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.     

Polarization of protons from the C(d,p)C reaction

The polarization of protons from the ¹²C(d, p)¹³C reaction has been measured for deuteron bombarding energies between 3.9 and 5.8 MeV. Angular distributions of the polarization for protons leaving ¹³C in its ground state have been measured for laboratory angles between 10° and 135° at several energies in the vicinity of a resonance at 4 MeV in order to determine the effect of that resonance on the polarization. Additional measurements were made at 0.4 MeV intervals throughout the energy range. These measurements demonstrate that the compound-nuclear resonances observed in the cross section do not significantly alter the polarization angular distributions except at back angles. The shape of the observed polarization angular distributions at all energies is quite similar to previous results obtained for deuteron bombarding energies up to 15 MeV.     

An DWBA Analysis of the Angular Distribution and Polarization of Neutrons from the Reaction 12C(d,n0)13N in the Deuteron Energy Range 1.7–2.8 MeV

The angular distribution and the polarization of neutrons from the reaction ¹²C(d, n₀)¹³N in the deuteron energy range 1.7–2.8 MeV have been analyzed in terms of the DWBA theory.     

Polarisation der Protonen aus der Reaktion10B(d,p 0)11B bei Deuteronenenergien von 1,15, 1,40 und 1,85 MeV

Angular distributions of the polarization of protons from the reaction¹⁰ B(d, p ₀)¹¹ B have been measured between 20 and 148° at deuteron energies of 1.15, 1.40 and 1.85 MeV. Measurements were made by double-scattering techniques using elastic scattering from carbon as the analyser. The results show a strong energy dependence and are in significant accordance with¹⁰ B(d, n ₀)¹¹C data. Calculations have been performed for the mirror reactions¹⁰B(d, p ₀)¹¹B and¹⁰B(d, n ₀)¹¹C in the framework of the Simon and Welton theory assuming two broad compound-states in¹²C, a 2⁺ state at 26.02 MeV and a 3^? state at 26.89 MeV excitation energy.     

Be9(d,p),(d,t),(d,a)反应研究

本文在E_d=0.1—2.5MeV能量范围内,研究了Be⁹(d,p₀)Be¹⁰(0),Be⁹(d,p₁)Be¹⁰(3.368MeV),Be⁹(d,t₀)Be⁸(0),Be⁹(d,α₀)Li⁷(0)及Be⁹(d,α₁)Li⁷(0.478MeV)诸反应。在E_d=0.150,0.220,0.401,0.706,1.005,1.301,1.484,1.750,2.000,2.250和2.500MeV共十一个能量上分别测量了这五群出射粒子在θ_L=10—155°区间的角分布。在θ_L=135°,E_d=0.1—2.5MeV,在θ_L=95°,E_d=0.1—2.2MeV,和在θ_L=112.5°,E_d=0.5—2.5MeV测量了Be⁹(d,p₀)Be¹⁰的激发函数。在θ_L=135°和112.5°,E_d=1.2MeV,用较厚靶(100—300μg/cm²)测量了Be⁹(d,p₀)Be¹⁰(0)反应的截面绝对值,结果为σ_(p0)(θ_L=135°)=1.60mb/sr,σ_(p0)(θ_L=112.5°)=1.55mb/sr。这样就得到了在此能区内,这五群出射粒子的截面情况。对所得结果进行了一些讨论。     

Polarization of protons from the Be(d,p)Be reaction at Ed = 12.0 MeV

The polarization of protons from the ⁹Be(d,p)¹⁰Be reaction at E_d = 12.0 MeV was measured for the ground state and first excited state transitions. The results obtained are compared with the predictions of DWBA theory. It was found that better fits to the experimental data can be obtained using volume absorption in the distorting potential of the deuteron elastic channel. A comparison of the present polarization data with the vector analysing power for the same reaction and the same incident deuteron energy has also been made.     

The Zr(d,n)Nb and Zr(d,n)Nb reactions

The (d, n) reaction on ⁹⁰Zr and ⁹⁶Zr has been studied at 12 MeV deuteron bombarding energy using the neutron time-of-flight technique with an overall neutron time resolution of 1.9 ns. Angular distributions of neutron groups leading to states in ⁹¹Nb and ⁹⁷Nb were measured in the angular range between 15° and 60°. The measured cross sections were analyzed in the framework of the distorted-wave theory of stripping reactions to deduce l-values and proton spectroscopic factors of states in the residual nuclei. The results are compared with the corresponding data available from (³He, d) studies. The fractionation of the single-particle proton states and their centroid energies are determined.     

A study of 14N using the 13C(d,n)14N reaction

Absolute differential cross sections for the ¹³C(d, n)¹⁴N reaction were measured at deuteron bombarding energies of 4.5, 5.0 and 5.5 MeV. Spectroscopic factors and statistical compound-nucleus contributions are obtained by treating the observed cross sections as an incoherent sum of distorted-wave Born approximation and compound-nucleus contributions. Energy-averaged spectroscopic factors are derived. An anomaly is observed in the yield for the 2.313 MeV T= 1 state.     

12C(12C, 8Be)16O angular distributions and excitation functions between 35 and 69 MeV bombarding energy

An array of eight detectors has been developed for identifying the particle unstable ⁸Be nucleus from nuclear reactions with high detection efficiency. Absolute cross sections have been measured for the reaction ¹²C(¹²C, ⁸Be_g.s.)¹⁶O to the ground state and to several excited states in ¹⁶O. Excitation functions at seven angles from 15° to 45° (lab) in 5° steps have been measured for bombarding energies between E¹²_C(lab) = 35 and 69 MeV. Excitation functions were obtained for the following states in the residual nucleus ¹⁶O which were found to be strongly populated: g.s.(0⁺); 6.1 MeV (0⁺, 3^?); 6.9 MeV (2⁺); 10.4 MeV (4⁺); 11.1 MeV (4⁺); 14.7 MeV (6⁺,…) and 16.3 MeV (6⁺,…). The energy range is covered in 250 keV (c.m.) steps; at certain energy ranges in ¹²⁵ keV or 50keV steps. All excitation functions exhibit a strong energy dependence of the cross section; pronounced gross structures with superimposed fine structures, similar to those observed for ¹²C+¹²C elastic and inelastic scattering at these energies, are observed. At 19.3 MeV, where resonant structures were observed in the reactions ¹²C(¹²C, p)²³Na, ¹²C(¹²C, n)²³Mg and ¹²C(¹²C, d)²²Na, no resonance is found for the reaction studied here. At 60, 61 and 63 MeV angular distributions have been measured in 1° and 2.5°(lab) angular steps. The excitation functions have been analyzed in terms of Ericson fluctuations and cross-correlation functions.     

Quasi-free contributions in the6Li(d,tp)4He-reaction atE d =0.465 MeV

The⁶Li(d, tp)⁴He reaction was investigated at a bombarding energy ofE _d =0.465 MeV in a kinematically complete experiment. Evidence was found for a quasi-free reaction.     

The reaction3He(d,p)4He with a polarized target

The left-right asymmetry for the³He(d, p)⁴He reaction has been measured with a polarized³He target at a bombarding energy of 12 MeV. The experimental results are compared with proton polarization measurements for unpolarized target and beam. The construction of the optically pumped³He target is described. A special design has been chosen to overcome the difficulty that the target contamination caused by the bombarding particles destroys the polarization. The target can easily be purified without removing it from the experimental set-up.     

Measurement of proton polarization in the 208Pb(d,p)209Pb reaction at an incident energy of 20 MeV

Angular distribution measurements of proton polarization in the ²⁰⁸Pb(d, p)²⁰⁹Pb reaction to the ground g_9/2 state were made at an incident deuteron energy of 20 MeV using a high efficiency proton polarimeter. Distorted wave Born approximation analysis and continuum discretized coupled channel analysis were performed on the data and compared with measurements of the angular distribution of the vector analyzing power for the same reaction. The result of the calculations predict that the angular distribution of the vector analyzing power should be similar to that of the polarization. However, the experimental data gives different angular distributions. The measured vector analyzing power is well reproduced by the calculations, while the polarization is not well reproduced.     

A study of the states of 30Si with the 28Si(t,p)30Si and 29Si(d,p)30Si reactions

The excitation energies of the levels in ³⁰Si have been measured up to an excitation of 9.46 MeV with the ²⁸Si(t, p)³⁰Si reaction at a triton energy of 6.0 MeV. Angular distributions have been measured of proton groups from the ²⁸Si(t, p)³⁰Si and ²⁹Si(d, p)³⁰Si reactions in a multi-angle magnetic spectrograph. Triton bombarding energies of 10.5 and 12.1 MeV were used and the deuteron incident energy was 10.0 MeV. States in ³⁰Si up to an excitation of 8 MeV were observed. Spins and parities of several states have been assigned using an empirical method for the (t, p) results and using a DWBA analysis for the (d, p) distributions. Spectroscopic factors for twelve states were obtained from the latter analysis. Two of these disagree with theoretical predictions. The state previously reported at an excitation of 6.63 MeV in ³⁰Si was observed to be formed by a strong L = 0 transition in the (t, p) reaction and also by a strong l = 1 transition in the (d, p) reaction. We deduce that there are two closely spaced states at about this excitation, one having a spin and parity of 0⁺ and the other 0^?, 1^? or 2^?.     

Polarization of protons from the Be(d, p)Be reaction

The polarization of protons from the ⁹Be(d, p)¹⁰Be reaction has been measured for deuteron energies between 1 and 6 MeV. Angular distributions of the polarization for the ground state proton group (Q=4.59 MeV) have been measured for laboratory angles 10° and 135° at 2.5, 4.0 and 5.5 MeV. The polarization at a laboratory angle of 30° was measured in 0.2 MeV steps between 1 and 6 MeV. In addition the polarization of protons leaving ¹⁰Be in its first excited state (Q=1.22 MeV) was measured between 10° and 90° for a deuteron bombarding energy of 5.5 MeV. Measurements were made by conventional double-scattering techniques using elastic scattering from helium at 45° as the analyser. The results show a strong energy dependence contrary to what one might expect on the basis of the lack of structure in the cross section. The maximum polarization observed at each energy is about 0.35.     

Angular distributions of protons from the reaction 12C(d,pγ)13C obtained by shape studies of γ-ray lines

A detailed study of the angular distributions of the emitted protons from the reaction ¹²C(d, p₁)¹³C in the deuteron energy range 1.4 to 3.2 MeV is presented. The angular distributions are obtained from the line shape of the Doppler shifted γ-rays. The excitation function for the reaction shows strong intensity fluctuations which are superimposed on an energy dependent average behaviour. The reaction is therefore assumed to proceed through direct interaction as well as compound nucleus formation, and the amplitudes for the two different reaction mechanisms are added linearly to form the total reaction amplitude. The ¹⁴N resonance structure obtained is also based upon studies of the reactions (d, p₂γ) and (d, p₃γ).     

Contribution of two-step mechanism to the isospin-forbidden16O(d, α)14N*(0+,T=1) reaction

Measurements of the isospin-forbidden¹⁶O(d, α)¹⁴N^*(0⁺,T=1) reaction have been extended to 50 MeV deuteron bombarding energy. A coupled-reaction-channels analysis of the reaction involving intermediate states in¹⁵O and¹⁵N underestimates the resonance-free region of the cross section by as much as an order of magnitude.     

Investigation of the 6Li(d, α)4He reaction between 1.5 and 11.5 MeV

The differential cross section σ₀(θ) and the analysing powers T₁₁(θ), T₂₀(θ), T₂₁(θ) and T₂₂(θ) of the reaction ⁶Li(d, α)⁴He have been measured for twelve energies between 1.5 and 11.5 MeV at c.m. angles between 3.5° and 90°. The results were fitted with Legendre polynomials. The energy dependence of the resulting coefficients indicates resonance-like behaviour at several energies corresponding to excitation between 22 and 32 MeV in ⁸Be. The reaction ⁶Li(d, α)⁴He shows excellent features as an analyser for deuteron vector and tensor polarization over the whole energy range investigated.     

The polarization of protons from the^{12} C\left( {d,\vec p_0 } \right)^{13} C reaction at low deuteron energies

The polarization of protons produced in the \(^{12} C\left( {d,\vec p_0 } \right)^{13} C\) reaction has been measured at 45° lab for deuteron energies between 0·25 and 1·15 MeV. Besides, the angular distribution of proton polarization at 0·975 MeV has also been measured. The result was analysed in terms of associated Legendre polynomials expansion.     

Deuteron elastic scattering and (d,p) reactions on 208Pb at Ed = 22 MeV and j-dependence of T20 in (d,p) reaction

An experimental study of deuteron elastic scattering and (d,p) reactions at E_d = 22 MeV was made for ²⁰⁸Pb target. A new j-dependence of T₂₀ for (d,p) reaction at backward angles was observed. A “model independent” optical potential method was applied to analyze deuteron elastic scattering in the 10–22 MeV energy range. A continuum discretized coupled channels (CDCC) analysis was performed for deuteron elastic scattering at 22 MeV and the deuteron breakup effect was elucidated. DWBA and CDCC (d,p) analyses were made for (d,p) reactions.     

Angular correlation measurements in the B10(d,p,γ)B11 reaction

Proton gamma angular correlations through the 6.76 and 8.92 MeV excited states of B¹¹ are measured at deuteron bombarding energies from 1.6 to 2.4 MeV. The correlations are measured at laboratory proton scattering angles 35? in both reaction and azimuthal planes. The correlation coefficientA ₂ ⁰ and the distortion parameterλ are calculated. A systematic shift of the symmetry axis from the recoil direction is observed. This shift tends to zero asE _d→Q. For the 8.92 MeV excited state of B¹¹(Q=0.32 MeV) the distortion parameterλ is close to the plane wave limit. The possible values of incoming channel spins as well as gamma-ray multipole mixing ratio for the 6.76 and 8.92 MeV states are obtained.