Contents Acknowledgement …...………………………………………………………..…Ⅰ Abstract ………………...………………………………………………………..…Ⅲ Contents ………………...……………………………………………………..…Ⅴ Table Captions ………………...……………………………………………….…Ⅸ Figure Captions………………...……………………………………………....…Ⅹ 1. Introduction ………………………………………………………………..…...1 Reference ……………………………………………..............................................5 2. Experiment .……………………………………………………………….........7 2-1. Apparatus of crossed beams …………………………………….……...............7 2-2. Experimental conditions ……...…………………………................................13 2-2-1. Atomic and molecular beams…………………………………….............13 2-2-2. Lasers ……………………………………………………………............17 2-2-3. Time-sliced velocity map ion imaging system…..……………………......18 Reference ……………………………………………..............................................22 3. Photodissociation of I2 and I2+ and velocity calibration …………..23 3-1. Photodissociation of I2 at 532nm ……………………………………………23 3-2. Photodissociation of I2+ at 532nm ……………………………………..........26 3-3. Dissociation energies of I2 and I2+ …………………………………………..33 3-4. The effective ionization region of velocity map ion imaging apparatus ……..35 Reference ……………………………………………..............................................38 4. Generation of highly vibrationally excited azulene molecular beam……………………………………………………………………………39 4-1. Some methods to generate excited molecules ………………………………39 4-2. Characterization of highly vibrationally excited molecular beam …………..42 Reference ……………………………………………..............................................50 5. Results and analysis of collisions between highly vibrationally excited azulene and rare gases ……..….………………........................52 5-1. Sensitivity and data analysis…………..………………………………………52 5-1-1. Outlines ………………………………….……………………………….52 5-1-2. The concentrations of hot and cold azulene in molecular beam ………....54 5-1-3. The summation and subtraction of images ……………………………....56 5-1-4. Calculation of sensitivities combined with concentrations ….……….......58 5-1-5. Calculating the image of hot scattering azulene……..…….………….......62 5-1-6. Calculation of Intensities v.s. ΔE ………………………….………….......64 5-2. Collisions of Azulene and Kr …………………………………………………65 5-2-1. Collision Energy = 170 cm-1 ………………………………………...........65 5-2-2. Collision Energy = 410 cm-1 ………………………………………...........68 5-2-3. Collision Energy = 780 cm-1 ………………………………………...........71 5-2-4. Energy transfer probability density functions after deconvolution ….............74 5-2-5. Comparison with theoretical calculations ……..……………………...........75 5-2-6. Discussion …………………………………………………………...........78 5-3. Collision of Azulene and Ar …………………………………........................81 5-3-1. Collision Energy = 200 cm-1 ………………………………………...........81 5-3-2. Collision Energy = 492 cm-1 ………………………………………...........83 5-3-3. Collision Energy = 747cm-1 ………………………………………............86 5-3-4. Collision Energy = 983 cm-1 ………………………………………...........89 5-3-5. Discussion …………………………………………………………...........93 Reference ……………………………..……………................................................96 Appendix of Chapter 5……………………………..................................................97 A5-1. Calculation of Sensitivity …….………………………………..…….........97 A 5-2. The content of program, “sensitivity” ……..………………………........104 A5-3. The content of program, “summation_2”…………….…….....................107 A5-4. The content of program, “subtraction_1to1” …….…………..…….........108 A5-5. The details of calculating the image of hot scattering azulene ……….....109 A5-6. The content of program, “Real_Hot_scattering_Liu”…………….……...110 A5-7. The details of calculating intensities v.s. ΔE ………………………….....112 A5-8. The content of program, “all_angles”…………………………….……...116 6. Results and analysis of collisions between highly vibrationally excited naphthalene and rare gases …...….……………....................118 6-1. Experiment….….…………………….………………………………………118 6-2. Sensitivity and data analysis…………………………………………………125 6-2-1. Outlines ……………………………………………………………….125 6-2-2. The concentration of hot naphthalene in molecular beam ...………...…126 6-2-3. The summation and subtraction of images ………………...…………....127 6-2-4. Calculation of sensitivities combined with concentrations….………….128 6-2-5. Calculating the image of hot scattering naphthalene …….....…………...129 6-2-6. Calculation of intensities v.s. ΔE ……………………….......……..…….130 6-3. Collisions of Naph. and Kr with 266 nm excitation laser ………………...…131 6-3-1. Images and sensitivity…..…………………………………………...........131 6-3-2. Analysis…………………………………………………...………...........135 6-3-3. Discussion ………………………………......……………………...........140 6-4. Collisions of Naph. and Kr with 248 nm excitation laser ………………..…144 6-4-1. Images and sensitivity……………………………………………...........144 6-4-2. Analysis…………………………………………………...………...........147 6-4-3. Discussion ………………………………………………..………...........151 6-5. Collisions of hot vibrational/rotational Naph. and Kr ...…...……………..…157 6-5-1. Rotational temperature and velocity distribution…………………...……157 6-5-2. Images and sensitivity..………………………………………..…….........159 6-5-3. Analysis…………………………………………………………….......160 6-5-4. Discussion ………………………………………………………….........163 6-6. Collisions of highly vibrationally naphthalene-d8 and Kr ………………..…173 6-6-1. Images and sensitivity……………………………………………...........173 6-6-2. Analysis…………………………………………………...………...........176 6-6-3. Discussion ………………………………………………..………...........180 6-7. Collisions of highly vibrationally excited naphthalene and Xe …...……...…184 6-7-1. Images and sensitivity……………………………………………...........184 6-7-2. Analysis…………………………………………………...………...........186 6-7-3. Discussion ………………………………………………..………...........189 Reference ……………………………………………............................................197 Appendix of Chapter 6……..………………………..............................................200 A6-1. Calculation of Sensitivity …….…………………………………….........200 A6-2. The content of program, “sensitivity” ……..……………………….........206 A6-3. The content of program, “Real_Hot_scattering” …………….…….........209 7. Conclusion …...…..……………………………………...................................210 Table Captions Table 2-1 The corresponding experimental conditions in the collision of azulene and rare gases with 266 nm excitation laser..………………….……………….……….14 Table 2-2 The corresponding experimental conditions in the collision of naphthalene and rare gases with 266 nm/248 nm excitation laser……………........………...15~16 Table 3-1 The assignment of different rings in Fig. 3-4 and peaks in Fig. 3-5 and 3-7.………………………………………………………...………………………….31 Table 5-1 The possible ion sources form azulene molecular beam with and without collision and 266 nm laser beam…………...………………………………..……….53 Table 5-2 An example of the distribution of azulene absorbing zero, one or multi-photons in molecular beam…...………………………...……………..……….55 Table 6-1 The possible ion sources form naphthalene molecular beam excited by 266 nm (or 248 nm) laser beam with and without collision…..…………………………125 Table 6-2 An example of the distribution of hot naphthalene in molecular beam.…127 Table 6-3 Velocity uncertainties and speed ratios of naphthalene molecular beam with 266 nm excitation laser, average energy transfer of Naph*-Kr complex and average energy transfer at various collision energies.………………………………….……134 Table 6-4 Velocity uncertainties and speed ratios of naphthalene molecular beam with 248 nm excitation laser.……………………………………..………………………144 Table 6-5 Velocity uncertainties and speed ratios of rotationally hot naphthalene molecular beam.…………………………………………………………….………158 Table 6-6 Velocity uncertainties and speed ratios of naphthalen-d8 molecular beam.………………………………………………………………………………173 Table 6-7 Spectral regions associated with different type of vibrations of naphthalene-d8 and naphthalen-h8…………………………………………………180 Table 6-8 Velocity uncertainties and speed ratios of naphthalene molecular beam in Naph-Xe experiments.………………………………………………………………186 Table 6-9 Relative gas sensitivities of Bayard-Alpert ionization gauge……………193 Figure Captions Figure 2-1 The side view of the entire crossed-beam apparatus………………………7 Figure 2-2 The top view of the entire crossed-beam apparatus...……………………..8 Figure 2-3 The schematic diagram of 25 degree collision angle. Nozzle 1 and nozzle 2 contain azulene/rare gas mixture and rare gas, respectively...…….………………..…9 Figure 2-4 The schematic diagram of 60 degree collision angle. Nozzle 1 and nozzle 2 contain compound (azulene or naphthalene)/rare gas mixture and rare gas, respectively..…………………………………………….……………………………11 Figure 2-5 The schematic diagram of 25 degree crossing geometry apparatus in the experiment of naphthalene. Nozzle 1 and nozzle 2 contain naphthalene/rare gas mixture and rare gas, respectively.…………………….……..………………………12 Figure 2-6 The equipments of ion optics….………………………………....………19 Figure 2-7 The schematic diagram of detector’s components coupling with the voltages of MCP and phosphor…………………...………………………………….20 Figure 2-8 The schematic diagram of delay times and gated durations of nozzle, excitation laser, ionization laser, Front MCP, and intensifier. Time is in unit of μs……………………………………….…………………………………………….21 Figure 3-1 Schematic diagram of experimental apparatus……………………...……24 Figure 3-2 The time-sliced ion images of different arrival times of I atoms from I2 dissociation at 532nm.……………..……….……....……………...…………………24 Figure 3-3 Image intensity profile of I atom from I2 dissociation at 532nm…...……25 Figure 3-4 Time-sliced I+ ion images. 118.24 nm laser pulse was 3-5 ns before 532.10 nm laser pulse..………………………………………………………………..……27 Figure 3-5 Partial angle integrated (from 65o to 115o and from 245o to 295o relative to the molecular beam direction) I + ion intensity as a function of radius from Fig. 3-4.……………………………………………………………………………………27 Figure 3-6 The electronic energy curves of I2+……...…………….…………………28 Figure 3-7 Partial angle integrated (from 65o to 115o and from 245o to 295o relative to the molecular beam direction) I + ion intensity as a function of energy from Fig. 3-4.…………………………………………..………………….…………….………30 Figure 3-8 The schematic diagram of I2 dissociated at different position.…….……..35 Figure 3-9 Images at delay times of 0.2 μs (blue) and 10 μs (orange). (a) The voltages (MV = +1015 V) of ion optics were set for the best energy resolution at the delay time of 0.2 μs. (b) The voltages (MV = +1002 V) of ion optics were set for the best energy resolution at both delay times……………...…………………………………………36 Figure 3-10 Image intensity profiles at delay times of 0.2μs (red) and others. (a) The voltages (MV = 1015V) of ion optics were set for the best energy resolution at the delay time of 0.2μs. (b) The voltages (MV = 1002V) of ion optics were set for the best energy resolution for the largest ionization region……….………………..……37 Figure 4-1 UV excitation method to generate highly vibrationally excited molecules……….…………………………………………………….………………40 Figure 4-2 The schematic picture of the apparatus which is used to measure the amount of zero, one, and multi-photon absorption of azulene. There are 29 electrodes to construct the ion optics.….……………………………………….……………..…46 Figure 4-3 Ion (m/e=128) intensity as a function of 266 nm laser fluence…………46 Figure 5-1 An example of the figure of intensities of 0, 1, and multi-photon absorption along the molecular beam were drawn…………………….…………..…56 Figure 5-2 The only one parameter (in the 14th line) need to change is the ratio of background.………………………………………………………………………..…57 Figure 5-3 The relative positions of azulene molecular beam, Kr atom beam, scattered azulene, 157 nm laser ionization region, and 266 nm laser beam.………………...…59 Figure 5-4 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 170 cm−1..……………………………………...….……………..…61 Figure 5-5 Images and Newton diagrams for collision energy 170 cm−1 of Az-Kr collision.…………………………………………………………….……………..…65 Figure 5-6 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 170 cm−1 of Az-Kr collision.…………………………………………………..……………..…66 Figure 5-7 Angular dependence of T-V/R and V/T cross-sections at Ecol = 170 cm-1 of Az-Kr collision.…………………………………….....…………….……………..…67 Figure 5-8 Images and Newton diagrams for collision energy 410 cm−1 of Az-Kr collision.…………………………………………………………….……………..…68 Figure 5-9 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 410 cm−1..……………………………………….……………..…69 Figure 5-10 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 410 cm−1 of Az-Kr collision.………………………………………….……….……………..…70 Figure 5-11 Angular dependence of T-V/R and V/T cross-sections at Ecol = 410 cm-1 of Az-Kr collision..…………………………………………………….……………..…70 Figure 5-12 Images and Newton diagrams for collision energy 780 cm−1 of Az-Kr collision.……………………………………….…………………………………..…71 Figure 5-13 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 780 cm−1..………………………………………………...…..…72 Figure 5-14 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 780 cm−1 of Az-Kr collision.……………………………………….………….……………..…72 Figure 5-15 Angular dependence of T-V/R and V/T cross-sections at Ecol = 780 cm-1 of Az-Kr collision..…………………………………………………….……………..…73 Figure 5-16 The shapes of energy down ΔEd V-T probability density functions after deconvolution at various scattering angles.…………………………………………74 Figure 5-17 The shape of total energy-transfer probability density functions for energy down ΔEd V-T collisions. Collision energies.……………………………..…76 Figure 5-18 The shape of total energy-transfer probability density functions for energy up ΔEu T-VR collisions. Collision energies.……………….……………..…76 Figure 5-19, Figure 5-20 Experimental and computed down-collision P(E,E’) of Az-Kr for four potentials.………………………………………….……………..…77 Figure 5-21 Images and Newton diagrams for collision energy 200 cm−1 of Az-Ar collision.……………………………………….…………………………………..…81 Figure 5-22 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 200 cm−1 of Az-Ar collision.…………………………….…..…82 Figure 5-23 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 200 cm−1 of Az-Ar collision.…………………………………………….…….……………..…82 Figure 5-24 Angular dependence of T-V/R and V/T cross-sections at Ecol = 200 cm-1 of Az-Ar collision.………………………………………….………….……………..…83 Figure 5-25 Images and Newton diagrams for collision energy 492 cm−1 of Az-Ar collision.…………………………………………………………….……………..…84 Figure 5-26 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 492 cm−1 of Az-Ar collision..………………………………..…84 Figure 5-27 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 492 cm−1 of Az-Ar collision.………………………………………………….……………..…85 Figure 5-28 Angular dependence of T-V/R and V/T cross-sections at Ecol = 492 cm-1 of Az-Ar collision.……………………………………….…………….……………..…86 Figure 5-29 Images and Newton diagrams for collision energy 747 cm−1 of Az-Ar collision.…………………………………………………………….……………..…87 Figure 5-30 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 747 cm−1 of Az-Ar collision..………………………………..…87 Figure 5-31 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 747 cm−1 of Az-Ar collision.……………………………………….………….……………..…88 Figure 5-32 Angular dependence of T-V/R and V/T cross-sections at Ecol = 747 cm-1 of Az-Ar collision.……………………………………….…………………………..…89 Figure 5-33 Images and Newton diagrams for collision energy 983 cm−1 of Az-Ar collision.…………………………………………………………….……………..…90 Figure 5-34 Sensitivity matrices as a function of velocity (in center-of-mass frame) for collision energy 983 cm−1 of Az-Ar collision.………………………………...…90 Figure 5-35 (a) and (b) are the shapes of energy down ΔEd V-T and up ΔEu T-VR probability density functions at various scattering angles at collision energy 983 cm−1 of Az-Ar collision.………………………………………………….……………..…91 Figure 5-36 Angular dependence of T-V/R and V/T cross-sections at Ecol = 983 cm-1 of Az-Ar collision..…………………………………………………….……………..…92 Figure 5-37 Differential cross-sections for large energy transfer of Az-Ar collisions..………………………………………………………….……………..…93 Figure 6-1 Energy diagram of naphthalene and corresponding photon energy….…119 Figure 6-2 The intensities of naphthalene ions with and without 248 nm excitation laser.……….……………………………………………………….……………..…120 Figure 6-3 An example of molecular beam’s velocity distribution in an image.…...122 Figure 6-4 Sensitivity matrix as a function of velocity (in center-of-mass frame) for collision energy 439 cm−1.……………..………………………….……………..…129 Figure 6-5 Images and Newton diagrams of Naph.-Kr collision with 266 nm excitation laser. These images are the scattered hot naphthalene images Ih(vx,vy).…132 Figure 6-6 Sensitivity matrixes as a function of velocity for Naph-Kr collision with 266 nm laser.…………………………………………………….……………..…133 Figure 6-7 Angular resolved V□T(R) energy transfer probability density functions at various collision energies.………………………………...……….……………..…136 Figure 6-8 Angular resolved T□VR energy transfer probability density functions at various collision energies.………………………………………………………..…137 Figure 6-9 Angular dependence of T□VR and V□T(R) cross-sections at various collision energies. These results were obtained from the Naph-Kr collisions with 266 nm laser.………………………………………………………….……………..…139 Figure 6-10 Energy transfer probability density functions at various collision energies.………………………………………………………….……………..…140 Figure 6-11 Images and Newton diagrams of Naph.-Kr collision with 248 nm excitation laser. These images are the scattered hot naphthalene images Ih(vx,vy).…145 Figure 6-12 Sensitivity matrixes as a function of velocity for Naph-Kr collision with 248 nm laser.…………………………………………………….……………..…146 Figure 6-13 The shapes of energy down ΔEd V-T probability density functions at various scattering angles of Naph-Kr collision with 248 nm excitation laser.……..148 Figure 6-14 The shapes of energy up ΔEu T-V(R) probability density functions at various scattering angles of Naph-Kr collision with 248 nm excitation laser.…..…149 Figure 6-15 Angular dependence of T□VR and V□T(R) cross-sections at various collision energies. These results were obtained from the Naph-Kr collisions with 248 nm laser.……………………………………………..…………….……………..…150 Figure 6-16 Angular resolved V□T energy transfer probability density functions at various collision energies. Gray, orange, and light green lines represents near forward, side way, and backward scatterings with 266 nm excitation laser. Black, red, and dark green lines represents near forward s sideway, and backward scatterings with 248 nm excitation laser..……………………………………….………………………..…152 Figure 6-17 Angular resolved T□VR energy transfer probability density functions at various collision energies. Gray, orange, and light green lines represents near forward, sideway, and backward scatterings with 266 nm excitation laser. Black, red, and dark green lines represents near forward s side way, and backward scatterings with 248 nm excitation laser..………………………………………………….……………..…153 Figure 6-18 The relatively absolute differential collision cross-sections with different excitation lasers. The solid lines and dashed lines are the cross-sections with 266nm and 248nm excitation laser, respectively.…………………………..……………….156 Figure 6-19 (a) and (b) are the NO A-X 1+1 REMPI spectra with 2850 torr and 100 torr He, respectively. The rotational temperature is (a) lower than 10K, (b) about 350K………………………………………………………………………………157 Figure 6-20 Images and Newton diagrams of Naph.-Kr collision. Naphthalene is rotationally and vibrationally hot molecule. These images are the scattered hot naphthalene images Ih(vx,vy).……………………………………………………..…159 Figure 6-21 Sensitivity matrixes as a function of velocity for Hot-R-Naph-Kr collision……………………………………………………………………………160 Figure 6-22 The shapes of energy down ΔEd V-T(R) energy up ΔEu T-VR probability density functions at various scattering angles of Naph-Kr collision.……………….161 Figure 6-23 Angular dependence of T□VR and V□T(R) cross-sections at various collision energies. These results were obtained from the Hot-R-Naph-Kr collisions.……………………….………………………………….……………..…162 Figure 6-24 The average vibrational energies of naphthalene as a function of temperature.……………………….……………………………….……………..…165 Figure 6-25 The comparison of energy down collision of rotationally cold and hot naphthalene at collision energy of about 100 and 420 cm-1. The angular resolved T□VR energy transfer probability density functions at various scattering angles are shown here.……………………………………….……………………………..…166 Figure 6-26 The comparison of energy up collision of rotationally cold and hot naphthalene at collision energy of about 100 and 420 cm-1. The angular resolved V□T(R) energy transfer probability density functions at various scattering angles are shown here.……………………………………….……………………………..…168 Figure 6-27 The relative cross-sections of rotationally hot and cold naphthalene colliding with Kr. The solid lines and dashed lines are the relative cross-sections of rotationally hot and cold naphthalene, respectively. This results were obtained at collision energy ~450 cm-1.…………………….………………….……………..…170 Figure 6-28 Energy transfer distribution functions for rotationally cold and hot naphthalene at two different collision energies..……………………………………170 Figure 6-29 Image intensity profiles for initially rotationally hot (thin red line) and cold (thick blue line) naphthalene at collision energy (a) ~100 cm-1 (b) ~350 cm-1 (c) ~430 cm-1 (d) ~600 cm-1. The profiles were obtained at the radii around the maximum intensity of backward peak, corresponding to the formation of complex. Part of the intensity increase at □ = 180 represents the formation of complex.……………...…172 Figure 6-30 Images and Newton diagrams of Naph-d8-Kr collision with 266 nm laser. These images are the scattered hot naphthalene images Ih(vx,vy).………………..…174 Figure 6-31 Sensitivity matrixes as a function of velocity for Naph-d8-Kr collision with 266 nm laser.……………………………………….…………………...…..…175 Figure 6-32 The shapes of energy down ΔEd V-T probability density functions at various scattering angles of Naph-d8-Kr collision with 266 nm excitation laser...…177 Figure 6-33 The shapes of energy up ΔEd V-T probability density functions at various scattering angles of Naph-d8-Kr collision with 266 nm excitation laser.…………...178 Figure 6-34 Angular dependence of T□VR and V□T(R) cross-sections at various collision energies. These results were obtained from the Naph-d8-Kr collisions at 266nm laser.……………………………………….……………………………..…179 Figure 6-35 Angular resolved energy transfer probability density functions for naphthalene-h8 and naphthalene-d8 in collisions with Kr at two collision energies..181 Figure 6-36 The relative total cross-sections of naphthalen-h8 and naphthalen-d8 colliding with Kr.……………………………………….…………….…………..…183 Figure 6-37 Images and Newton diagrams of Naph-Xe collision with 266 nm laser. These images are the scattered hot naphthalene images Ih(vx,vy)…………………...184 Figure 6-38 Sensitivity matrixes as a function of velocity for Naph-Xe collision with 266 nm laser.……………………………………….…………………………..…185 Figure 6-39 The shapes of energy down ΔEd V-T(R), energy up ΔEu T-VR probability density functions at various scattering angles of Naph-Xe collision with 266 nm…187 Figure 6-40 Angular dependence of T□VR and V□T(R) cross-sections at various collision energies. These results were obtained from the Naph-Xe collisions at 266nm laser…………………………………………………………………………………188 Figure 6-41 Energy transfer probability density functions in collisions with Xe at various collision energies. Thin black line: 463 cm -1; gray line 891 cm-1; thick black line 1005 cm-1..…………………………………………………….……………..…191 Figure 6-42 The relatively absolute cross-sections of naphthalene colliding with Kr and Xe..…………………………………………………………………………..…195