Recent Articles

2.102-MeV level in ${}^{206}{Hg}$ and the spin gyromagnetic ratio of the $3 - s$ proton

J. A. Becker, J. B. Carlson, R. G. I anier, L. G. Mann, G. L. Struble, K. H. Maier, L. Ussery, W. Stöffl, T. Nail, R. K. Sheline, and J. A. Cizewski

Phys. Rev. C 26, 914 (1982) - Published 1 September, 1982

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The nuclear gyromagnetic ratio, spin parity, and lifetime of the ${}^{206}{Hg}$ 2.102-MeV level have been measured to be $g = 1.09 \pm 0.01$ , $J^{π} = 5^{-}$ , and $τ_{m} = 3.1 \pm 0.3$ μsec, respectively. The level was populated via the ${}^{204}{Hg} (t, p) {}^{206}{Hg}$ reaction. The perturbed angular distribution technique was employed to measure $g$ . Using known data, the spin gyromagnetic ratio for a proton in the $3 s$ orbital has been deduced: $g_{s} (π; 3 s) = 3.6 \pm 0.3$ . For the 1.068-MeV level, $J^{π} = 2^{+}$ .

NUCLEAR REACTIONS ${}^{204}{Hg} (t, p)$ , $E_{t} = 16$ MeV. For ${}^{206}{Hg}$ ( $E_{x} = 2.102$ MeV), measured $τ_{m} = 3.1 \pm 0.3$ μsec, $g = 1.09 \pm 0.01$ , and $J^{π} = 5^{-}$ . For $E_{x} = 1.068$ MeV, $J^{π} = 2^{+}$ . Deduce $g (π; 3 s) = 3.6 \pm 0.3$ .

Inelastic electron scattering from ${}^{208}{Pb}$ at 180°

R. S. Hicks, R. L. Huffman, R. A. Lindgren, B. Parker, G. A. Peterson, S. Raman, and C. P. Sargent

Phys. Rev. C 26, 920 (1982) - Published 1 September, 1982

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Inelastic cross sections for 180° electron scattering from ${}^{208}{Pb}$ have been measured at incident energies of 40.5, 50.4, 60.3, and 75.2 MeV. Transverse electric form factors have been determined for the $3^{-}$ state at 2.614 MeV, the $5^{-}$ states at 3.198 and 3.708 MeV, the $2^{+}$ states at 4.085 and 6.21 MeV, the $4^{+}$ state at 4.323 MeV, and the $6^{+}$ state at 4.422 MeV. The results for these natural parity states are compared to the predictions of an incompressible, irrotational current model, and of a particle-hole model. All transverse electric form factors show strong contributions from intrinsic magnetization currents. Transverse form factors were obtained for the proposed $1^{+}$ state at 4.84 MeV, for the group of $1^{+}$ states at 7.48 MeV, and for several proposed $2^{-}$ states. A search for $M 1$ transition strength was made up to excitation energies of 19 MeV. The future of electron scattering as a tool for probing $M 1$ strength in ${}^{208}{Pb}$ is discussed.

NUCLEAR REACTIONS ${}^{208}{Pb} (e, e^{'})$ , $E = 40.5, 50.4, 60.3, and 75.2$ MeV, measured $σ (180 °)$ . ${}^{208}{Pb}$ deduced levels and transverse form factors. Enriched target, magnetic spectrometer.

Nuclear reactions in Rb, Sr, Y, and Zr targets

S. Regnier, B. Lavielle, M. Simonoff, and G. N. Simonoff

Phys. Rev. C 26, 931 (1982) - Published 1 September, 1982

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Excitation functions of all stable or long-lived krypton isotopes were measured or estimated for incident protons and neutrons in Rb, Sr, Y, and Zr targets. Experimental data concern mostly Y and Zr targets bombarded with 0.059 to 24 GeV protons. The products ${}^{78 - 86}{Kr}$ , ${}^{74}{As}$ , ${}^{75}{Se}$ , ${}^{83, 84, 86}{Rb}$ , ${}^{85}{Sr}$ , ${}^{88}Y$ , ${}^{88, 95}{Zr}$ , and ${}^{92}{Nb}^{m}$ were measured using high-sensitivity mass spectrometry and nondestructive $γ$ counting. Lighter products such as ${}^{38, 39, 42}{Ar}$ and 12 radioactive isotopes from ${}^{7}{Be}$ to ${}^{65}{Zn}$ were also measured in some cases and their cross sections are given in an appendix. Most excitation functions pass through a maximum between 0.4 and 0.8 GeV, and the peak energy could depend on the $Δ A$ value. The results, combined with a general survey of nuclear reactions in Ga to Nb targets, permitted the development of new systematics leading to the calculation of spallation-produced Kr isotopes in the moon bombarded with galactic and solar cosmic rays. Compared to cosmogenic krypton measured in nine well-documented lunar samples, ${}^{83}{Kr}$ is predicted with a precision better than 33% ( $1 σ$ ) and the production ratios ${}^{i}{Kr}$ / ${}^{83}{Kr}$ are predicted to better than 25%. It is concluded that the cosmogenic ratios ${}^{86}{Kr}$ / ${}^{83}{Kr}$ and ${}^{81}{Kr}$ / ${}^{83}{Kr}$ are dependent on the main target element concentrations. This should be taken into account in strontium-rich samples when calculating exposure ages of extraterrestrial materials.

NUCLEAR REACTIONS ${}^{89}Y$ and Zr, ( $p$ , spallation) $E = 0.059 - 24$ GeV; measured $σ (E)$ for ${}^{78 - 86}{Kr}$ and 12 radioactive products. Systematics of $p$ - and $n$ -induced reactions in Rb, Sr, Y, and Zr. Cosmogenic krypton.

Elastic scattering of 65 MeV polarized protons

H. Sakaguchi, M. Nakamura, K. Hatanaka, A. Goto, T. Noro, F. Ohtani, H. Sakamoto, H. Ogawa, and S. Kobayashi

Phys. Rev. C 26, 944 (1982) - Published 1 September, 1982

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Elastic scattering of 65 MeV polarized protons from 25 nuclei ( ${}^{16}O$ — ${}^{209}{Bi}$ ) has been measured. The volume integral of the real central part of the optical potential ( $J_{R}$ ) shows a behavior similar to the binding energy curve for the target mass number. The mean square radius of the real central part of the optical potential is found to obey the relation ${〈 r^{2} 〉}_{pot} = (0.937 \pm 0.012) A^{\frac{2}{3}} + (6.42 \pm 0.21)$ ${fm}^{2}$ . By comparing with the systematics of the charge distributions obtained from electron scattering data, it is found that the effective two-body interaction range between an incident proton and a nucleon in the target has a target mass number dependence given by ${〈 r^{2} 〉}_{int} = (0.132 \pm 0.013) A^{\frac{2}{3}} + (4.24 \pm 0.24)$ ${fm}^{2}$ . Assuming this relation, root mean square radii of the point nucleon distributions are obtained. The dependences of the $J_{R}$ value and the ${〈 r^{2} 〉}_{pot}$ value on the mass number and energy obtained here are compared critically with recent microscopic optical potential calculations.

NUCLEAR REACTIONS ${}^{16}O$ , ${}^{24}{Mg}$ , ${}^{28}{Si}$ , ${}^{40}{Ar}$ , ${}^{40, 44, 48}{Ca}$ , ${}^{46, 48, 50}{Ti}$ , ${}^{54, 56}{Fe}$ , ${}^{58, 60, 62, 64}{Ni}$ , ${}^{89}Y$ , ${}^{90}{Zr}$ , ${}^{98, 100}{Mo}$ , ${}^{144}{Sm}$ , ${}^{208}{Pb}$ , ${}^{209}{Bi} (\vec{p}, p)$ , $E = 65$ MeV; measured $σ (θ)$ , $A (θ)$ ; deduced optical-model parameters, mean-square nuclear radii, and volume integrals for the real central potential.

${}^{40}{Ca} (p, p n) {}^{39}{Ca}$ and ${}^{48}{Ca} (p, p n) {}^{47}{Ca}$ neutron knockout reactions at 149.5 MeV

J. W. Watson, M. Ahmad, D. W. Devins, B. S. Flanders, D. L. Friesel, N. S. Chant, P. G. Roos, and J. Wastell

Phys. Rev. C 26, 961 (1982) - Published 1 September, 1982

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The reactions ${}^{40}{Ca} (p, p n) {}^{39}{Ca}$ and ${}^{48}{Ca} (p, p n) {}^{47}{Ca}$ were studied at 149.5 MeV in coplanar geometries. An overall separation energy resolution of about 1 MeV was achieved. Probable neutron-hole strength is seen for $1 d_{\frac{5}{2}}$ and $1 p$ shell knockout from both targets. The data are compared with distorted-wave-impulse-approximation calculations and spectroscopic factors are extracted for neutron-hole states.

NUCLEAR REACTIONS ${}^{40, 48}{Ca} (p, p n) {}^{39, 47}{Ca}$ , $E = 149.5$ MeV; measured $p - n$ coincidences; extracted neutron separation energy spectra and cross sections $\frac{d^{3} σ}{d Ω_{n} d Ω_{p} d E_{p}}$ for neutron-hole states. Compared cross sections with distorted-wave-impulse-approximation calculations; extracted spectroscopic factors $C^{2} S$ for neutron-hole states.

${}^{176}{Yb} (t, p) {}^{178}{Yb}$ reaction

J. D. Zumbro, C. P. Browne, J. F. Mateja, H. T. Fortune, and R. Middleton

Phys. Rev. C 26, 965 (1982) - Published 1 September, 1982

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Fourteen levels up to 3.1 MeV in ${}^{178}{Yb}$ have been identified using the ${}^{176}{Yb} (t, p)$ reaction. Measured angular distributions were compared with the results of distorted-wave Born approximation calculations. For six levels we make $J^{π}$ assignments based on $L$ values and the systematics of the lighter even Yb isotopes. The first three members of the ground-state band, the first two members of the excited $K^{π} = 0^{+}$ band, and the $2^{+}$ $γ$ -vibrational state are suggested by the systematics. Based only on $L$ values, $J^{π}$ assignments are made for two states and tentative assignments are suggested for four other states. The $Q$ value for the ${}^{176}{Yb} (t, p) {}^{178}{Yb}$ reaction is also reported.

NUCLEAR REACTIONS ${}^{176}{Yb} (t, p) {}^{178}{Yb}$ , $E_{t} = 15$ MeV, $σ (θ, E_{p})$ , DWBA analysis; ${}^{178}{Yb}$ deduced $L$ , $J$ , $π$ , enriched target, magnetic spectrograph.

Neutron-capture resonances for ${}^{82}{Se}$

J. C. Browne and B. L. Berman

Phys. Rev. C 26, 969 (1982) - Published 1 September, 1982

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Strong neturon-capture resonances for ${}^{82}{Se}$ have been found at 3.63, 7.1, and 9.51 keV and weaker ones have been found at 0.58, 1.15, and possibly 13.54 and 16.5 keV. None was found at lower neutron energies; this absence of strong epithermal capture resonances invalidates the hypothesis that the depth dependence of the abundance ratio of ${}^{78}{Kr}$ to ${}^{83}{Kr}$ found in meteoritic studies owes its origin to anomalous ${}^{83}{Kr}$ production by neutron capture on ${}^{82}{Se}$ . Precise energies have been assigned to neutron-capture resonances up to 40 keV for all the other selenium isotopes as well.

NUCLEAR REACTIONS ${}^{82}{Se}$ , ${}^{nat}{Se} (n, γ)$ ; neutron time of flight; resonance energies; abundance ratio of ${}^{78}{Kr}$ to ${}^{83}{Kr}$ .

Finite range effects in ( $\vec{d}$ , ${}^{3}{He}$ ) reactions on ${}^{54}{Fe}$ at $E_{d} = 80$ MeV

M. A. Nagarajan and R. Shyam

Phys. Rev. C 26, 977 (1982) - Published 1 September, 1982

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Results of the first full finite range distorted-wave Born-approximation calculation, employing a microscopic form factor for the projectile-ejectile overlap, for the ( $\vec{d}$ , ${}^{3}{He}$ ) reaction on the ${}^{54}{Fe}$ target at $E_{d} = 80$ MeV, are compared with those of a zero range distorted-wave Born-approximation calculation in which finite range effects are accounted for by a local energy approximation, to point out the region where this approximation breaks down.

NUCLEAR REACTIONS ${}^{54}{Fe} (\vec{d}, {}^{3}{He}) {}^{53}{Mn}$ , $E_{d} = 80.0$ MeV; full finite range DWBA with microscopic form factor and zero range DWBA calculations.

Fusion of Li and C and a search for entrance channel limitations to fusion cross sections

L. C. Dennis, K. M. Abdo, A. D. Frawley, and K. W. Kemper

Phys. Rev. C 26, 981 (1982) - Published 1 September, 1982

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Excitation functions have been measured for reaction products from the ${}^{6}{Li}$ and ${}^{7}{Li}$ induced reactions ${}^{6}{Li}$ + ${}^{12}C$ , ${}^{6}{Li}$ + ${}^{13}C$ , ${}^{7}{Li}$ + ${}^{12}C$ , and ${}^{7}{Li}$ + ${}^{13}C$ . These data cover the energy range from $E_{lab} = 9 to 36$ MeV. It was found that the maximum fusion cross sections for these reactions are 780 and 770 mb for the ${}^{6}{Li}$ + ${}^{12}C$ and ${}^{6}{Li}$ + ${}^{13}C$ , respectively, and 960 and 930 mb for the ${}^{7}{Li}$ + ${}^{12}C$ and ${}^{7}{Li}$ + ${}^{13}C$ , respectively. The relative uncertainties for these maximum fusion cross sections are about 5%. Comparisons between optical model calculations of the total reaction cross sections and the measured fusion cross sections indicate that total fusion cross sections are substantially smaller than the total reaction cross sections for all four reactions at all energies. For each of the four entrance channels, energy and angular distributions have been measured at four energies for individual mass groups between $A = 9 and 19$ u. Most of these products appear to be evaporation residues. The critical angular momenta deduced from the experimental fusion cross sections are discussed in terms of entrance channel and compound nucleus limitation models for compound nucleus formation. The individual mass groups are discussed in terms of systematics for evaporation residues.

NUCLEAR REACTIONS ${}^{6}{Li}$ + ${}^{12}C$ , $E_{{}^{6}{Li}} = 10 to 36$ MeV; ${}^{6}{Li}$ + ${}^{13}C$ , $E_{{}^{6}{Li}} = 9.23 to 35.08$ MeV; ${}^{7}{Li}$ + ${}^{12}C$ , $E_{{}^{7}{Li}} = 10 to 38$ MeV; ${}^{7}{Li}$ + ${}^{13}C$ , $E_{{}^{7}{Li}} = 10 to 34$ MeV, measured $\frac{d^{2} σ}{d Ω dE}$ for reaction products from $A = 9 to 19$ . Extracted $σ_{fus}$ .

Fusion between heavy ions at sub-barrier energies

Q. Haider and F. Bary Malik

Phys. Rev. C 26, 989 (1982) - Published 1 September, 1982

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The $S$ factors for the capture process of the systems ${}^{16}O$ + ${}^{16}O$ , ${}^{16}O$ + ${}^{14}N$ , ${}^{16}O$ + ${}^{12}C$ , ${}^{14}N$ + ${}^{14}N$ , ${}^{14}N$ + ${}^{12}C$ , ${}^{11}B$ + ${}^{12}C$ , and ${}^{10}B$ + ${}^{12}C$ are calculated at sub-Coulomb barrier energies in a model using an inverted parabola which joins smoothly onto the Coulomb potential between two heavy ions. The model does not have any discontinuous potential surface and has proper asymptotic forms for the wave functions and has been successful in understanding fusion cross sections at higher energies. The calculated energy dependence of the $S$ factor follows in general the experimental trend and in many instances, the observed magnitudes can be reproduced remarkably well.

NUCLEAR REACTIONS Heavy-ion fusion; sub-barrier region; $S$ factor calculations for ${}^{16}O$ + ${}^{16}O$ , ${}^{16}O$ + ${}^{14}N$ , ${}^{16}O$ + ${}^{12}C$ , ${}^{14}N$ + ${}^{14}N$ , ${}^{14}N$ + ${}^{12}C$ , ${}^{11}B$ + ${}^{12}C$ , and ${}^{10}B$ + ${}^{12}C$ .

Reactions to resolved states and to non-fusion channels for ${}^{16}O$ + ${}^{48}{Ca}$ at $E_{lab} = 158.2$ MeV

T. J. Humanic, H. Ernst, W. Henning, and B. Zeidman

Phys. Rev. C 26, 993 (1982) - Published 1 September, 1982

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In a study of the system ${}^{16}O$ + ${}^{48}{Ca}$ at $E_{lab} ({}^{16}O) = 158.2$ MeV, we have measured elastic, inelastic, and single-nucleon transfer cross sections to resolved final states, and the non-fusion reaction cross section. The measured cross sections to resolved states generally agree with the predicted magnitudes and angular distributions from exact finite-range distorted-wave Born approximation calculations. The total non-fusion reaction cross section, $σ_{NF}$ , is measured to be ${0.66}_{- 0.07}^{+ 0.27}$ b. These results are compared with other studies made at different bombarding energies, and for other systems.

NUCLEAR REACTIONS ${}^{48}{Ca}$ ( ${}^{16}O$ , ${}^{16}O$ ), ${}^{48}{Ca}$ ( ${}^{16}O$ , ${}^{16}O$ '), ${}^{48}{Ca}$ ( ${}^{16}O$ , ${}^{15}N$ ), ${}^{48}{Ca}$ ( ${}^{16}O$ , ${}^{17}O$ ), ${}^{48}{Ca} ({}^{16}O, X)$ , $X = L i - A l$ , $E_{lab} = 158.2$ MeV; measured $σ (θ)$ , $σ_{X}$ ; optical model and DWBA analysis.

Minimal coupling schemes in $N$ -body reaction theory

A. Picklesimer, P. C. Tandy, and R. M. Thaler

Phys. Rev. C 26, 315 (1982) - Published 1 August, 1982

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A new derivation of the $N$ -body equations of Bencze, Redish, and Sloan is obtained through the use of Watson-type multiple scattering techniques. The derivation establishes an intimate connection between these partition-labeled $N$ -body equations and the particle-labeled Rosenberg equations. This result yields new insight into the implicit role of channel coupling in, and the minimal dimensionality of, the partition-labeled equations.

NUCLEAR REACTIONS Scattering theory, multiple scattering, connected kernel reaction theory, minimal coupling, coupling schemes.

Nuclear dynamics and quasi-elastic electron scattering

L. S. Celenza, W. S. Pong, M. M. Rahman, and C. M. Shakin

Phys. Rev. C 26, 320 (1982) - Published 1 August, 1982

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We present results of calculations of the longitudinal and transverse response function for inelastic electron scattering from ${}^{56}{Fe}$ and ${}^{12}C$ . In the impulse approximation it is found that the calculated longitudinal response is approximately forty percent too large for ${}^{56}{Fe}$ . We discuss those aspects of nuclear dynamics which could account for this discrepancy and suggest that the depletion of the shell model orbitals through various (short-range) correlation effects may play an important role. It is suggested that a significant longitudinal response may exist at energies above the quasi-elastic domain; this response would involve the excitation of 2p-2h states. In our model there is a significant disagreement between theory and experiment for the transverse response. We ascribe this disagreement to meson-exchange-current effects; however, we present no calculations of such effects in this work. Quantitative studies of these effects in finite nuclei are required. If our model for the quenching of the longitudinal response in the quasi-elastic domain proves to be correct, we can infer that quasi-elastic electron scattering studies may provide a measurement of the average probability of the occupation of a shell model orbital.

NUCLEAR REACTIONS Quasi-elastic electron scattering; transverse and longitudinal response functions; finite nucleus calculations in a modified impulse approximation.

Corrections to the ${}^{11}B (p, γ_{0}) {}^{12}C$ cross section and its implications

M. T. Collins, S. Manglos, N. R. Roberson, A. M. Sandorfi, and H. R. Weller

Phys. Rev. C 26, 332 (1982) - Published 1 August, 1982

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We have performed two independent measurements of the ${}^{11}B (p, γ_{0}) {}^{12}C$ reaction over the energy range of $E_{p} = 5 - 14$ MeV. The two measurements are in good agreement with each other and indicate that the previously accepted results are in error. The new values for the $γ_{0}$ cross section reported here resolve several outstanding conflicts. Their implications are discussed.

NUCLEAR REACTIONS ${}^{11}B (p, γ_{0}) {}^{12}C$ , $5 \leq E_{p} \leq 14$ MeV; measured $E_{γ}$ , absolute cross sections for $\frac{d σ}{d Ω}$ (90°, $E_{γ_{0}}$ ), $\frac{d σ}{d Ω}$ (90°, $E_{γ_{1}}$ ).

Elastic magnetic scattering of electrons from ${}^{13}C$

R. S. Hicks, J. Dubach, R. A. Lindgren, B. Parker, and G. A. Peterson

Phys. Rev. C 26, 339 (1982) - Published 1 August, 1982

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The form factor for elastic magnetic scattering of electrons from ${}^{13}C$ has been measured to a maximum momentum transfer of 3.29 ${fm}^{- 1}$ . No reasonable $p$ -shell model, with or without one-pion exchange currents, could be found to explain the relative enhancement observed in the $M 1$ form factor above $q ≃ 2$ ${fm}^{- 1}$ .

NUCLEAR REACTIONS ${}^{13}C (e, e)$ , $E = 80 - 338$ MeV; measured $σ (E, θ)$ . ${}^{13}C$ deduced $M 1$ form factor. Comparison with shell model.

Antisymmetrized deuteron stripping

R. C. Johnson, N. Austern, and M. H. Lopes

Phys. Rev. C 26, 348 (1982) - Published 1 August, 1982

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A three-body model of the antisymmetrized deuteron-nucleus system is evaluated approximately in terms of an effective neutron-proton interaction that can be used in the standard distorted-wave Born approximation matrix element for stripping. Although there is a significant reduction of interior contributions to stripping at low bombarding energy, this effect becomes less important at higher energy; in particular, it has little influence on the reaction ${}^{24}{Mg} (p, d)$ at 94 MeV.

NUCLEAR REACTIONS Scattering theory, antisymmetrized three-body model for deuteron stripping. Application to ${}^{24}{Mg} (p, d)$ at 94 MeV.

Deuteron breakup by 140 MeV alpha particles at quasifree scattering conditions

J. M. Lambert, P. A. Treado, P. G. Roos, N. S. Chant, A. Nadasen, I. Slaus, and Y. Koike

Phys. Rev. C 26, 357 (1982) - Published 1 August, 1982

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The ${}^{2}{He} (α, α p) n$ reaction has been studied with 140 MeV alpha particles at $p - α$ quasifree scattering conditions in the $θ_{c . m .}$ angular region of 50° to 144°. Energy spectra are presented for six angle pairs. Three-body model calculations provide excellent fits to the data. Reasons for the success of the relatively limited three-body model used are discussed.

NUCLEAR REACTIONS ${}^{2}H (α, α p) n$ , $E_{α} = 140$ MeV; measured $σ (E_{α}, E_{p}, θ_{α}, θ_{p})$ ; three body Faddeev analysis; energy and angle dependence.

Elastic scattering of polarized tritons from $A = 26 - 28$ nuclei at 17 MeV

P. Schwandt, Ronald E. Brown, F. D. Correll, R. A. Hardekopf, and G. G. Ohlsen

Phys. Rev. C 26, 369 (1982) - Published 1 August, 1982

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Differential cross sections and analyzing powers for elastic scattering of 17-MeV polarized tritons from ${}^{26}{Mg}$ , ${}^{27}{Al}$ , and ${}^{28}{Si}$ were measured in the angular range 20° to 160°. Significant target dependence of the analyzing power was observed, and reaction mechanisms other than shape-elastic scattering appear to contribute at large scattering angles. An optical-model analysis of these data was carried out to determine potential parameters that fit both observables simultaneously. The central potentials are resonably well defined by the data, but strong absorption limits our ability to determine reliably the parameters of the spin-orbit potential; at the present low triton energy, the scattering appears to be sensitive predominantly to the spin-orbit strength in the outer surface region of the nucleus.

NUCLEAR REACTIONS ${}^{26}{Mg}$ , ${}^{27}{Al}$ , ${}^{28}{Si} (\vec{t}, t)$ ; $E = 17$ MeV; measured $σ (θ)$ ; $A_{y} (θ)$ . Optical-model analysis.

Multistep direct reaction analysis of continuum spectra in reactions induced by light ions

T. Tamura, T. Udagawa, and H. Lenske

Phys. Rev. C 26, 379 (1982) - Published 1 August, 1982

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Analyses of continuum spectra of light-ion reactions, in terms of multistep direct reaction methods are discussed. The formulation used in the calculations is presented first, and is followed by several examples which show that this method works rather well in a variety of cases. Comparison with related theories is also made.

NUCLEAR REACTIONS Multistep direct reaction method, calculations of cross sections, and polarizations of continuum spectra of reactions induced by light ions.

Selective excitations of $α$ -cluster states in ${}^{150}{Nd}$

J. Jänecke, F. D. Becchetti, D. Overway, and C. E. Thorn

Phys. Rev. C 26, 405 (1982) - Published 1 August, 1982

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The $α$ -cluster pickup reaction ${}^{154}{Sm} (d, {}^{6}{Li}) {}^{150}{Nd}$ has been investigated at $E_{d} = 33$ MeV. The observed spectra are dominated by transitions to the $0^{+}$ , $2^{+}$ , and $4^{+}$ members of the ground state rotational band in ${}^{150}{Nd}$ and by transitions to newly observed states at $E_{x} = 2050 \pm 25, 2225 \pm 25, and 2460 \pm 25$ keV. Spin-parity assignments for the latter group of states are compatible with $0^{+}$ , $2^{+}$ , and $4^{+}$ . The summed reduced $α$ width for this group of excited states, presumably a rotational band, is approximately equal to that for the ground state rotational band. The presence of strongly excited $α$ -cluster states at low excitation energy in the deformed nucleus ${}^{150}{Nd}$ , while not understood, is similar to the situation observed in the deformed actinide nuclei ${}^{228}{Ra}$ and ${}^{234}{Th}$ .

NUCLEAR REACTIONS ${}^{154}{Sm} (d, {}^{6}{Li}) {}^{150}{Nd}$ , $E_{d} = 33$ MeV; measured $σ (θ, E_{x})$ ; ${}^{150}{Nd}$ deduced levels, $S_{α}$ , ${γ_{α}}^{2}$ , rotational bands.

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2.102-MeV level in ${}^{206}{Hg}$ and the spin gyromagnetic ratio of the $3 - s$ proton

Inelastic electron scattering from ${}^{208}{Pb}$ at 180°

Nuclear reactions in Rb, Sr, Y, and Zr targets

Elastic scattering of 65 MeV polarized protons

${}^{40}{Ca} (p, p n) {}^{39}{Ca}$ and ${}^{48}{Ca} (p, p n) {}^{47}{Ca}$ neutron knockout reactions at 149.5 MeV

${}^{176}{Yb} (t, p) {}^{178}{Yb}$ reaction

Neutron-capture resonances for ${}^{82}{Se}$

Finite range effects in ( $\vec{d}$ , ${}^{3}{He}$ ) reactions on ${}^{54}{Fe}$ at $E_{d} = 80$ MeV

Fusion of Li and C and a search for entrance channel limitations to fusion cross sections

Fusion between heavy ions at sub-barrier energies

Reactions to resolved states and to non-fusion channels for ${}^{16}O$ + ${}^{48}{Ca}$ at $E_{lab} = 158.2$ MeV

Minimal coupling schemes in $N$ -body reaction theory

Nuclear dynamics and quasi-elastic electron scattering

Corrections to the ${}^{11}B (p, γ_{0}) {}^{12}C$ cross section and its implications

Elastic magnetic scattering of electrons from ${}^{13}C$

Antisymmetrized deuteron stripping

Deuteron breakup by 140 MeV alpha particles at quasifree scattering conditions

Elastic scattering of polarized tritons from $A = 26 - 28$ nuclei at 17 MeV

Multistep direct reaction analysis of continuum spectra in reactions induced by light ions

Selective excitations of $α$ -cluster states in ${}^{150}{Nd}$

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