UNCLASSIFIED EhhmomhohioEI

1 AD-A138 250 SPECTROSCOPY AND KINETICS of lead OXIDE I/CHEMILUMINESCENCE(U) AIR FORCE INST OF TECHWRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERINGUNCLASSIFIED C M RITCHEY 12 DEC 83 AFIT/GEP/PH/B3D-IO F/G 7/2 NLEhhmomhohioEIEhhhmmhmmhmhhumEshhhohhoh EEEEImlEllllllllEEIIIEIIIIEEIIEILA' MAOMICROCOPY RESOLUTION TEST CHARTNA lltjNAL Yf'URIAL, ()I SIANDARDfl 1 A00 DICE-~u~ -~ -ELECTEDWubW=U8~W FEB20 OPARIIOF 1141 AIR FORCE BAN UWWIRUT 4 ATC)AI f-ORC INSTSTUT Air Fete* *eS.,Ohio1402 4 AFIT/GEP/PH/83D-1 OSPECTROSCOPY AND KINETICSOF LEAD OXIDE CHEMILUMINESCENCETHESISC onrad M. RitcheyCaptain, for Public Release; Distribution UnlimitedAFIT/GEP/PH/83D-10 SPECTROSCOPY AND KINETICSOF LEAD OXIDE CHEMILUMINESCENCETHESISP resented to the Faculty of the School of Engineeringof the Air Force Institute of TechnologyAir Universityin Partial Fulfillment of theRequirements for the Degree ofMaster of ScienceConrad M.

2 Ritchey, , USAFI )\December 1983 Approved for Public Release; Distribution UnlimitedPrefaceThis thesis is part of an on-going project by AFITand Air Force Weapons Laboratory researchers to identifypossible candidates for chemical lasers. I found thisproject to be both challenging and rewarding, and I amproud of my contribution to am especially grateful to Dr. E. A. Dorko for themany stimulating conversations and for his invaluableassistance in the preparation of this manuscript. Iwould like to thank Mr. Carl Shortt, Mr. David Paine,and Mr. John Brohas of the AFIT Fabrication Shop fortheir expertise and responsiveness in making flow tubemodifications and on-the-spot repairs.

3 I am deeplyindebted to Mr. Robert Wade for his excellent crafts-manship in producing the Pyrex manifold. Finally, Iwish to thank my loving wife, Nancy, for her patienceand understanding throughout this M. Ritchey(This thesis typed by Sharon A. Gabriel)iiTable of ContentsP agePreface------------------------------ --------------------- iiList of Figures--------------------------------- ---------- vList of Tables---------------------------------- --------- viiAbstract----------------------------- -------------------- ViiiI. Introduction---------------------------- ------------ 1 Background------------------------------ ------ 1 Problem--------------------------------- ------ 1 Approach-------------------------------- -------- 2Ii.

4 Theory---------------------------------- ----------- 3 Overview of PbO Spectroscopy------------------ 3 Singlet, Delta Oxygen--------------------------- 10 Kinetics-------------------------------- ------- 12 Literature Review------------------------------- 15 III. Experimental Equipment and Operational Procedures 22 Flow Tube System------------------------------- 22 Vacuum---------------------------------- ----- 22 Flow Tube------------------------------------ 24optical------------------------------- ------ 28 Detection and Recording---------------------- 29 Experimental Procedures ---------------------- 30 Alignment------------------------------- ------ 31 Calibration----------------------------- ----- 32 Signal-to-Noise Ratio------------------------ 33 Resolution------------------------------ ----- 35 Spectra--------------------------------- ------ 35 Temperature Experiments

5 -------------------- 35IV. Results and Analysis------------------------------- 37 System Modifications--------------------------- 37 Zirconia Felt Insulation--------------------- 37 Flame Optimization-------------------------- 37 Vacuum Transition Section ----------------------39 Spectra--------------------------------- --------410 Kinetics-------------------------------- ------- 69 Presence of Excited Pb----------------------- 69Pb + 0 2( 3 ) Reaction Mechanisms ----------- -78Pb + 0 2( 1 A) Reaction------------------------- 83 Table of Contents (Cont'd)PageV. Conclusions and Recommendations--------------------- 85 Conclusions----------------------------- -------- 85 Recommendations----------- ------------------- 87 New Grating--------------------------------- - 37 New Manifold-------------------------------- --327 Photon Counter------------------------------- 87 Modulated Spectra----------------------------398 Flame Measurements---------------------------3 88Pb Concentrations-------------------------- -- 88 Activation Energies-------------------------- 88 Bibliography---------------------------- ---------------- 89 Appendix A.

6 Photograph------------------------------ ---- 92 Appendix B: Power Supply ------------------------------- 95 Appendix C: Grating Response---------------------------- 96 Appendix D: Photomultiplier Tubes----------------------- 97 Appendix E: Start-up and Shut-down Steps--------------- 99 Appendix F: Pressure Variation Spectra -----------------101 Appendix G: Temperature Measurements withHeater Off -0 2( 3E)----------------------- 110 Vita------------------------------------ ------------------ IllAcce~siofl ForNTIS GRA&1bc DTIC TAB [UnannounC~dDistribution/Availa~bility CodesAvail and/orDist ISpecialiv5 List of FiguresFigure Page1 Vertical Transitions----------------------------- --- 72 Overlapping Eigenfunctions----------------------- 73 PbO, Correlation Diagram----------------------------- 94 Energy Levels of 0 2# Pb.]

7 And PbO ----------------- 135 Reaction Process--------------------------------- --- 156 Flow Tube System---------------------------------- -- 237 Vacuum Transition Sections------------------------- 258 Pyrex Oxidizer Manifold -------------------------- 279 Low Pass Filter---------------------------------- --- 3110 PMT Signal-to-Noise Ratios------------------------- 3411 Low Resolution Spectrum---------------------------- 4112 Medium Resolution Spectrum------------------------- 4213 High Resolution Spectrum--------------------------- 4314 Deslandres Table for the a -X Transitionof the Pb + 0 ( 3 ) Reaction------------------------ 5915 Deslandres Table for the A -X Transition1of the Pb + 02( A) Reaction------------------------ 6016 Deslandres Table for the B -X Transitionof the Pb + 02(1 A) Reaction------------------------ 6117 Spectrum from 3000 A to 4000 A forthe Pb + 02 (1 A) Reaction--------------------------- 6218 Deslandres Table of Intensities for thea -X Transition of the Pb + 0 2( 3 ) Reaction------ 6419 Deslandres Table of Intensities for theA -X Transition of the Pb + 0 2( 1A)---------------- 649vAllList of Figures (Cont'd)

8 Figure Page20 Deslandres Table of Intensities for theB -X Transition of the Pb + 0 2( 1A) Reaction------ 6521 Low Dispersion Spectrum from thePb + 0 2(3 E) Reaction------------------------------- 6622 Low Dispersion Spectrum from thePb + 0( A) Reaction------------------------------- 6723 Intensity and Temperature DecayVersus Time for Pb +0 2(3E Reaction--------------- 7224 Logarithmic Intensity Decay VersusTime for Pb + 0O2( 3 ) Reaction---------------------- 7225 Excited State Energies and ReactionExothermicities----------------- ------------------- 81A-i Flow Tube System---------------------------------- - 92A-2 Furnace Chamber--------------------------------- --- 92A-3 Oxidizer Manifolds------------------------------- -- 93A-4 Discharge Cavity Assembly-------------------------- 93A-5 Chemiluminescent Flame----------------------------- 94B-i Power Supply---------------------------------- ------ 95B-2 Power Supply Schematic----------------------------- 95D-1 PMT Characteristics------------------------- ------- 97D-2 PMT)

9 Response-------------------------------- -------- 97D-3 New PMT and Housing-------------------------------- 98viList of TablesTable PageI Electronic State Energies------------------------- 4II Lifetimes of Excited States of PbO -----------------16 III Observed PbO Bandheads and Their Assignmentsfor the Pb + 0 2 Z Reaction ----------- 4IV Observed PbO Bandheads and Their Assignmentsfor the Pb + 02 (1 A) Reaction----------------------- 48V Intensity Ratios for the a -XA -X and B -X Transitions------------------------ 68VI Energy Levels of Pb-------------------------------- 74 VII Transition Probabilities BetweenExcited States of Pb------------------------------- 75 VIII Heats of Formation------------------------------- --- 79Ix Reaction Exothermicities of Pb( 3Pn ) + 0 Z )where n = 0,1,2----------------------------------- 79X Activation Energies-------------------------------- 80viiAFIT/GEP/PH/83D-10 Abstract-Chemiluminescence from lead oxide has been o servedfrom the reaction between lead (Pb) vapor and Ol(,i).

10 Thespectrum obtained from this emission has been compared tothat obtained from the chemiluminescence observed duringthe reaction between Pb and ground state 2 A signi-ficant enhancement of the A and B states over the a statewas noted. Spectral analysis has led to the assignmentof 225 transitions from the a, b, A, B, C, C', D and Eexcited states to the ground state. A simple kineticanalysis was performed for the two reactions in which aplot of the logarithm of the intensity of a spectral bandvs l/Ti was prepared. From the slope of the straightlines produced, the activation energies of the two reactionswere calculated The activation energy for the Pb + 02(I;)reaction was fond to be about 21 Kcal/mole with a stronginverse dependency on oven temperature.