William Jackson

Laser chemistry, laser photochemistry, and cometary astrochemistry. The main goal of this research is to unravel the key photochemical sinks of important molecules in planetary atmospheres, in our and other solar systems, around stars, and the interstellar medium. This kind of information will allow us to trace the detailed molecular history of our universe. The principle molecules we are studying are N2, CO and CO2. We measure the branching ratio for the production of different states of the product atoms. For example, the N2 molecule can dissociate into N(4S), N(2D) and N(2P) atoms, and the CO molecule can dissociate into C(1S), C(1D), C(3P), O(1S), O(1D), and O(3P) atoms. By determining the branching ratios in all of the available products we can explore excited potential energy surfaces of the respective molecules.

Education, Awards and Professional Highlights

• 2021 Julius Edgar Lilienfeld Prize Recipient
• Astronomical Society of the Pacific, Arthur B.C. Walker II Award, 2019
• Distinguished Emeritus Award, UC Davis (2015)
• Visiting Professor, University of Paris-Est Créteil/LISA (May-June 2013)
• Visiting Humboldt Professor, Technical University Munich (April-May 2013)
• Emile A. Dickenson Professor, UC Davis (2013)
• Bennie Trailblazer Award, Morehouse College (2011)
• Distinguished Research and Emeritus Professor (2006-present)
• Visiting Committee, Jet Propulsion Laboratory (2004-2007)
• Sigma Xi Distinguished Lecturer (2003-2005)
• American Association for the Advancement of Science Fellow (2004)
• ACS Fellow (2010)
• Chair, Department of Chemistry, UC Davis (2000-2006)
• Distinguished Professor, UC Davis (1998-2006)
• American Association for the Advancement of Science Lifetime Mentor Award (1997)
• Alexander von Humboldt Foundation, Humboldt Research Award for Senior US Scientist (1996)
• Planetary Society named asteroid 4322 Billjackson=1081 EE37 (1996)
• American Physical Society Fellow (1995)
• Guggenheim Fellow (1989)
• Miller Professor, University of California (1988)
• German Academic Exchange Service Study Fellowship, Astrophysics Institute at the University of Erlangen, Germany (1981)
• Appointed to UC Davis faculty as Professor (1985)
• Appointed to faculty, Howard University (1974-1985)
• Visiting Associate Professor, University of Pittsburgh (1969-1970)
• Staff Chemist; Staff Scientist, Goodard Space Flight Center, NASA (1964-1969; 1969-1974)
• National Research Council Postdoctoral Research Associate, National Bureau of Standards, National Academy of Sciences, Washington, D.C. (1963-1964)
• Research Scientist, Martin-Marietta Company, Maryland (1961-1963)
• Ph.D. Catholic University of America (1961)
• B.S. Morehouse College (1956)

Representative Publications

• 176. Communication: Vacuum ultraviolet laser photodissociation studies of small molecules by the vacuum ultraviolet laser photoionization time-sliced velocity mapped ion imaging method, Yang Pan, Hong Gao, Lei Yang, Jingang Zhou, C. Y. Ng, and William M. Jackson, J. Chem. Phys. 135, 071101 (2011). Top 20 most read JCP articles in August 2011.
• 177. Time-sliced velocity-mapped imaging studies of the predissociation of single ro-vibronic energy levels of N2 in the extreme ultraviolet region using vacuum ultraviolet photoionization, Hong Gao, Lei Yang, Yang Pan, Jingang Zhou, C. Y. Ng, and William M. Jackson, J. Chem. Phys., 135, 134319 (2011).
• 178. Communication: Branching ratio measurements in the predissociation of 12C16O by time-slice velocity-map ion imaging in the vacuum ultraviolet region, Hong Gao, Yu Song, Lei Yang, Xiaoyu Shi, Qingzhu Yin, C. Y. Ng, and William M. Jackson, J. Chem. Phys., 135, 221101 (2011).
• 179. Time-slice velocity-map ion imaging studies of the photodissociation of NO in the vacuum ultraviolet region, Hong Gao, Yang Pan, Lei Yang, Jingang Zhou, C. Y. Ng, and William M. Jackson, J. Chem. Phys., 136, 134302 (2012). This paper has been selected for the May 2012 issue of Virtual Journal of Ultrafast Science.
• 180. Combining two VUV lasers with the time-sliced velocity mapped imaging method for studying photodissociation of small molecules, Yu Song, Hong Gao, C. Y. Ng and William M. Jackson, European Conference on Laboratory Astrophysics - ECLAC. Stehl´e, C. Joblin and L. d’Hendecourt (eds) EAS Publications Series, 58, 295–299 (2012).
• 181. Branching ratio measurements of the predissociation of 12C16O by time-slice velocity map ion imaging in the energy region from 108,000 to 110,500 cm-1, Hong Gao, Yu Song, Lei Yang, Xiaoyu Shi, Qing-Zhu Yin, C. Y. Ng, and William M. Jackson, J. Chem. Phys., 137, 034305 (2012).
• 182. Branching ratio measurements of the photodissociation of 12C16O by time-slice velocity map imaging photoion method in the vacuum ultraviolet region from 102,500 to 106,300 cm-1, Hong Gao, Yu Song, Yih-Chung Chang, Xiaoyu Shi, Qing-Zhu Yin, Roger C. Wiens, William M. Jackson, and C. Y. Ng, J. Phys. Chem. A, (invited), Article, 117, 6185 (2013).
• 183. State-to-state photodissociation study 12C16O by the VUV-VUV pump-probe Time Slice Velocity-Map Imaging Photoion Method, Hong Gao, Yu Song, William M. Jackson, and C. Y. Ng, , Communication, J. Chem. Phys., 138, 191102 (2013).
• 184. Communication: Direct measurements of nascent O(3P0,1,2) fine structure distributions and branching ratios of correlated spin-orbit resolved product channels CO(ã 3P; v) + O(3P0,1,2) and CO( X 1Σ+u ; v) + O(3P0,1,2) in VUV photodissociation of CO2, Zhou Lu, Yih Chung Chang, Hong Gao, Yanice Benitez, Yu Song, C. Y. Ng, and W. M. Jackson, The Journal of Chemical Physics 140, 231101 (2014); doi: 10.1063/1.4883515.
• 185. Photodissociation of CO2 between 13.540 eV and 13.678 eV, Yu Song, Hong Gao, Yih Chung Chang, Zhou Lu, C. Y. Ng and William M. Jackson, Phys. Chem. Chem. Phys. 16, 563 (2014).
• 186. Evidence for direct molecular oxygen production in CO2 photodissociation, Z. Lu, Y. C. Chang, Q. Z. Yin, C. Y. Ng and W. M. Jackson, Science 346, 61 (2014).
• 187. State-to-state vacuum ultraviolet photodissociation study of CO2 on the formation of state-correlated CO(X1S+;v') with O(1D) and O(1S) photoproducts at 11.95-12.22 eV, Zhou Lu, Y.  C. Chang, Yanice Benitez, Z. Luo,  Adel Ben Houria, Tarek Ayari, Muneerah Mogren Al Mogren, Madji Hochlaf, Cheuk Y. Ng, and W. M. Jackson, Phys. Chem. Chem. Phys. 17, 11752 (2015).
• 188. Quantum-State-Dependence of Product Branching Ratios in Vacuum Ultraviolet Photodissociation of N2, Yu Song, Hong Gao, Yih Chung Chang, D. Hammoutène, H. Ndome, M. Hochlaf, William M. Jackson, and C. Y. Ng, Ap. J., 819:23 (13pp), 2016.
• 189. Branching Ratios in Vacuum Ultraviolet Photodissociation of CO and N2 :Implications for Oxygen and Nitrogen Isotopic Compositions of the Solar Nebula, Xiaoyu Shi, Qing-Zhu Yin, Hong Gao, Yih-Chung Chang, William M. Jackson, Roger C. Wiens, and Cheuk-Yiu Ng, Ap. J., 850:48 (12 pp), 2017 Nov. 20.
• 190 Erratum: “Quantum-state Dependence of Product Branching Ratios in Vacuum Ultraviolet Photodissociation of N2, Yu Song, Hong Gao, Yih Chung Chang, D. Hammoutène, H.Ndome, M. Hochlaf, William M. Jackson, and C. Y. Ng, (2016), ApJ, 819, 23), Ap. J.,854:185 (1 p). 2018 Feb. 20.
• 191. Branching Ratio Measurements of the Predissociation of 12 C 16 O by Time-Slice Velocity-Map Ion Imaging in the Energy Region from 106 250 to 107 800 cm –1 Xiaoyu Shi, Hong Gao, Qing-Zhu Yin, Yih-Chung Chang, Roger C. Wiens, William M. Jackson, and Cheuk-Yiu Ng, The Journal of Physical Chemistry A 2018 122 (41), 8136- 8142, DOI: 10.1021/acs.jpca.8b08058
• 192. Branching Ratios of the N( 2 D 0 3/2 ) and N( 2 D 0 5/2 ) Spin-Orbit States Produced in the State-Selected Photodissociation of N 2 Determined Using Time-Sliced Velocity Mapped-Imaging Photoionization Mass Spectrometry (TSVMI-PI-MS). Y. C. Chang, K. Liu, K. S. Kalogerakis, C.-Y. Ng and W. M. Jackson, J. Phys. Chem. A, 2019, 123, (12), 2289-2300, DOI:10.1021/acs.jpca.8b11691.
• 193. Ab Initio Study of Ground-State CS Photodissociation via highly excited electronic states, Zhongxing Xu, Nan Luo, S. R. Feldman, William M. Jackson, Cheuk-Yiu Ng, Lee Ping Wang and Kyle N. Crabtree, Ap. J, 882:86 (18pp), 2019.
• 194. Photodissociation Branching Rations of 13C16O in the Vacuum Ultraviolet Region from 102,745 to 106,340 cm-1. Xiaoping Chi, Pan Jiang, Qihe Zhu, William M. Jackson, Min Cheng, and Hong Gao, Ap. J, (12pp), 2020.
• 195. Photodissociation Branching Ratios of 12C16O from 108000 cm-1 to 113200 cm-1 Measured by Two-Color VUV-VUV Laser Pump-Probe
  Time-Slice Velocity-Map Ion Imaging Method: Observation of Channels for Producing O (1D), Hong Gao, Yu Song, William M. Jackson, and Cheuk-Yiu Ng, Chin. J. Chem. Phys., 33, 91 (10 pp) 2020.