Browsing by Author "Smith, Mica C."

Now showing 1 - 4 of 4

Electronic quenching of O(D-1) by Xe: Oscillations in the product angular distribution and their dependence on collision energy
(2015-08-07)
Garofalo, Lauren A.
;
Smith, Mica C.
;
Dagdigian, Paul J.
;
Klos, Jacek
;
Alexander, Millard H.
The dynamics of the O(D-1) + Xe electronic quenching reaction was investigated in a crossed beam experiment at four collision energies. Marked large-scale oscillations in the differential cross sections were observed for the inelastic scattering products, O(P-3) and Xe. The shape and relative phases of the oscillatory structure depend strongly on collision energy. Comparison of the experimental results with time-independent scattering calculations shows qualitatively that this behavior is caused by Stueckelberg interferences, for which the quantum phases of the multiple reaction pathways accessible during electronic quenching constructively and destructively interfere. (C) 2015 AIP Publishing LLC.
Energy dependent oscillations in the angular distribution of O(D-1) + Xe inelastic scattering
(2014-08-10)
Garofalo, Lauren A.
;
Smith, Mica C.
;
Boering, Kristie A.
;
Lin, Jim Jr-Min
;
應用化學系
The UV absorption spectrum of the simplest Criegee intermediate CH2OO
(2014)
Ting, Wei-Lun
;
Chen, Ying-Hsuan
;
Chao, Wen
;
Smith, Mica C.
;
Lin, Jim Jr-Min
SO2 scavenging and self-reaction of CH2OO were utilized for the decay of CH2OO to extract the absorption spectrum of CH2OO under bulk conditions. Absolute absorption cross sections of CH2OO at 308.4 and 351.8 nm were obtained from laser-depletion measurements in a jet-cooled molecular beam. The peak cross section is (1.23 +/- 0.18) x 10(-17) cm(2) at 340 nm.
UV absorption spectrum of the C2 Criegee intermediate CH3CHOO
(2014-08-21)
Smith, Mica C.
;
Ting, Wei-Lun
;
Chang, Chun-Hung
;
Takahashi, Kaito
;
Boering, Kristie A.
The UV spectrum of CH3CHOO was measured by transient absorption in a flow cell at 295 K. The absolute absorption cross sections of CH3CHOO were measured by laser depletion in a molecular beam to be (1.06 +/- 0.09) x 10(-17) cm(2) molecule-1 at 308 nm and (9.7 +/- 0.6) x 10(-18) cm(2) molecule-1 at 352 nm. After scaling the UV spectrum of CH3CHOO to the absolute cross section at 308 nm, the peak UV cross section is (1.27 +/- 0.11) x 10(-)1(7) cm(2) molecule-1 at 328 nm. Compared to the simplest Criegee intermediate CH2OO, the UV absorption band of CH3CHOO is similar in intensity but blue shifted by 14 nm, resulting in a 20% slower photolysis rate estimated for CH3CHOO in the atmosphere. (C) 2014 AIP Publishing LLC.