M. Vogel

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PRECISION SPECTROSCOPY ON HIGHLY CHARGED IONS
M. Vogel for the SPECTRAP collaboration
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DOUBLE-RESONANCE SPECTROSCOPY IN HCI
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HCI level scheme
H-like ion in external B-field hyperfine levels
are split into Zeeman sublevels
example 209Bi82 I9/2
FIJ, FI-J J1/2 (ground state)
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relations
nuclear g-factor gI electronic g-factor gJ atomic
(ionic) g-factor gF
using this relation measure any 2 numbers
independently and get the third one
free e.g. gI from NMR (but diamagnetic
shielding) gJ from Stern-Gerlach-Experiments gF
from double-resonance experiments
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known values
gJ
wHFS
a large number of gI from NMR
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double-resonance technique
idea perform a laser-microwave double-resonance
experiment and use the light from the optical
transition as a probe for the Zeeman transitions
gF
gF
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case 1 only one gF measured
we can use
to get either
I,F
small, well-known from theory
I,F
or
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case 2 two gF measured
if gF is measured for two different F, then we
can simulaneously and independently get
and
(this only works for Igt1/2)
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this means
...we can obtain electronic and nuclear magnetic
moments (g-factors) simultaneously with a
relative accuracy of 10-7 or better (depending on
the system) ...we are independent from
diamagnetic shielding, i.e. shielding effects can
for the first time be measured and theory can be
tested
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BLIND SPECTROSCOPY
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optical spectroscopy by MW measurement
idea perform laser cooling on forbidden
transition and probe the effect by the
corresponding motional frequency shift in a
magnetic bottle.

• forbidden transition can be identified with a
  precision of better than 10-10
• using only a single ion
• no optical detection

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axial laser cooling magnetic bottle
wz
initial resistive cooling, pick up, rf
frequency measurement
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frequency shift
i.e. 10-6 to 10-5 shift
10-10 sensitivity
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sideband spectrum
Pb1
Pb81
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cooling rates
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conclusion
pro estimated accuracy better than 10-10 needs
only a single ion no optical detection system
necessary acceptable laser cooling times due to
high detection sensitivity can use
existing/planned g-factor setup (replace MW by
cooling laser) Thank you for your attention ?