The d(7Li,p)8Li cross section near E cm = 0.61 MeV

The absolute cross section σ of the d(⁷Li, p)⁸Li reaction near the E_cm = 0.61 MeV resonance has been measured using a ⁷Li ion beam and a windowless gas target system filled with D₂ gas. The proton yield of the reaction and the β-delayed α-activity of the residual nuclides ⁸Li were observed both concurrently with the elastic scattering yield, relating σ to the Rutherford scattering cross section σ_R. The resulting values, σ (from p) = 143.6 ± 8.9 mb and σ (from ⁸Li) = 151 ± 20 mb, lead to a weighted mean value of σ = 153 ± 6 mb (χ² = 2.26) including all available values and σ = 146 ± 5 mb (χ² = 0.05) removing some values from the data set. The consequences for the expected flux of high-energy solar neutrinos are discussed.     

Measurement of (p,n) and (n,p) reactions on 6Li and 7Li at 800 MeV

The measured ⁷Li(p,n), and ⁶Li(n,p) cross sections at 0° show a high-energy peak (≈25 MeV/c FWHM) which we attribute primarily to nuclear charge exchange leading to final states in ⁷Be, ⁶Be, and ⁶He, respectively. By contrast, the ⁷Li(n,p) cross section at O° shows a broad weak high-energy peak believed due mostly to break-up processes. At 16°, the ^6,7Li(n,p) cross sections are dominated by quasi-elastic scattering.     

A test for the Cohen-Kurath wave functions in (p,d)-reactions

The experimental data for (p, d)-reactions on the 1p-shell nuclei atE _p –33 MeV are used to test the Cohen and Kurath wave functions and the intermediate coupling. The experimental excitation energies and their order for all law transitions of the 1p-shell nuclei are compared with the theoretical predictions of Cohen and Kurath. The integrated cross-sections (0–90) for these transitions are also compared with their theoretical predictions for one-neutron pick-up. The good agreement between these data indicates a success for the Cohen-Kurath wave functions and for their model of calculations.     

Optical model analysis of28Si(d,d) angular distributions in the rangeE d =5.1–12.8 MeV

Elastic scattering of deuterons on²⁸Si was measured in the energy range of 1.5–6.5 MeV. An optical model analysis was performed at 5.1, 5.3, 5.5, 5.7, 5.9, 6.5, 9.0, 10.0, 10.9, 11.8 and 12.8 MeV. Good fits could be obtained in most cases. In order to get the energy dependence of the optical model parameters, straight lines were fitted to the values obtained at the different energies. A detailed study of the optical model parameter ambiguities was carried out. Transmission coefficients have been calculated from the optical potentials obtained.     

Thed(7Li,p)8Li cross section nearE cm=0.61 MeV

The absolute cross sectionσ of thed(⁷Li,p)⁸Li reaction near theE _cm=0.61 MeV resonance has been measured using a⁷Li ion beam and a windowless gas target system filled with D₂ gas. The proton yield of the reaction and theβ-delayedα-activity of the residual nuclides⁸Li were observed both concurrently with the elastic scattering yield, relatingσ to the Rutherford scattering cross sectionσ _R. The resulting values,σ (fromp)=143.6±8.9 mb andσ (from⁸Li)=151±20 mb, lead to a weighted mean value ofσ=153±6 mb (x ²=2.26) including all available values andσ=146±5 mb (x ²=0.05) removing some values from the data set. The consequences for the expected flux of high-energy solar neutrinos are discussed.     

DWBA Analysis of Polarization of Protons from the 9Be(d,p0)10Be Reaction at Ed = 6.0; 7.8 and 10.0 MeV

The polarization of protons from the ⁹Be(d, p₀)¹⁰Be reaction has been analyzed in terms of the DWBA theory at the deuteron energies 6.0, 7.8, and 10.0 MeV.     

Role of the RMS radius in DWBA calculations of the (p,d) reaction

The single-neutron pick-up reaction cross sections appear to be better correlated with the rms radius of the neutron orbit rather than with r₀, the radius parameter of the single-particle Woods-Saxon well. Form factors which correspond to particles bound by the experimental separation energies and which have rms radii for the $\text{2}\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, 1}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{and}\text{1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ orbits obtained from Coulomb energy shifts, lead to spectroscopic factors and S_>/S_< ratio for the ^46,48,50Ti(p, d) reactions which are in a much better agreement with theoretical expectations than those obtained with constant r₀.     

Five-nucleon transfer in the12C(d,7Li)7be reaction atE lab=78.0 MeV

Angular distributions of the¹²C(d,⁷Li)⁷Be reaction to the ground and to the unresolved first excited states of⁷Li or⁷Be nuclei were measured in the entire angular region in the centre of mass system atE _lab=78.0 MeV. Both the one-step five-nucleon cluster transfer as well as two-step sequential transfers were considered in the theoretical analysis. The former mechanism was found to dominate, but the latter is also not negligible.     

DWBA analysis of (3He,d) reactions at 90MeV and contributions from the nuclear interior

Differential cross sections of ³He elastic scatterings and (³He, d) reactions have been measured at 90 MeV for ²⁸Si, ⁵⁴Fe, ⁵⁸Ni, ⁹⁰Zr and ¹²⁴Sn. From the optical-model analysis of the elastic scattering, both shallow ($\text{V ? 105}\text{MeV}$) and deep ($\text{V ? 150}\text{MeV}$) potentials of ³He were obtained. The shallow potentials correspond to the ones which were determined uniquely from other measurements extended to more backward angles. The (³He, d) reactions have been analyzed with the DWBA using the shallow and deep potentials for ³He. The calculations using the deep potentials reproduced the data well, but those using the shallow ones did not. The contributions from the nuclear interior were investigated through the radial cutoff in the DWBA. The calculations using the shallow potentials reproduced the data well when the radial cutoffs were introduced. The effects of the radial cutoff were very small when the deep potentials were used. It was found that a much greater reduction of the contributions from the nuclear interior was needed when the shallow potentials were used in the DWBA calculations.     

Fluctuations in 88Sr(p,p0) and 90Zr(p,p′) in the energy region from 12 MeV TO 13 MeV

The low cross sections in the diffraction minima of elastic proton scattering at 12.5 MeV incident energy and far backward scattering angles for target nuclei with mass numbers A of about 90 were used to investigate compound nucleus effects in the framework of the statistical model. In the case of ⁹⁰Zr(p, p′) energy averaged T^< fluctuations are observed, while in the case of ⁸⁸Sr(p, p₀) resolved structures with a coherence width of Γ = 22 keV are found, which is assumed to be the coherence width Γ^> of overlapping T^> states.     

A microscopic DWBA analysis of (6Li, 6He) reactions

The spin-isospin flip (⁶Li, ⁶He) reaction has been studied. The experiment was performed with a 34 MeV ⁶Li beam incident upon ^{25, 26}Mg and ²⁷Al targets. Angular distributions associated with the lowest $\text{5}\text{2}{}^{\mathrm{+}}\text{,}\text{1}\text{2}{}^{\mathrm{+}}\text{,}\text{7}\text{2}{}^{\mathrm{+}}{}^{25}\text{Al}\text{, 5}{}^{\mathrm{+}}\text{, 3}{}^{\mathrm{+}}\text{, 1}{}^{\mathrm{+}}{}^{26}\text{Al and}\text{5}\text{2}{}^{\mathrm{+}}{}^{27}\text{Si}$ states were measured. Microscopic DWBA calculations were performed using Yukawa central and r². Yukawa (r² · Y) tensor (μ = 1.0 fm^?1) potentials averaged over the ⁶Li(⁶He) cluster model wave functions. Knock-on (KO) exchange corrections corresponding to the central interaction are included using the local-energy approximation (LEA) method. The conclusion is that the quasi-elastic process is of major importance in the (⁶Li, ⁶He) transition studied in this work.     

Phase-shift analysis of πp scattering in the energy region from 160 to 600 MeV

A phase shift analysis ofπN scattering has been carried out at 18 discrete energies in the region 160–600 MeV. Charge splitting of theP ₃₃ phase shift (～-2 degree) is observed with a change of sign at ～-350 MeV and vanishing at ～-600 MeV. Marked deviations from an earlier analysis are found forS andP-amplitudes as a result of using new precision data and an untraditional method of the analysis.     

The (d,p) Reactions below 3.0 MeV

Excitation functions for a number of proton groups for the reactions ²³Na(d, p)²⁴Na and ²⁷Al(d, p)²⁸Al were measured in the energy range E_d = 1.5 to 3.0 MeV. The angular distributions for a number of proton groups were measured at a number of deuteron energies below 3.0 MeV for the three reactions ¹²C(d, p)¹³C, ²³Na(d, p)²⁴Na and ²⁷Al(d, p)²⁸Al. The theory of deuteron stripping reactions at incident energies below the Coulomb barrier has been considered. A closed analytical form for the differential cross-section has been obtained considering three cases according to the incident deuteron and outgoing proton energies. An attempt has been made to fit the angular distribution measurements at a number of deuterons bombarding energies accordingly.     

Excitation functions for48Ca(d,p)49Ca(0) in the rangeE d=3.0–5.5 MeV

Excitation curves for⁴⁸Ca(d, p)⁴⁹Ca(0) have been measured at 12 angles in the energy region from 3.0–5.5 MeV with the aim to investigate the charge exchange effect expected at the analogous (d, n) threshold opening at 4.3 MeV. A broad flat minimum is seen in the 165° excitation curve around this threshold which is however much less significant than the charge exchange cusps observed in theA ≈ 90 mass region. More significant structure is seen atE _d≈5 MeV which possibly may be connected with⁴⁸Ca(4.611) core excitation or due to an intermediate state in⁵⁰Sc.     

The45Sc(3He,d)46Ti reaction. DWBA analysis of transitions to states between 7.6 and 11.0 MeV

Angular distributions of transitions to 29 states in⁴⁶Ti between 7.6 and 11.0 MeV excitation energy from the⁴⁵Sc (³He,d) reaction at 15 MeV have been compared with DWBA predictions. The results support previously suggestedT=2 states in⁴⁶Ti.     

A study of reaction mechanisms for the Li(p, 2d)He reaction at 45 MeV

The first kinematically complete experiment involving a (p, 2d) reaction is reported. It is found that at 45 MeV bombarding energy a significant part of the ⁷Li(p, 2d)⁴He reaction cross section arises from contributions from sequential decay processes through excited states of ⁶Li. A new three-body break-up mechanism involving the quasi-free interaction of the proton with the bound triton is discussed.     

Reaction rate of8Li(d,t)7Li

The astrophysical S(E) factor of⁸Li(d,t)⁷Li has been deduced from available data of the inverse reaction⁷Li(t,d)⁸ Li and is consistent with data of direct measurements in the overlapping energy range. The deduced reaction rate at T₉=1 is about an order of magnitude higher than assumed previously.