Experiments with Supersonic Beams as a Source of Cold Atoms

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are pulsed methods, and cannot operate on a continuous basis. As such, the pulsed source provided by the Even-Lavie valve limits the amount of wasted gas released into the vacuum chamber. The uniquely short pulse lengths that the valve is capable of producing also provide a precise start time for the slowing experiments, permitting a simplification in the control electronics. Finally, since the overall goal of these experiments is to produce cold atoms that can be used for precision measurements, the high beam brightness produced by the Even-Lavie valve is an important asset, as this maximizes the number of atoms available. 19
Chapter 3 Slowing Supersonic Beams via Specular Reflection: The Atomic Paddle As experimental control of atomic motion has improved, the wave nature of atomic beams has become an important factor in many experiments. Quantum me- chanics states that like light, matter is both a particle and a wave. This has given birth to a new class of experiments which exploit the wave nature of atoms and manipulate beams of atoms in a particle analog to optical manipulation of beams of light. This growing field is known as atom optics, and much research has recently gone into developing a toolbox for manipulating atomic beams. Most of the work in atom optics has used laser cooled atoms [38, 39], which provide several advantages. Since the atoms are laser cooled they are quite cold, and beams can be produced at low velocities. This accentuates the wave nature of the particles, as λ = 2π (3.1) p where λ is the de Broglie wavelength of a particle, and p is the particle’s momentum. Furthermore, laser cooled atoms have an accessible transition an experimentalist can use to both manipulate and detect the atoms in the beam. There are some drawbacks to using laser cooled atoms however, most notably their sensitivity to stray fields. It is rather difficult to effectively control the atomic motion of ground state helium, due to the lack of accessible transitions with current laser technology. How- ever, helium is known to reflect well from single crystal surfaces [40], which suggests 20
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 and 12: Table of Contents Acknowledgments v
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: The gas throughput of the nozzle ca
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
Page 71 and 72: the RGA does have an effect on the
Page 73 and 74: Chapter 4 The Atomic and Molecular
Page 75 and 76: field. In the L − S coupling regi
Page 77 and 78: 3 P2 E Figure 4.2: This graph gives
Page 79 and 80: For intermediate fields, the full p
Page 81 and 82: Figure 4.4: This figure illustrates
Page 83 and 84: The same effect is also responsible
Page 85 and 86: (a) (b) (c) Time Figure 4.5: A pict
Page 87 and 88:
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
Page 103 and 104:
-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
Page 111 and 112:
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
Page 137 and 138:
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
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
Page 145 and 146:
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
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Figure 5.13: Time of flight plot of
Page 155 and 156:
500 l/s Turbo Pump Supersonic Nozzl
Page 157 and 158:
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
Page 165 and 166:
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 |
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Appendix 164
Page 183 and 184:
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
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[110] N. Kolachevsky, J. Alnis, S.
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[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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