Experiments with Supersonic Beams as a Source of Cold Atoms

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experiment for slowing and trapping of atomic hydrogen isotopes at around 100 mK using a room temperature apparatus is described. A method for further cooling of magnetically trapped hydrogen ensembles, single-photon cooling, is proposed. x
Table of Contents Acknowledgments v Abstract ix List of Tables xiv List of Figures xv Chapter 1. Introduction 1 1.1 Cooling an Effusive Beam . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1.1 Laser Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1.2 Buffer-Gas Cooling . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Methods of Controlling Supersonic Beams . . . . . . . . . . . . . . . . 4 1.3 Dissertation Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Chapter 2. An Overview of Supersonic Beams 7 2.1 Thermodynamics of Ideal Gases . . . . . . . . . . . . . . . . . . . . . 8 2.1.1 Steady State Gas Flow in 1D . . . . . . . . . . . . . . . . . . . 9 2.1.2 Mach Number and Supersonic Beams . . . . . . . . . . . . . . 11 2.1.3 Supersonic Beam Velocities . . . . . . . . . . . . . . . . . . . . 12 2.2 The Supersonic Beam as a Bright General Source of Cold Atoms and Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.3 The Even-Lavie Nozzle for Generating Pulsed Beams . . . . . . . . . 16 Chapter 3. Slowing Supersonic Beams via Specular Reflection: The Atomic Paddle 20 3.1 Using Helium for Atom Optics Experiments . . . . . . . . . . . . . . 22 3.2 Reflecting Atoms from Surfaces: Atomic Mirrors . . . . . . . . . . . . 23 3.2.1 Crystal Choice: Si(111) . . . . . . . . . . . . . . . . . . . . . . 25 3.2.2 Crystal Preparation and Wet Etching . . . . . . . . . . . . . . 26 3.2.3 Crystal Characterization . . . . . . . . . . . . . . . . . . . . . . 28 3.3 The Experimental Apparatus . . . . . . . . . . . . . . . . . . . . . . . 28 3.3.1 The Vacuum System . . . . . . . . . . . . . . . . . . . . . . . . 30 3.3.2 The Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 xi
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: General Methods of Controlling Atom
Page 13 and 14: Chapter 5. Towards Trapping and Coo
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
Page 67 and 68:
eceding crystal. Each curve is the
Page 69 and 70:
calculated slow beam velocity is qu
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the RGA does have an effect on the
Page 73 and 74:
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
Page 79 and 80:
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
Page 107 and 108:
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
Page 113 and 114:
closed. With the new thyristor gate
Page 115 and 116:
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.
Page 129 and 130:
8 Ω LN2 Liquid Nitrogen Dewar Nozz
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Figure 4.33: Molecular oxygen slowi
Page 133 and 134:
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
Page 139 and 140:
250V 1MΩ 3x 2.2mF TTL 5V feedback
Page 141 and 142:
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
Page 151 and 152:
Photodiode Signal (V) Time (s) Figu
Page 153 and 154:
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.
Page 161 and 162:
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
Page 167 and 168:
where k1 · pi = − k2 · pi, wh
Page 169 and 170:
the electron g-factor which causes
Page 171 and 172:
Figure 5.24: A schematic of the tel
Page 173 and 174:
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
Page 179 and 180:
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
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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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