Experiments with Supersonic Beams as a Source of Cold Atoms

3.0, and 2.4 A respectively. The initial phase used in generating the timing files for
these results is 55 ◦ . The final velocities of the slowed beams for these magnetic fields
are 409.3 ± 9.1 m/s for 400 A and 416 ± 22 m/s for 320 A. The speed of the beam
created by operating the slower at 240 A is not determined as the slowed peak could
not be sufficiently resolved.
4.5 The Atomic Coilgun: Stopping Metastable Neon
Having successfully slowed a beam of metastable neon using the proof-of-
principle apparatus, the next step was to show the scalability of the coilgun method.
Additionally, a goal of the next apparatus was to show that the coilgun could slow the
beam enough to enable trapping of the slow packet. While this experiment did not
attempt to trap the slowed beam, it was important to show that the coilgun method
could produce beams slow and cold enough that trapping the beam at the exit of the
coilgun is a realistic application of the coilgun.
To this end, a 64 stage coilgun was constructed using the lessons learned from
the proof-of-principle experiment, and incorporating improvements in both the coil
design and the electronics. A dedicated vacuum system was built to house the 64
stage coilgun, and the signal processing was optimized. Using the 64 stage coilgun
with metastable neon allowed full control of the velocity of the slowed beam. Neon is
slowed from an initial velocity of 446.5 ± 2.5 m/s to velocities as low as 55.8 ± 4.7m/s,
with this lower limit set by the transverse expansion of the beam from the end of the
slower to the detector. The coilgun effectively stops the beam as more than 99% of
the initial kinetic energy is removed and the remaining velocity is only kept to allow
the atoms to propagate to the detector.
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