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Strona główna » Instytut » Pracownicy » Andrzej Pelc

dr hab. Andrzej Pelc

Zakład

Zakład Spektrometrii Mas

Stanowisko:

adiunkt

Kontakt:

pokój: 43A
telefon: (081) 537-61-78
e-mail: andrzej.pelc@umcs.pl

Specjalność naukowa:

fizyka

Funkcje pełnione w IF UMCS:

Zastępca Dyrektora Instytutu Fizyki 2013-2017

Publikacje: Ukryj abstrakty

  1. A. Pelc,S. Hałas, In vacuo reduction of silver orthophosphate with graphite for high-precision oxygen isotope analysis, Rapid Communications in Mass Spectrometry, 24(), 2010, 2827-2830

  2. S. Hałas, A. Pelc, New isotope ratio mass spectrometric method of precise d37Cl determinations, Rapid Comm. in Mass Spectrom., 23(), 2009, 1061-1064

  3. Pelc, A. Hałas, S., Negative ion source for chlorine isotope ratio measurements, Rapid Communications in Mass Spectrometry, 22(), 2008, 3977-3982

  4. Pelc, A. Hałas, S., New method of investigations of chlorine stable isotope ratio, Final Programmae & Abstract Book, Abstract of Joint European Stable Isotope User Meeting “JESIUM 2008”, Presquile de Giens French Mediterranean Coast , (), 2008, 301

  5. Pelc, A. Hałas, S., Nowa metoda analizy izotopów stabilnych chloru, Lublin, Abstracts of All-Polish Scientific Conference “Dating of Minerals and Rocks X”, (), 2008, 33

  6. Pelc, A. Hałas, S., Spektrometr mas do analizy izotopowej chloru i bromu, Janów Lubelski, IV Kongres Polskiego Towarzystwa Próżniowego, VIII Krajowa Konferencja Techniki Próżni, (), 2008, 0-05

  7. Hałas, S. Pelc, A., New IRMS method of precise δ37Cl measurement,Geophysical Research Abstracts, Abstract of EGU General Assembly 2008, Geophysical Research , 10(), 2008, EGU2008-A-10640

  8. Pelc, A. Scheier, P. Mark, T.D., Low-energy electron interaction with nitrobenzene: C6H5NO2, Vacuum, 81(10), 2007, 1180-1183

    Abstract:
    Low-energy electron attachment to C6H5NO2 (nitrobenzene) in the gas phase is reported in the electron energy range from about 0 up to 10eV with an energy resolution of 120 meV. Dissociative and nondissociative electron attachment to nitrobenzene were observed. From the numerous ions observed, the two most abundant were NO2- and C6H5NO2-. Based on comparison of the abundance of studied ions with Cl- in the dissociative electron attachment to CCl4 at 0.8 eV, estimates of cross sections for the all observed ions were obtained for the first time (e.g. sigma(NO2-) = 4.6 x 10(-20) m(2) and sigma(C6H5NO2-) = 3.8 x 10(-21) m(2)). (c) 2007 Elsevier Ltd. All rights reserved.

  9. Pelc, A. Sailer, W. Scheier, P. Mark, T. D., Generation of (M-H)(-) ions by dissociative electron attachment to simple organic acids M, Vacuum, 78(2-4), 2005, 631-634

    Abstract:
    Low energy (similar to 0-3.5 eV) dissociative electron attachment to the simplest organic acids (formic, acetic and propanoic) is studied at high electron energy resolution (60 meV) by means of mass spectrometric detection of the product anions. For all (M-H)(-) negative fragment ions produced, vibrational structure in the attachment spectra is observed. The energy gaps between the vibrational levels in HCOO-, CH3COO- and CH3CH2COO- are derived (ranging from 250 +/- 60 meV up to 350 +/- 60 meV). (c) 2005 Elsevier Ltd. All rights reserved.

  10. Pelc, A. Sailer, W. Scheier, P. Mark, T. D. Illenberger, E., Fragmentation of propanoic acid by subexcitation electrons, Chemical Physics Letters, 392(4-6), 2004, 465-469

    Abstract:
    Low energy electron attachment to propanoic acid (CH3CH2COOH) leads to a variety of negative fragment ions formed by dissociative electron attachment. The most intense reactions are operative at subexcitation energies (<3 eV) at cross- sections on the 10(-20) m(2) scale. They are due to dehydrogenation from the O site (direct cleavage of the O-H bond), but also more complicated reactions associated with hydrogen transfer and substantial geometric and electronic rearrangement. The present results demonstrate the potential of slow electrons to efficiently decompose organic acids. (C) 2004 Elsevier B.V. All rights reserved.

  11. Cicman, P. Gluch, K. Pelc, A. Sailer, W. Matt-Leubner, S. Scheier, P. Matejcik, S. Lukac, P. Robertson, W. D. Compton, R. N. Mark, T. D., Electron impact ionization of CHF2Cl: Unusual ordering of ionization energies for parent and fragment ions, Journal of Chemical Physics, 119(22), 2003, 11704-11711

    Abstract:
    Electron impact ionization of the chlorodifluoromethane molecule is studied using crossed beams of high-resolution electrons and an effusive molecular beam of CHF2Cl. Ionization energies (IEs) for many positive ions from CHF2Cl (CHF2Cl+,CF2Cl+,CHFCl+,CFCl+,CHF2+,CF2+,HCl+,Cl+,CF+,CH+,F+ C+) are determined from a careful examination of the threshold behavior of the ionization cross sections. Reaction pathways for the dissociative ionization products are suggested using known thermodynamic quantities. Surprisingly, it is observed that the ionization threshold for the parent positive ion IE(CHF2Cl+/CHF2Cl)=12.50(+/-0.05) eV lies above that for the fragment ions CHF2+, CHFCl+, and CF+ [IE(CHF2+/CHF2Cl)=12.24(+/-0.03) eV, IE(CHFCl+/CHF2Cl)=12.3(+/- 0.05) eV, and IE(CF+/CHF2Cl)=11.5(+/-0.1) eV]. Experiments using a three sector field BEE mass spectrometer provide evidence for the existence of two states of the parent CHF2Cl+ ion, one exhibiting a short lifetime of about 2 mus and another parent ion state which appears to be stable on the time scale of the experiment (>20 mus) with an IE of 12.50 eV. (C) 2003 American Institute of Physics.

  12. Sailer, W. Pelc, A. Limao-Vieira, P. Mason, N. J. Limtrakul, J. Scheier, P. Probst, M. Mark, T. D., Low energy electron attachment to CH3CN, Chemical Physics Letters, 381(1-2), 2003, 216-222

    Abstract:
    Low energy electron attachment cross sections for acetonitrile (CH3CN) are reported in the energy range from about 0 up to 10 eV determined with an energy resolution of 140 meV. Electron attachment is shown to be a purely dissociative process with the production of the five anionic fragments: CH2CN-, CHCN-, CCN-, CN- and CH3- observed in two energy regions, the first between 1 and 4 eV, the second in excess of 6 eV. Quantum chemical and trajectory calculations have been carried out to complement the experimental results. (C) 2003 Elsevier B.V. All rights reserved.

  13. Pelc, A. Sailer, W. Matejcik, S. Scheier, P. Mark, T. D., Dissociative electron attachment to nitroethane: C2H5NO2, Journal of Chemical Physics, 119(15), 2003, 7887-7892

    Abstract:
    Dissociative electron attachment (DEA) to nitroethane (C2H5NO2) in the gas phase is studied using a crossed electron-molecule beams technique. The ion yields for particular fragment ions were measured in the electron energy range from 0 to 9.5 eV with an electron energy resolution of about 120 meV. In contrast to previous studies additional negative ions, i.e., HCN- and NO-, were observed. Measures for the absolute partial cross sections were obtained for the ions using a calibration technique involving a comparison with the known cross section of the 0.8 eV peak in DEA to CCl4. The dominant negative ion product is NO2- with a cross section of approximately 11x10(- 22) m(2) at 0.75 eV. The values of the cross section estimates for the other ions are about sigma(C2H3NO2-)=4x10(-24) m(2) at similar to0 eV, sigma(O-)=5x10(-24) m(2) at 5.7 eV, sigma(OH- )=2x10(-24) m(2) at 5.7 eV, sigma(CN-)=5x10(-25) m(2) at 1.7 eV, sigma(CNO-)=3x10(-25) m(2) at similar to4.5 eV, sigma(HCN- )=2x10(-25) m(2) at similar to4.5 eV and sigma(NO-)=3x10(-25) m(2) at similar to8 eV. (C) 2003 American Institute of Physics.

  14. Cicman, P. Pelc, A. Sailer, W. Matejcik, S. Scheier, P. Mark, T. D., Dissociative electron attachment to CHF2Cl, Chemical Physics Letters, 371(3-4), 2003, 231-237

    Abstract:
    We present results of a crossed electron/molecule beams study concerning dissociative electron attachment (DEA) to CHF2Cl. This study was performed in the electron energy range from about 0-10 eV and at a gas temperature of 300 K. Four fragment negative ions (Cl-, F-, CCIF- and CF2-) were observed. The following partial absolute cross-sections for DEA to CHF2Cl were obtained, 2 x 10(-19) cm(2) at the 1.1 eV resonance for Cl-, 3 x 10(-20) cm(2) at the 3.4 eV resonance for F- ,approximate to 2 x 10(-21) at the 3.0 eV resonance for CCIF- and 3 x 10(-21) at the 8.6 eV resonance for CF2-. Using the cross-section functions obtained, total rate coefficients for DEA to CHF2Cl were calculated giving a value of 9.0 x 10(-13) cm(3)s(-1) at room temperature. Present results are compared with previous data allowing thus to clarify existing discrepancies. (C) 2003 Elsevier Science B.V. All rights reserved.

  15. Sailer, W. Pelc, A. Matejcik, S. Illenberger, E. Scheier, P. Mark, T. D., Dissociative electron attachment study to nitromethane, Journal of Chemical Physics, 117(17), 2002, 7989-7994

    Abstract:
    Dissociative electron attachment (DEA) to CH3NO2 in the gas phase was studied in the electron energy range from zero up to 10 eV with an energy resolution of 140 meV. For the most intense negative fragments NO2-, O-, OH-, CN-, CNO- estimates for the absolute partial cross sections were obtained for the first time [sigma(NO2)approximate to10(-21) m(2) at 0.62 eV, sigma(O-)approximate to10(-23) m(2) at 5.4 eV, sigma(OH- )approximate to10(-24) m(2) at 4 eV, sigma(CN-)approximate to10(-24) m(2) at 1.7 eV, and sigma(CNO-)approximate to10(-25) m(2) at 4 eV]. In the case of OH-, CN-, and CNO-, ion formation at very low electron energies (approximate to0 eV) has been observed in contrast to previous studies. The formation of OH- and CNO- at these low electron energies is explained in terms of DEA to vibrationally excited molecules. Analyzing measured partial cross sections, the standard enthalpy of formation of the CH3NO (nitroso-methane) and the CNO radical has been estimated, as Delta(f)H(g)(o)(CH3NO)=129+/-30 kJ/mol and Delta(f)H(g)(o)(CNO)=323+/-30 kJ/mol, respectively. (C) 2002 American Institute of Physics.

  16. Pelc, A. Sailer, W. Scheier, P. Probst, M. Mason, N. J. Illenberger, E. Mark, T. D., Dissociative electron attachment to formic acid (HCOOH), Chemical Physics Letters, 361(3-4), 2002, 277-284

    Abstract:
    Dissociative electron attachment to formic acid as a fundamental center in enzymatic activity is studied. A prominent resonance is observed peaking at 1.25 eV which decomposes into the formate anion HCOO- and a hydrogen radical. Resonances at higher energy are associated with O- and OH- formation on a considerably smaller intensity scale. On the basis of high level ab initio calculations, the low energy feature arises from different closely spaced single particle shape resonances with no specific valence character. The HCOO- ion yield carries structure which is tentatively ascribed to vibrational excitation in the formate anion. (C) 2002 Elsevier Science B.V. All rights reserved.

  17. Sailer, W. Drexel, H. Pelc, A. Grill, V. Mason, N. J. Illenberger, E. Skalny, J. D. Mikoviny, T. Scheier, P. Mark, T. D., Low energy electron attachment to SF5CF3, Chemical Physics Letters, 351(1-2), 2002, 71-78

    Abstract:
    Low energy electron attachment to the potent greenhouse gas SF5CF3 is studied at high energy resolution by means of mass spectrometric detection of the product anions. A large dissociative electron attachment (DA) cross-section forming SF5- + CF3 is observed within a very narrow energy range close to zero eV. In addition, comparatively weak resonances are observed near 1 eV yielding the fragment ions CF3- and F-. Some implications for the atmospheric lifetime of SF5CF3 and hence its global warming potential (GWP) are considered. (C) 2002 Elsevier Science B.V. All rights reserved.

  18. Pelc, A. Michalak, L., Electron ionization study of ammonia microclusters, Rapid Communications in Mass Spectrometry, 14(16), 2000, 1455-1461

    Abstract:
    An electron impact ion source on a double focusing sector field mass spectrometer was used to investigate ammonia micro- clusters produced by the adiabatic free jet expansion of ammonia gas. The appearance energies for [NH3](n)(+), n less than or equal to 9, ions have been determined. Results of measurements of appearance pressures of selected clusters are described for a range of operating conditions. An empirical formula describing the ammonia clusters production is proposed. Copyright (C) 2000 John Wiley & Sons, Ltd.

  19. Michalak, L. Pelc, A., Homologous micro-clusters of carbon disulphide, Vacuum, 57(1), 2000, 61-70

    Abstract:
    Mass spectrometric investigations of homologous micro-clusters (n less than or equal to 6) of carbon disulphide are studied by using an electron impact ion source and a double focusing sector field mass spectrometer. Clusters are produced by adiabatic gas expansion of mixture of CS, vapour and Ar. The appearance potentials for ions (CS2)(n)S+, (CS2)(n)CS+, (CS2)(n)S-2(+) (n = 1 and 2), CS2C+ and (CS2)(3)S+ are determined. The temperature dependences of selected clusters are also presented. (C) 2000 Elsevier Science Ltd. All rights reserved.

  20. Pelc, A. Michalak, L., Production of carbon disulphide dimers by an adiabatic gas expansion method, International Journal of Mass Spectrometry, 194(1), 2000, 85-91

    Abstract:
    The production of carbon disulphide dimers by adiabatic gas expansion of a mixture comprised of CS2 vapour and Ar is studied by using an electron impact ion source and a double focusing sector field mass spectrometer. Results of measurements of the generation of (CS2)(2)(+) cluster ions versus the stagnation pressure (0-160 kPa) at several stagnation temperatures (267-300 K) are described. An empirical formula describing the carbon disulphide dimer production is proposed. (C) 2000 Elsevier Science B.V.

  21. Pelc, A. Michalak, L., Electron impact study of argon clusters, Nukleonika, 44(2), 1999, 317-327

    Abstract:
    The production of argon clusters Ar-n, n less than or equal to 21, by adiabatic gas expansion of Ar is studied by using an electron impact ion source and a double focusing sector field mass spectrometer. Results of measurements of appearance pressures of selected clusters are described for a range of operating conditions. The appearance pressures of observed clusters showed a slowly increasing dependence on cluster size.

  22. Pelc, A. Michalak, L., Electron impact study of carbon disulphide micro-clusters, Vacuum, 52(3), 1999, 261-268

    Abstract:
    The production of carbon disulphide micro-clusters (CS2)(n) n less than or equal to 11, by adiabatic gas expansion of mixture of CS2 vapour and Ar is studied by using an electron impact ion source and a double focusing sector field mass spectrometer. The appearance potentials for clusters n less than or equal to 9 decreased as n increased but was not a simple function of 1/n. The appearance pressures of observed clusters showed a slowly increasing dependence on cluster size. Results of measurements of appearance potentials and appearance pressures of selected clusters are described for a range of operating conditions. (C) 1999 Elsevier Science Ltd. All rights reserved.


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