Dave Long

B.A., Chemistry and Mathematics, Kenyon College, 2007
Third-year graduate student

I am utilizing a novel spectroscopic technique – frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) – which allows for ultrahigh measurement sensitivity and precision. Cavity ring-down is a spectroscopic technique whereby a high-finesse optical cavity (two highly reflective mirrors with the sample between them) is utilized to perform measurements of gas analytes. FS-CRDS takes the next step by actively stabilizing the length of the cavity. This removes much of the frequency noise of the resulting measurements; therefore, allowing one to study even weaker spectroscopic features.

My research has utilized FS-CRDS to measure features in the so-called O2 A-band. The A-band is a spectroscopic feature in the near-infrared (760 nm) that has been frequently used in satellite measurements of the Earth’s atmosphere. In particular the A-band is utilized by JAXA’s GOSAT (Greenhouse Gases Observing Satellite), which launched this past January (the A-band was also intended to be used by OCO (Orbiting Carbon Observatory)).

This work is performed in collaboration with Drs. Joseph T. Hodges and Dan Havey of NIST and Drs. Charles E. Miller and Linda R. Brown of the NASA Jet Propulsion Laboratory.


Publications
  1. Robichaud, D.J., L.Y. Yeung, D.A. Long, M. Okumura, D.K. Havey, J.T. Hodges, C.E. Miller, and L.R. Brown, “Experimental Line Parameters of the b1&Sigmag+ &larr X3&Sigmag- Band of Oxygen Isotopologues at 760 nm Using Frequency-Stabilized Cavity Ring-Down Spectroscopy,” J. Phys. Chem. A 113 (2009): 13089-13099.

  2. Havey, D.K., D.A. Long, M. Okumura, C.E. Miller, and J.T. Hodges,"Ultra-Sensitive Optical Measurements of High-J Transitions in the O2 A-band," Chem. Phys. Lett. 483 (2009): 49-54.

  3. Long, D.A., D.K. Havey, M. Okumura, H.M. Pickett, C.E. Miller, and J.T. Hodges, "Laboratory measurements and theoretical calculations of O2 A-band electric quadrupole transitions," Phys. Rev. A 80 (2009): 042513.

  4. Chodroff, L., T.M. O’Neal, D.A. Long, and S. Hemkin, “An education approach to computationally modeling dynamical systems,” J. Chem. Ed. 86 (2009): 1072-1076.

  5. Long, D.A., L. Chodroff, T.M. O’Neal, and S.Hemkin, “A true chemical clock: Serially coupled chlorite-iodide oscillators,” Chem. Phys. Lett. 447 (2007): 340-344.

  6. Long, D.A., K. Unal, R.C. Pratt, M. Malkoch, and J. Frommer, “Localized ‘click’ chemistry through dip-pen nanolithography,” Adv. Mater. 19 (2007): 4471-4473.

  7. Lohmeijer, B.G.G., R.C. Pratt, F. Leibfarth, J.W. Logan, and D.A. Long, et al., “Guanidine and amidine organocatalysts for ring-opening polymerization of cyclic esters,” Macromolecules 39 (2006): 8574-8583.

  8. Pratt, R.C., B.G.G. Lohmeijer, D.A. Long, P.N.P. Lundberg, A.P. Dove, H. Li, C.G. Wade, R.M. Waymouth, and J.L. Hedrick, “Exploration, optimization, and application of supramolecular thiourea-amine catalysts for the synthesis of lactide (co)polymers,” Macromolecules 39 (2006): 7863-7871.

  9. Pratt, R.C., B.G.G. Lohmeijer, D.A. Long, R.M. Waymouth, and J.L. Hedrick, “Triazabicyclodecene: A simple bifunctional organocatalyst for acyl transfer and ring-opening polymerization of cyclic esters,” J. Am. Chem. Soc. 128 (2006) 4556-4557.

  10. Hunsen, M., D.A. Long, C.R. D'Ardenne, and A.L. Smith, “Mild one-pot preparation of glycosyl bromides,” Carbohydr Res. 340 (2005): 2670-2674.

  11. Long, D.A. and J.B. Anderson, “Bond-based corrections to semi-empirical and ab initio electronic structure calculations,” Chem. Phys. Lett. 402 (2005): 524-528.
Funding

National Defense Science and Engineering Graduate Fellowship, 2007-
National Science Foundation Graduate Fellowship

Extracurricular Interests

Hiking, camping, ultimate Frisbee, poetry, books, the Los Angeles Angels of Anaheim