scholarly journals Supplementary material to "Spatially Resolved Infrared Radiofluorescence: Single-grain K-feldspar Dating using CCD Imaging"

Author(s):  
Dirk Mittelstraß ◽  
Sebastian Kreutzer
Geochronology ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 299-319
Author(s):  
Dirk Mittelstraß ◽  
Sebastian Kreutzer

Abstract. The success of luminescence dating as a chronological tool in Quaternary science builds upon innovative methodological approaches, providing new insights into past landscapes. Infrared radiofluorescence (IR-RF) on K-feldspar is such an innovative method that was already introduced two decades ago. IR-RF promises considerable extended temporal range and a simple measurement protocol, with more dating applications being published recently. To date, all applications have used multi-grain measurements. Herein, we take the next step by enabling IR-RF measurements on a single grain level. Our contribution introduces spatially resolved infrared radiofluorescence (SR IR-RF) on K-feldspars and intends to make SR IR-RF broadly accessible as a geochronological tool. In the first part of the article, we detail equipment, CCD camera settings and software needed to perform and analyse SR IR-RF measurements. We use a newly developed ImageJ macro to process the image data, identify IR-RF emitting grains and obtain single-grain IR-RF signal curves. For subsequent analysis, we apply the statistical programming environment R and the package Luminescence. In the second part of the article, we test SR IR-RF on two K-feldspar samples. One sample was irradiated artificially; the other sample received a natural dose. The artificially irradiated sample renders results indistinguishable from conventional IR-RF measurements with the photomultiplier tube. The natural sample seems to overestimate the expected dose by ca. 50 % on average. However, it also shows a lower dose component, resulting in ages consistent with the same sample's quartz fraction. Our experiments also revealed an unstable signal background due to our cameras' degenerated cooling system. Besides this technical issue specific to the system we used, SR IR-RF is ready for application. Our contribution provides guidance and software tools for methodological and applied luminescence (dating) studies on single-grain feldspars using radiofluorescence.


Author(s):  
Dirk Mittelstraß ◽  
Sebastian Kreutzer

Abstract. The success of luminescence dating as a chronological tool in Quaternary science builds upon innovative methodological approaches, providing new insights into past landscapes. Infrared radiofluorescence (IR-RF) on K-feldspar is such an innovative method already introduced two decades ago. IR-RF promises considerable extended temporal range and a simple measurement protocol, with more dating applications published recently. To date, all applications use multi-grain measurements. Herein, we take the next step by enabling IR-RF measurements on a single grain level. Our contribution introduces spatially resolved infrared radiofluorescence (SR IR-RF) on K-feldspars and intends to make SR IR-RF broadly accessible as a geochronological tool. In the first part of the manuscript, we detail equipment, CCD camera settings and software needed to perform and analyse SR IR-RF measurements. We use a newly developed ImageJ macro to process the image data, identify IR-RF emitting grains and obtain single-grain IR-RF signal curves. For subsequent analysis, we apply the statistical programming environment R and the package Luminescence. In the second part of the manuscript, we test SR IR-RF on two K-feldspar samples. One sample was irradiated artificially; the other sample received a natural dose. The artificially irradiated sample renders results, indistinguishable from conventional IR-RF measurements with the photomultiplier tube. The natural sample seems to overestimate the expected dose by ca 50 % on average. However, it also shows a lower dose component resulting in ages consistent with the same sample's quartz fraction. Our experiments also revealed an unstable signal background due to our cameras' degenerated cooling system. Besides this technical issue specific to the system we used, SR IR-RF is ready for application. Our contribution provides guidance and software tools for methodological and applied luminescence(-dating) studies on single grain feldspars using radiofluorescence.


Cryogenics ◽  
1990 ◽  
Vol 30 (5) ◽  
pp. 397-400 ◽  
Author(s):  
J. Mannhart ◽  
R. Gross ◽  
R.P. Huebener ◽  
P. Chaudhari ◽  
D. Dlmos ◽  
...  

1989 ◽  
Vol 134 ◽  
pp. 452-453
Author(s):  
J.B. Hutchings ◽  
S.G. Neff ◽  
J.H. van Gorkom

We present results of observations of the double-nucleus galaxy Markarian 266 (NGC 5256) from 3 principal sources. These are 1:CCD imaging with the Canada-France-Hawaii telescope in broad and narrow bands. These indicate that the galaxy has extended, complex, faint outer plumes which indicate that a recent merger has occurred. The narrow-band images reveal remarkable knotty structure of the [O III] emitting gas, extending over the whole central part of the galaxy. This is not seen in Hα (see figure 1).2:21cm imaging with the VLA, covering velocity space near that of the optical nuclei. The continuum image reveals resolved triple structure, with the two outer peaks coincident with the optical nuclei. The 21cm velocity profiles indicate the presence of considerable H I absorption near the optical emission line velocities.3:Spatially resolved optical spectroscopy with the DAO 1.8m telescope. These data reveal the details of the [O III] velocity field and some of the physical parameters of the gas. The complexity and extended nature of the gas explains some conflicting redshift measurements in the literature. Together with the imaging data, we derive estimates of nuclear reddening and luminosity.


1994 ◽  
Vol 375 ◽  
Author(s):  
P.-C. Wang ◽  
G. S. Cargill ◽  
I. C. Noyan

AbstractWe describe a system being developed to use x-rays for spatially resolved measurements of strain, microstructure and composition in thin films. These capabilities are particularly important for improved understanding of electromigration, stress relaxation, and associated reliability issues in microelectronics. The system uses white radiation collimated and focused with a tapered glass capillary, an area CCD detector for measuring Laue patterns, and an energy sensitive Si detector for measuring lattice spacings. Examples are shown of strain measurements for a 4 μm thick Al film on a Si substrate with 300 μm and 30 μm x-ray beams; of Laue diffraction from a single grain for a 40 μm thick Al foil with a 0.3 μm x-ray beam; and of x-ray fluorescence mapping for a patterned Cu film with a 30 μm x-ray beam.


1987 ◽  
Vol 122 ◽  
pp. 177-178
Author(s):  
Edward W. Brugel ◽  
Reinhard Mundt ◽  
Thomas Bührke

Optical jets, and collimated outflows, are now recognized as a common phenomena associated with young stars (Mundt 1985, Strom et al. 1986). Presented here are the results of new CCD imaging and spatially resolved spectroscopy for ten such objects. Using these and previously published data on twenty known jets, we compiled a set of observational criteria describing the phenomena. From this compilation we addressed several physical questions pertaining to the nature of collimated outflows associated with young stars.


2020 ◽  
Author(s):  
Guillaume Guérin ◽  
Christelle Lahaye ◽  
Maryam Heydari ◽  
Martin Autzen ◽  
Jan-Pieter Buylaert ◽  
...  

Abstract. Statistical analysis has become increasingly important in the field of OSL dating since it has become possible to measure signals at the single grain scale. The accuracy of large chronological datasets can benefit from the inclusion, in chronological modelling, of stratigraphic constraints and shared systematic errors. Recently, a number of Bayesian models have been developed for OSL age calculation; the R package BayLum allows implementing different such models, in particular for samples in stratigraphic order which share systematic errors. We first show how to introduce stratigraphic constraints in BayLum; then, we focus on the construction, based on measurement uncertainties, of dose covariance matrices to account for systematic errors specific to OSL dating. The nature (systematic versus random) of errors affecting OSL ages is discussed, based – as an example – on the dose rate determination procedure at the IRAMAT-CRP2A laboratory (Bordeaux). The effects of the stratigraphic constraints and dose covariance matrices are illustrated on example datasets. In particular, the interest of combining the modelling of systematic errors with independent ages, unaffected by these errors, is demonstrated. Finally, we discuss other common ways of estimating dose rates and how they may be taken into account in the covariance matrix by other potential users and laboratories. Test datasets are provided as supplementary material to the reader, together with an R Markdown tutorial allowing to reproduce all calculations and figures presented in this study.


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