Articles | Volume 20, issue 21
Technical note
12 Nov 2020
Technical note |  | 12 Nov 2020

Technical Note: Effect of varying the λ = 185 and 254 nm photon flux ratio on radical generation in oxidation flow reactors

Jake P. Rowe, Andrew T. Lambe, and William H. Brune

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Cited articles

Atkinson, R.: Kinetics and mechanisms of the gas-phase reactions of the hydroxyl radical with organic compounds under atmospheric conditions, Chem. Rev., 86, 69–201, 1986. a, b
Dawes, A., Pascual, N., Hoffmann, S. V., Jones, N. C., and Mason, N. J.: Vacuum ultraviolet photoabsorption spectroscopy of crystalline and amorphous benzene, Phys. Chem. Chem. Phys., 19, 27544–27555,, 2017. a
Huang, Y., Coggon, M. M., Zhao, R., Lignell, H., Bauer, M. U., Flagan, R. C., and Seinfeld, J. H.: The Caltech Photooxidation Flow Tube reactor: design, fluid dynamics and characterization, Atmos. Meas. Tech., 10, 839–867,, 2017. a
Lambe, A. T., Ahern, A. T., Williams, L. R., Slowik, J. G., Wong, J. P. S., Abbatt, J. P. D., Brune, W. H., Ng, N. L., Wright, J. P., Croasdale, D. R., Worsnop, D. R., Davidovits, P., and Onasch, T. B.: Characterization of aerosol photooxidation flow reactors: heterogeneous oxidation, secondary organic aerosol formation and cloud condensation nuclei activity measurements, Atmos. Meas. Tech., 4, 445–461,, 2011. a, b
Lambe, A. T., Krechmer, J. E., Peng, Z., Casar, J. R., Carrasquillo, A. J., Raff, J. D., Jimenez, J. L., and Worsnop, D. R.: HOx and NOx production in oxidation flow reactors via photolysis of isopropyl nitrite, isopropyl nitrite-d7, and 1,3-propyl dinitrite at λ=254, 350, and 369 nm, Atmos. Meas. Tech., 12, 299–311,, 2019. a, b, c
Short summary
We conducted a series of experiments in which the 185 to 254 nm photon flux ratio (I185 : I254) emitted by low-pressure mercury lamps installed in an oxidation flow reactor (OFR) was systematically varied using multiple novel lamp configurations. Integrated OH exposure values achieved for each lamp type were obtained as a function of OFR operating conditions. A photochemical box model was used to develop a generalized OH exposure estimation equation as a function of [H2O], [O3], and OH reactivity.
Final-revised paper