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A total of 38 angular distributors have been measured for the [sup 19]F([sup 6]Li,[ital d])[sup 23]Na reaction leading to states in the excitation energy region 6.3--13.25 MeV. For many of them, [ital L] values have been assigned and spectroscopic factors extracted, using standard distorted-wave techniques.

In the [sup 20]Ne([ital t],[ital p])[sup 22]Ne reaction at a bombarding energy of 15 MeV, excitation energies have been measured for 81 levels up to [ital E][sub [ital x]]=13.4 MeV. Thirteen new levels were identified. Distorted-wave Born-approximation (DWBA) calculations with spherical and deformed potentials were used to analyze the angular distributions. Two-step processes were found to make important contributions to the reaction. For most low-lying positive-parity levels, results are analyzed with two-particle transfer amplitudes from a realistic shell-model calculation. We have assigned spin-parities to 42 levels above 6.6 MeV based on the success of the DWBA analysis.

By using the {sup 77}Se({ital t},{ital p}){sup 79}Se reaction at 17 MeV, angular distributions have been measured for transitions leading to 34 states or groups of states in {sup 79}Se up to an excitation energy of approximately 3.2 MeV. Twelve of these states are reported for the first time. Comparisons with distorted-wave Born-approximation calculations have allowed the {ital L} transfer for most of the transitions observed to be determined. Four {ital L}=0 transitions are seen, leading to assignments of {ital J}{sup {pi}}=1/2{sup {minus}} to the states populated. The {ital J}{sup {pi}} values for the majority of the other final states have been restricted to one of two values.

Complete angular distributions are presented (t-italich-italice-italict-italica-italic/sub c.m./ = 9X(de--90/sup 0/) for the reaction /sup 13/C(/sup 13/C, ..cap alpha..)/sup 22/Ne in the energy range E-italic/sub c.m./ = 6.25--9.125 MeV. The data exhibit significant nonstatistical behavior and have been fitted to a linear Legendre polynomial sum using a least-squares procedure. A second procedure makes a grid search to find a best fit to an amplitude squared equation. The correlations with structures in other C+C systems are discussed.

At E(/sup 7/Li) = 22.0 MeV, forward-angle angular distributions have been measured for 37 states (or groups of states) up to an excitation energy of 9.1 MeV, using a multiangle spectrograph and a gas target.

Results are presented for the reaction /sup 10/B(/sup 7/Li,p)/sup 16/N, at E( /sup 7/Li) = 16.0 MeV, leading to states up to 6.61 MeV excitation.

Twenty levels in K38 up to an excitation energy of 10.26 MeV have been identified in a study of the Ca40(d, )K38 reaction at an incident deuteron energy of 22.8 MeV. Differential cross sections were measured at forty-four angles in an angular range 11°165°. Distorted-wave Born approximation analysis has been performed for eight transitions using two-nucleon spectroscopic amplitudes derived from a full sd shell-model calculation. For other levels, distorted-wave Born approximation calculations were performed assuming simple two-nucleon configurations. The 7.32-MeV level is found to be populated by L=0+2 transfer and hence has J=1+. A newly identified level at 9.88 MeV is found to be excited by L=2 transfer and hence has J=1+, 2+, or 3+. NUCLEAR REACTIONS Ca40(d, )K38, Ed=22.8 MeV, measured E and (, E), DWBA analysis, deduced levels, L transfer. © 1983 The American Physical Society.

The 12 C( 14 N, α) 22 Na reaction has been investigated at 14 N bombarding energies of 30.3, 35.0, 40.0 and 45.5 MeV, and the 14 N( 12 C, α) 22 Na reaction has been investigated at a 12 C bombarding energy of 39.3 MeV. The α-particle reaction products were recorded using a multiple-gap spectrograph. One hundred eighty-five levels below 17.86 MeV have now been observed in 22 Na, many of them for the first time. Though some “resonance”-like behavior is observed, the overall results are consistent with a compound-nucleus reaction mechanism.

Earlier /sup 1/4N(t,p)/sup 1/6N data for levels between 5.5 and 8.5 MeV excitation have been subjected to a distorted-wave Born-approximation analysis in order to extract L values and place limits on J/sup ..pi../. Three 1/sup +/ levels are located at 6422, 6512, and 7006 keV, and possibly at 5520 keV. Several levels are suggested to be unresolved doublets.

Symmetric fission of 24 Mg into two 12 C nuclei following inelastic scattering of 120 MeV α-particles has been studied. The 12 C g.s. + 12 C g.s. and the 12 C g.s. + 12 C(4.44 MeV) decay modes were identified in the excitation energy ranges of 24 Mg, 22 MeV ≦ E x ≦ 26 MeV and 25 MeV ≦ E x ≦ 32 MeV, respectively. Depending on the assumptions made about the α'-inclusive spectrum, lower and upper limits have been obtained for the average partial width 〈 Γ CC / Γ 〉.

States populated in the /sup 15/N(/sup 6/Li,d)/sup 19/F reaction at 22 MeV are compared with those in /sup 16/O(/sup 6/Li,d)/sup 20/Ne at the same energy. Cross section ratios are in good agreement with a weak-coupling model, in contrast to previous observations via the (/sup 7/Li,t) reaction. Two strong transitions are observed to states at E/sub x/ = 8.288 and 8.957 MeV in /sup 19/F. The measured angular-distribution shapes and alpha-transfer strengths for these states are consistent with their being, respectively, the (13/2)/sup -/ and (11/2)/sup -/ members of the K/sup ..pi../ = (1/2)/sup -/ band in /sup 19/F. A comparison between the measured alpha-particle widths for these states and the single-particle alpha widths calculated in a Woods-Saxon well supports the above assignments.

The 24 Mg(t, α) 23 Na reaction has been studied at bombarding energies of 15.0 and 23.5 MeV. Spectroscopic strengths extracted at the two energies are in good agreement and indicate a diffuse, rather than a sharp Nilsson Fermi surface for 23 Na and 24 Mg. Significant population of high-spin states indicates the importance of multistep and/or compound processes. Data were also taken for 28 Si(t, α) 27 Al at 23.5 MeV. A FR/NL DWBA normalization of 11 ± 2 was consistent with all three (t, α) data sets.

Complete angular distributions (theta/sub c.m./ = 9/sup 0/--90/sup 0/) for the reaction /sup 13/C( /sup 13/C,..cap alpha..) /sup 22/ Ne in the energy range E/sub c.m./ = 6.25--13.38 MeV have been subjected to a battery of tests to determine the existence of a significant nonstatistical component in the cross section. The autocorrelation function, distribution of cross sections, and channel correlations were investigated. The data were also compared with the predictions of Hauser-Feshbach calculations. A large nonstatistical component was found in all tests and comparisons.

The reaction 12 C + 13 C → α + 21 Ne has been investigated at a c.m. bombarding energy of 14.5 MeV using beams of both 12 C and 13 C. The α-particle reaction products were recorded using a multiple-angle spectrograph. Seventy-six levels were observed below 12.56 MeV in 21 Ne; 28 levels from 9.42 to 12.56 MeV are reported for the first time. The data are consistent with a compound-nucleus reaction mechanism.

The reaction /sup 41/K(t,p)/sup 43/K has been investigated with a 15-MeV triton beam. Twenty levels of /sup 43/K (many of them unreported previously) have been identified up to about 3.4 MeV excitation energy. Angular distributions were measured for all levels. Comparison with distorted-wave Born-approximation calculations allows extraction of L values for most of them. Three multiplets arising from the couplings of (1f/sub 7/2/)= 2/sup 2/ and (1f/sub 7/2/)= 4/sup 2/ transferred neutrons with the 1d/sub 3/2/ proton hole have been identified in /sup 43/K. Their energy centroids are closely related to the (1f/sub 7/2/)/sup 4/ spectrum of /sup 44/Ca. The general sum rules for two-nucleon transfer reactions and a more specialized sum rule give a good account of the data and suggest spin and parity assignments for many of the observed states. The positive parity states in /sup 43/K are compared with f/sub 7/2//sup 4/(d/sub 3/2/s/sub 1/2/)-1 and f/sub 7/2//sup 3/ p/sub 3/2/d/sub 3/2//sup -1/ shell-model calculations.

Angular distributions have been measured at a bombarding energy of 28 MeV for the reaction /sup 24/Mg(d,/sup 6/Li) /sup 20/Ne, populating most of the known levels below 9.1 MeV excitation. Results were compared with distorted wave Born-approximation calculations, and ..cap alpha.. spectroscopic factors extracted. Those for the g.s. band are in reasonable agreement with theoretical predictions. Members of the 7.20-MeV band are found to possess very large spectroscopic factors, in agreement with the core-excited nature of this band.

The /sup 76/Se(t,p)/sup 78/Se reaction has been studied at an incident energy of 17 MeV. Excitation energies for 80 states (or groups of states) up to 6.16 MeV have been measured. Angular distributions have been obtained for 61 of them, below E/sub x/ = 5.03 MeV. Comparison of the data with distorted-wave Born approximation calculations, using pure configurations for the transfer amplitudes, have enabled the L transfer (and hence J/sup ..pi../ value) to be determined for 58 of these states. Of these assignments, 52 are new.

Excitation functions for 12 C( 3 He, α) reactions leading to the ground state, first and third excited states of 11 C have been measured at selected angles for E 3 He = 12 to 18 MeV. Angular distributions were measured at bombarding energies of 16,17 and 18 MeV for the ground state and four excited states to study the energy dependence of extracted spectroscopic factors. The ground state reaction is well represented at all energies by a zero-range, local DWBA calculation for neutron pickup with a renormalization factor of R ≈ 40, which is twice as large as the generally accepted value. At E 3 He = 18 MeV angular distributions leading to the ground state and first ten excited states of 11 C were measured. In general the pickup calculations for the excited state reactions do not give a good representation of the measurements when the ground state optical parameters are used.

A method is outlined for performing finite-range distorted-wave Born-approximation calculations for pickup reactions in which the ejectile is unbound with respect to the transferred particle.

Wave functions for /sup 18/O derived from fits to particle-transfer and ..gamma..-decay data have been used in finite-range distorted-wave calculations of the reaction /sup 14/C(/sup 7/Li,t)/sup 18/O. The agreement between experimental and theoretical cross sections is excellent.

We have measured a (..pi../sup +/,..pi../sup /minus//) angular distribution for the transition to the double isobaric analog state of a T = 2 target nucleus, /sup 56/Fe, at T/sub ..pi../ = 180 MeV. The data are compared to measurements on T = 1 targets and to theoretical predictions. The angular dependence is different from that observed in measurements on T = 1 targets. Some features of the data are reproduced by the theoretical predictions, but significant discrepancies remain. 15 refs., 3 figs., 1 tab.

L-value decompositions are presented for angular distributions of 22 levels below 3-MeV excitation in /sup 53/V, for the reaction /sup 51/V(t,p)/sup 53/V. Correspondence with /sup 52/Ti is discussed.