Experiments with Supersonic Beams as a Source of Cold Atoms

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3.3.2.1 Initial Design . . . . . . . . . . . . . . . . . . . . . . . 34 3.3.2.2 Vibration and Balancing . . . . . . . . . . . . . . . . . 39 3.3.2.3 Improved Spindle Design . . . . . . . . . . . . . . . . . 42 3.3.3 Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.4 Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.4 Data and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3.4.1 Static Reflection . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3.4.2 Beam Slowing . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 3.4.3 Crystal Lifetime . . . . . . . . . . . . . . . . . . . . . . . . . . 52 3.5 Potential Applications . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Chapter 4. The Atomic and Molecular Coilgun: Using Pulsed Magnetic Fields to Slow Supersonic Beams 56 4.1 Atoms in External Magnetic Fields . . . . . . . . . . . . . . . . . . . 57 4.1.1 The Zeeman Effect . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.1.2 The Paschen-Back Effect . . . . . . . . . . . . . . . . . . . . . 61 4.1.3 Adiabatic Following and Spin Flips . . . . . . . . . . . . . . . . 62 4.2 Magnetic Fields from Electromagnetic Coils . . . . . . . . . . . . . . 63 4.2.1 Switching of Electromagnetic Coils . . . . . . . . . . . . . . . . 65 4.3 Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 66 4.3.1 Phase Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4.3.2 Electromagnetic Coils as a Waveguide . . . . . . . . . . . . . . 72 4.4 Proof-of-Principle Experiment: Slowing Metastable Neon . . . . . . . 74 4.4.1 Beam Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 4.4.2 18 Stage Coil Design . . . . . . . . . . . . . . . . . . . . . . . . 77 4.4.3 18 Stage Electronics and Coil Switching . . . . . . . . . . . . . 78 4.4.4 18 Stage Apparatus and Vacuum Chamber . . . . . . . . . . . 83 4.4.5 18 Stage Data and Results . . . . . . . . . . . . . . . . . . . . 87 4.5 The Atomic Coilgun: Stopping Metastable Neon . . . . . . . . . . . . 89 4.5.1 64 Stage Coil Design . . . . . . . . . . . . . . . . . . . . . . . . 90 4.5.2 64 Stage Electronics and Coil Switching . . . . . . . . . . . . . 94 4.5.3 64 Stage Apparatus and Vacuum Chamber . . . . . . . . . . . 100 4.5.4 64 Stage Data and Results . . . . . . . . . . . . . . . . . . . . 105 4.6 The Molecular Coilgun: Stopping Molecular Oxygen . . . . . . . . . . 109 4.6.1 Oxygen’s Magnetic Levels . . . . . . . . . . . . . . . . . . . . . 110 4.6.2 Oxygen Beam Creation and Detection . . . . . . . . . . . . . . 111 4.6.3 Oxygen Data and Results . . . . . . . . . . . . . . . . . . . . . 113 xii
Chapter 5. Towards Trapping and Cooling of Atomic Hydrogen Isotopes 116 5.1 Hydrogen Motivation and Structure . . . . . . . . . . . . . . . . . . . 117 5.2 The Hydrogen Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . 119 5.2.1 Slowing Coils and Electronics . . . . . . . . . . . . . . . . . . . 119 5.2.1.1 Slowing Coil Geometry . . . . . . . . . . . . . . . . . . 120 5.2.1.2 Slowing Coil Electronics and Switching . . . . . . . . . 121 5.2.2 Trapping Coils and Electronics . . . . . . . . . . . . . . . . . . 125 5.2.2.1 Principle of Operation of the Trap . . . . . . . . . . . 126 5.2.2.2 Trapping Coil Geometry and Fields . . . . . . . . . . . 128 5.2.2.3 Trapping Electronics and Switching . . . . . . . . . . . 130 5.2.3 Beam Creation and Detection . . . . . . . . . . . . . . . . . . . 135 5.2.4 Vacuum Chambers . . . . . . . . . . . . . . . . . . . . . . . . . 137 5.3 Simulations of Hydrogen Trapping . . . . . . . . . . . . . . . . . . . . 141 5.3.1 Slowing and Trapping . . . . . . . . . . . . . . . . . . . . . . . 142 5.3.2 Ejection Simulations . . . . . . . . . . . . . . . . . . . . . . . . 145 5.4 Future Directions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 5.4.1 Laser Detection and Spectroscopy of Hydrogen Isotopes . . . . 148 5.4.1.1 Two-Photon Excitation of Hydrogen . . . . . . . . . . 148 5.4.1.2 The Hydrogen Laser . . . . . . . . . . . . . . . . . . . 152 5.4.1.3 Spectroscopic Goals . . . . . . . . . . . . . . . . . . . . 155 5.4.2 An Adiabatic Coilgun . . . . . . . . . . . . . . . . . . . . . . . 156 5.4.3 Single-Photon Cooling of Hydrogen . . . . . . . . . . . . . . . . 157 Appendix 164 Appendix A. Reflection From a Spinning Rotor 165 Bibliography 168 Vita 189 xiii
Page 1 and 2: Copyright by Adam Alexander Libson
Page 3 and 4: General Methods of Controlling Atom
Page 5 and 6: Acknowledgments First and foremost,
Page 7 and 8: to problems, and I frequently went
Page 9 and 10: General Methods of Controlling Atom
Page 11: Table of Contents Acknowledgments v
Page 15 and 16: List of Figures 2.1 Comparison of e
Page 17 and 18: 5.12 Faraday Rotation Signal During
Page 19 and 20: producing a cold sample. Alternativ
Page 21 and 22: place inside a dilution refrigerato
Page 23 and 24: atoms or molecules are slowed using
Page 25 and 26: 2.1 Thermodynamics of Ideal Gases F
Page 27 and 28: Since there will be no heat exchang
Page 29 and 30: Using equation 2.17 to modify equat
Page 31 and 32: Normalized Effusive Beam Flux Norma
Page 33 and 34: general method for producing cold a
Page 35 and 36: The gas throughput of the nozzle ca
Page 37 and 38: Chapter 3 Slowing Supersonic Beams
Page 39 and 40: 3.1 Using Helium for Atom Optics Ex
Page 41 and 42: Figure 3.1: Calculated elastic scat
Page 43 and 44: that they can be prepared ex-situ a
Page 45 and 46: successful. Any water that remains
Page 47 and 48: Skimmer 300 l/s Turbo Pump Even-Lav
Page 49 and 50: Figure 3.5: A CAD image of the dete
Page 51 and 52: from tubular aluminum welded togeth
Page 53 and 54: Figure 3.7: A CAD image of the roto
Page 55 and 56: Figure 3.10: A CAD image of large c
Page 57 and 58: Figure 3.11: This plot shows the am
Page 59 and 60: approximations are made in this cal
Page 61 and 62: 3.3.3 Detection An SRS [61] residua
Page 63 and 64:
TTL pulse to the data acquisition c
Page 65 and 66:
A comparison of the time-of-flight
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eceding crystal. Each curve is the
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calculated slow beam velocity is qu
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the RGA does have an effect on the
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Chapter 4 The Atomic and Molecular
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field. In the L − S coupling regi
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3 P2 E Figure 4.2: This graph gives
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For intermediate fields, the full p
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Figure 4.4: This figure illustrates
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The same effect is also responsible
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(a) (b) (c) Time Figure 4.5: A pict
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which the particles enter). The oth
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the coil can instead be switched be
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the magnitude of the field some dis
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nozzle front surface aluminum catho
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Figure 4.9: A CAD overview of the s
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258V 1MΩ 5V 1mF DC/DC Converter TT
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Figure 4.12: An oscilloscope trace
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(a) (b) Figure 4.14: A CAD image of
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-HV PS 4 M MCP Anode 10 M 1 M Trans
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Signal [V] 2.5 2.0 1.5 1.0 0.5 refe
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Figure 4.20: An exploded view of th
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(a) (b) (c) (e) Figure 4.21: A pict
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258V 1MΩ TTL 2.2mF 50Ω TTL 5V 5V
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closed. With the new thyristor gate
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HeNe M2 M1 BB /2 L BB PC coil PC PD
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Table 4.1: Peak magnetic fields mea
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Figure 4.28: A cut-away CAD image o
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ameters. The coilgun chamber consis
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Table 4.2: Final velocities (vf), s
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MCP Signal [arb. units] 2.0 1.5 (1)
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viability for molecules essential.
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8 Ω LN2 Liquid Nitrogen Dewar Nozz
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Figure 4.33: Molecular oxygen slowi
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Chapter 5 Towards Trapping and Cool
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Energy meV 0.05 0.00 0.05 0.0 0.2 0
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10 mm 2.0 T 1.8 1.6 1.4 1.2 1.0 0.8
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250V 1MΩ 3x 2.2mF TTL 5V feedback
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Magnetic Field (T) 1.9 1.7 1.5 1.3
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5.2.2.1 Principle of Operation of t
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Figure 5.8: Photograph of the trapp
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4.1.3. In an anti-Helmholtz trap, t
Page 149 and 150:
Figure 5.11: Photograph of the hydr
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Photodiode Signal (V) Time (s) Figu
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Figure 5.13: Time of flight plot of
Page 155 and 156:
500 l/s Turbo Pump Supersonic Nozzl
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Ionizer 500 l/s Turbo Pump Ion Opti
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guided the design of the apparatus.
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Z − Velocity (m/s) 100 60 30 0
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Atom Number 60 50 40 30 20 10 0.6 0
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scattered photon to extract informa
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where k1 · pi = − k2 · pi, wh
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the electron g-factor which causes
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Figure 5.24: A schematic of the tel
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prevent the determination of the is
Page 175 and 176:
(a) (b) time Figure 5.25: A 1D illu
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experiment, where a being is capabl
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potential position 2 x 243 nm Lα |
Page 181 and 182:
Appendix 164
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y x V i Figure A.1: The geometry us
Page 185 and 186:
Bibliography [1] H.J.MetcalfandP.va
Page 187 and 188:
[17] Brian C. Sawyer, Benjamin L. L
Page 189 and 190:
[34] R. Campargue. Progress in over
Page 191 and 192:
[51] O. Carnal, M. Sigel, T. Sleato
Page 193 and 194:
[70] Edvardas Narevicius, Adam Libs
Page 195 and 196:
[87] Willis E. Lamb and Robert C. R
Page 197 and 198:
[96] G.Gabrielse,N.S.Bowden,P.Oxley
Page 199 and 200:
[110] N. Kolachevsky, J. Alnis, S.
Page 201 and 202:
[125] Andreas Osterwalder, Samuel A
Page 203 and 204:
[142] C. Cohen-Tannoudji, B. Diu, a
Page 205 and 206:
[161] Paulo F. Bedaque, Aurel Bulga
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Experiments with Supersonic Beams as a Source of Cold Atoms

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