TA05 THE ROTATIONAL SPECTRA OF O-17

SUBSTITUTED OXYGEN SINGLET DELTA

BRIAN J. DROUIN, HARSHAL GUPTA, SHANSHAN YU, CHARLES E. MILLER, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099

HOLGER S.P. MÜLLER I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937, Köln, Germany

The Big Picture (from TA04)

6/19/2012 The Rotational Spectra of 17O Substituted Oxygen Singlet Delta 2

• Oxygen has 3 bound states below 3P dissociation barrier

• Transitions below UV are magnetic

• Isotopic bands are observable in Earth atmosphere

Previous Work on 1D O2

• O. Leshchishina, et al., J. Quant. Spectrosc. Radiat. Trans., 112, 1257-1265 (2011). (17O IR delta band)

• S. Kassi, et al., Chem. Phys. Lett. 502, 37-41 (2011). (16O ,18O IR delta band)• H. Gupta et al. RC03 2010 (18O iso / THz).• B.J. Drouin et al. J. Quant. Spectrosc. Radiat. Trans. 111, 1167-1173 (2010).

(16O / THz)• E.A. Cohen, et al., J. Mol. Spectrosc. 352/353, 283-287 (1995). (16O, 18O / MW)• K. W. Hillig, et al., J. Mol. Spectrosc. 109, 205 (1985). (16O / MW)• G. Cazzoli et al., Chem. Phys. Lett. 100, 99-101 (1983). (16O / MW)• A. Scalabrin, et al., J. Molec. Spectrosc. 89, 344-351 (1981). (16O / LMR)• T. A. Miller, J. Chem. Phys. 54, 330 (1971). (16O / EPR)• C. A. Arrington Jr., et al., J. Chem. Phys. 55, 909-914 (1971). (17O / EPR)

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Static Dicharge Cell• Previsously described by H. Gupta et al. RC03 2010 (18O iso / THz).

• Gas is introduced through a con-flat metal valve that is also ground electrode• Two con-flat / quartz transitions on either end of cell• Hot electrode is externally connected to power supply and shielded with Teflon• THz radiation is passed through angled quartz windows• Amorphous quartz attenuates 20% of 500 GHz, 50% of 1000 GHz, 100% 1600 GHz• After conditioning, gas pressure stays close to ignition pressure for days

6/19/2012 The Rotational Spectra of 17O Substituted Oxygen Singlet Delta 4

RC03 2010 Review

24 June 2010 H. Gupta, 65th OSU Meeting 5

18O216O18O16O2

Large range in N

Modest to deep integration

S/N adequate to observe v = 1

New Data - 16O17O• Despite better throughput at < 500 GHz, best SNR was near 1000 GHz• Observed by mixing 90% 17O2 with natural sample 50/50• Discharge Voltage 2kV, 40 mA• Hyperfine Pattern from I = 5/2 17O nucleus• spin-orbit coupling dominates

• Boltzmann peak for rotational distribution near 1200 GHz• Integration time unlimited• Cell contamination and harmonic purity are issues• (Blue) prediction from Yu et al. JCP 2012

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New Data - 17O2• Observed by discharging 90% 17O2 • Hyperfine pattern from two equivalent I = 5/2 17O nuclei

• (Blue) prediction from Yu et al. JCP 2012

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Present Data Set (pure rotation)

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a) B.J. Drouin et al. J. Quant. Spectrosc. Radiat. Trans. 111, 1167-1173 (2010). b) K. W. Hillig, et al., J. Mol. Spectrosc. 109, 205 (1985).c) E.A. Cohen, et al., J. Mol. Spectrosc. 352/353, 283-287 (1995).

Dunham Analysis

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1) S. Yu, et al., J. Chem. Phys. (in press) also TA046) E.A. Cohen, et al., J. Mol. Spectrosc. 352/353, 283-287 (1995).

New!

Hyperfine Analysis

The Rotational Spectra of 17O Substituted Oxygen Singlet Delta 10

O = O 3S1D

34. J.S.M. Harvey, Proc. R. Soc. Lond. A 285, 581-596 (1965).39. G. Cazzoli, et al., Nuovo Cimento 62 B 243 (1981).40. H.P. Kelly, Phys. Rev. 180, 55-61 (1969).

Born-Oppenheimer Breakdown

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d01 = d01,nonad + d01,ad + d01,Dun

11. Th. Klaus, et al. JMS. 186, 416-421 1997.23. L. Veseth, Mol. Phys. 36,1255-1260 (1978).25. H. Christensen, L. Veseth, JMS, 72, 438-444 (1978).26. Th. Klaus, et al. JMS, 180, 197-206 (1996).27. W.L. Meerts, et al., Chem. Phys. 22, 319-324 (1977).28. R. Farrenq, et al. JMS., 149, 375-390 (1991).

Acknowledgements

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John Pearson

Tim Crawford

NASA - ACLAB / ACLR