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High resolution far-IR spectroscopy of HFC-134a at cold temperatures
Andy wong Chris Medcraft Chris Thompson Evan G. Robertson Dominique Appadoo Don McNaughton
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Outline PhD HFC-134a Experimental Results Conclusions
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Outline PhD HFC-134a Experimental Results Conclusions
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1,1,1,2-tetrafluoroethane Atmospheric properties Outline Refrigerant
Greenhouse gas GWP = 1300 13 year lifetime 63 ppt (2011) Outline PhD HFC-134a Experimental Results Conclusions
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1,1,1,2-tetrafluoroethane Spectroscopic properties Outline
Near prolate asymmetric top κ ≈ Outline PhD HFC-134a Experimental Results Conclusions
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1,1,1,2-tetrafluoroethane Spectroscopic properties Outline
Near prolate asymmetric top κ ≈ Cs symmetry at equilibrium 18 fundamental vibrations 11 A′ and 7 A″ ν8 (A′) ~ cm-1 a/b-hybrid band Outline PhD HFC-134a Experimental Results Conclusions E σh Linear, rotations Quadratic A′ 1 x, y, Rz x2, y2, z2, xy A″ -1 Rx, Ry, z yz, xz
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Australian Synchrotron
“Decay” mode 200 mA to 150 mA External source Far-IR beamline Synchrotron source Bruker IFS125 spectrometer Maximum resolution of cm-1 z Outline PhD HFC-134a Experimental Results Conclusions
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Australian Synchrotron
“Decay” mode 200 mA to 150 mA External source Far-IR beamline Synchrotron source Bruker IFS125 spectrometer Maximum resolution of cm-1 Enclosive flow cooling (EFC) cell White-type multipass cell Cooled with cold N2 gas to 176 K k Outline PhD HFC-134a Experimental Results Conclusions
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Australian Synchrotron
“Decay” mode 200 mA to 150 mA External source Far-IR beamline Synchrotron source Bruker IFS125 spectrometer Maximum resolution of cm-1 Enclosive flow cooling (EFC) cell White-type multipass cell Cooled with cold N2 gas to 176 K Optics Boron-doped silicon photodetector KBr windows and beamsplitter Outline PhD HFC-134a Experimental Results Conclusions
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Outline PhD HFC-134a Experimental Results Conclusions
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Outline PhD HFC-134a Experimental Results Conclusions
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Spectrum T = 176 K ν8 band (CF3-deformation) Outline PhD HFC-134a
Experimental Results Conclusions
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Transition assignment
MacLoomis (Loomis-Wood plot) Outline PhD HFC-134a Experimental Results Conclusions
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Transition assignment
MacLoomis (Loomis-Wood plot) Outline PhD HFC-134a Experimental Results Conclusions
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Transition assignment
MacLoomis (Loomis-Wood plot) Ground state combination differences Pickett’s SPFIT software ΔJ = ΔKc = 2, ΔKa = 0 (a-type) ΔJ = ΔKa = ΔKc = 2 (b-type) Outline PhD HFC-134a Experimental Results Conclusions
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Transition assignment
MacLoomis (Loomis-Wood plot) Ground state combination differences Pickett’s SPFIT software ΔJ = ΔKc = 2, ΔKa = 0 (a-type) ΔJ = ΔKa = ΔKc = 2 (b-type) 4344 assigned transitions Ka′ max = 26 J′ max = 66 Outline PhD HFC-134a Experimental Results Conclusions
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Fitting the rotational constants
SPFIT Watson’s S-reduced Hamiltonian (Ir). Outline PhD HFC-134a Experimental Results Conclusions
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Fitting the rotational constants
SPFIT Watson’s S-reduced Hamiltonian (Ir). Resonances Coriolis Fermi Outline PhD HFC-134a Experimental Results Conclusions
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Fitted rotational and centrifugal distortion constants (MHz)
Outline PhD HFC-134a Experimental Results Conclusions
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Fitted rotational and centrifugal distortion constants (MHz)
Outline PhD HFC-134a Experimental Results Conclusions
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Residuals Obs - calc Outline PhD HFC-134a Experimental Results
Conclusions
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Synchrotron FIR spectroscopy
Far-IR high resolution beamline HFC-134a EFC Cell Coupled to Bruker IFS125 spectrometer Cold temperature (176 K) Reduced spectral congestion Spectral analysis Transition assignment MacLoomis and GSCD’s Fitting of rotational constants and spectral simulation Pickett’s SPFIT and SPCAT Outline PhD HFC-134a Experimental Results Conclusions
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Acknowledgements Monash University Spectroscopy group Outline Advisors
Chris Medcraft (Newcastle, UK) Advisors Don McNaughton (Monash) Chris Thompson (Monash) Evan Robertson (La Trobe) Dominique Appadoo (AS) Australian Synchrotron Far-IR beamline Dominique Appadoo Outline PhD HFC-134a Experimental Results Conclusions
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