Burchard, M.

Dedera, S.

Glasmacher, U. A.

Schöppner, N.

Trautmann, Christina

Zdorovets, M.

GSI Repository

Spectroscopic study on ion irradiated calcites and gypsum ∗N. Scho¨ppner †1, S. Dedera1, U.A. Glasmacher1, M. Burchard1, M. Zdorovets2,3, and ChristinaTrautmann41Institute of Earth Sciences, University of Heidelberg, Germany; 2Institute of Nuclear Physics, Almaty, Kazakhstan;3Gumilyov Eurasian National University, Astana, Kazakhstan; 4TU Darmstadt and GSI Helmholtzzentrum Darmstadt,GermanyWithin geosciences, the use of fission tracks in vari-ous minerals as a thermochronological analytical techniqueis of high importance. The visualization of spontaneousand induced fission tracks uses the well established etch-ing technique. Carbonate minerals have been tested in thepast with differentiated results. The latest research clearlyindicates that fission tracks develop in carbonate mineralsand that they can be revealed by specific etching condi-tions [1], [2]. As carbonate minerals are excellent mineralsfor spectroscopic analytical techniques, the application ofthose techniques to non-destructively deduce informationon fission tracks was tested.Various carbonate minerals were irradiated within twodifferent ion energy ranges. Ions of GeV kinetic en-ergy were available at the GSI, while irradiations at lowerenergy were performed at the RGP Institute YadernoiFiziki, Astana, Kazakhstan. Mono crystalline samplesof carbonate used in these experiments are trigonal cal-cite (CaCO3), rhomboedric aragonite (CaCO3), mono-cline malachite (Cu2[(OH)2/CO3]), trigonal rhodochrosite(MnCO3), trigonal dolomite (MgCO3), and monoclinegypsum (CaSO4*2H2O). At GSI, the carbonate miner-als were irradiated at the UNILAC accelerator with 11.1MeV/u 197Au and 209Bi ions, applying fluences of 1×106,5×106, 1×107, 5×107, 1×108, 1×1011, and 1×1012ions/cm2. At the RGP Institute, the samples were irradi-ated at the Astana accelerator with 1.7 MeV/u 84Kr ionsapplying fluences between 1×1010 and 1×1012 ions/cm2.The lower mass and energy of these Kr ions is closer to theconditions given by natural fission fragments from 238U.All crystals were analyzed by Raman spectroscopy us-ing the LabRam HR800 UV spectrometer equipped withan OLYMPUS BXFM-ILHS optical microscope, a gratingwith 1800 grooves per millimeter and a Peltier-cooled CCDdetector. During the spectroscopic measurements an ob-jective of 50x magnification was used. The spectra wereexcited by laser light of wavelength 473.03 nm. The lat-eral resolution was ∼2 µm, the wave number accuracy0.5 cm−1 and the spectral resolution was 1 cm−1. First re-sults are provided for irradiated calcite and gypsum (Figs.1, 2). The revealed Raman spectra are similar up to a flu-ences of 5×1011 84Kr-ions/cm2. Above those fluences anew Raman band appears at about ∼430 cm−1. In addi-tion, at 5×1011 84Kr-ions/cm2 a shoulder appears at theleft side of the main Raman band at about 1100 cm−1.Significant changes in the Raman spectra of gypsum ap-∗Work supported by GSI(UNILAC), Work supported by GSI-HD co-operation contract and HGS-HIRe graduate school† nicole.schoeppner@geow.uni-heidelberg.deFigure 1: Spectra of calcites irradiated with fluences be-tween 1×1010 and 1x1013 84Kr-ions/cm2 and a spectrumof a non-irradiated calcite crystal.pear above a fluence of 1×1010 84Kr-ions/cm2. Withincreasing fluences the peak intensities decrease and thefull width at half maximum of the bands (FWHM) be-come larger. This applies especially to the Raman bandat 3404 cm−1, which characterizes the H2O band (Fig.1). The amplitude decrease is an indication of irradiation-induced release of water. Similar effects were observed forirradiation of gypsum with neutrons [1, 2].Figure 2: Raman spectra of gypsum before and after irra-diation with 84Kr -ions.References[1] http://www.patent-de.com/20060406/DE102004052158A1.html(2006). (Stand: 14.02.2014)[2] A. R. Patel, K. S. Raju (1970): Radiation damage in gypsum.J. Phys. Chem. Solids, 31, 331-335.GSI SCIENTIFIC REPORT 2013 PNI-MF-03doi:10.15120/GR-2014-1-PNI-MF-03 179

Spectroscopic study on ion irradiated calcites and gypsum

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Spectroscopic study on ion irradiated calcites and gypsum

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