The nuclear structure of198Au from the reaction197Au(n, γ)198Au

Precise energies and intensities of about 450γ-rays of the¹⁹⁷Au(n, γ)¹⁹⁸Au reaction have been investigated in the energy range from 30 keV to 1 MeV with a bentcrystal spectrometer. Prompt and delayedγ-γ coincidences have been studied with Ge(Li) detectors. A half-life of 124±4 ns has been measured for the state at 312.036 keV, which is found to decay to the ground state through the cascade 97.195–214.841 keV. A new level scheme based on these results has been constructed which contains 160 transitions. Spin and parity assignments have been made for most of the levels.     

Fission products from the197Au(d,f) reaction

Cumulative and independent fission product yields of the reaction¹⁹⁷Au(d,f) were determined at a beam energy of 80 MeV at the Jülich isochronous cyclotron. Off-beamγ-ray measurements applying a catcher foil technique and chemical separation, and in inbeam kinetic energy measurements of fission products were performed. The complete yield distribution of post neutron emission fission fragments is represented by a single function, consisting of the product of two Gaussians. The mass distribution is characterized by the widthσ _A =12.5amu. The width of theZ-distribution for eachA-chain is given byσ _Z =0.63amu.     

Spins of198Au levels from the (n, γ) reaction using polarized neutrons and polarized197Au nuclei

The¹⁹⁷Au(n, γ) reaction was studied with the aid of polarized thermal neutron beams. Two kinds of experimental data were obtained: i) circular polarization of gamma rays of high energy due to capture of polarized neutrons by unoriented¹⁹⁷Au nuclei, and ii) angular distribution of such gamma rays observed after capture of polarized neutrons by polarized¹⁹⁷Au nuclei. Spins of several levels of¹⁹⁸Au could be uniquely assigned or could be restricted. The sign of the hyperfine field of Au in AuFe has been determined to be negative.     

The t-dn vertex function and the (t,d) reaction

Estimates are made of the t-dn vertex function which is proportional to D², a multiplicative factor appearing in the differential cross section for (t, d) reactions at sub-Coulomb energies. The factor D² is calculated using various triton internal wave functions and also by using dispersion relations for d-n scattering. Calculations also are made of the ³He-dp vertex functions, as well as the factor D²₀ which appears in the differential cross sections at higher energies.     

Pole approximation in the quasi-free t + p scattering and the t(p,d)d reaction via the t + d interaction

The t(p,p)t and t(p,d)d channels have been investigated in an indirect way through the ²H(t,tp)n and ²H(t,dd)n three-body reactions performed at E _t = 35.5?MeV in quasi-free kinematics. The agreement with direct data supports the pole approximation at energies above the Coulomb barrier.     

The influence of distortions and other effects on theD(d,t)H reaction

The differential cross section for the reactionD(d, t)H has been calculated in the distorted wave Born approximation including finite range effects. All 6 interactions between the 4 nucleons are explicitly evaluated. It has been found that the interactions neglected by earlier work are significant. Distortions are necessary to reproduce the minimum at 37.5° observed at an incident energy of 25.3 MeV in the cross section. The absolute cross section at 14.3° is predicted by theory to be 23.5 mb/sr as against the experimental 16.4 mb/sr. Better agreement with experiment at backward angles may be obtained with the use of an expanded deuteron and the inclusion ofd-state effects.     

The (d,t) and (d,t) reactions on 18O and the 1p spin-orbit splitting

The reactions ¹⁸O(d, t)¹⁷O and ¹⁸O(d, τ)¹⁷N have been investigated at ifE_{d = 52 MeV}. Energy spectra of tritons and τ particles have been measured up to excitation energies of 25 MeV in ¹⁷O and 12 MeV ¹⁷N, respectively, and spectroscopic factors have been obtained by a DWBA analysis of the measured angular distributions. From a comparison of the t-and τ-spectra the distribution of $\text{T =}\text{1}\text{2}\text{and}\text{3}\text{2}$ spectroscopic strengths in ¹⁷O could be deduced and analog relations between $\text{T =}\text{3}\text{2}$ states in ¹⁷N and ¹⁷O could be established. Nearly the total $\text{T =}\text{3}\text{2}$ strengths of the $\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{and}\text{1}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ shells and nearly the complete $\text{T =}\text{1}\text{2}$ strength of the $\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ shell have been found, whereas only one third of the $\text{T =}\text{1}\text{2}$ strength of the $\text{1}\text{p}\text{3}\text{2}$. Shell could be clearly identified. The observed centroid energies are understood from the different $\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$$\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?}}\text{1)}$ and $\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ effective residual interactions. This supports a strong isospin dependence of the 1p spin-orbit splitting.     

Vector analysing power of the pick-up reaction C(d, t)C

The vector analysing power has been measured for the reaction ¹³C(d, t)¹²C initiated by 12.1 MeV polarized douterons and proceeding to the ground and 4.43 MeV states of ¹²C. Large analysing powers were observed especially for the ground state reaction. The results have been compared with the predictions of the distorted waves Born approximation and with data for the ¹²C(d, p)¹³C reaction     

The Ar(p, d)Ar reaction

The ³He spin analysing power of hydrogen (protons) has been measured at a c.m. energy of 20 MeV at 14 c.m. angles from 40° to 160°. The measurement of ³He target polarization was calibrated by measuring the ³He spin analysing power of ⁴He at an energy and angle where it was ?1.00. The proton-³He differential elastic scattering cross section is also reported at a c.m. energy of 20.0 MeV for 36 c.m. angles from 20° to 170°.     

(π, d) Pick-up reaction

The reaction π + A → d + B at low energy is studied in a one-step DWBA framework. The nuclear structure aspects of the reaction are investigated. The reaction involves mostly neutron or proton pairs of the target nucleus with large total momentum and with total spin equal to zero. In the case of even-even nuclei with a partially filled shell, the coherence of the contributions from different orbitals produces an enhancement of the ground state to ground state transitions. Distortion effects are found to be very large. The final-state interaction is crucial in bringing the magnitude of the differential cross section into satisfactory agreement with the experimental value.     

The (p,d) reaction at 65 MeV

The (p, d) reaction on ¹²C, ¹⁴N, ¹⁶O, ⁴⁰Ca and ⁹⁰Zr has been studied with 65 MeV incident protons. DWBA calculations have been carried out to investigate the importance of finite range and non-locality effects. The experimental angular distributions for the strong transitions have been compared to DWBA calculations to study the effect of the deuteron optical potential. This comparison supports the use of the adiabatic deuteron potential which includes the effect of deuteron breakup.     

The (t,p) reaction on the zinc isotopes

Multichannel spectrograph studies of the (t, p) reaction on the Zn isotopes have provided energy-level data, cross-section measurements and many new spin and parity determinations. The systematics of the energy spectra of the even zinc isotopes are discussed.     

The 198Au βhalf-life in the metal Au⋆

For the β^--decay of ¹⁹⁸Au in a Au metallic environment the half-life was observed to be longer by 0.4±0.7% at room temperature (T = 293K) and by 4.0±0.7% when the metal was cooled to T = 12K, both compared to the literature value of T _1/2 = 2.6943±0.0008d.     

Some (γ, π− xn) reactions on197Au at intermediate energies

The yields for some (γ, π ^? xn)-reactions on¹⁹⁷Au have been measured from threshold to 750 MeV by use of the activation method. The experimental mean cross sections are compared to results obtained from other experiments on similar reactions and to cascade-evaporation calculations.     

On the (d,Li) reaction

General features of the (d, ⁶Li) reaction are discussed in connections with some residual forces. An enhancement of ground state transitions among superconducting nuclei is found. Some examples in the lp shell are also worked out and coherence is found between the T = 0 and T = 1 channels of the residual force.     

The C13(d,α)B11 reaction

Russian Physics Journal -     

The46Ti(d,τ)45Sc reaction

The⁴⁶Ti(d, τ)⁴⁵Sc reaction has been investigated at an incident energy of 52 MeV. Angular distributions have been taken for 14 τ-groups corresponding to excitation energies below 4 MeV in⁴⁵Sc. Spectroscopic factors were extracted through DWBA calculations. Spins and parities of 5/2⁺ are proposed for states at 1.30, 1.80, 2.91, 3.48, and 3.72 MeV. The hole state spectrum of⁴⁵Sc closely resembles that of⁴⁷Sc. A strong fractionation of the 1d _3/2 strength was not observed in contrast to other recent work. The data provide evidence for (1f _7/2 · 1f _5/2 ¹) components in the ground state wave function of⁴⁶Ti, which demonstrates that such configurations are not restricted to neutron excitations.