Burnett, D.S.

Davidson, J.

Eng, P.J.

Jurewicz, A.J.G.

Schmeling, Martina

Stubbs, J.E.

Genesis flight sample 30580 was analyzed by grazing incidence X-ray fluorescence spectrometry for subsequent calculation of Mn and Ni fluences

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Loyola University ChicagoLoyola eCommonsChemistry: Faculty Publications and Other Works Faculty Publications2015Grazing Incidence X-ray FluorescenceMeasurements of Genesis Sample 30580 forDetermination of Manganese and Nickel FluencesMartina SchmelingLoyola University Chicago, mschmel@luc.eduJ. DavidsonP.J. EngJ.E. StubbsA.J.G. JurewiczSee next page for additional authorsThis Conference Proceeding is brought to you for free and open access by the Faculty Publications at Loyola eCommons. It has been accepted forinclusion in Chemistry: Faculty Publications and Other Works by an authorized administrator of Loyola eCommons. For more information, pleasecontact ecommons@luc.edu.This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.© Schmeling et al., 2015.Recommended CitationSchmeling, Martina; Davidson, J.; Eng, P.J.; Stubbs, J.E.; Jurewicz, A.J.G.; and Burnett, D.S.. Grazing Incidence X-ray FluorescenceMeasurements of Genesis Sample 30580 for Determination of Manganese and Nickel Fluences. Lunar and Planetary SciencesConference, , : , 2015. Retrieved from Loyola eCommons, Chemistry: Faculty Publications and Other Works,AuthorsMartina Schmeling, J. Davidson, P.J. Eng, J.E. Stubbs, A.J.G. Jurewicz, and D.S. BurnettThis conference proceeding is available at Loyola eCommons: http://ecommons.luc.edu/chemistry_facpubs/68Grazing Incidence X-ray Fluorescence Measurements of Genesis Sample 30580 for Determination of Manga-nese and Nickel FluencesM. Schmeling1, J. Davidson1, P.J. Eng2, J.E. Stubbs2, A.J.G. Jurewicz3, D.S. Burnett41Loyola University Chicago, Chicago, IL 60660, mschmel@luc.edu; 2GSECARS, University of Chicago, Argonne,IL 60439; 3Arizona State University, Tempe, AZ 85004; 4California Institute of Technology, Pasadena, CA 91125.Introduction: The Genesis mission was the firstmission returning solar material to Earth since theApollo program [1,2]. Unfortunately the return of thespace craft on September 8, 2004 resulted in a crashlanding, shattering the samples into small fragmentsand exposing them to desert soil and other debris. Onlysmall fragments of the original collectors are availablewith each of them having a different degree of surfacecontamination and thorough surface cleaning is neces-sary to allow for subsequent analysis of solar windmaterial embedded within. Initial cleaning is carriedout at Johnson Space Center (JSC), but typically re-moves only larger sized particulates and a thin filmorganic contamination acquired during collection inspace [3]. Some contaminants like those embeddedwithin the scratches or crevices of the samples requiremore aggressive cleaning methods. These additionalcleaning steps consist of acid and/or organic solventtreatment and typically reduce or at best remove thenotorious contaminants. Total reflection X-ray fluores-cence analysis (TXRF) is then used to identify remain-ing contaminants and select the most suitable samplesfor further analyses [4].After pre-selection by TXRF some samples are an-alyzed using grazing incidence X-ray fluorescence(GIXRF), a non destructive method capable of identi-fying first row transition metals below the surfacequantitatively even when only minor surface contami-nants are present. GIXRF analysis was already suc-cessfully employed for determination of Fe fluences insilicon samples [5,6]. Unfortunately other transitionmetals of interest for the Genesis mission specificallyMn and Ni cannot be determined in silicon collectorsdue to peak overlap of remaining surface contaminantsand bulk material sum peaks. The most suitable mate-rial to analyze those two elements appears to be sap-phire (Al2O3) and several sapphire flight samples wereTXRF screened and cleaned to obtain a promisingsample for GIXRF analysis. Flight sample 30580showed the least surface contaminants left and wasselected.Experimental: Analyses of Genesis sample30580, a sapphire flight control, and a sapphire implantcontaining 3x1013 atoms/cm2 Mn and Ni, were per-formed at the GeoSoilsEnviro Consortium for Ad-vanced Radiation Sources (GSECARS) 13-ID-C undu-lator beamline in grazing incidence X-ray fluorescenceset-up. All three samples underwent surface inspectionby TXRF analysis prior to GIXRF measurements:S2PicoFox, excitation energy 17.4 keV (Mo- Anode),counting time 3600 seconds (1hour) [4]. The 13-ID-Cbeamline of the GSECARS at the Advanced PhotonSource at Argonne National Laboratory where GIXRFanalysis was performed is equipped with a cryogenicSi (111) double crystal monochromator, a Vortex® Si-drift detector and a reflectivity detector. The sampleswere mounted in a He-flow chamber with a Kapton®window and data acquisition time was adjusted forexpected fluences i.e. longer acquisition times for30580 than for control and implant. [5,6].Results and Conclusion: Figure 1 shows the sur-face spectrum of sample 30580 after cleaning with awater, hydrochloric acid, and nitric acid (1:1:1) solu-tion. Cr, Mn, Fe, Ni, and Br are the most prominentelements recognizable as surface contaminants leftwith Br stemming from the hydrochloric acid cleaning.In addition Si can be seen as well.Figure 1: TXRF spectrum of Genesis sample 30580 showingelements present at the surface.Figure 2 shows a normalized angle scan of thesame sample acquired with GIXRF. The black linerepresents beam reflectivity, which is at its highest atsmall angles before the beam penetrates below the sur-face. Aluminum (red) is the collector material and in-creases with beam penetration depth. Ni (magenta) andFe (green) appear to be present at and slightly belowthe surface whereas Mn (blue) seems to be slightlybelow the surface. In contrast to layered materials suchas silicon on sapphire collectors, data for single crys-talline materials are more difficult to interpret and X-ray standing wave calculations will be necessary to2238.pdf46th Lunar and Planetary Science Conference (2015)identify how much material is embedded below thesurface.Figure 2: GIXRF analysis of Genesis sample 30580. The blackline shows beam reflectivity, the red line the Al collector material,green, magenta and blue are elements either at the surface or in thebulk (Mn, Fe, Ni).To aid in this process a sapphire implant samplecontaining 3x1013 atoms/cm2 55Mn and 60Ni implantedat 55kV and 60kV, respectively, and a flight controlsample were measured by GIXRF as well. The latterone was hand cleaved and cleaned at JSC prior toanalyses. TXRF measurements showed only minortraces of Cr, Fe and Ni as surface contaminants left.The implant had only some Fe on the surface, but wasotherwise clean and was used as standard for discrimi-nating between material at or below the surface. Figure3 shows the normalized GIXRF spectrum of the con-trol sample and figure 4 the normalized GIXRF spec-trum of the implant.Figure 3: GIXRF data for sapphire flight control sample.Figure 4: GIXRF data for 3x1013 Mn and Ni implanted in sap-phire.As seen in figure 3, Mn, Fe and Ni show a distinctpeak structure with a maximum at maximum reflectivi-ty for the control sample. This is an indication that allthree elements appear to be particle like contaminantspresent at the surface. Mn shows a similar pattern forthe flight sample, but slightly shifted towards higherincidence angles, possibly indicating its presence be-low the surface.The implant sample shows almost identical signalsfor Mn and Ni, clearly below the surface and roughlyat the intersection between reflectivity and Al bulkmaterial signal. Fe on the other hand is present mostlyat the surface following approximately the shape of thereflectivity curve.Figure 5 shows the normalized spectrum of flightsample 30580 again, but this time only for Si and Febesides Al bulk signal and reflectivity. This graph in-dicates that the Fe peak is shifted slightly into the bulkas compared to Si, indicating that Fe is also presentslightly below the surface.Figure 5: GIXRF analysis of Genesis sample 30580 showing Siand Fe.As discussed above the graphical interpolation ofthe different elements is not sufficient to clearly identi-fy the location and concentration of each element. Forthis X-ray standing wave calculations have to be per-formed, which will be the next step for this sample[5,6].References:[1] Burnett D.S. et al. (2003), Space Science Reviews,105, 509-534.[2] Jurewicz A.J.G. et al. (2003) Space Science Reviews,105, 535-560.[3] Calaway M.J. et .al. (2009), LPSC XXXX, Paper#1183.[4] Schmeling M. et. al. (2012), Adv. X-ray Anal. 55,264-271.[5] Kitts K. et al. (2009), J. Applied Phys. 105:6, 064905.[6] Kitts K. et al. (2009), LPSC XXXX, Paper #1439.Acknowledgements: The authors would like to expresstheir gratitude to the Genesis sample curators at John-son Space Center. This research was supported byNASA grant NNX10AH05G.2238.pdf46th Lunar and Planetary Science Conference (2015)

Grazing Incidence X-ray Fluorescence Measurements of Genesis Sample 30580 for Determination of Manganese and Nickel Fluences

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