J. Ney

Level-crossing-Untersuchung der Hyperfeinstruktur des 3d10 4p2P3/2-Terms von Cu63 und Cu65

The level-crossing technic has been used to investigate the hyperfinestructur of the 3d10 4p2P3/2-term in Copper I by scattering the resonance line λ=3248 Å on an atomic beam of separated isotop Cu63 respectively Cu65 in an external magnetic field. From the level-crossing signals values for the magnetic dipol interaction constantsA and for the electric quadrupol interaction constantsB are deduced to beeA(Cu63)=(194,72±0,15) Mc/secB(Cu63)=−(28,8±0,6) Mc/secA(Cu65)=(208,57±0,15) Mc/secB(Cu65)=−(25,9±0,6) Mc/sec.With theA-value of the 3d10 4p2P1/2-term from optical measurements the ratioA(2P3/2)∶A(2P1/2)≈0,4 is about twice greater than for an unperturbetalkali-like2P-term. From the width of the level-crossing signals a mean lifetime of the 3d10 4p2P3/2-term τ=(7,0±0,2) · 10−9 sec is deduced.

Hyperfeinstrukturuntersuchung der 4p und 5p2P3/2-Terme im K I-Spektrum durch Resonanzstreuung von Licht zur Bestimmung der Kernquadrupolmomente von K39 und K41

In order to determine the nuclear quadrupol moments of the stable K-isotopes, the hyperfine structure of the 4p and5p2P3/2-states was investigated by resonance scattering of light. The scattered intensityR(H) from separated isotopes in a sealed off resonance cell, as function of an external magnetic fieldH was observed with different polarisations (σ- andπ-components perpendicular toH) both in exciting and scattered light.Because the hfs-splitting of the investigated states is comparable to the radiation widthГ, the measured change in intensityΔR(H)/ΔH is due to interference effects (Hanle-effect, level-crossing, anti-crossing) and decoupling of electronic and nuclear spin (Heydenburg-effect). The different effects are not distinguishable in contrary to an usual level-crossing experiment and therefore the measured signal-structure is compared with line shape calculations according to Breits-formula. Assuming “white” excitation andgJ=4/3, the measured signal-structure can be explained with the following values:Γ/2π (4p)=5.7 (4) MHzΓ/2π (4p)=5.7 (4) MHz K39:A(4p)=6.13(5) MHzB(4p)=2.72(12) MHzA(5p)=1.97(2) MHzB(5p)=0.85 (3) MHz K41:A(4p)=3.40(8) MHzB(4p)=3.34(24) MHzA(5p)=1.08(2) MHzB(5p)=1.06 (4) MHz.Without Sternheimer corrections one obtains from these values Q(K39)=0.062 · 10−24 cm2 and Q(K41)=0.076 · 10−24 cm2 for the electrical nuclear quadrupolmoments of K39 and K41.

Hyperfeinstrukturuntersuchung des 6p2P3/2-Terms im Au I-Spektrum durch Resonanzstreuung von Licht

The hyperfine structure of the 6p2P3/2-state in the Au I-spectrum was investigated by level-crossing technique. The magnetic field dependence of the resonance radiation (σ−orπ-components in exciting and scattered light) was observed between Zeeman and Paschen-Back region. The measured structure of the signals yields ¦A¦=14.0 (5) MHz, ¦B¦=327.6 (1.6) MHz,B/A=+23.4(8). The measured radiation widthγ/2π=34.6 (2.0) MHz has the same order in magnitude as the magnetic coupling constant. Therefore interference and decoupling effects had to be considered. The positive sign of theB/A ratio could be deduced by comparing the measured with the calculated signal-structure. Without the Sternheimer correction from the measuredB/A ratio of the 6p2P3/2-state results Q=1.04 · 10−24 cm2, fromB and the fine structure splitting results Q=0.57 · 10−24 cm2.

Untersuchung des 4p^(2)P_(3/2)- und 5p^(2)P_(3/2)-Terms des KI-Spektrums durch Resonanzstreuung von Licht zur Bestimmung des Kernquadrupolmoments von K 40

Resonance scattering of light as function of magnetic field has been used to investigate the hyperfine structure of the 4p2P3/2- and 5p2P3/2-terms in the potassiumI-spectrum, using a sample enriched in the K40-isotope. With increasing magnetic field strength a structure containing two characteristic signals for K40 was observed. Taking into account the small ratio of hyperfine structure splitting to radiation width, these signals could be interpreted as an overlapping of three level-crossings. The line shape and magnetic field strength of these signals can be understood by taking for the magnetic interaction constantsA40(4p2P3/2)=(−7.59±0.06) Mc/s,A40(5p2P3/2)=(−2.45±0.02) Mc/s and the electric quadrupol coupling constantsB40(4p2P3/2)=(− 3.5 ±0.5) Mc/s,B40(5p2P3/2)=(−1.1± 0.2) Mc/s usinggJ=4/3. The values ofB/A yield withSternheimer corrections for the nuclear electric quadrupolmomentQ(K40=−0.07 · 10−24 cm2.

Level-crossing-Experiment zur Untersuchung der Hyperfeinstruktur von Au197 im5d106p2P3/2-Term

The scattering of Au-resonance line λ=2427 Å on an atomic heam was observed in external magnetic field by level crossing technic. Using the assumed interpretationB/A ≫ 1 for the hyperfinestructure-interaction of Au197 in the2P3/2-term a valueB ≈ll mK for the nuclear quadrupol-interaction constant is deduced.

Hyperfeinstrukturanomalie und Kernquadrupolwechselwirkungskonstanten des angeregten 3d94s 4p4P3/2-Terms im Cu I-Spektram von Cu63 und Cu65

The hyperfine structure of the excited 3d9 4s 4p4P3/2-term of the Cu I-spectrum was investigated in a level-crossing experiment using an atomic beam with copper in natural abundance as absorber. From the level-crossing signals the following relations for the hyperfine structure constants were deducedA(Cu63)=2184.66 (17)gJ/1.75 Mc/sec,B(Cu63)=−38.65 (11) gJ/1.75 Mc/sec,A(Cu65)=2340.15 (19)gJ/1.75 Mc/sec,B(Cu65)=−35.69 (17) gJ/1.75 Mc/sec. The ratio of the magnetic hyperfine structure constants of Cu63 and Cu65 was determined with high accuracy to beA(Cu63)/A(Cu65)=0.93355 (2). From this ratio a hyperfine structure anomaly63Δ65(4P3/2)=1.4·10−4(4) was deduced. The width of the zero field crossing yielded a lifetime τ=3.2 (3) · 10−7 sec for the excited4P3/2-term.

Level-crossing-Experiment zur Untersuchung des Einflusses eines elektrischen Feldes auf die Hyperfeinstruktur des 4p2P3/2-Terms im Cu I-Spektrum

Level-crossing technique applying parallel electric and magnetic fields has been used to investigate the influence of an electric fieldEz on the hyperfine structure of the 4p2P3/2-state. The Stark shift of the level-crossing nearHz=155 Oe and the modification of the magnetic zero-field level-crossing signal due to the electric fieldEz was observed. Both experimental results can be explained with a Stark-constantβ=7.2(1.1)kc(kV/cm)−2.