The magnetic dipole moment of 55Co

The ground state g-factor for ⁵⁵Co has been measured as $\text{¦g¦= 1.378±0.001}$ by the technique of nuclear magnetic resonance on oriented nuclei. The temperature dependence of γ-ray anisotropy in the ⁵⁵Fe daughter decay determines both the 1408 keV level spin and the ⁵⁵Co ground state spin to be $\text{7}\text{2}$, and yields values of mixing ratios in the 1037 keV β-transition and the 477 keV γ-transition. The configuration mixing model is used to discuss 1f_{$\text{7}\text{2}$} moment systematics.     

Recoil-distance measurements of the g-factor of 22Ne(21+)

Time-differential recoil-into-vacuum measurements with a plunger have been performed on the first-excited I^π = 2⁺ state of ²²Ne. The state was populated with the ⁴He(¹⁹F, p)²²Ne reaction on ⁴He-implanted foils. The measurements lead to a $\text{g-}\text{factor}\text{of}\text{¦g¦ = 0.326 ± 0.012}$ and to a mean life of τ_m = 5.2 ± 0.3 ps. The analysis also yields the population of excited two-electron ions and indicates that the population may depend on the thickness of the ¹²C contamination layer through which the ions recoil into vacuum.     

Magnetic moment of the 10−, 2.53 ms state in 208Bi measured by in-beam NMR-PAD

The g-factor of the 10^? isomeric state in ²⁰⁸Bi has been measured by the method of inbeam NMR-PAD. From the experimental value $\text{¦g¦= 0.2666(27)}$ the magnetic moment of the $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron hole state is deduced. The result is compared with experimental values of neighbouring nuclei and theoretical predictions.     

On the sign of the ρ-ω mixing charge asymmetric nn potential

The sign of the single-particle exchange nucleon force due to ρ°-ω mixing is shown on experimental and theoretical grounds to make the resulting charge asymmetric potential, V_nn ? V_pp in the ¹S₀ state, attractive. The sign agrees quite well with the binding energy difference in the A = 3 mirror nuclei and is not inconsistent with present knowledge of NN scattering lengths, predicting $\text{0 < ¦}\text{a}{}_{\mathrm{nn}}\text{¦ ? ¦a}{}_{\mathrm{<mtext>pp</mtext>}}\text{¦ ? 1}\text{fm}$.     

Franck-condon factors for diatomic molecules and the factorization method

By means of the factorization method, recurrence relations for the matrix elementS$\text{<ψ}{}_{\mathrm{<mtext>v\text{'}</mtext>}}\text{¦r}{}^{\mathrm{N}}\text{¦ψ}{}_{\mathrm{<mtext>v</mtext>}}\text{<}$ for an arbitrary positive integer N are obtained in the framework of α-averaging for the Morse potential. The method of calculating the matrix element$\text{<ψ}{}_{\mathrm{<mtext>v\text{'}</mtext>}}\text{¦R}{}_{\mathrm{<mtext>e</mtext>}}\text{¦ψ}{}_{\mathrm{<mtext>v</mtext>}}\text{<}$ is outlined, provided a dependence of the electronic transition moment R_e on the internuclear distance r can be approximated by the polynomial R_e(r)=a₀+a₁r+a₂r²+…+ainNr^N. Recurrence relations are also obtained for the case of the exponential dependence R_e(r).     

Adsorption of oxygen on a Cu{110} surface with and without the influence of A keV Ne+ beam: Stage I: Coverages up to half a monolayer

Low Energy Ion Scattering has been used to study the interaction of molecular oxygen with a Cu{110} surface. The amount of adsorbed atomic oxygen was monitored by the 4 keV Ne⁺¦O reflection signal. In the first adsorption stage (coverage less than half a monolayer) the sticking probability varied proportional to the number of empty adsorption sites: S = S₀ (1 ? $\text{}\text{?}$gq). It turned out not to be influenced by the Ne⁺ bombardment. The initial sticking probability S₀ was found to be ≈ 0.24. In this first adsorption stage the oxygen-covered surface is reconstructed according to the “missing row” model, leading to a (2 × 1) LEED pattern.     

Large angle production of stable particles heavier than the proton and a search for quarks at the CERN intersecting storage rings

Measurements have been performed on production of particles with mass 1.5 GeV/c² and charge $\text{?}\text{2}\text{3}$ for θ_lab = 62.5° and $\text{s}\text{= 53}\text{GeV}$. At p_T = 0.7 GeV/c the relative rate of production of antideuterons to π^? is (5 ± 1) × 10^?5. The deuteron to antideuteron ratio is 3.7 ± 1.2. No new stable particle has been amongst 0.7 × 10⁸ charged particles entering our detector.     

Nuclear structure effect in internal conversion of the isomeric transition in 191Os

Measurements have been performed on relative conversion line intensities of the hindered 74.38 keV isomeric transition in ¹⁹¹Os with the $\text{1}\text{2}\text{π√13}$ iron-free β-ray spectrometer. Anomalies were observed for the L, M and N subshell intensity ratios and were explained with a nuclear structure parameter λ = 9.4 ± 0.5 and a mixing ratio $\text{¦δ(}\text{E4/M3}\text{)¦ = (3.0 ± 0.3) × 10}{}^{\mathrm{?3}}$.     

Nuclear reaction studies of 168Tm

The intrinsic structure of ¹⁶⁸Tm has been studied using the (³He, d) and (α, t) proton stripping reactions as well as the (d, t) and (³He, α) neutron pick-up reactions. The beams of 24 MeV ³He particles, 25 MeV α-particles and 12 MeV deuterons were obtained from the McMaster tandem Van de Graaff accelerator. The reaction products were analyzed with an Enge-type magnetic spectrograph and detected with photographic emulsions. The spectra have been interpreted in terms of the coupling of an odd proton and an odd neutron, each moving independently in a spheroidal potential, which gives rise to intrinsic two-quasiparticle states with $\text{K = ¦Ω}{}_1\text{±Ω}{}_2\text{¦}$. The identification of the intrinsic states was made by comparing the experimental cross-section patterns with those predicted with the aid of Coriolis coupling and distorted-wave Born approximation (DWBA) calculations. Rotational bands superimposed on the K^π = 3⁺ and $\text{K}{}^{\mathrm{\pi }}\text{= 4}{}^{\mathrm{+}}\text{, {}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}{}_{\mathrm{n}}\text{±}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{p}}\text{}}$ configurations, the first of which is the ground state, ha been observed in the spectra of all four reactions. New assignments have been made for configurations resulting from coupling the $\text{1}\text{2}$^? [541], $\text{7}\text{2}$⁺ [404], $\text{5}\text{4}$⁺ [402] and $\text{1}\text{2}$^? [530] p to the $\text{7}\text{2}$⁺ [633] neutron state. The neutron pick-up measurements confirmed the earlier assignments based on (d, t) reaction studies and suggested tentative assignments for the {$\text{1}\text{2}$⁺ [400]_n±$\text{1}\text{2}$⁺ [411]_p} and {$\text{3}\text{2}$⁺ [402]_n±$\text{1}\text{2}$⁺ [411]_p}     

Measurement of the g-factor and mean lifetime of the 13C(52+1) state

The g-factor and mean life of the $\text{5}\text{2}{}^{\mathrm{+}}{}_1$ state at 3.85 MeV in ¹³C have been determined by a recoil-into-vacuum plunger measurement. The state was populated by the ²H(¹²C, p) reaction at E = 15.0 MeV. The analysis of the time-differential deorientation effect on the p-γ angular correlation leads to a g-factor of $\text{¦g¦ = 0.558 ± 0.015}$. For the mean lifetime a value of τ = 12.2 ± 0.4ps is obtained.     

The microwave spectrum of C-fluorophosphaethyne FCP: Structure determination,dipole moment,and vibration-rotation data

The microwave spectrum of the new linear triatomic molecule C-fluorophosphaethyne FCP which is produced when CF₃PH₂ vapor passes over solid KOH at room temperature and ca. 20 μmHg pressure has been studied. Transitions belonging to the two isotopic variants ¹⁹F¹²C³¹P and ¹⁹F¹³C³¹P have been analyzed and the resulting structural data are $\text{r(}\text{FC}\text{) = 1.285 ± 0.005}\text{A}\text{?}$ and $\text{r(}\text{CP}\text{) = 1.541 ± 0.005}\text{A}\text{?}$. The study has yielded the following spectroscopic parameters for ¹⁹F¹²C³¹P: B₀ = 5257.80 ± 0.03 MHz, α₂ = ?11.95 ± 0.05 MHz, q₂ = 4.478 ± 0.002 MHz, and μ = 0.279 ± 0.001 Debye.     

Microwave spectral study of 2-fluorophenol: cis conformer

The microwave spectra of 2-fluorophenol and its deuterated species have been observed and analyzed in the frequency ranges 12.5–18.0 GHz (KU band) and 21.5–26.0 GHz (K band) in the ground vibrational state at room temperature. For the normal species, the radio frequency-microwave double resonance spectrum has been recorded in the frequency range 30.0–38.0 GHz. Three rotational and five quartic centrifugal distortion constants for the normal species, $\text{A}\text{?}\text{= 3337.86 ± 0.02}$, $\text{B}\text{?}\text{= 2231.92 ± 0.01}$, $\text{C}\text{?}\text{= 1337.52 ± 0.01}$, d_J = (3.5 ± 2.9) × 10^?4, d_JK = (?4.9 ± 1.5) × 10^?3, d_K = (?3.2 ± 1.0) × 10^?3, d_WJ = (?2.0 ± 1.0) × 10^?7, d_WK = (2.6 ± 0.8) × 10^?6 (in MHz), and three rotational constants for the deuterated species, $\text{A}\text{?}\text{= 3324.70 ± 0.03}$, $\text{B}\text{?}\text{= 2177.95 ± 0.03}$, $\text{C}\text{?}\text{= 1315.96 ± 0.03}$ (in MHz), have been obtained. Consideration of the r_s coordinate of the hydroxyl hydrogen atom leads to the assignment of the spectra to the cis conformer of the molecule. An r₀ structure for the cis conformer has been proposed. The nonbonded OH ? F distance is lower by about 0.3 Å than the sum of the van der Waals radii.     

Microscopic calculation of cross sections for the reactions 12C(p, 2p) and 16O(p, 2p): U. Wille and R. Lipperheide Nucl. Phys. A189 (1972) 113

Isomeric states of ⁶⁹Se were produced via the heavy-ion compound-nucleus process and from the positon decay of ⁶⁹Br, the former producing a high-spin state and the latter preferentially populating a low-spin state. Ge(Li) detectors as well as scintillation counting showed that the high-spin state decays with T_{$\text{1}\text{2}$} = 14.0 ± 1.0 min to levels in ⁶⁹As, giving rise to γ-rays of 116, 166 and 282 keV. The low-spin state decays predominantly to a state giving rise to a 145 keV γ-ray with T_{$\text{1}\text{2}$} = 1.8 ± 0.2 min. The beta end-point energy of both isomers is 5.2 ± 0.2 MeV. It is deduced that the high-spin state, assigned J^π = $\text{9}\text{2}$⁺, is the ground state; the isomeric state had J^π = $\text{3}\text{2}$^?. The angular momentum inversion as compared to neutron-excess Se isotopes is attributed to Coriolis coupling to a deformed core as described by Malik and Scholz.     

Mean lifetimes of excited levels of Ar II. I. Time correlation measurements

Mean Lifetimes of excited levels of Ar II have been measured using the method of time-correlated photons in cascade. The following results were obtained: for 4p⁴S^°_{$\text{3}\text{2}$}, τ = 7·2±0·3ns; for 4p′²F^°_{$\text{7}\text{2}$}, τ = 8·8±0·2 ns; for 4p′²F^°_{$\text{5}\text{2}$}, τ = 8·0±0·2 ns. These results are compared with experimental and theoretical values.     

Determination of the atomic-state population in A Kr-Br2 mixture

The atomic-state populations of the 5s[1$\text{1}\text{2}$]° metastable level of Kr and of the 5s²P_{$\text{3}\text{2}$} resonant level of Br in a Kr-Br₂ mixture have been determined as functions of current strength. Occurrence of energy transfer from the Kr-level to the Br-level has been verified.     

Microwave spectrum of dimethyldichlorosilane

The microwave spectrum of dimethyldichlorosilane has been observed and the rotational constants and centrifugal distortion constants have been determined for ³⁵Cl₂ and ³⁵Cl³⁷Cl species. From these constants, the molecular structure is determined as $\text{r(}\text{SiCl}\text{) = 2.055 ± 0.003}\text{A}\text{?}$, $\text{r(}\text{SiC}\text{) = 1.845 ± 0.005}\text{A}\text{?}$, ∠ClSiCl = 107.2 ± 0.3°, ∠CSiC = 114.7 ± 0.3°. An analysis of the ³⁵Cl₂ quadrupole splittings leads to quadrupole coupling constants of χ_aa = ?19.6 ± 0.3 MHz, χ_bb = ?3.7 ± 1.4 MHz, χ_cc = 23.3 ± 1.4 MHz, χ_bond = ?38.0 ± 1.6 MHz, and η_bond = 0.22 ± 0.08.     

Magnetic moment of the 72+[404] ground state of 10.5 h 175Ta

The magnetic hyperfine splitting ν_M = |gμ_NB_HF/h| of ${}^{175}\text{Ta}\text{(J}{}^{\mathrm{\pi }}\text{=}\text{7}\text{2}{}^{\mathrm{+}}$; $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 10.5}\text{h}\text{)}$ in Fe has been measured with the technique of nuclear magnetic resonance on oriented nuclei as 320.4(1) MHz. With the known hyperfine field $\text{B}{}_{\mathrm{<mtext>HF</mtext>}}\text{(}\text{Ta}\text{Fe}\text{) = ?648(13)}\text{kG}$ the magnetic moment of the $\text{7}\text{2}{}^{\mathrm{+}}\text{[404]}$ ground state of ¹⁷⁵Ta is deduced to be $\text{¦μ¦ = 2.27(5)μ}{}_{\mathrm{<mtext>N</mtext>}}$.     

Nuclear magnetic moment of the 9.7 h 12− isomer 196mAu

The magnetic hyperfine splitting v_M=|gμ_NB_HF/h| of ^196mAu (j^π=12^?; configuration ¦(π$\text{11}\text{2}$($\text{v}\text{13}\text{2}{}^{\mathrm{+}}\text{)〉}{}_{12}{}^{\mathrm{?}}$; $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 9.7}\text{h}\text{)}$ as dilute impurity in Ni has been determined with nuclear magnetic resonance on oriented nuclei as 96.0(2) MHz. With the known hyperfine field B_HF = ?264.4(3.9) kG corrected for hyperfine anomalies the g-factor and magnetic moment of ^196mAu are deduced to be |g| = 0.476(7) and |μ| = 5.72(8) μ_N. Taking into account the known magnetic properties of $\text{π}\text{1}\text{2}{}^{\mathrm{?}}$ and $\text{v}\text{13}\text{2}{}^{\mathrm{+}}$ isomeric states in the neighbouring odd Pt, Au and Hg nuclei the structure of the 12^? state is discussed.     

Recoil-distance measurements of g-factors for 24Mg(21+) and 20Ne(21+)

Time-differential recoil-into-vacuum measurements have been performed with a plunger on the first-excited I^π = 2⁺ states of ²⁴Mg and ²⁰Ne. The states were populated by the reactions ¹²C(¹⁶O, α)²⁴Mg and ¹²C(¹²C, α)²⁰Ne. The measured anisotropy of the α-γ angular correlation was greatly increased by means of a vertical slit on the annular particle detector. Values of $\text{¦g¦= 0.51 ± 0.02}\text{and}\text{0.54 ± 0.04}$ have been deduced for the ²⁴Mg and ²⁰Ne g-factors, respectively. The mean lives of these states have been determined as τ_m = 2.09 ± 0.13 ps and 0.8 ± 0.2 ps, respectively. Various theoretical calculations are discussed and compared with the measured g-factors.The analysis of the measurement also yields values for the populations of electronic states contributing to the hyperfine interaction. For ²⁰Ne the populations of the different electronic configurations are compared with the results of a separate time-integral measurement, in which the correlations were measured for each ionic state separately. Large fractions of two-electron excited states are found to contribute.     

Isospin-forbidden particle decays in light nuclei: (II). Widths of T = 32 levels of 17O

The lowest four $\text{T =}\text{3}\text{2}$ levels of ¹⁷O have been observed as resonances in the ¹³C(α, n)¹⁶O reaction. Excitation energies and widths obtained for these levels are 11.076 ± 0.005 MeV, Γ_c.m. = 5.0 ± 1.1 keV; 12.458 ± 0.005 MeV, Γ_c.m. = 8 ± 2 keV; 12.944 ± 0.006 MeV, Γ_c.m. = 6 ± 2 keV; 12.993 ± 0.006 MeV, Γ_c.m. < 3 keV. The total and partial decay widths for the lowest $\text{T =}\text{3}\text{2}$ level are much larger than those of the analogue level in ¹⁷F, implying significant isotensor components in the $\text{T =}\text{1}\text{2}$ admixtures.