Recent Articles

Measurements and analysis of the ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{13}{C)}$ , ( ${}^{12}C$ , ${}^{11}B$ ), and ( ${}^{12}C$ , ${}^{14}C$ ) reactions

K. S. Toth, J. L. C. Ford, Jr., G. R. Satchler, E. E. Gross, D. C. Hensley, S. T. Thornton, and T. C. Schweizer

Phys. Rev. C 14, 1471 (1976) - Published 1 October, 1976

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A ${}^{208}{Pb}$ target was bombarded with 97.9-MeV ${}^{12}C$ ions accelerated in the Oak Ridge isochronous cyclotron and the reaction products detected with a 60-cm long position-sensitive proportional counter placed at the focal plane of an Elbek spectrograph. Differential cross sections were measured for the ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{11}B$ ), ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{13}C$ ), and ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{14}C$ ) reactions. The single-nucleon transfer data, together with previous measurements taken for the same two reactions at 77.4 and 116.4 MeV, were analyzed using exact finite-range, full-recoil, distorted-wave Born-approximation calculations. Elastic scattering for ${}^{11}B$ + ${}^{209}{Bi}$ at 74.6 MeV and ${}^{13}C$ + ${}^{207}{Pb}$ at 86.1 MeV was also measured and optical optical potential fits obtained to provide potentials for use in the distorted-wave Born-approximation calculations. Both Woods-Saxon and folded potentials were used in fitting the elastic data. The importance of the various interaction terms in the distorted-wave Born approximation was studied. Good agreement was found between theory and experiment for the ( ${}^{12}C$ , ${}^{13}C$ ) reactions, and the spectroscopic factors deduced were satisfactory. The data for the ( ${}^{12}C$ , ${}^{11}B$ ) reactions, although also yielding satisfactory spectroscopic factors, tend to peak at smaller angles than the predicted curves. This discrepancy increases as the $Q$ value becomes more negative or the bombarding energy is reduced; that is, as the mismatch increases between the grazing angular momenta in the entrance and exit channels.

NUCLEAR REACTIONS ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{13}C$ ), ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{11}B$ ), $E_{lab} = 77.4, 97.9, 116.4$ MeV; ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{14}C$ ), $E_{lab} = 97.9$ MeV; ${}^{207}{Pb}$ ( ${}^{13}C$ , ${}^{13}C$ ), $E_{lab} = 86.1$ MeV; ${}^{209}{Bi}$ ( ${}^{11}B$ , ${}^{11}B$ ), $E_{lab} = 74.6$ MeV; measured $σ (θ)$ ; optical model and DWBA analyses; deduced spectroscopic factors.

Absolute cross section of the reaction ${}^{48}{Ca}$ ( ${}^{18}O$ , ${}^{16}O$ ) ${}^{50}{Ca}$

Da Hsuan Feng, Taro Tamura, Takeshi Udagawa, James Lynch, and K. S. Low

Phys. Rev. C 14, 1484 (1976) - Published 1 October, 1976

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It is shown that the long standing difficulty of very small theoretical cross sections for heavy-ion-induced two-nucleon transfer reactions appears to have been solved, at least for the case of the ${}^{48}{Ca}$ ( ${}^{18}O$ , ${}^{16}O$ ) ${}^{50}{Ca}$ reaction.

NUCLEAR REACTIONS ${}^{48}{Ca}$ ( ${}^{18}O$ , ${}^{16}O$ ) ${}^{50}{Ca}$ , $E = 50$ MeV, $0^{+}$ ground state and $2^{+}$ excited state. DWBA and coupled-reaction-channel analysis, density-dependent correlations.

Self-consistent heavy-ion potentials

P. G. Zint and U. Mosel

Phys. Rev. C 14, 1488 (1976) - Published 1 October, 1976

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Calculations of the real part of the heavy-ion potential have been performed for the systems ${}^{12}C$ + ${}^{12}C$ , ${}^{16}O$ + ${}^{16}O$ , and ${}^{40}{Ca}$ + ${}^{40}{Ca}$ using the Hartree-Fock method with a constraint on the center-of-mass distance. The interaction used is the Skyrme force SIII. For the case of ${}^{16}O$ + ${}^{16}O$ a detailed discussion of the nuclear structure with increasing overlap of the ions is given. It is found that the individual shell structures of the two ${}^{16}O$ nuclei survive until the density in the neck region has reached about 50% of its maximum value. The calculated potentials have been used in an optical model code to calculate elastic excitation functions. The agreement with the empirically determined best fit potentials is remarkable.

NUCLEAR REACTIONS Self-consistent constrained Hartree-Fock calculations of HI potentials. Structure of ${}^{16}O$ + ${}^{16}O$ at large overlap; potentials calculated for ${}^{12}C$ + ${}^{12}C$ , ${}^{16}O$ + ${}^{16}O$ , ${}^{40}{Ca}$ + ${}^{40}{Ca}$ ; compared with experimental fits.

Electrofission and photofission of ${}^{238}U$ in the energy range 6-60 MeV

J. D. T. Arruda Neto, S. B. Herdade, B. S. Bhandari, and I. C. Nascimento

Phys. Rev. C 14, 1499 (1976) - Published 1 October, 1976

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Experimental results are presented for the electrofission and photofission of ${}^{238}U$ in the energy range 6 to 60 MeV. The importance of the inclusion of the Coulomb corrections in the calculation of the virtual photon spectrum is emphasized and the relative $E 1$ contribution to the electrofission process has been evaluated using the distorted-wave Born-approximation analysis of the experimental data.

NUCLEAR REACTIONS, FISSION Measured electrofission and photofission cross sections of ${}^{238}U$ in the energy range 6-60 MeV. Deduced relative $E 1$ contribution to the electrofission process using DWBA analysis of the experimental data.

Production of ${}^{7}{Be}$ , ${}^{22}{Na}$ , and ${}^{28}{Mg}$ from Mg, Al, and ${SiO}_{2}$ by protons between 82 and 800 MeV

H. R. Heydegger, Anthony L. Turkevich, A. Van Ginneken, and P. H. Walpole

Phys. Rev. C 14, 1506 (1976) - Published 1 October, 1976

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Cross sections for the production of ${}^{7}{Be}$ , ${}^{22}{Na}$ , and ${}^{28}{Mg}$ from Mg, Al, and ${SiO}_{2}$ by protons in the 80 to 800 MeV energy range have been determined by direct foil $γ$ -ray spectrometry. These nuclides are of interest in several fields of astrophysics, cosmochemistry, and nuclear science. The values obtained are compared with other experimental values and with values predicted using empirical formulas and Monte Carlo methods. A mathematical form for the $Al (p, X) {}^{22}{Na}$ excitation function above 100 MeV is proposed.

NUCLEAR REACTIONS Natural Mg, Al, $Si O_{2} (p, X) {}^{7}{Be}$ , ${}^{22}{Na}$ , ${}^{28}{Mg}$ , $E = 82 - 800$ MeV; measured $σ (E)$ .

Negative pion interactions with ${}^{19}F$ , ${}^{27}{Al}$ , and ${}^{51}V$ near the $Δ (1232)$ resonance

B. J. Lieb, W. F. Lankford, S. H. Dam, H. S. Plendl, H. O. Funsten, W. J. Kossler, V. G. Lind, and A. J. Buffa

Phys. Rev. C 14, 1515 (1976) - Published 1 October, 1976

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Prompt $γ$ rays from $π^{-}$ interactions with ${}^{19}F$ , ${}^{27}{Al}$ , and ${}^{51}V$ near the $Δ (1232)$ resonance were detected. Deexcitation $γ$ rays from residual nuclei formed by single and multiple nucleon removal and by inelastic and charge exchange scattering were identified, and cross sections for excitation of residual states were determined. Nuclear recoil momenta were determined from observed Doppler broadening. Where possible, the cross sections were corrected for $γ$ feeding from higher states. The results are compared with the results of previous experiments and of intranuclear cascade/evaporation code calculations.

[NUCLEAR REACTIONS ${}^{19}F$ , ${}^{27}{Al}$ , ${}^{51}V (π^{-}, X γ)$ , $E_{av} \approx 230$ MeV, measured relative $γ$ -ray yields at $θ = 90 °$ , calculated $σ$ , nuclear recoil momenta.]

Production of Sc nuclides in the interaction of ${}^{238}U$ with 1-300 GeV protons

Ø. Scheidemann and N. T. Porile

Phys. Rev. C 14, 1534 (1976) - Published 1 October, 1976

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Cross sections and thick-target recoil properties of several Sc nuclides formed in the interaction of ${}^{238}U$ with 1-300 GeV protons have been determined. The ranges of all the products decrease markedly between 1 and 10 GeV and only slightly thereafter. The forward-to-backward emission ratios peak at 3 GeV and decrease to a value of unity at 300 GeV. The excitation functions increase sharply up to ∼ 10 GeV and go through a very shallow peak at this energy. The results are analyzed within the context of the two-step model of high-energy reactions and found to require a larger ratio of transverse to forward momentum transfer than expected on this basis. The emission of an excited hadron in the cascade can also account for the data. The systematics of fragment momenta are developed.

[NUCLEAR REACTIONS Measured $σ$ , $2 W (F + B)$ , and $\frac{F}{B}$ of various Sc nuclides formed in interaction of ${}^{238}U$ with 1-300 GeV protons.]

Absolute differential cross section measurements for proton-proton elastic scattering at 647 and 800 MeV

H. B. Willard, B. D. Anderson, H. W. Baer, R. J. Barrett, P. R. Bevington, A. N. Anderson, H. Willmes, and Nelson Jarmie

Phys. Rev. C 14, 1545 (1976) - Published 1 October, 1976

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Absolute differential cross sections for elastic proton-proton scattering have been measured in the center-of-mass angular interval from 20° to 90° at 647 and 800 MeV with overall uncertainties of ± (3-10)% and ± (3-5)%, respectively. The data at 800 MeV are the most accurate so far reported at that energy. Comparison is made to earlier measurements and contemporary phase-shift analyses.

NUCLEAR REACTIONS ${}^{1}H (p, p) {}^{1}H$ , $E = 647$ , 800 MeV; measured $σ (θ)$ ; $θ = 23 ° - 90 °$ , $Δ θ = 3 °$ .

Spallation of copper by 25-GeV ${}^{12}C$ ions and 28-GeV protons

J. B. Cumming, R. W. Stoenner, and P. E. Haustein

Phys. Rev. C 14, 1554 (1976) - Published 1 October, 1976

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Relative yields of 35 products extending from ${}^{7}{Be to}$ ${}^{67}{Ga}$ have been measured for the interaction of 25-GeV (2.1-GeV/amu) ${}^{12}C$ ions with Cu. For purposes of comparison, cross sections of 48 nuclides produced by the irradiation of Cu with 28-GeV protons are also reported. The mass yield curve deduced for the 2.1-GeV/amu ${}^{12}C$ ions is very similar to that reported for 0.28-GeV/amu ${}^{14}N$ , which implies that there is little energy dependence of target fragmentation cross sections in this energy range where meson production effects in nucleon-nucleon collisions become important. Charge dispersion curves for products with $37 \leq A \leq 64$ are the same within errors for ${}^{12}C$ and protons. Compared with 28-GeV protons, the mass yield curve for ${}^{12}C$ shows some favoring of products near the target (possibly due to increased secondary effects). Formation of light fragments such as ${}^{7}{Be}$ and ${}^{24}{Na}$ is significantly enhanced possibly due to highly damaging central collisions of the heavy ions. The results are discussed in terms of the concepts of limiting fragmentation and factorization.

NUCLEAR REACTIONS Cu( ${}^{12}C$ , spallation), $E = 25$ GeV; measured relative $σ (A, Z)$ , 35 products ${}^{7}{B e -}$ ${}^{67}{Ga}$ . Cu $p$ , spallation), $E = 28$ GeV; measured $σ (A, Z)$ , 48 products ${}^{7}{B e -}$ ${}^{67}{Ga}$ . Natural targets, Ge(Li) detectors, radiochemistry.

Multiple-scattering analysis of the $π^{-} He$ system at high energies

Yukap Hahn

Phys. Rev. C 14, 1564 (1976) - Published 1 October, 1976

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Elastic scattering of negative pions by ${}^{4}{He}$ nuclei at 1.12 GeV is analyzed using the multiple scattering theory. The contribution of the higher order optical potentials is found to be large in the region of the second diffraction maximum; it comes mainly from the center of mass pair correlations enhanced by a large relativistic kinematic correction. The effects of the dynamical correlation, the fixed scatterer approximation as a result of the closure, and the off-shell property of the $π N$ amplitude are found to be negligible. The calculated cross section is in fair agreement with the experiment for $q^{2} ≲ 0.4$ ${(G e V / c)}^{2}$ .

NUCLEAR REACTIONS $π^{-} {}^{4}{He}$ elastic scattering at 1.12 GeV; analyzed by multiple-scattering theory, effect of higher-order optical potentials.

Decays of ${}^{126}{Ba}$ and ${}^{126}{Cs}$

B. P. Pathak, L. Lessard, L. Nikkinen, and I. L. Preiss

Phys. Rev. C 14, 1573 (1976) - Published 1 October, 1976

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The neutron deficient ${}^{126}{Ba}$ has been produced by the reactions ${}^{115}{In} ({}^{16}O, 5 n) {}^{126}{La} \overset{β +, E C}{\to} {}^{126}{Ba}$ , ${}^{121}{Sb} ({}^{11}B, 6 n) {}^{126}{Ba}$ , and ${}^{133}{Cs} (p, 8 n) {}^{126}{Ba}$ . Its decay properties have been studied in equilibrium with the daughter activity of ${}^{126}{Cs}$ . About 100 $γ$ rays have been observed to be associated with the decay of the ${}^{126}{B a -}$ ${}^{126}{Cs}$ mass chain. The assignment of $γ$ rays to ${}^{126}{Ba}$ and ${}^{126}{Cs}$ activities has been done by measuring $γ$ -ray spectra gated by $K$ x rays of Cs and Xe, respectively. The $γ - γ$ and $β - γ$ coincidence studies have been performed by using large volume Ge(Li) and plastic detectors and a two parameter analyzer system. Conversion coefficients of intense $γ$ transitions have been measured by using a conversion electron spectrometer consisting of a Ge(Li) detector and a cooled Si(Li) detector. Decay schemes of ${}^{126}{Cs}$ and ${}^{126}{Ba}$ are proposed. The levels in ${}^{126}{Xe}$ are compared with predictions of the collective model.

RADIOACTIVITY ${}^{126}{Ba}$ , ${}^{126}{Cs}$ [from ${}^{115}{In} ({}^{16}O, 5 n)$ , ${}^{121}{Sb} ({}^{11}B, 6 n)$ , and ${}^{133}{Cs} (p, 8 n)$ ]; measured $E_{γ}$ , $I_{γ}$ , $I_{ce}$ , $β - γ$ , $x - γ$ , $γ - γ$ coincidence; deduced levels, $J$ , $π$ , $log ft$ , CC, multipolarities; Ge(Li), Si(Li), plastic detectors; natural targets.

Decay of mass-separated ${}^{190}{Tl}$ and ${}^{190}{Hg}$

C. R. Bingham, L. L. Riedinger, F. E. Turner, B. D. Kern, J. L. Weil, K. J. Hofstetter, J. Lin, E. F. Zganjar, A. V. Ramayya, J. H. Hamilton, J. L. Wood, G. M. Gowdy, R. W. Fink, E. H. Spejewski, W. D. Schmidt-Ott, R. L. Mlekodaj, H. K. Carter, and K. S. R. Sastry

Phys. Rev. C 14, 1586 (1976) - Published 1 October, 1976

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Radioactive sources containing ${}^{190}{Tl}$ and ${}^{190}{Hg}$ have been produced and mass separated with the University Isotope Separator on line to the Oak Ridge isochronous cyclotron. Multiscaled spectra of $γ$ rays, x rays, conversion electrons, and positrons were obtained, and $γ - γ$ and $γ$ -x-ray coincidences were measured. Two isomers in ${}^{190}{Tl}$ decay have half-lives of 2.6 ± 0.3 min ( $2^{-}$ ) and 3.7 ± 0.3 min ( $7^{+}$ ). From $β$ decay endpoint energies the $7^{+}$ and $2^{-}$ isomers lie within 0.1 MeV of each other, but which is the ground state was not determined. Both isomers have ground-state $Q_{EC}$ values of approximately 7 MeV. The $2^{-}$ level undergoes $β$ decay primarily to the $2^{+}$ states at 416.4 and 1099.9 keV in ${}^{190}{Hg}$ , while the decay of the $7^{+}$ isomer feeds a number of different states with spins ranging from 5 to 9. We observed the $5^{-}$ , $7^{-}$ , and $9^{-}$ members of the previously identified structure of negative-parity states resulting from coupling of a rotation-aligned $i_{\frac{13}{2}}$ neutron with $3 p_{\frac{3}{2}}$ and $2 f_{\frac{5}{2}}$ neutrons. Some additional states having decays consistent with ( $6^{-}$ ) and ( $8^{-}$ ) assignments perhaps are candidates for less aligned members of the ${13 / 2}^{+}$ band coupled with $p_{\frac{3}{2}}$ and $f_{\frac{5}{2}}$ neutrons. The 20-min ${}^{190}{Hg}$ isotope decays approximately 65% of the time to a level at 171.5 keV, thus making it difficult to study other levels in ${}^{190}{Au}$ . Four new states in ${}^{190}{Au}$ were definitely established, while several new ones were suggested by the present work. The populated levels are predominantly low spin and are fairly closely spaced. The $log ft$ value for the transition to the 171.5 keV level is 5.7, so it is likely that this state has a spin and parity of $1^{+}$ .

RADIOACTIVITY ${}^{190}{Tl}$ , ${}^{190}{Tl}^{m}$ , ${}^{190}{Hg}$ [from Ta, $W ({}^{16}O, x p + y n)$ , $E = 143, 124$ MeV]; mass-separated radioactivities. Measured $T_{\frac{1}{2}}$ , $E_{γ}$ , $I_{γ}$ , $I_{ce}$ , $E_{β}$ , $γ γ$ coin, $γ x$ coin. Deduced $log ft$ , $Q$ . ${}^{190}{Hg}$ , ${}^{190}{Au}$ deduced levels, $J$ , $π$ , ICC, $Λ$ .

Beta decay of ${}^{51}{Sc}$ to states in ${}^{51}{Ti}$

C. N. Davids, S. L. Tabor, E. B. Norman, R. C. Pardo, and L. A. Parks

Phys. Rev. C 14, 1601 (1976) - Published 1 October, 1976

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${}^{51}{Sc}$ was produced with the ${}^{48}{Ca} (α, p) {}^{51}{Sc}$ reaction at $E_{α} = 18$ MeV and pneumatically transferred to a shielded counting area. The $β$ decay scheme of ${}^{51}{Sc}$ was determined from measurements of the $γ$ singles and $γ - γ$ coincidence spectra using ${50 - c m}^{3}$ Ge(Li) detectors. This investigation yielded a more accurate determination of the ${}^{51}{Sc}$ half-life (12.4 ± 0.1 s), the observation of previously unknown $β$ branches to ${}^{51}{Ti}$ levels at 2691, 2731, 2919, 3062, 3237, 3619, 4095, 4186, and 4881 keV, and the assignment of new levels in ${}^{51}{Ti}$ at 3062, 4095, and 4186 keV. In addition, the decay scheme provides parity assignments and spin restrictions for a number of states in ${}^{51}{Ti}$ .

RADIOACTIVITY ${}^{51}{Sc}$ , measured $T_{\frac{1}{2}}$ , $E_{γ}$ , $I_{γ}$ , $γ - γ$ coincidence; deduced decay scheme, $log ft$ . ${}^{51}{Ti}$ deduced levels, $J$ , $π$ . Enriched targets, Ge(Li) detectors.

Anisotropic angular correlation between the $γ$ rays and the $K$ x rays following internal conversion in ${}^{169}{Tm}$

S. K. Sen, R. P. Gupta, and E. Tomchuk

Phys. Rev. C 14, 1608 (1976) - Published 1 October, 1976

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The angular distribution of $K$ x rays emitted following $K$ conversion has been investigated theoretically. It is shown that the static nuclear quadrupole moment may sufficiently perturb the innermost electron shell to cause anisotropy in the angular distribution between the $K$ x rays and the coincident $γ$ rays, as suggested by Sen and subsequently confirmed experimentally by Sen, Salie, and Tomchuk.

RADIOACTIVITY ${}^{169}{Tm}$ ; calculated $γ x (θ)$ accompanying $K$ conversion when perturbed by the static nuclear quadrupole moment.

Self-consistent $K$ -matrix-model calculation for finite and superheavy nuclei

R. Y. Cusson, H. P. Trivedi, H. W. Meldner, M. W. Weiss, and R. E. Wright

Phys. Rev. C 14, 1615 (1976) - Published 1 October, 1976

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A model two-body $K$ matrix is introduced which leads to simple Brueckner-Hartree-Fock equations similar to those resulting from Skyrme forces. The main features of the present model are determined by basic nuclear matter properties. Experimental nucleon removal energies for finite closed-shell nuclei are used as a criterion for setting the single-particle energy levels in our model. This is accomplished by parametrizing the Brueckner rearrangement potential which augments the single-particle potential producing single-particle level densities in better agreement with experiment than Skyrme-potential models or density matrix expansion theories. Good fits are also obtained to total binding energies, rms radii, and electron scattering form factors of the magic nuclei ${}^{16}O$ , ${}^{40}{Ca}$ , ${}^{90}{Zr}$ , ${}^{208}{Pb}$ . Extrapolated results for the magic superheavy nucleus ${}^{298}114$ are presented and discussed.

NUCLEAR STRUCTURE Nuclear matter; fitted Brueckner $K$ -matrix model parameters, ${}^{16}O$ , ${}^{40}{Ca}$ , ${}^{48}{Ca}$ , ${}^{90}{Zr}$ , ${}^{208}{Pb}$ , ${}^{298}114$ ; computed, and compared with exp. $W_{tot}$ , $R_{rms}$ , $E_{s . p .}$ , $ρ (\vec{r})$ , electron scattering data. Oscillator basis, self-consistent BHF method.

Electromagnetic transitions in ${}^{49}{Cr}$

Ashok Dhar and Kumar Bhatt

Phys. Rev. C 14, 1630 (1976) - Published 1 October, 1976

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Deformed configuration mixing shell model calculations based on Hartree-Fock theory within the full $1 f - 2 p$ shell space have been carried out for ${}_{24}^{49}{Cr}_{25}$ using modified Kuo-Brown effective interaction. The calculation gives rise to an excited $K = \frac{1}{2}$ band in addition to the $K = \frac{5}{2}$ ground state band. The spectrum of the latter is in excellent agreement with the experimental one. The calculated $B (E 2)$ , $B (M 1)$ values, $(\frac{E 2}{M 1})$ mixing ratios, branching ratios, and lifetimes compare reasonably well with the available observed values.

NUCLEAR STRUCTURE ${}^{49}{Cr}$ ; calculated spectrum, $B (E 2)$ , $B (M 1)$ , $(\frac{E 2}{M 1})$ mixing ratios, branching intensities, lifetimes, predicted $K = \frac{1}{2}$ band, deformed configuration mixing shell model calculation based on projected Hartree-Fock theory in ${(f - p)}^{n}$ space, modified Kuo-Brown interaction, least squares fitted effective charges. Comparison with experiment and rotation-particle-coupling calculations.

Application of the projected Hartree-Fock method to rotational motion in $1 p$ -shell odd- $A$ nuclei

F. Brut and S. Jang

Phys. Rev. C 14, 1638 (1976) - Published 1 October, 1976

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The rotational properties of $A = 7, 9, 11, and 13$ nuclei are studied in a self-consistent way using the effective two-body interactions derived either from the Sussex relative harmonic-oscillator matrix elements or from energy-level fitting. Special care is taken in choosing the appropriate solution among others corresponding to oblate or prolate deformed orbitals. In particular, a pronounced band mixing in $A = 9$ and $A = 11$ nuclei is investigated by diagonalizing the effective Hamiltonian within the orthonormalized basis setup with the Hartree-Fock projected states. Moments of inerita of $A = 6, 8, 10, and 12$ nuclei are also computed by means of the cranking model. The energy levels and the magnetic dipole moments, as well as the $M 1$ transition rates, are in good agreement with shell-model calculations which use the same effective two-body interactions.

NUCLEAR STRUCTURE ${}^{7}{Li}$ , ${}^{9}{Be}$ , ${}^{11}B$ , ${}^{13}N$ ; calculated levels, moments, and transition rates. Calculated moments of inertia of $A = 6, 8, 10, and 12$ nuclei. Projected Hartree-Fock method, cranking model.

Statistical properties of low-lying $1^{+}$ levels in odd-odd mass nuclei near $A = 50$

M. Beckerman

Phys. Rev. C 14, 1648 (1976) - Published 1 October, 1976

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Statistical aspects of low-lying $1^{+}$ levels populated in odd-odd mass nuclei in the $1 f_{\frac{7}{2}}$ shell are examined. The spacing distribution is found to be consistent with a Wigner distribution and a level density can be introduced. Level densities, temperatures, and spin-cutoff factors are deduced for ${}^{46 - 50}{Sc}$ , ${}^{48 - 52}V$ , ${}^{52 - 56}{Mn}$ , and ${}^{56 - 58}{Co}$ .

NUCLEAR STRUCTURE ${}^{46, 48, 50}{Sc}$ , ${}^{48, 50, 52}V$ , ${}^{52, 54, 56}{Mn}$ , ${}^{56, 58}{Co}$ ; deduced level densities, temperatures and spin-cutoff factors.

RAPID COMMUNICATION

Evidence for sideward emission of Sc fragments in the interaction of ${}^{238}U$ with 400 GeV protons

D. R. Fortney and N. T. Porile

Phys. Rev. C 14, 1652(R) (1976) - Published 1 October, 1976

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Thick-target recoil properties of Sc fragments produced in the interaction of ${}^{238}U$ with 400 GeV protons have been determined. The anisotropy parameter $\frac{b}{a}$ was obtained from measurements on targets oriented either parallel or perpendicular to the proton beam on the assumption that the angular distribution of the fragments in the moving system has the form $a + b {cos}^{2} θ$ . The weighted average value of $\frac{b}{a}$ for four Sc nuclides is -0.67 ± 0.12 indicating that the angular distribution must show strong sideways peaking.

NUCLEAR REACTIONS ${}^{238}U (p, f) {}^{44}{Sc}^{m}$ , ${}^{46}{Sc}$ , ${}^{47}{Sc}$ , ${}^{48}{Sc}$ , $E_{p} = 400$ GeV. Measured thick-target recoil properties; deduced anisotropy parameter.

RAPID COMMUNICATION

Multinucleon removal induced by 80-MeV ${}^{3}{He}$

P. P. Singh, M. Sadler, A. Nadasen, L. A. Beach, and C. R. Gossett

Phys. Rev. C 14, 1655(R) (1976) - Published 1 October, 1976

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$γ$ ray spectra were observed following the bombardment of thin ${}^{24}{Mg}$ , ${}^{26}{Mg}$ , ${}^{27}{Al}$ , Fe, ${}^{58}{Ni}$ , and ${}^{64}{Zn}$ targets with an 80-MeV ${}^{3}{He}$ beam. Product nuclei were identified using their characteristic $γ$ rays. Qualitative features of the results can be understood in terms of the evaporation process preceded by pre-equilibrium emission. Results with ${}^{3}{He}$ are similar to those obtained with comparable energy proton and pion beams. Systematics are discussed.

NUCLEAR REACTIONS: ( ${}^{3}{He}, x n y p z α γ$ ) with ${}^{24}{Mg}$ , ${}^{26}{Mg}$ , ${}^{27}{Al}$ , Fe, ${}^{58}{Ni}$ , and ${}^{64}{Zn}$ targets. Measured $γ$ -ray spectra. Deduced relative cross sections for production of final nuclei following multinucleon removal.

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Measurements and analysis of the ${}^{208}{Pb}$ ( ${}^{12}C$ , ${}^{13}{C)}$ , ( ${}^{12}C$ , ${}^{11}B$ ), and ( ${}^{12}C$ , ${}^{14}C$ ) reactions

Absolute cross section of the reaction ${}^{48}{Ca}$ ( ${}^{18}O$ , ${}^{16}O$ ) ${}^{50}{Ca}$

Self-consistent heavy-ion potentials

Electrofission and photofission of ${}^{238}U$ in the energy range 6-60 MeV

Production of ${}^{7}{Be}$ , ${}^{22}{Na}$ , and ${}^{28}{Mg}$ from Mg, Al, and ${SiO}_{2}$ by protons between 82 and 800 MeV

Negative pion interactions with ${}^{19}F$ , ${}^{27}{Al}$ , and ${}^{51}V$ near the $Δ (1232)$ resonance

Production of Sc nuclides in the interaction of ${}^{238}U$ with 1-300 GeV protons

Absolute differential cross section measurements for proton-proton elastic scattering at 647 and 800 MeV

Spallation of copper by 25-GeV ${}^{12}C$ ions and 28-GeV protons

Multiple-scattering analysis of the $π^{-} He$ system at high energies

Decays of ${}^{126}{Ba}$ and ${}^{126}{Cs}$

Decay of mass-separated ${}^{190}{Tl}$ and ${}^{190}{Hg}$

Beta decay of ${}^{51}{Sc}$ to states in ${}^{51}{Ti}$

Anisotropic angular correlation between the $γ$ rays and the $K$ x rays following internal conversion in ${}^{169}{Tm}$

Self-consistent $K$ -matrix-model calculation for finite and superheavy nuclei

Electromagnetic transitions in ${}^{49}{Cr}$

Application of the projected Hartree-Fock method to rotational motion in $1 p$ -shell odd- $A$ nuclei

Statistical properties of low-lying $1^{+}$ levels in odd-odd mass nuclei near $A = 50$

Evidence for sideward emission of Sc fragments in the interaction of ${}^{238}U$ with 400 GeV protons

Multinucleon removal induced by 80-MeV ${}^{3}{He}$

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