Optical pumping of ions in buffer gases

Weber, E. W.; Ackermann, H.; Laulainen, N. S.; Putlitz, G. zu

doi:10.1007/bf01397375

Cited by 14 publications

(11 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The analysis, however, showed that only He, N 2 and 02 contributed to the measured relaxation rate, while the contribution of the other gases was smaller than the eperimentally uncertaincy of 7. The results of the fitting procedure are: Our results can be in part compared to those obtained on alkali-like ions: for He as buffer gas the cross sections for Sj/2-ground states are of the order of 10 -2~ cm 2 [5], while for excited P-states one finds about 10-14 cm 2 [6], In those cases, however, the P-states are close to other excited states, which are mixed in during the collision and thus give rise to a large cross section.…”

Section: Resultsmentioning

confidence: 94%

Collisional relaxation measurements on Pb+ hyperfine levels

Zhang

Feng

et al. 1993

Z Phys D - Atoms, Molecules and Clusters

View full text Add to dashboard Cite

Abstract. The time constants for population relaxation of optically pumped Pb + ions in a Paul ion trap have been determined in a He buffer gas atmosphere with additional components of other gases. For the 6 P1/2 ground state of Pb + and an ion temperatur of 104K we find cross sections of 0.72(0.33). 10 -17 cm2; 0.59(0.38). 10 15 cm2; and 2.56 (0.74). 10-14 c m 2 for He, N2 and 02, respectively. The error includes an estimated 20% uncertaincy in the pressure calibration of a residual gas analyser. 31.70.Hq; 32.80.Bx; 32.80.Pj The method of microwave-optical double resonance in radio-frequency ion traps is a well established technique to obtain accurate groundstate hyperfine splittings of ions. Isotopes of alkali-like ions have been measured with very high precision, and uncertainties below 10-1~ are almost routinely obtained [t ]. Those experiments have been performed on single ions as well as on ion clouds. While in the first case the ultimate precision is extremely high and uncertainties below 10 -15 seem feasible, the signal-tonoise ratio is of course much better for large ion clouds, containing up to 106 ions. Consequently this is preferred in experiments, where extreme accuracy is not required. Ion clouds, however, have to be cooled to a certain extend to prevent ions loss from the trap by energy pick-up from the time varying electric trapping fields in particular by those ions, which move at the boundary of large ion clouds. This is most easily performed by collisions of the stored ions with buffer gas atoms, which reduce the ions temperature, if the mass of the neutral atoms is much smaller than the ions mass. Collisions, however, may perturb the ionic eigenstates and thus limit the precision by relaxation processes. PACS:Cross sections for relaxation between optically pumped states have been determined in a number of experiments * Permanent address: Department of Radio-electronics, Peking University, Beijing, PR China on alkali-like ions for S~/2 ground-and P3/2 excited states in collisions with noble gases [2]. In the course of an iontrap experiment for a precision determination of the hyperfine splitting of the 6 2p~/2 ground state of 2°Tpb+ [3] we have performed a number of measurements on the relaxation rates with different background gases. ExperimentAbout 10 6 2°Tpb+ ions were confined continuously for several weeks in a Paul ion trap. They were moderately cooled by collisions with light buffer gases. Selective excitation of the F = 0, mF----0 ground state ])yperfine level by a narrow band tunable laser lead to a complete depletion of this state. This was indicated by the exponential decay of the fluorescence count rate tbllowing the excitation. At 50 mW laser output power the straylight level was reached after about 2 s. The laser than was blocked to allow the depleted state to fill up by coltisional relaxation. After a delay time A t the laser was turned on again and the fluorescence reappeared. The number of counts in a time window of 56 ms, corresponding approximately to the excited state lif...

show abstract

Section: Resultsmentioning

confidence: 94%

Collisional relaxation measurements on Pb+ hyperfine levels

Zhang

Feng

et al. 1993

Z Phys D - Atoms, Molecules and Clusters

View full text Add to dashboard Cite

show abstract

“…Likewise no influence of the gas discharge and of the He (Ne) buffer gas on the relaxation of the nuclear spin of 17SLu+ can be detected. In the case of this ~So ion no significant increase of the noble gas depolarization cross section due to the ionic charge seems to be present, in contrast to the case of ions with 2S~/2 ground states compared to the isoelectronic atoms [19].…”

Section: Measurementsmentioning

confidence: 81%

Precision measurement of the nuclear magnetic dipole moment of175Lu by optical pumping of free Lu+ ions

Müller

Weber

1975

Z Physik A

Self Cite

View full text Add to dashboard Cite

Abstract. Nuclear spin polarization in the 4fZ46s2 aSo ground state of lVSLu+(I=7/2) ions is achieved by optical pumping with the resonance line (1So-~Pt, 2=261.5nm). Nuclear magnetic resonance of the free ions in He buffer gas yields for the magnetic dipole moment /~(75Lu)=2.2240(11)#, (with diamagnetic correction). This value can be used for a more accurate determination of the magnetic dipole moments of other Lu isotopes from known A factor ratios. A comparison with nuclear induction measurements in solids results in the chemical shifts 6(LuB12)=-23(5).

show abstract

“…All three effects contribute to the strong decrease of the signal height S(p) and thus do not allow to observe the change in sign of (Sz)F= 2" For He and Ne the magnitude of the three effects is comparatively much smaller in the applied pressure range because of the almost constant ion production rate, the lower diffusion and particularly, the lower relaxation rate (compare with the data for the Sr + 281/2 ground state [17]). …”

Section: Odd (I=3/2) Isotopes Of Ba + Ionsmentioning

confidence: 86%

Collisional relaxation of ionic2 P 3/2 excited states in rare gases

Buttler

Weber

1978

Z Physik A

Self Cite

View full text Add to dashboard Cite

Optical pumping with the D2 line is used to study the depolarization of the first excited 2p3/2 states of alkaline earth ions and Yb + ions in collisions with rare gas atoms. The deorientation cross sections for the even isotopes ofBa + and Yb + ions are obtained (in units of 10-t6 cm2): rare gas He Ne Ar Kr Xe al (Ba + 6p 2p3/2 ) 79(11) 89 (13) 123 (18) 152 (22) 204(30) ax (Yb + 6p 2p3/2) 60(10) 62 (9) 107 (18) 133 (17) 167 (37) The cross sections are discussed in comparison with theoretical calculations and those of isoelectronic atoms. The comparison of the 2P3/2 relaxation of even and odd (I = 3/2) isotopes of Ba + allows to draw conclusions on the nature of the depolarization interaction.

show abstract

Optical pumping of ions in buffer gases

Cited by 14 publications

References 23 publications

Collisional relaxation measurements on Pb+ hyperfine levels

Collisional relaxation measurements on Pb+ hyperfine levels

Precision measurement of the nuclear magnetic dipole moment of175Lu by optical pumping of free Lu+ ions

Collisional relaxation of ionic2 P 3/2 excited states in rare gases

Contact Info

Product

Resources

About