 2019

Opt. Mater. Express

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The photoluminescence properties of the phosphor (Sr,Mg) 3 (PO 4) 2 :Sn 2+ were investigated for luminescence thermometry in fluids. The luminescence emission intensity at 300 K is on the order of 10 6 photons per particle and the lifetime is 26 µs. With increasing temperature, the wide emission band exhibits a pronounced blue shift which can be exploited for temperature imaging using a two-colour ratiometric approach. The measured temperature sensitivity in an imaging configuration is 0.6%/K at 300 K. The T 50 quenching temperature is 650 K, similar to the phosphor BaMgAl 10 O 17 :Eu 2+ , but the estimated temperature sensitivity at 700 K is a factor 7 higher (0.36%/K). Moreover, the excitation laser fluence has a negligible effect on the measured temperature (0.6 K for a 10% change in the fluence), a five-to-tenfold improvement over phosphors previously investigated for fluid thermometry. The phosphor (Sr,Mg) 3 (PO 4) 2 :Sn 2+ therefore offers significant improvements for thermometry applications in turbulent flows in the 300-900 K range.

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Section: Liquid Dispersion and Particle Countingmentioning

confidence: 99%

Section: Spectroscopymentioning

confidence: 99%

Section: Emission Intensity Per Particlementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of the tin-doped phosphor (Sr,Mg)₃(PO₄)₂:Sn²⁺ for fluid temperature measurements

Fond

Abram

Pougin

et al. 2019

Opt. Mater. Express

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“…Note that these ZnO particles are produced on an industrial scale using a gas phase process which could potentially introduce different spectroscopic properties for different batches. Using a dispersed particle characterisation system (Fond et al 2019) we therefore verified that the absolute luminescence signal (5 × 10 15 photons per milligram of dispersed particles) was approximately the same for this batch of ZnO as for different batches of the same product purchased on prior occasions.…”

Section: Laser Diagnosticsmentioning

confidence: 56%

Time-resolved temperature and velocity field measurements in gas turbine film cooling flows with mainstream turbulence

et al. 2020

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Gas turbine film cooling strategies must provide adequate cooling performance under high levels of mainstream turbulence. Detailed information about the structure, dynamics and transport of the cooling films is needed to understand the flow physics and develop suitable numerical simulation tools. Here, we study film cooling flows in a wind tunnel with mainstream turbulence generated by an active turbulence grid. Gas temperature and velocity fields are measured using a laser-imaging method based on thermographic phosphor tracer particles. By replacing the previously used tracer BaMgAl10O17:Eu2+ with ZnO, significant gains in accuracy and precision could be achieved. The increased sensitivity (~ 1%/K) of ZnO led to a threefold improvement in the single-shot, single-pixel temperature precision to ± 5 K. The smaller particle size (dp,v ~ 600 nm) and agglomerated nanoparticle structure also reduced the tracing response time to ~ 5 µs allowing accurate tracking of turbulent fluctuations approaching 10 kHz. Moreover, no uncertainty arising from multiple scattering effects were observed using ZnO particles in this enclosed wind tunnel geometry at an estimated average seeding density of 2 × 1011 particles/m3. Time-average, fluctuation and single-shot temperature–velocity fields are presented for two mainstream turbulence levels ($$\overline{u}^{\prime}$$ u ¯ ′ /$${\overline{u}}_{\mathrm{m}}$$ u ¯ m = 7% and 14%) and two momentum ratios (IR = 4.7 and 9.3) at a fixed density ratio of 1.55. These flow conditions produce a cooling jet which is detached from the surface. High main flow turbulence causes faster mixing with the surrounding hot gas, increasing the wall-normal spreading of the cooling jet. The instantaneous flow fields show that mainstream turbulence has a significant effect on the shear layer velocity fluctuations and consequently on the streamwise and wall-normal turbulent heat flux, which is derived from the simultaneously acquired temperature–velocity data. We found that high mainstream turbulence reduces the heat flux away from the wall, suggesting that mainstream turbulence can act to diminish cooling performance. Sets of instantaneous measurements recorded at a 6 kHz repetition rate also reveal the dynamic interactions between the main flow turbulence and the cooling jet. These findings and the recorded data can be used to advance turbulence modelling for numerical simulations. Graphic abstract

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A Ho³⁺‐Based Luminescent Thermometer for Sensitive Sensing over a Wide Temperature Range

Swieten

et al. 2020

Advanced Optical Materials

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on luminescence thermometry offers an alternative that is capable of measuring heat generation and diffusion on the microscopic scale. [3] Among the various choices of luminescent systems, [4-9] crystals doped with lanthanide (Ln 3+) ions represent a particularly promising class of luminescent thermometers, because their dimensions can be tuned from a few nanometers to several micrometers and their photoluminescence spectrum is sensitive to temperature. A characteristic feature of Ln 3+ ions is their rich energy level structure, which results in emission spectra with well-separated lines. Typically, the luminescence intensity ratio (LIR) between two of these emission lines is used as a sensitive measure for the temperature of the Ln 3+-doped crystal. After insertion of these ratiometric thermometers into a system of interest, remote operation simply involves excitation by light and detection of the luminescence with standard spectroscopic equipment. The performance of a ratiometric thermometer is determined by how sensitively the LIR reacts to temperature. In general, the performance at a given temperature (T) is quantified in terms of the relative sensitivity [10]

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Characterisation of dispersed phosphor particles for quantitative photoluminescence measurements

Cited by 28 publications

References 37 publications

Investigation of the tin-doped phosphor (Sr,Mg)₃(PO₄)₂:Sn²⁺ for fluid temperature measurements

Investigation of the tin-doped phosphor (Sr,Mg)₃(PO₄)₂:Sn²⁺ for fluid temperature measurements

Time-resolved temperature and velocity field measurements in gas turbine film cooling flows with mainstream turbulence

A Ho³⁺‐Based Luminescent Thermometer for Sensitive Sensing over a Wide Temperature Range

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Characterisation of dispersed phosphor particles for quantitative photoluminescence measurements

Cited by 28 publications

References 37 publications

Investigation of the tin-doped phosphor (Sr,Mg)3(PO4)2:Sn2+ for fluid temperature measurements

Investigation of the tin-doped phosphor (Sr,Mg)3(PO4)2:Sn2+ for fluid temperature measurements

Time-resolved temperature and velocity field measurements in gas turbine film cooling flows with mainstream turbulence

A Ho3+‐Based Luminescent Thermometer for Sensitive Sensing over a Wide Temperature Range

Contact Info

Product

Resources

About

Investigation of the tin-doped phosphor (Sr,Mg)₃(PO₄)₂:Sn²⁺ for fluid temperature measurements

Investigation of the tin-doped phosphor (Sr,Mg)₃(PO₄)₂:Sn²⁺ for fluid temperature measurements

A Ho³⁺‐Based Luminescent Thermometer for Sensitive Sensing over a Wide Temperature Range