Air Force Research Laboratory VUV FLUORESCENCE OF JETCOOLED
Air Force Research Laboratory VUV FLUORESCENCE OF JETCOOLED WATER AS A VEHICLE FOR SATELLITE THRUSTER PLUME CHARACTERIZATION. June 2016 Justin W. Young Ryan S. Booth Kristen M. Lemke Christopher J. Annesley Jaime A. Stearns Space Vehicles Directorate Air Force Research Lab Kirtland AFB, NM Integrity Service Excellence 1
Chemistry in Space: Emerging Satellite Applications ~36, 000 km 2
Dissociation of Water H 2 O+hν→ OH(A) Water & OH Potential Energy Surfaces Water Absorption Spectrum Fillion, et al. , J. Phys Chem. A. , 105, 11414 (2001). Harich et al. J. Chem. Phys 2000, 113, 10073 3
Chemistry in Space: Emerging Satellite Applications • STS-63 (Discovery) rendezvous with Mir in 1995 • 390 km orbit • spectra of PRCS burn N 2 O 4 + CH 3 NHNH 2 N 2, H 2 O, CO 2, H 2, OH, NO, H OH + 310 nm OH(A, low N) H 2 O + 121. 6 nm OH(A, high v, N) H 2 O + 103 nm OH(A, very high v, N) Bernstein et al. J. Phys. Chem. A 2003, 107, 10695. 4
Experimental Setup ) 5
H 2 O+hν→ OH(A) Emission Spectrum of OH(A) → OH(X) 0’- 0” 1’- 1” 1’- 0” 6
Cooling Vs Lower Excitation Energy Change Excitation λ Change Temp. nm 7
Possible Explanation Harich et al. J. Chem. Phys 2000, 113, 10073 8
Analysis Methods 3 2 1 OH(A) Assume OH(X) Divide the spectrum into sections Ia Ib… exp Lvl 2 sim Solve a system of equations for all Ni ν … 9
Simulation Results 10
Simulation Results 11
Simulation Results 12
Lowering Excitation Energy OH(A), v=0, N 127. 1 nm 128. 3 nm Change Excitation λ 13
Cooling the Sample OH(A), v=0, N Change Temp. 22 C 127. 1 nm Jet 127. 1 nm 14
Conclusions • For the dissociation of water form the H 2 O(B) state to OH(A) temperature information is preserved. • Rotational analysis is possible even with modest resolution. Fillion, et al. , J. Phys Chem. A. , 105, 11414 (2001). 15
Acknowledgements Dr. Justin Dr. Ryan Dr. Kristen Dr. Chris Dr. Jaime Young Booth Lemke Annesley Stearns (BC) Alumni • Dr. Russell Cooper • Dr. Alex Zolot Collaborators • Dr. Jerry Boatz (AFRL) • Dr. Steven Chambreau (AFRL) • Dr. Thomas Peng (AFRL) • Prof. Joe Subotnik (Penn) • Prof. Terefe Habteyes (UNM) • Dr. Rainer Dressler (SSI) Acknowledgements • AFOSR Molecular Dynamics • National Research Council • Boston College Institute for Scientific Research • Space Scholars Program • DOD High Performance Computing Modernization Program 16
Analysis Methods 3 2 1 a b c ν Assume Divide the spectrum into sections Solve a system of equations Zanganeh et al. J. Chem. Phys. , 2000, 112, p 5660 17
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