The γ-decay of the g92 analogue state in 59Cu

An investigation of the γ-decay of the $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ analogue state in ⁵⁹Cu has been performed using the ⁵⁸Ni(p, γ)⁵⁹Cu reaction. The (p, γ) excitation function has been taken in the range E_p = 3450–3650 keV. The decay schemes of the (p, γ) resonances at E_p = 3483, 3532 and 3547 keV, measured with Ge(Li) detectors, lead to eight new levels in ⁵⁹Cu with excitation energies between 1.8 and 4.7 MeV and to spin assignments of several states. The spins of the first two resonances are found to be ($\text{1}\text{2}$, $\text{3}\text{2}$) and ($\text{5}\text{2}$). The spin of the E_p = 3547 keV resonan is, from angular distributions, uniquely determined to be $\text{J}{}^{\mathrm{\pi }}\text{=}\text{9}\text{2}{}^{\mathrm{+}}$ and this state is found to be the unfragmented analogue state of the $\text{E}{}^1\text{= 3.062}\text{MeV}$, $\text{J}{}^{\mathrm{\pi }}\text{=}\text{9}\text{2}{}^{\mathrm{+}}$ parent state in ⁵⁹Ni. The measured complete decay scheme of this resonance shows that its isovector M1 decay is in disagreement with all existing theoretical predictions.     

f72 neutron occupancies in the Ca isotopes

Methods of obtaining nucleon occupancies from total energy-weighted sum rules for spectroscopic factors are described and applied to $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ neutron transfer data for Ca isotopes. The $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ neutron occupancies obtained are consistent with shell model expectations and, for ⁴¹Ca and ⁴³Ca, with values previously obtained from an analysis using non-energy-weighted sum rules.     

Hyperfine interaction in the 4D32 and the 4D52 levels of sodium

We have excited the $\text{4D}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ and $\text{4D}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ levels of sodium using Doppler-free two-photon excitation. By measuring the polarization rate in zero magnetic field of the fluorescence lines, we have deduced the following values for the hyperfine interaction $\text{|A(}\text{4D}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{) | =}\text{0.23 ± 0.12 MHz}$ and $\text{|A(}\text{4D}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)| <}\text{0.28 MHz}$. The value of $\text{A(}\text{4D}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{)}$ is in disagreement with the one reported by Schenk and Pillof.     

The d52 analog strength in 59Cu

Isobaric analog states of the strongest $\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ parent states in ⁵⁹Ni were investigated in the reaction ⁵⁸Ni + p. Proton spectroscopic factors were derived whose sum was found to be in good agreement with the sum of the parent strengths. The absolute transition probability of the E1 γ-decay populating the ⁵⁹Cu ground state was estimated and compared with single-particle predictions.     

Gamma-ray spectroscopy of 64Zn and 65Zn and the role of the g92 orbital

Measurements of γ-ray excitation functions, γ-γ coincidence spectra and γ-ray angular distributions have been made. following the reactions ⁶¹Ni(α, n)⁶⁴Zn, ⁶²Ni(α, n)⁶⁵Zn, ⁵⁶Fe(¹⁴N, αnp)⁶⁴Zn, ⁵⁶Fe(¹²C, 2pn)⁶⁵Zn, and ⁵⁴Fe(¹²C, 2p)⁶⁴Zn. Among the new levels observed in ⁶⁴Zn are those at 5624 keV, 6765 keV, 6940 keV, and 6124 keV, the last one with a suggested assignment of (9^?). In ⁶⁵Zn. ten new levels probably in the positive-parity chain, with spin up to ($\text{21}\text{2}$), and a few others, have been found. Comparison of the ⁶⁵Zn positive-parity levels with the ⁶⁴Zn ground-state band supports the concept of a single neutron in the $\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ orbital weakly coupled to a core essentially identical to ⁶⁴Zn. Many high-spin states in ⁶⁴Zn itself can be aggregated into bands whose band heads are suggestive of two-quasiparticle states involving one $\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ excitation.     

Gamma-ray spectroscopy of 66Zn and 67Zn and the role of the g92 orbital

Measurements of γ-ray yield functions, γ-γ coincidence spectra and y-ray angular distributions following the ⁶⁴Ni(α, n) and (α, 2n) reactions have been made. Beam energies of 17 to 25 MeV were used. Among the new levels observed, with their proposed spin-parity assignments, are: in ⁶⁶Zn, 3708 keV, (5)⁺; 3896 keV, 5^?; 4812 keV, (7^?); 5110 keV, (8^?); 6417 keV; (10^?); 7516 keV, (12⁺); and in ⁶⁷Zn, 2937 keV, $\text{13}\text{2}{}^{\mathrm{+}}$; 3491 keV, $\text{17}\text{2}$ or $\text{19}\text{2}$; 3492 keV, ($\text{13}\text{2}$(si+)); 4221 keV, ($\text{19}\text{2}$^?); 4631 keV, ($\text{21}\text{2}{}^{\mathrm{+}}$); 4685 keV, ($\text{21}\text{2}$^?). Comparison between the ground-state sequence, 0⁺ to 6⁺, in ⁶⁶Zn and the first $\text{9}\text{2}$⁺ to $\text{21}\text{2}$⁺ levels in ⁶⁷Zn strongly suggests that the latter be described as a g_{$\text{9}\text{1}$} neutron orbital weakly coupled to the ⁶⁶Zn core. Other sequences of high-spin ⁶⁶Zn states are proposed to be formed from two-quasiparticle states containing the g_{$\text{9}\text{2}$} excitation, coupled to the same ground-state sequence.     

The binding energy of the deeply bound 0g92 hole coupled to active protons in the same shell

The binding energy of the $\text{0}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ hole state observed in neutron pick-up reactions is calculated in the framework of the shell model. Isospin symmetry and coupling between the hole and active protons in the same shell are taken into account.     

Infrared reflectivity analysis of perovskite ceramics Sr(Sr13Nb23)O3

The infrared reflection of polycrystalline samples of perovskite $\text{Sr(Sr}{}_{\mathrm{<mtext>1</mtext><mtext>3</mtext>}}\text{Nb}{}_{\mathrm{<mtext>2</mtext><mtext>3</mtext>}}\text{)O}{}_3$ are reported and analysed with Kramers-Kronig inversion. Results give information on the structures of the high-temperature and low-temperature forms of the atomic arrangements.     

The distribution of 3p12 strength in 209Bi

An optimized Woods-Saxon potential, which gives excellent fits to the observed proton states in ²⁰⁹Bi and ²⁰⁷Tl, is used to calculate the excitation energy of the unbound $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ proton state in ²⁰⁹Bi. Using the wave functions given by the above potential, the strength of the core-particle interaction is calculated. The effect of the vibration of the core on the fragmentation of the $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state is estimated. It is found that the $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state at 5.123 MeV loses more than 80% of its strength to five $\text{1}\text{2}{}^{\mathrm{?}}$ collective states in ²⁰⁹Bi and the observed $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state at 3.64 MeV is actually an almost equal mixture of the $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ single-proton state and the ($\text{4}{}^{\mathrm{+}}\text{, 1}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$) collective state.     

The γ-decay of the 1g92 and 2p inner-hole states in 111Sn via the 112Sn(3He, αγ) reaction at 32 MeV

The γ-decay of the deeply-bound hole states in ¹¹¹Sn has been investigated at 32 MeV incident energy by means of the ¹¹²Sn(³He, αγ) reaction. The α-particles emitted near 0° were detected in a Si counter located at the image plan of the superconducting solenoidal spectrometer SOLENO. The γ-rays in coincidence with the α-particles were detected by two Ge(Li) detectors located at 90° and 142° with respect to the beam direction, respectively. Energies, spins and decay schemes have been established for the low-lying states up to 2.5 MeV excitation energy in ¹¹¹Sn. The γ-decay of the broad bump, located around 4.2 MeV and previously attributed to neutron pick-up from the inner $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{, 2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{,}\text{and}\text{2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ neutron. Subshells, reveals the importance of quasiparticle-phonon m the spreading mechanism of the inner-hole strengths. The $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ and 2p strength functions have been deduced from the α-decay of the enhanced structures (3 ≦ E_x≦ 8 MeV). They are compared to the ones measured in previous inclusive neutron pick-up experiments and to those calculated in the framework of the quasiparticle-phonon nuclear model.     

The 1h92 proton orbit size in 209Bi

Angular distributions of α-particles from the reaction ²⁰⁹Bi(t, α)²⁰⁸Pb (ground state) have been measured at bombarding energies E_t = 8.5 MeV and E_t = 9.0 MeV. Zero-range (ZR) DWBA analyses of the data are used to determine the radial extent of the wave function of the $\text{lh}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ orbit in which the transferred proton is bound in ²⁰⁹Bi. The applicability of the sub-Coulomb ZR DWBA treatment is investigated by comparison of ZR and exact finite-range DWBA calculations. A value of the (t, α) normalization constant of (20.8 ± 3.1) × 10⁴ MeV² · fm³, based on forward dispersion relations, has been obtained from this comparison. The asymptotic amplitude of the wave function is measured directly and the rms radius is extracted via a Woods-Saxon model. A value of √〈r²〉 = 6.10_?0.08^+0.12 fm, corresponding to a point proton and to a local Woods-Saxon potential, is obtained. The rms radius and radial wave function of the $\text{1}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ proton are compared with the results of electron scattering and muonic atom data on targets of ²⁰⁹Bi and ²⁰⁸Pb and with the results of Hartree-Fock calculations.     

Detection of the 6 D52 − 6 S12 double quantum transition in ionized heliun

The $\text{D}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{? S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ double quantum r.f. transition in the n = 6 state of ionized helium has been observed using electron impact excitation in a helium atmosphere. The possibilities of the method are discussed.     

2p32 Alignment of silver by 0.1–5.1 MeV proton impact ionization

The $\text{2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ alignment of silver following 0.1–5.1 MeV proton impact ionization has been determined from the polarization of the L₃M₁ X-ray transition, as measured by a Johansson-type crystal spectrometer. The results were corrected for thick target effects and are in agreement with the results of thin target measurements as well as theoretical predictions.     

The l-forbidden 1i112 → 2g92 M1 transition in 209Pb

The mean lifetime of the 0.78 MeV first excited state in ²⁰⁹Pb was measured by the recoil distance method to be τ_m = 11.1±1.3 ps. The B(M1) for the l-forbidden transition is in good agreement with one of several recent theoretical predictions.     

The l-forbidden 3p32 → 2f52M1 transition in 207Pb

The branching ratio for the transition from the 0.90 MeV second excited to the 0.57 MeV first excited state in ²⁰⁷Pb has been measured to be (0.59 ± 0.09)%. The corresponding B(M1) exceeds recent theoretical predictions.     

On the question of fine structure in νp and EK for 233U and 235U

The question of fine structure in the variation of the average number of prompt neutrons, $\text{ν}{}_{\mathrm{<mtext>p</mtext>}}$, emitted per fission with energy in the neutron fission of ²³³U and ²³⁵U has been examined. Consistent structure has been found in measurements of both $\text{ν}{}_{\mathrm{<mtext>p</mtext>}}\text{and}\text{E}{}_{\mathrm{<mtext>K</mtext>}}$ (the average total fission fragment kinetic energy) for ²³³U. Channel analysis of the neutron fission cross section of ²³³U allows the structure to be calculated quantitatively provided the collective energy at the second hump in the fission barrier is weakly coupled to the nuclear degrees of freedom at scission. A similar calculation for neutron fission of ²³⁵U supports the case for the absence of fine structure in $\text{ν}{}_{\mathrm{<mtext>p</mtext>}}\text{and}\text{E}{}_{\mathrm{<mtext>K</mtext>}}$ for this nucleus.     

Magnetic moment of the 1h113 single-proton state in 141pr

A magnetic dipole core polarization was studied by investigating a magnetic moment of the 1117 keV $\text{1}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ single-proton state in ¹⁴¹Pr. The ¹³⁹La(α, 2nγ)¹⁴¹Pr reaction was used to populate the $\text{1}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ state with spin aligned in a plane perpendicular to the beam axis. The magnetic moment was obtained by measuring perturbed angular distributions of the 972 keV gamma rays from the $\text{1}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ state. The g-factor of the $\text{1}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ state in ¹⁴¹Pr was determined to be g = 1.30 ± 0.08. The isovector spin g-factor was deduced from the present result and the data for $\text{1}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$. neutron states. It is $\text{g}{}_{\mathrm{s?}}{}^{\mathrm{<mtext>eff</mtext>}}\text{g}{}_{\mathrm{s?}}{}^{\mathrm{<mtext>free</mtext>}}\text{= 0.45 ± 0.1}$. The reduction is explaine spin-isospin (M1) core polarization.The isovector M1 core polarization factor (nuclear M1 susceptibility) is found to be one third of the M2 core polarization factor (nuclear M2 susceptibility) for the $\text{1}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ state.     

Flux peaking of channeled ions in interstitial compounds NbO and ZrO13

A double flux peaking has been observed in a planar channeling of a NbO single crystal, while a single peak has been seen on a $\text{ZrO}{}_{\mathrm{<mtext>1</mtext><mtext>3</mtext>}}$ crystal. The experimental results are compared with an analytical calculation based on the continuum model.     

Parity violating neutral current interactions and 2S12→2S′12 transitions in hydrogenic ions

Measurement of parity nonconservation in magnetic dipole transitions between Zeeman split $\text{2}\text{S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ states in hydrogenic ions is considered as a probe of the weak neutral current interaction between electrons and nucleons.