The infrared spectrum of 12C32S and 12C34S

The 2-0 vibration-rotation bands of ¹²C³²S and ¹²C³⁴S near 2530 cm^?1 have been measured with a high resolution spectrometer. The spectroscopic constants for these bands are given, as well as an improved set of Dunham coefficients for the X¹Σ⁺ state of ¹²C³²S.     

The ν3 band of 16O12C34S and 16O13C34S

The ν₃ fundamental of OCS has been measured with a resolution of about 0.03 cm^?1 for the isotopic species ¹⁶O¹²C³⁴S and ¹⁶O¹³C³⁴S. The associated transition 01¹1-01¹0 has also been measured. The transition 10⁰1-00⁰0 is also reported for the ¹⁶O¹²C³⁴S species.     

Heterodyne frequency measurements (at 11.6 μm) on isotopic species of carbonyl sulfide,OC34S,O13CS,OC33S, 18OCS,and O13C34S

Heterodyne frequency measurements between a frequency-stabilized ¹³CO₂ reference laser and a tunable diode laser (either tuned or locked to various carbonyl sulfide absorption peaks) have been made on a number of 10⁰0-00⁰0 band transitions in the isotopic species of carbonyl sulfide: OC³⁴S, O¹³CS, OC³³S, ¹⁸OCS, and O¹³C³⁴S. These OCS frequency measurements have been combined with existing microwave data and new sets of molecular constants obtained. These constants will be used later to form part of a frequency calibration compendium based on OCS.     

Multi-nucleon transfer near the coulomb barrier induced by 32S and 34S

Neutron excess targets of ⁷⁶Ge, ^92,94,96Zr and ¹⁰⁰Mo have been bombarded with ³²S and ³⁴S at beam energies around the Coulomb barrier. Multi-nucleon transfer reactions involving 3p, 4p, 3pn, 4pn (projectile → target) and 3n, 4n, 6n (target → projectile) have been observed by measuring the corresponding back-scattered radioactive products like ²⁹Al, ²⁸Mg, ²⁸Al, ²⁷Mg, ³⁷S and ³⁸S. In some cases excitation functions and angular distributions have been measured.     

Absolute frequency measurements of 12C16O and 13C16O laser transitions

The absolute frequencies of one 5.2 μm ¹²C¹⁶O laser line and one 5.3 μm ¹³C¹⁶O laser line have been measured against 10 μm band transitions of the CO₂ laser by heterodyning in a tungsten-nickel diode. The frequencies, wavelengths and wave numbers of these lines are reported to an accuracy of one part in 10⁷.     

High-resolution Fourier transform infrared spectra of 12C32S, 12C33S, 12C34S,and 13C32S

The v = 1-0 infrared absorption bands of the ¹²C³²S, ¹²C³³S, ¹²C³⁴S, and ¹³C³²S isotopes and the v = 2-1 “hot” band of ¹²C³²S all in the ground electronic state were measured using a high-resolution Fourier transform spectrometer coupled to a long-path absorption cell. P- and R-branch transitions, up to J = 41 for ¹²C³²S, have been measured at 0.004 cm⁻¹ unapodized resolution. Rotational and centrifugal distortion parameters which are improved over those obtained in previous diode laser measurements for the less abundant ¹²C³³S and ¹³C³²S isotopes are reported. Improved v = 1-0 band origins of the various isotopes are also reported. Analysis included published microwave data along with the present IR measurements. The present results are compared with previous infrared diode laser, Fourier transform spectrometer, and microwave measurements.     

13C16O2, 13C18O2: Emission spectra in the 4.5-μm region

In this paper the same kind of results are given for ¹³C¹⁶O₂,and ¹³C¹⁸O₂ as for ¹²C¹⁸O₂ [D. Bailly and C. Rossetti, J. Mol. Spectrosc.105, 215–228 (1984)]. Forty seven vibrational bands are analyzed from which spectroscopic constants are computed. These constants reproduce wavenumbers with a RMS of the order of 3 × 10^?5 cm^?1 for the best measurements. For each species, a set of molecular parameters is given for Σ-Σ transitions.     

Static moments of the first excited states of 32, 34S and 204, 206Pb

The reorientation effect in Coulomb excitation has been used to measure the following static quadrupole moments: $\text{Q}{}_2\text{+ (}{}^{32}\text{S}\text{) = ?0.066 ± 0.017}\text{b}\text{, Q}{}_2\text{+ (}{}^{34}\text{S}\text{) = 0.026 ± 0.023}\text{b}\text{, Q}{}_2\text{+ (}{}^{204}\text{Pb}\text{) = 0.19 ± 0.14}\text{b}$. Interference effects from higher excited states have been included in the analysis, with the signs of the E2 matrix elements taken from an anharmonic model. The value obtained for $\text{Q}{}_2\text{+ (}{}^{32}\text{S}\text{)}$ is in disagreement with two previous measurements. We attribute the discrepancy to the smaller internucleon separation distances involved in the previous experiments, which can cause deviations from Coulomb excitation cross sections. The other quadrupole moments have not been measured previously. The B (E2: 0⁺ → 2⁺) measured were: $\text{0.0305 ± 0.0016 e}{}^2\text{·}\text{b}{}^2\text{(}{}^{32}\text{S}\text{), 0.025 ± 0.004 e}{}^2\text{·}\text{b}{}^2\text{(}{}^{34}\text{S}\text{),}\text{and}\text{0.166 ± 0.009 e}{}^2\text{·}\text{b}{}^2\text{(}{}^{204}\text{Pb}\text{)}$. From the angular distribution of the de-excitation γ-rays of the Pb nuclei following recoil into vacuum, we have determined the following $\text{g-}\text{factors}\text{: ¦g}{}_2\text{+ (}{}^{204}\text{Pb}\text{)¦ < 0.08}$ (two standard deviations), $\text{¦g}{}_2\text{+ (}{}^{206}\text{Pb}\text{)¦ = 0.07}{}^{\mathrm{+\; 0.07}}{}_{\mathrm{?\; 0.03}}$. Our value of $\text{g}{}_2\text{+ (}{}^{206}\text{Pb}\text{)}$ is in agreement with a previous measurement.     

Four-nucleon transfer with the 32S(16O, 12C)36Ar reaction

Angular distributions have been measured for the ³²S(¹⁶O,¹²C)³⁶Ar reaction at 45.5 MeV leading to excited states between E_x, = 0 and 8 MeV. Experimental cross sections are compared with exact finite-range DWBA calculations in combination with extensive shell-model calculations, which include sd- and fp-shell configurations. Transitions to low-energy positive-parity states and bound negative-parity states are well reproduced. The calculations, however, fail to describe some high-energy positive-parity states. Calculations with a complete cluster expansion for the four transferred nucleons give about 50% larger cross sections, but can not explain the observed discrepancies. Possible interference of reaction processes other than direct α-transfer and special structure effects are discussed.     

Photoneutron cross section of 34S

Using an enriched ³⁴S target, the reaction ³⁴S(γ, sn) has been measured from below threshold (10.4 MeV) to 28 MeV by directly counting the photoneutrons as a function of bremsstrahlung energy. The resultant cross section shows gross splitting in the GDR region. The integrated cross section is discussed in the light of the systematics of similar nuclei having two neutrons outside a doubly closed shell/sub-shell core.     

Isospin and symmetry structure in 34S

The interacting boson model-3(IBM-3) has been used to study the energy levels and electromagnetic transitions for the nucleus 34 S.The main components of the wave function,isoscalar and isovector parts in the M1 and E2 transitions for low-lying states have been investigated.According to this study,the theoretical calculations are in agreement with experimental data,and the nucleus 34 S is in transition from U(5) to S U(3).     

~6Li~(32)S双原子分子的光谱和辐射跃迁理论研究

在aug-cc-pV5Z/CASSCF/MRCI水平上讨论了~6Li~(32)S双原子分子的9个较低能量电子态(X~2∏,a~4△,B~2△,b~4△,A~2∑~+,C~2∏,F~2∑~-,E~2∑~+和D~2∏)的势能函数和光谱常数;其中基态平衡核间距、谐振频率、转动常数等均与实验值相符;b~4∏,C~2∏,D~2∏态的平衡核间距均超过了0.4 nm,并且离解能较小,不稳定.D~2∏态是离子对态,离解极限为Li~+(~1S_g)+S~-(~1S_g).预测了最低激发态A~2∑~+跃迁到基态X~2∏的电子跃迁偶极矩、爱因斯坦自发发射系数、弗兰克-康登因子和辐射寿命.     

Elastic scattering of neutrons from 28Si and 32S

The excitation functions in the elastic scattering of neutrons have been measured at several angles in the energy range 600–3600 keV. Data have been analyzed in terms of the Ericson fluctuation and energy-averaged angular distributions have been analyzed using the optical model including Hauser-Feshbach theory.     

17Zn and 33S nuclear magnetic shielding in zinc chalcogenides

Narrow ⁶⁷Zn and ³³S NMR signals have been detected in powdered ZnS, ZnSe, and ZnTe. Large chemical shifts relative to aqueous reference solutions have been found. The nuclear magnetic shielding of ⁶⁷Zn in these solids is given in the absolute atomic reference scale together with the Knight-shift for the metallic state taken from literature.     

Search for intermediate structure in 36Ar via the 24Mg(12C, α)32S reaction

The ²⁴Mg(¹²C,α)³²S reaction was investigated in the energy range E_c.m. = 11.9–19.4 MeV by measuring excitation functions of the α₀ and α₁ groups. Angular distributions (θ_c.m. = 12–97°) were also measured at a number of energies. The excitation functions were subjected to a statistical analysis by means of evaluating correlation and deviation functions; no statistically significant anomalies were found. The α₀ angular distributions display fairly high angular-momentum selectivity as pairs of Legendre polynomials provide acceptable fits to most of them: however, only one, at E_c.m. = 18.1 MeV, is strongly dominated by a single partial wave, l = 11. Excitation functions as well as angular distributions of both α₀ and α₁ cross sections were found to be in good qualitative agreement with Hauser-Feshbach calculations throughout the energy range studied. Thus, the analysis of the data shows that intermediate resonant structures, if present, are weak and interfere strongly with the statistical compound-nucleus background, which effectively prevents their clear observation and identification in the present study.     

12C1 and 8Be production in 12C + 208Pb collisions

The mechanisms involved in the production of fast α-particles in ¹²C-induced reactions have been studied for the ¹²C + ²⁰⁸Pb system at the bombarding energies of E_12c = 132, 187 and 230 MeV. Absolute cross sections for the reactions ²⁰⁸Pb(¹²C. ¹²C¹→α + ⁸Be), ²⁰⁸Pb(¹²C, ⁸Be(g.s.)) and ²⁰⁸Pb(¹²C, ⁸Be(2.94 MeV)) have been determined by coincidence measurement of two or three correlated α-particles. Inclusive α-particle production cross sections were also measured at E_12c = 187 MeV. It is found that the inelastic process (¹²C, ¹²C¹→α + ⁸Be) does not contribute significantly to fast α-particle production but that the production of ⁸Be by projectile fragmentation is an important source of α-particles. At the highest bombarding energy (230 MeV) it appears that the ¹²C → 3α fragmentation reaction becomes more prominent at the expense of the ¹²C→α + ⁸Be fragmentation channel.     

16O, 24, 26Mg, 28Si, 32S, 40Ca(α, 12C) and multi-α-cluster transfer reactions

The (α, ¹²C) reaction has been studied on a variety of nuclei, A = 16 to 40, at E_α = 90.3 MeV. The data indicate a rapid fall-off of cross sections with increasing target mass, approximately as A_t^{?5 ± 1}. This and other systematics are used to estimate cross sections for multi-α-cluster transfer reactions in heavy nuclei and suggest σ_T < 10^?34 cm² consistent with present experimental limits. The data for ²⁴Mg(α, ¹²C)¹⁶O has been studied in more detail and indicates a selective population of final states including ¹⁶O g.s., with oscillatory angular distributions in some instances. Finite-range distorted-wave Born approximation calculations for direct ⁸Be pickup have been performed utilizing cluster overlap amplitudes obtained with zero-order SU(3) wave functions. The calculations are in qualitative, and often quantitative, agreement with shapes and absolute magnitudes of the measured angular distributions although the cross sections for certain α-cluster states (2⁺, E_x ≈ 7 MeV; 4⁺, E_x ≈ 10.3 MeV) are greatly overestimated with this model. Other more complicated mechanisms, such as successive α-transfer, cannot be excluded. The systematics of the calculated ⁸Be cluster overlaps and the calculated and measured (α, ¹²C) cross sections are investigated, and implications for multi-α-cluster transfer reactions are discussed.     

Determination of laser line frequencies and vibrational-rotational constants of the 12C18O2, 13C16O2, and 13C18O2 isotopes from measurements of CW beat frequencies with fast HgCdTe photodiodes and microwave frequency counters

The frequencies of ¹²C¹⁸O₂, ¹³C¹⁶O₂, and ¹³C¹⁸O₂ isotope lasers have been measured to better than 3 MHz (0.0001 cm^?1) by comparing with a ¹²C¹⁶O₂ reference laser. Heterodyne techniques were used to generate 139 difference frequencies in a liquid nitrogen cooled HgCdTe photodiode. Microwave frequency counter measurements of the difference frequencies were then used to calculate new values for the band centers and rotational constants of the rare isotopes. Procedures to achieve further improvements are discussed.     

Atomic antiproton states in 16O, 18O, 32S, 40Ca, 44Ca and 122Sn

Atomic levels for the systems p? plus ¹⁶O, ¹⁸O, ³²S, ⁴⁰Ca, ⁴⁴Ca and ¹²²Sn are calculated in optical potentials based on the N?N interaction of Dover and Richard.