On the applications of IBA techniques to biological samples analysis: PIXE and RBS

On the Applications of IBA Techniques to Biological Samples Analysis: PIXE and RBS J. M. FalcónGonzález, J. BernalAlvarado, M. GarcíaLeón, R. GarcíaTenorio, Y. Morilla García, and M. Sosa Citation: AIP Conference Proceedings 1032, 179 (2008); doi: 10.1063/1.2979262 View online: http://dx.doi.org/10.1063/1.2979262 View Table of Contents: http://scitation.aip.org/content/aip/proceeding/aipcp/1032?ver=pdfcov Published by the AIP Publishing This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 148.204.139.225 On: Fri, 14 Mar 2014 21:51:27 On the Applications of IBA Techniques toOn the Applications of IBA Techniques toOn the Applications of IBA Techniques toOn the Applications of IBA Techniques to Biological Samples Analysis: PIXE and RBSBiological Samples Analysis: PIXE and RBSBiological Samples Analysis: PIXE and RBSBiological Samples Analysis: PIXE and RBS J. M. Falcón-GonzálezJ. M. Falcón-GonzálezJ. M. Falcón-GonzálezJ. M. Falcón-González1**1**1**1**,J.Bernal-Alvarado,J.Bernal-Alvarado,J.Bernal-Alvarado,J.Bernal-Alvarado1*1*1*1*,M.García-León,M.García-León,M.García-León,M.García-León2222,R.,R.,R.,R. García-TenorioGarcía-TenorioGarcía-TenorioGarcía-Tenorio3333,Y.Morilla García,Y.Morilla García,Y.Morilla García,Y.Morilla García2222andM.Sosaand M. Sosaand M. Sosaand M. Sosa1111 1)Instituto de F1)Instituto de F1)Instituto de F1)Instituto de Fíííísica de la UniversidaddeGuanajuato, A.P. E-143, 37150 Lesica de la Universidad de Guanajuato, A.P. E-143, 37150 Lesica de la Universidad de Guanajuato, A.P. E-143, 37150 Lesica de la Universidad de Guanajuato, A.P. E-143, 37150 Leóóóón, Guanajuaton, Guanajuaton, Guanajuaton, Guanajuato 2)Centro Nacional de Aceleradores, Sevilla, Spain2)Centro Nacional de Aceleradores, Sevilla, Spain2)Centro Nacional de Aceleradores, Sevilla, Spain2)Centro Nacional de Aceleradores, Sevilla, Spain 3)Universidad de Sevilla, Sevilla, Spain3)Universidad de Sevilla, Sevilla, Spain3)Universidad de Sevilla, Sevilla, Spain3)Universidad de Sevilla, Sevilla, Spain *)[email protected], **)[email protected]o.mx*)[email protected], **)[email protected]o.mx*)[email protected], **)[email protected]o.mx*)[email protected], **)[email protected]o.mx AbstractAbstractAbstractAbstract.The analytical techniques based on ion beamsorIBA techniques give quantitative.The analytical techniques based on ion beamsorIBA techniques give quantitative.The analytical techniques based on ion beamsorIBA techniques give quantitative.The analytical techniques based on ion beamsorIBA techniques give quantitative informationonelemental concentration in samples of awide variety of nature. In this work, weinformation on elemental concentration in samples of awide variety of nature. In this work, weinformation on elemental concentration in samples of awide variety of nature. In this work, weinformation on elemental concentration in samples of awide variety of nature. In this work, we focus on PIXE technique,analyzing thick target biologicalspecimens (TTPIXE), using 3MeVfocus on PIXE technique,analyzing thick target biologicalspecimens (TTPIXE), using 3MeVfocus on PIXE technique,analyzing thick target biologicalspecimens (TTPIXE), using 3MeVfocus on PIXE technique,analyzing thick target biologicalspecimens (TTPIXE), using 3MeV protons produced by an electrostatic accelerator.Anuclear microprobe was used performingprotons produced by an electrostatic accelerator.Anuclear microprobe was used performingprotons produced by an electrostatic accelerator.Anuclear microprobe was used performingprotons produced by an electrostatic accelerator.Anuclear microprobe was used performing PIXEand RBS simultaneously, in order to solvethe uncertainties produced in the absolute PIXEPIXE and RBS simultaneously, in order to solvethe uncertainties produced in the absolute PIXEPIXE and RBS simultaneously, in order to solvethe uncertainties produced in the absolute PIXEPIXE and RBS simultaneously, in order to solvethe uncertainties produced in the absolute PIXE quantifying. Theadvantages of using both techniquesand anuclear microprobe arediscussed.quantifying. Theadvantages of using both techniquesand anuclear microprobe arediscussed.quantifying. Theadvantages of using both techniquesand anuclear microprobe arediscussed.quantifying. Theadvantages of using both techniquesand anuclear microprobe arediscussed. Quantitative resultsare shown to illustrate themultielemental resolution of the PIXE technique;Quantitative results are shown to illustrate themultielemental resolution of the PIXE technique;Quantitative results are shown to illustrate themultielemental resolution of the PIXE technique;Quantitative results are shown to illustrate themultielemental resolution of the PIXE technique; for this,ablood standardwas used.for this,ablood standardwas used.for this,ablood standardwas used.for this,ablood standardwas used. KeywordsKeywordsKeywordsKeywords:IBA techniques,PIXE, TTPIXE, RBS, nuclearmicroprobe.:IBA techniques,PIXE, TTPIXE, RBS, nuclearmicroprobe.:IBA techniques,PIXE, TTPIXE, RBS, nuclearmicroprobe.:IBA techniques,PIXE, TTPIXE, RBS, nuclearmicroprobe. PHYSICAL PRINCIPLESPHYSICAL PRINCIPLESPHYSICAL PRINCIPLESPHYSICAL PRINCIPLES Particle InducedX-Ray Emission,Particle Induced X-Ray Emission,Particle Induced X-Ray Emission,Particle Induced X-Ray Emission, PIXE,PIXE,PIXE,PIXE, is an analytical method based upon X-rayis an analytical method based upon X-rayis an analytical method based upon X-rayis an analytical method based upon X-ray spectrometry whereabeam of protons is used to ejectinner-shell electrons from atomsspectrometry where abeam of protons is used to ejectinner-shell electrons from atomsspectrometry where abeam of protons is used to ejectinner-shell electrons from atomsspectrometry where abeam of protons is used to ejectinner-shell electrons from atoms in aspecimenin aspecimenin aspecimenin aspecimen1111.When the resultingvacancies are filled by outer-shell electrons,.When the resultingvacancies are filled by outer-shell electrons,.When the resultingvacancies are filled by outer-shell electrons,.When the resultingvacancies are filled by outer-shell electrons, characteristic X-rayswhose energies identify the particular atom are emitted. Thecharacteristic X-rayswhose energies identify the particular atom are emitted. Thecharacteristic X-rayswhose energies identify the particular atom are emitted. Thecharacteristic X-rayswhose energies identify the particular atom are emitted. The transition filling vacancies in the innermost shell are called KX-rays and those fillingtransition filling vacancies in the innermost shell are called KX-rays and those fillingtransition filling vacancies in the innermost shell are called KX-rays and those fillingtransition filling vacancies in the innermost shell are called KX-rays and those filling the next shell are LX-rays, whose energies are much lower.the next shell are LX-rays, whose energies are much lower.the next shell are LX-rays, whose energies are much lower.the next shell are LX-rays, whose energies are much lower. The quantitative PIXE analysis is based on the relationship betweenthe total areaThe quantitative PIXE analysis is based on the relationship between the total areaThe quantitative PIXE analysis is based on the relationship between the total areaThe quantitative PIXE analysis is based on the relationship between the total area underthe characteristic X-ray peak and the real concentration of the given element inunder the characteristic X-ray peak and the real concentration of the given element inunder the characteristic X-ray peak and the real concentration of the given element inunder the characteristic X-ray peak and the real concentration of the given element in thesample. To find the yield of characteristic X-rays fromaparticular elementalthe sample. To find the yield of characteristic X-rays fromaparticular elementalthe sample. To find the yield of characteristic X-rays fromaparticular elementalthe sample. To find the yield of characteristic X-rays fromaparticular elemental constituent homogeneously distributed within athick biological specimen, we useconstituent homogeneously distributed within athick biological specimen, we useconstituent homogeneously distributed within athick biological specimen, we useconstituent homogeneously distributed within athick biological specimen, we use the factthat it sets the final proton energy to zero. Therefore, the yield equation forthe fact that it sets the final proton energy to zero. Therefore, the yield equation forthe fact that it sets the final proton energy to zero. Therefore, the yield equation forthe fact that it sets the final proton energy to zero. Therefore, the yield equation for thicksamples in PIXE isthick samples in PIXE isthick samples in PIXE isthick samples in PIXE is ∫∫∫∫ ==== 0000 0000))))(((( ))))(((())))(((( ))))(((( EEEE zzzzzzzz zzzz zzzzzzzziiiizzzzavavavav dEdEdEdE EEEESSSS EEEETTTTEEEE AAAA qCqCqCqCFFFFNNNN ZZZZYYYY σσσσ εεεεωωωω (1)(1)(1)(1) 177 CP1032, Medical Physics -Tenth Symposium on Medical Physics, edited by G. Herrera Corral and L. M. Montaño Zetina ©2008 American Institute of Physics 978-0-7354-0556-1/08/$23.00 179 This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 148.204.139.225 On: Fri, 14 Mar 2014 21:51:27 which gives the relationship between the X-rays amount and the elementalwhich gives the relationship between the X-rays amount and the elementalwhich gives the relationship between the X-rays amount and the elementalwhich gives the relationship between the X-rays amount and the elemental concentrations, whereconcentrations, whereconcentrations, whereconcentrations, where AAAAzzzzis theatomic mass of the element,is the atomic mass of the element,is the atomic mass of the element,is the atomic mass of the element, NNNNavavavav the Avogadro´sthe Avogadro´sthe Avogadro´sthe Avogadro´s number,number,number,number, ωωωωzzzzthe fluorescence yield, the transition probabilities between two differentthe fluorescence yield, the transition probabilities between two differentthe fluorescence yield, the transition probabilities between two differentthe fluorescence yield, the transition probabilities between two different shellsare given byshells are given byshells are given byshells are given by FFFFiiiiandandandand εεεεzzzzis the absolute detection efficiency. The concentration ofis the absolute detection efficiency. The concentration ofis the absolute detection efficiency. The concentration ofis the absolute detection efficiency. The concentration of theelement Zofinterest is Cthe element Zofinterest is Cthe element Zofinterest is Cthe element Zofinterest is Czzzz.Inthe integral we can seethe ionization cross section.Inthe integral we can seethe ionization cross section.Inthe integral we can seethe ionization cross section.Inthe integral we can seethe ionization cross section for proton energy,for proton energy,for proton energy,for proton energy, σσσσzzzz(E). Thematrix stopping powers S(E), is calculated using Bragg´s(E). The matrix stopping powers S(E), is calculated using Bragg´s(E). The matrix stopping powers S(E), is calculated using Bragg´s(E). The matrix stopping powers S(E), is calculated using Bragg´s rule forlinear combination of the component stopping powers. The quantity Trule for linear combination of the component stopping powers. The quantity Trule for linear combination of the component stopping powers. The quantity Trule for linear combination of the component stopping powers. The quantity Tzzzz(E)(E)(E)(E) describes thetransmission of photons from successive depths in the matrix.describes thetransmission of photons from successive depths in the matrix.describes thetransmission of photons from successive depths in the matrix.describes thetransmission of photons from successive depths in the matrix. The main uncertainties in the absolute quantifying of PIXE elementalThe main uncertainties in the absolute quantifying of PIXE elementalThe main uncertainties in the absolute quantifying of PIXE elementalThe main uncertainties in the absolute quantifying of PIXE elemental concentrations are the total deposited beam chargeconcentrations are the total deposited beam chargeconcentrations are the total deposited beam chargeconcentrations are the total deposited beam charge the “the “the “the “qqqq”factor in Eq. (1)”factor in Eq. (1)”factor in Eq. (1)”factor in Eq. (1) andandandand the localmatrix composition. This is particularly true in our case while workingthe local matrix composition. This is particularly true in our case while workingthe local matrix composition. This is particularly true in our case while workingthe local matrix composition. This is particularly true in our case while working microbeam PIXE analysis with thick targetbiological samples.microbeam PIXE analysis with thick targetbiological samples.microbeam PIXE analysis with thick targetbiological samples.microbeam PIXE analysis with thick targetbiological samples. On the other hand, theOn the other hand, theOn the other hand, theOn the other hand, the Rutherford Backscattering Spectrometry,Rutherford Backscattering Spectrometry,Rutherford Backscattering Spectrometry,Rutherford Backscattering Spectrometry, RBS,RBS,RBS,RBS, detects thedetects thedetects thedetects the energies andamount of the elastic backscattered ions from asolid target due to theenergies and amountofthe elastic backscattered ions from asolid target due to theenergies and amountofthe elastic backscattered ions from asolid target due to theenergies and amountofthe elastic backscattered ions from asolid target due to the Coulomb interaction withthe atom nuclear structureCoulombinteraction with the atom nuclear structureCoulombinteraction with the atom nuclear structureCoulombinteraction with the atom nuclear structure2222.... The use of simultaneous RBS analysis can solve the uncertainties in PIXE analysisThe use of simultaneous RBS analysis can solve the uncertainties in PIXE analysisThe use of simultaneous RBS analysis can solve the uncertainties in PIXE analysisThe use of simultaneous RBS analysis can solve the uncertainties in PIXE analysis in many cases. Provided the RBS spectrum can be well modelled, its shape givesin many cases. Provided the RBS spectrum can be well modelled, its shape givesin many cases. Provided the RBS spectrum can be well modelled, its shape givesin many cases. Provided the RBS spectrum can be well modelled, its shape gives informationonthe local matrix composition, while the total area dependsonthe totalinformation on the local matrix composition, while the total area dependsonthe totalinformation on the local matrix composition, while the total area dependsonthe totalinformation on the local matrix composition, while the total area dependsonthe total beam charge. The ratio between thetrue chargeand the measured charge (the “q”beam charge. The ratio between thetrue chargeand the measured charge (the “q”beam charge. The ratio between thetrue chargeand the measured charge (the “q”beam charge. The ratio between thetrue chargeand the measured charge (the “q” factor) can then be used to normalise the PIXE datafactor) can then be used to normalise the PIXE datafactor) can then be used to normalise the PIXE datafactor) can then be used to normalise the PIXE data3333.RBS also provides information.RBS also provides information.RBS also provides information.RBS also provides information on those elements with low atomic numbers, this is very useful when we are trying toon those elements with low atomic numbers, this is very useful when we are trying toon those elements with low atomic numbers, this is very useful when we are trying toon those elements with low atomic numbers, this is very useful when we are trying to analyze biological samples.analyze biological samples.analyze biological samples.analyze biological samples. In this way, PIXE is amulti-elemental technique with excellent sensitivity andIn this way, PIXE is amulti-elemental technique with excellent sensitivity andIn this way, PIXE is amulti-elemental technique with excellent sensitivity andIn this way, PIXE is amulti-elemental technique with excellent sensitivity and detection limits across awide rangeofatomic number. Additionally, PIXE providesdetection limits across awide rangeofatomic number. Additionally, PIXE providesdetection limits across awide rangeofatomic number. Additionally, PIXE providesdetection limits across awide rangeofatomic number. Additionally, PIXE provides relatively precise measurements from very smallamounts of material.relatively precise measurements from very smallamounts of material.relatively precise measurements from very smallamounts of material.relatively precise measurements from very smallamounts of material. EXPERIMENTAL SETUPEXPERIMENTAL SETUPEXPERIMENTAL SETUPEXPERIMENTAL SETUP PIXE andRBS techniques were performed simultaneously within anuclearPIXE and RBS techniques were performed simultaneously within anuclearPIXE and RBS techniques were performed simultaneously within anuclearPIXE and RBS techniques were performed simultaneously within anuclear microprobe (Fig. 1) and they were carried out using the 3MVpeletron tandemmicroprobe (Fig. 1) and they were carried out using the 3MVpeletron tandemmicroprobe (Fig. 1) and they were carried out using the 3MVpeletron tandemmicroprobe (Fig. 1) and they were carried out using the 3MVpeletron tandem accelerator at Centro Nacional de Aceleradores (CNA), Sevilla, Spain. The calledaccelerator at Centro Nacional de Aceleradores (CNA), Sevilla, Spain. The calledaccelerator at Centro Nacional de Aceleradores (CNA), Sevilla, Spain. The calledaccelerator at Centro Nacional de Aceleradores (CNA), Sevilla, Spain. The called micro-PIXE simply involves focusing the beam down to small areal dimensions, 4micro-PIXE simply involves focusing the beam down to small areal dimensions, 4micro-PIXE simply involves focusing the beam down to small areal dimensions, 4micro-PIXE simply involves focusing the beam down to small areal dimensions, 4 μμμμminour case, so that it can be scanned acrossthe surface of aspecimen and thusminour case, so that it can be scanned acrossthe surface of aspecimen and thusminour case, so that it can be scanned acrossthe surface of aspecimen and thusminour case, so that it can be scanned acrossthe surface of aspecimen and thus provide concentration data as afunction of position. Magnetic lenses such as coilsprovide concentration data as afunction of position. Magnetic lenses such as coilsprovide concentration data as afunction of position. Magnetic lenses such as coilsprovide concentration data as afunction of position. Magnetic lenses such as coils wound to generate aquadrupolar field produce ademagnified image of the objectwound to generate aquadrupolar field produce ademagnified image of the objectwound to generate aquadrupolar field produce ademagnified image of the objectwound to generate aquadrupolar field produce ademagnified image of the object aperture at the specimen surface. Scanning across abiological specimen becomesaperture at the specimen surface. Scanning across abiological specimen becomesaperture at the specimen surface. Scanning across abiological specimen becomesaperture at the specimen surface. Scanning across abiological specimen becomes possible to obtain concentration maps. Hence, the final intensity of the beam is verypossible to obtain concentration maps. Hence, the final intensity of the beam is verypossible to obtain concentration maps. Hence, the final intensity of the beam is verypossible to obtain concentration maps. Hence, the final intensity of the beam is very low in ordertoavoid the damage in biological samples.low in order to avoid the damage in biological samples.low in order to avoid the damage in biological samples.low in order to avoid the damage in biological samples. A3MeV proton beam was used to irradiate the sample. ASi(Li) detector wasA3MeV proton beam was used to irradiate the sample. ASi(Li) detector wasA3MeV proton beam was used to irradiate the sample. ASi(Li) detector wasA3MeV proton beam was used to irradiate the sample. ASi(Li) detector was employedtocollect the X-rays with a80mmemployed to collect the X-rays with a80mmemployed to collect the X-rays with a80mmemployed to collect the X-rays with a80mm 2222active area and asurface barrieractive area and asurface barrieractive area and asurface barrieractive area and asurface barrier detector was used to collect the backscattered particles.detector was used to collect the backscattered particles.detector was used to collect the backscattered particles.detector was used to collect the backscattered particles. 178 180 This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 148.204.139.225 On: Fri, 14 Mar 2014 21:51:27 FIGURE 1.FIGURE 1.FIGURE 1.FIGURE 1. We can show the nuclearmicroprobe (left), where amicroscope is installed in order to seeWe can show the nuclear microprobe (left), where amicroscope is installed in order to seeWe can show the nuclear microprobe (left), where amicroscope is installed in order to seeWe can show the nuclear microprobe (left), where amicroscope is installed in order to see the micrometric beam.The quadrupolar lenses and scanning system are also shown.the micrometric beam.The quadrupolar lenses and scanning system are also shown.the micrometric beam.The quadrupolar lenses and scanning system are also shown.the micrometric beam.The quadrupolar lenses and scanning system are also shown. The Si(Li)detectorhas a“funny filter”The Si(Li) detectorhas a“funny filter”The Si(Li) detectorhas a“funny filter”The Si(Li) detectorhas a“funny filter”4444placed in the window because is aplaced in the window because is aplaced in the window because is aplaced in the window because is a convenient choice for biological specimens. Those samples are insulating targets, forconvenient choice for biological specimens. Those samples are insulating targets, forconvenient choice for biological specimens. Those samples are insulating targets, forconvenient choice for biological specimens. Those samples are insulating targets, for this reason we used acarbon foil spraying electrons with the purpose to avoid thethis reason we used acarbon foil spraying electrons with the purpose to avoid thethis reason we used acarbon foil spraying electrons with the purpose to avoid thethis reason we used acarbon foil spraying electrons with the purpose to avoid the samples charge up.samples charge up.samples charge up.samples charge up. RESULTSRESULTSRESULTSRESULTS Example of PIXE spectra obtained from electronic chain (detector, multichannelExample of PIXE spectra obtained from electronic chain (detector, multichannelExample of PIXE spectra obtained from electronic chain (detector, multichannelExample of PIXE spectra obtained from electronic chain (detector, multichannel analyzer andcomputer) for A-13 IAEA´s standard (freeze dried animal blood) isanalyzer and computer) for A-13 IAEA´s standard (freeze dried animal blood) isanalyzer and computer) for A-13 IAEA´s standard (freeze dried animal blood) isanalyzer and computer) for A-13 IAEA´s standard (freeze dried animal blood) is shown in Fig. 2.shown in Fig. 2.shown in Fig. 2.shown in Fig. 2. 246810 12 14 16246810 12 14 16246810 12 14 16246810 12 14 16 1111 10101010 100100100100 1000100010001000 10000100001000010000 100000100000100000100000 Counts perchannelCounts perchannelCounts perchannelCounts perchannel Energy (keV)Energy (keV)Energy (keV)Energy (keV) A13Standard(freeze driedanimal blood)A13Standard(freeze driedanimal blood)A13Standard(freeze driedanimal blood)A13Standard(freeze driedanimal blood) FeFeFeFe (ZnZnZnZnkkkkα ααα α +Cu+Cu+Cu+Cukkkkβ βββ β) CuCuCuCu KKKK CaCaCaCa ClClClCl NaNaNaNa FIGURE 2.FIGURE 2.FIGURE 2.FIGURE 2. PIXE spectra obtained in our experimental setup. The spectra shows somePIXE spectra obtained in our experimental setup. The spectra shows somePIXE spectra obtained in our experimental setup. The spectra shows somePIXE spectra obtained in our experimental setup. The spectra shows some characteristic X-Ray peaks for abiological standard given by the International Atomic Energy Agency.characteristic X-Ray peaks for abiological standard given by the International Atomic Energy Agency.characteristic X-Ray peaks for abiological standard given by the International Atomic Energy Agency.characteristic X-Ray peaks for abiological standard given by the International Atomic Energy Agency. 179 181 This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 148.204.139.225 On: Fri, 14 Mar 2014 21:51:27 TABLE 1.TABLE 1.TABLE 1.TABLE 1. Elemental concentrations given inElemental concentrations given inElemental concentrations given inElemental concentrations given in ppmppmppmppm.The certified concentrations aregivenbythe.The certified concentrations aregivenbythe.The certified concentrations aregivenbythe.The certified concentrations aregivenbythe IAEA, while the concentrations for A13 experiment are experimentally obtained.IAEA, while the concentrations for A13 experiment are experimentally obtained.IAEA, while the concentrations for A13 experiment are experimentally obtained.IAEA, while the concentrations for A13 experiment are experimentally obtained. Sample Na PSCl KCaFeCuZnBrRbSample Na PSCl KCaFeCuZnBrRbSample Na PSCl KCaFeCuZnBrRbSample Na PSCl KCaFeCuZnBrRb A13A13A13A13 CertifiedCertifiedCertifiedCertified 12600940 6500 NC 2500 286 2400 41322212600940 6500 NC 2500 286 2400 41322212600940 6500 NC 2500 286 2400 41322212600940 6500 NC 2500 286 2400 413222 A13A13A13A13 Experiment 132411021 6614 7748 2581 292 2399 413212Experiment 132411021 6614 7748 2581 292 2399 413212Experiment 132411021 6614 7748 2581 292 2399 413212Experiment 132411021 6614 7748 2581 292 2399 413212 The PIXE spectra were analyzed with the GUPIXWIN softwareThe PIXE spectra were analyzed with the GUPIXWIN softwareThe PIXE spectra were analyzed with the GUPIXWIN softwareThe PIXE spectra were analyzed with the GUPIXWIN software (http://pixe.physics.uoguelph.ca) and the elemental concentrations were obtained by(http://pixe.physics.uoguelph.ca) and the elemental concentrations were obtained by(http://pixe.physics.uoguelph.ca) and the elemental concentrations were obtained by(http://pixe.physics.uoguelph.ca) and the elemental concentrations were obtained by normalizingPIXE data to the irradiated mass and charge obtained from the RBSnormalizing PIXE data to the irradiated mass and charge obtained from the RBSnormalizing PIXE data to the irradiated mass and charge obtained from the RBSnormalizing PIXE data to the irradiated mass and charge obtained from the RBS spectra. Thecertified values for thestandard are shown in the Table 1and they arespectra. Thecertified values for thestandard are shown in the Table 1and they arespectra. Thecertified values for thestandard are shown in the Table 1and they arespectra. Thecertified values for thestandard are shown in the Table 1and they are compared with those obtained in the experiment.compared with those obtained in the experiment.compared with those obtained in the experiment.compared with those obtained in the experiment. From the Table 1wecan observe than the certified values are very close to thoseFrom the Table 1wecan observe than the certified values are very close to thoseFrom the Table 1wecan observe than the certified values are very close to thoseFrom the Table 1wecan observe than the certified values are very close to those obtained for our experiment.obtained for our experiment.obtained for our experiment.obtained for our experiment. Therefore, after reducing theuncertainties obtained by PIXE fitting the spectra viaTherefore, after reducing the uncertainties obtained by PIXE fitting the spectra viaTherefore, after reducing the uncertainties obtained by PIXE fitting the spectra viaTherefore, after reducing the uncertainties obtained by PIXE fitting the spectra via RBS, the obtained values are the expected values. Moreover, we can see that the useRBS, the obtained values are the expected values. Moreover, we can see that the useRBS, the obtained values are the expected values. Moreover, we can see that the useRBS, the obtained values are the expected values. Moreover, we can see that the use of 3MeV protons, the nuclear microprobe, the funny filter and all the otherof 3MeV protons, the nuclear microprobe, the funny filter and all the otherof 3MeV protons, the nuclear microprobe, the funny filter and all the otherof 3MeV protons, the nuclear microprobe, the funny filter and all the other components in our experiment, increase the confidence level on the results.components in our experiment, increase the confidence level on the results.components in our experiment, increase the confidence level on the results.components in our experiment, increase the confidence level on the results. ACKNOWLEDGMENTSACKNOWLEDGMENTSACKNOWLEDGMENTSACKNOWLEDGMENTS This work was supportedbyCONACyT, CONCyTEG and University ofThis work was supported by CONACyT, CONCyTEG and University ofThis work was supported by CONACyT, CONCyTEG and University ofThis work was supported by CONACyT, CONCyTEG and University of Guanajuato. We also want to thank to Centro Nacional de Aceleradores of theGuanajuato. We also want to thank to Centro Nacional de Aceleradores of theGuanajuato. We also want to thank to Centro Nacional de Aceleradores of theGuanajuato. We also want to thank to Centro Nacional de Aceleradores of the University of Sevilla, Spain.University of Sevilla, Spain.University of Sevilla, Spain.University of Sevilla, Spain. REFERENCESREFERENCESREFERENCESREFERENCES 1. S.A.E Johansson and J.L Campbell.1. S.A.E Johansson and J.L Campbell.1. S.A.E Johansson and J.L Campbell.1. S.A.E Johansson and J.L Campbell. PIXE Anovel technique for elemental analysisPIXE Anovel technique for elemental analysisPIXE Anovel technique for elemental analysisPIXE Anovel technique for elemental analysis,. John Willey,. John Willey,. John Willey,. John Willey and Sons.1988.and Sons.1988.and Sons.1988.and Sons.1988. 2. Chu, W. K.,Mayer, J. W., Nicolet, M.A.2. Chu, W. K.,Mayer, J. W., Nicolet, M.A.2. Chu, W. K.,Mayer, J. 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X-ray Anal., 17 560(1973) 180 182 This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 148.204.139.225 On: Fri, 14 Mar 2014 21:51:27 View publication statsView publication stats