Measurements of hyperfine structure and shift for atomic uranium by laser induced-fluorescence spectroscopy

The paper reports that the isotope shift between natural uranium isotope 235and 238 and the hyperfine sturcture width width of U~(235) were measured by means of laser-in-duced fluorescence spectroscopy.The A and B hyperfine structure splitting constants of U~(235)were also given for 14643 cm~(-1),15720 cm~(-1)and 15631 cm~(-1) levels.     

Isotope shifts and hyperfine structure of 38–47K by laser spectroscopy

Laser optical spectroscopy on a thermal atomic beam has been performed on the $\text{4}{}^2\text{S}{}_{\mathrm{<mtext>sol1</mtext><mtext>2</mtext>}}\text{?4}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{D}{}_2$ line of ^{38,39,41–47}K. Hyperfine structure constants and isotope shifts have been measured. Magnetic moments and changes in the mean square charge radii are deduced.     

High resolution dye laser spectrometer for measurements of isotope and isomer shifts and hyperfine structure

A high resolution cw dye laser spectrometer with a frequency calibration system of 100 kHz resolution is described. Two examples of measured isotope shifts will be discussed.     

Investigation of hyperfine structure and isotope shift of the 605.5 nm-line of Lu176 by laser spectroscopy

Using a tunable single mode dye laser the hyperfine structure of the transition 5d6s ^{2 2} D _5/2 — 5d6s6p ⁴ F _5/2 has been investigated for the Lu-isotopes Lu¹⁷⁵ and Lu¹⁷⁶. From our measurements the following values for the hyperfine constantsA andB could be deduced Lu¹⁷⁶ 5d6s6p ⁴ F _5/2:A=698.4 (0.4) MHz,B=1,564 (10) MHz 5d6s ^{2 2} D _5/2:A=104.1 (0.3) MHz.B=2,631 (6) MHz Lu¹⁷⁵ 5d6s6p ⁴ F ^5/2:A=987.2(0.4) MHz,B=1,117(6) MHz. The isotope shift between the line centers has been determined to be IS(176-175, 605.5 nm)=?420(10) MHz.     

Hg绿谱线超精细结构分析及相互作用常数计算

比较了Hg的546.1 nm绿谱线超精细结构的理论计算值和实验值,定出了原子超精细结构磁偶极矩相互作用常数Am和电四极矩相互作用常数Be.     

Isotope shift and hyperfine structure of43Ca by laser spectroscopy

The isotope shift⁴⁰Ca-⁴³Ca in the 4s ^{2 1} S ₀-4s4p ³ P ₁ intercombination line as well as the hyperfine structure splitting of the 4s4p ³ P ₁ state of⁴³Ca have been remeasured by saturation spectroscopy with a tunable stabilizedcw dye laser and an atomic beam of natural Ca as absorber. The nuclear charge radius of⁴³Ca obtained here reconciles our result with the radius obtained from measurements in muonic Ca-atoms and in the Ca resonance line. It reconfirms the fact that the charge radius of⁴³Ca is considerably smaller than the ones of both neighbouring even isotopes. The discrepancy of our previous measurement for this charge radius was due to a wrong assignment of so far unobserved absorption lines of probably molecular origin occuring in the neighbourhood of the atomic resonances under study.     

钕离子同位素移位和超精细结构光谱

原子光谱中,同位素移位和超精细结构光谱是少数几个能够将原子物理和原子核物理这两个不同的物理分支联系起来的课题之一.利用共线快离子束-激光光谱学方法测量了单电荷态钕离子4f45d6G3/2→(26041)°5/2跃迁(波长577.21 nm)的共振光谱,得到了所有7个稳定同位素(A=142～146,148,150)之间的能量移位和2个奇同位素(A=143,145)的超精细结构光谱.     

Isotope shifts and hyperfine structure of erbium,dysprosium, and gadolinium by atomic-beam diode-laser spectroscopy

A commercial diode laser system, without external frequency stabilization, has been used to study the isotope shifts and hyperfine structure in a near infrared transition of erbium, dysprosium and gadolinium. Specific mass shifts and relative values for the change in the radial nuclear charge parameters of the isotopes were obtained for erbium and dysprosium that compare well with literature values. The hyperfine structure constants measured for erbium fell within the range predicted from the results of other workers. The isotope shifts in the gadolinium transition investigated were too small for the spectrum to be resolved.     

Measurement of isotope shifts,fine and hyperfine structure splittings of the lithium D lines

The lithium D lines were studied using a diode laser that was frequency modulated by an electro-optic modulator, to excite an atomic beam. The transmission of part of the laser beam through an etalon was monitored to correct for the nonlinearity of the laser scan. The results for the ^6,7Li 2 S _1/2 and 2 P _1/2 hyperfine splittings agree very well with the best existing data while those for the D1 isotope shift and ^6,7Li fine structure splittings disagree significantly from data obtained by a previous laser atomic beam experiment. Our result for the D1 isotope shift is very close to the latest value computed using Hylleraas variational theory. Received 8 April 2002 / Received in final form 26 June 2002 Published online 21 January 2003 RID="a" ID="a"e-mail: wvw@yorku.ca     

Stark effect,hyperfine structure and isotope shifts in highly excited states of BaI and CaI

The electric dipole polarizabilities of 9 even-parity barium states (6s8s ¹ S ₀,³ S ₁; 6s7d ¹ D ₂,³ D _1,2; 5d7s ¹ D ₂ and 6p ^{2 3} P _0,1,2) in the interval 33,800–35,800 cm^?1 have been measured with high resolution laser-atomic-beam spectroscopy. Simultaneously, values of isotope shifts and hyperfine coupling constants for theJ=1 states have been obtained. Comparison of the experimental polarizabilities with calculated values as well as inspection of the data on isotope shifts and hyperfine structure from the present and earlier work strongly suggests erroneous assignments of theJ=2 states, with an exception for the 5d 7s ¹ D ₂ state. The influence of an electric field on the 3d ^{2 3} P _0,1,2 states of calcium has also been studied. A marked departure from a quadratic Stark effect has been observed at relatively small field strengths. This can be attributed to the large polarizabilities of neighbouring Rydberg states. The low field data allow the determination of admixtures of Rydberg states into the 3d ^{2 3} P-states as small as 0.02%.     

Hyperfine structure and isotope shift studies of rhenium by laser optogalvanic spectroscopy

Doppler-limited high resolution laser optogalvanic spectra of six transitions of rhenium lying in the range 560–620 nm have been recorded. Isotope shifts between the two natural isotopes of rhenium,¹⁸⁵Re and¹⁸⁷Re, have been calculated in all the six transitions. Hyperfine coupling constants for eight levels belonging to the configurations 5d ⁵6s ², 5d ⁶6s, 5d ⁴6s ²6p and 5d ⁵6s6p are reported. Wherever possible our constants are compared with those given by others.     

Application of the laser ion source for isotope shift and hyperfine structure investigation

The study of nuclei far from stability requires high sensitivity of the experimental technique. The method of Resonance Ionization Spectroscopy in a Laser Ion Source (RIS/LIS) allows one to carry out measurements of the isotope shifts and hyperfine splittings for isotopes at the production rate about 10² atoms per second. The sensitivity of this method is determined by the high efficiency of the laser ion source and the low background of the detection system afforded by characteristic α particle registration. The isotope shifts and hyperfine structures of ¹⁵⁵Yb, ¹⁵⁴Tm (I=9 and I=2) and ¹⁵³Tm (I=11/2) have been measured and the isotopic changes in mean square charge radii and nuclear electromagnetic moments have been determined. The further development of this experimental method – enhanced Target Ion Source system aimed to suppress thermionic background – enables direct detection of the photoions and widens the range of the applicability of the RIS/LIS method. This revised version was published online in August 2006 with corrections to the Cover Date.     

Lamb shift, fine structure and hyperfine structure in helium like ions by fast beam laser spectroscopy

Using Doppler tuned fast beam laser spectroscopy with a continuous wave CO₂ laser the following energy intervals in helium like ions have been measured: 1s2s ¹S₀–1s2p ³P^1,F, ³P₀ in ^14,15N⁵⁺; 1s2p ³P_2,F–1s2p ³P_1,F' in ¹⁹F⁷⁺; and 1s2p ³P₀–1s2p ³P₁ in ²⁴Mg¹⁰⁺. The results test modern relativistic and QED atomic theory. This revised version was published online in August 2006 with corrections to the Cover Date.     

High resolution measurements of hyperfine structure and isotope shifts in 9 spectral lines of Nd I

Nine transitions in Nd I, originating from various levels belonging to the 4f ⁴6s ² ground state configuration, have been studied with high resolution using an actively stabilized C.W. ring dye laser in a crossed laser-atomic-beam set-up. Accurate values for the isotope shifts in all transitions as well as for the hyperfine structure constants of 7 excited states have been obtained.     

Isotope shifts and hyperfine structure of natural dysprosium

Isotype shifts and hyperfine structure measurements for five transitions in natural dysprosium have been performed using a CW tunable dye laser and a collimated atomic beam. The consistency of experimental isotope shifts is tested and values of the change in rms radius of the nuclear charge distribution are calculated.     

Topics in atomic hyperfine structure and isotope shift

Recent developments in atomic hyperfine structure and isotope shift are discussed under the following aspects: (i) Precise evaluation of nuclear moments and isotopic change of nuclear charge radii by quantitative computation of atomic structure or by calibration of the atomic constants through results from electronic and mesic X-ray spectroscopy. (ii) How to apply spectroscopic methods to nuclei far off stability. (iii) What can be learned from a systematic investigation of long isotopic chains.     

原子光谱中同位素位移和超精细结构分裂

利用共线快离子束-激光光谱学方法测量了钕离子所有7个稳定同位素(A=142～146,148,150)之间的同位素位移和两个奇同位素(A=143,145)的超精细结构分裂．