M. Vogel for the SPECTRAP collaboration PRECISION SPECTROSCOPY ON HIGHLY CHARGED IONS

DOUBLE-RESONANCE SPECTROSCOPY IN HCI

Manuel Vogel HCI level scheme H-like ion in external B-field: hyperfine levels are split into Zeeman sublevels example: 209 Bi 82+ I=9/2 F=I+J, F=I-J J=1/2 (ground state)

Manuel Vogelrelations nuclear g-factor g I electronic g-factor g J atomic (ionic) g-factor g F using this relation: measure any 2 numbers independently and get the third one free e.g. g I from NMR (but: diamagnetic shielding) g J from Stern-Gerlach-Experiments g F from double-resonance experiments

Manuel Vogel known values + a large number of g I from NMR gJgJ  HFS

Manuel Vogel 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 gFgF g F‘

Manuel Vogel case 1: only one g F measured we can use to get either or I,F small, well-known from theory

Manuel Vogel case 2: two g F measured if g F is measured for two different F, then we can simulaneously and independently get and (this only works for I>1/2)

Manuel Vogel this means...we can obtain electronic and nuclear magnetic moments (g-factors) simultaneously with a relative accuracy of 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

BLIND SPECTROSCOPY

Manuel Vogel 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 using only a single ion no optical detection

Manuel Vogel axial laser cooling – magnetic bottle zz initial resistive cooling, pick up, rf frequency measurement

Manuel Vogel frequency shift i.e to shift sensitivity

Manuel Vogel sideband spectrum Pb 1+ Pb 81+

Manuel Vogel cooling rates

Manuel Vogel pro: estimated accuracy better than 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 conclusion