Recent Articles

RAPID COMMUNICATION

Systematic nuclear-structure dependence of analyzing powers for ( $\vec{p}$ , $t$ ) reactions on mediummass vibrational nuclei

K. Yagi, S. Kunori, Y. Aoki, K. Nagano, Y. Tagishi, and Y. Toba

Phys. Rev. C 19, 285(R) (1979) - Published 1 January, 1979

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A neutron-number ( $N$ ) dependence of analyzing powers $A (θ)$ has been observed in ( $\vec{p}$ , $t$ ) reaction leading to the quadrupole vibrational states ( $2_{1}^{+}$ ) in ${}^{98}{Ru}$ , ${}^{102, 108}{Pd}$ , ${}^{114}{Cd}$ , ${}^{116}{Sn}$ , and ${}^{120, 126}{Te}$ . Although analyzing powers for the ground-state transitions $A (θ, 0_{g}^{+})$ are very similar to each other, $A (θ, 2_{1}^{+})$ for the nuclei belonging to the beginning of the $N = 50 - 82$ shell are markedly different, having almost opposite signs, from those for nuclei belonging to the latter half of the shell.

NUCLEAR REACTIONS ${}^{100}{Ru}$ , ${}^{104, 110}{Pd}$ , ${}^{116}{Cd}$ , ${}^{118}{Sn}$ , ${}^{122, 128}{Te}$ ( $\vec{p}$ , $t$ ), $E = 22.0$ MeV; measured $σ (θ)$ , $A_{y} (θ)$ ; enriched targets.

RAPID COMMUNICATION

Ambiguities in the inference of precompound emission from excitation function analysis

M. Blann and R. L. Ferguson

Phys. Rev. C 19, 289(R) (1979) - Published 1 January, 1979

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We address several indirect methods of deducing neutron emission energies in heavy ion reactions. It is shown that a pure statistical decay process can lead to apparently very high average neutron kinetic energies. It is shown that the result follows from prejudicial gating due to ignoring charged particle emission, and that the error is present even if only the $xn$ channels are measured and analyzed. It is concluded that interpretation of experimental results vis-à-vis precompound particle emission must be performed with extreme caution when other than direct particle spectral measurements are performed.

NUCLEAR REACTIONS Interpretation of excitation functions, neutron multiplicities in terms of statistical or nonstatistical behavior.

RAPID COMMUNICATION

Search for band crossing in ${}^{44}{Ti}$ through the ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{4}{He}$ ) ${}^{40}{Ca}$ reaction

R. Singh, K. A. Eberhard, and John G. Cramer

Phys. Rev. C 19, 291(R) (1979) - Published 1 January, 1979

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The α particles from the ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{4}{He}$ ) ${}^{40}{Ca}$ reaction were detected at laboratory angles of 124, 134, 144, 154, and 164° for laboratory bombarding energies of $E ({}^{16}O) = 25, 30, 35, 40, and 45$ MeV, in a search for channel-coupling effects arising from band crossings in the ${}^{44}{Ti}$ compound system. No evidence for such effects was found, but the measured angle-integrated cross sections are consistent with Hauser-Feshbach calculations of α emission from the compound nucleus.

NUCLEAR REACTIONS ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{4}{He}$ ), $E = 25 - 45$ MeV; measured $σ (E)$ ; enriched target; Hauser-Feshbach calculations.

RAPID COMMUNICATION

Search for $α α^{*}$ rotational levels in ${}^{8}{Be}$

R. E. Warner, G. C. Ball, W. G. Davies, A. J. Ferguson, and J. S. Forster

Phys. Rev. C 19, 293(R) (1979) - Published 1 January, 1979

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The differential cross sections for ${}^{2}H ({}^{6}{Li}, α) α^{*}$ (20.08 MeV) and ${}^{2}H ({}^{6}{Li}, α) α$ were measured at 30° c.m. for $E_{Li} = 10 to 31$ MeV. Possible evidence is presented for ${}^{8}{Be}$ states decaying by $α^{*}$ emission, near the $3^{-}$ and $4^{+}$ levels of an $α α^{*}$ rotational band in ${}^{8}{Be}$ predicted by resonating group calculations.

NUCLEAR REACTIONS ${}^{2}H {({}^{6}{Li}, α)}^{*}$ and ${}^{2}H ({}^{6}{Li}, α) α$ , $E = 10 to 31$ MeV. ${}^{8}{Be}$ levels.

Erratum: Semiempirical nuclear level density formula with shell effects

S. K. Kataria, V. S. Ramamurthy, and S. S. Kapoor

Phys. Rev. C 19, 297 (1979) - Published 1 January, 1979

Nuclear excitation of ${}^{115}{In}$ by positron annihilation with $K$ -shell electrons

Yoshihisa Watanabe, Takeshi Mukoyama, and Sakae Shimizu

Phys. Rev. C 19, 32 (1979) - Published 1 January, 1979

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When a positron annihilates with a $K$ -shell electron, the excess liberated may be given to the nucleus involved. In the case when this energy is just the right energy for any excited state within its level width of a fraction of an electron volt, nuclear excitation can be expected, and if the excited level cascades down to an isomeric state with appreciable lifetime we can confirm the occurrence of this annihilation mode by observing $γ$ transitions or conversion electrons from this isomeric level. In the present work we observed $γ$ rays from ${}^{115}{In}^{m}$ after irradiation of natural indium foils by positrons from the $β^{+}$ decay of ${}^{64}{Cu}$ . Using the observed induced $γ$ activity of ${}^{115}{In}^{m}$ and assuming this phenomenon to be the two-step process, we have evaluated the cross sections of nuclear excitation by positron annihilation for 1078- and 1464-keV levels of ${}^{115}{In}$ ; (3.9±1.4)× $10^{- 24}$ ${cm}^{2}$ and (1.4±0.5)× $10^{- 22}$ ${cm}^{2}$ , respectively.

NUCLEAR REACTIONS ${}^{115}{In}$ ; evaluated excitation cross sections for 1078- and 1464-keV levels by positron annihilation with $K$ -shell electrons.

Fragmentation of a previously reported $g_{\frac{9}{2}}$ analog state in ${}^{63}{Cu}$

G. Vourvopoulos, T. Paradellis, G. Bergdolt, G. J. Costa, and F. Diez

Phys. Rev. C 19, 38 (1979) - Published 1 January, 1979

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The $γ$ decay of resonances in the reaction ${}^{62}{Ni}$ ( $p$ , $γ$ ) ${}^{63}{Cu}$ in the energy range $E_{p} = 3766 to 3865$ keV has been investigated. For a number of prominent resonances that seemed to decay to the 2509 keV $\frac{9}{2^{+}}$ level in ${}^{63}{Cu}$ angular distributions were taken. These angular distributions show that the multipolarity of the transition gamma rays is not of pure $M 1$ character as one would expect from a $T_{>}$ to a $T_{<}$ transition. Futher investigation with a thick target did not alter the overall results, which show that the $g_{\frac{9}{2}}$ analog state is most likely fragmented in such a way that none of the fragments has an observable strength contrary to a previous report.

NUCLEAR REACTIONS ${}^{62}{Ni}$ ( $p$ , $γ$ ), $E = 3766 - 3865$ keV; measured $E_{γ}$ , $I_{γ}$ , $ω_{γ}$ . ${}^{63}{Cu}$ deduced $g_{\frac{9}{2}}$ analog resonances. Enriched target.

Small-angle cross sections for ${}^{50, 52}{Cr}$ ( ${}^{3}{He}$ , $d$ ) ${}^{51, 53}{Mn}$ at 18 MeV

J. E. Park, W. W. Daehnick, and M. J. Spisak

Phys. Rev. C 19, 42 (1979) - Published 1 January, 1979

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The reactions ${}^{50, 52}{Cr}$ ( ${}^{3}{He}$ , $d$ ) were investigated at an incident energy of 18 MeV with 12-15 keV resolution. Special emphasis was placed on small-angle measurements of the angular distributions, including $θ = 0 °$ in order to study new ${}^{51, 53}{Mn}$ levels and to document deviations from standard distorted-wave Born-approximation predictions, which appear to depend on the total-angular momentum transfer $j$ . Absolute differential cross sections were obtained in small angular steps for $0 ° \leq θ \leq 45 °$ in ${}^{51}{Mn}$ and $0 ° \leq θ \leq 30 °$ in ${}^{53}{Mn}$ using a high-resolution position-sensitive (helix) gas counter and photographic emulsions as detectors. $l$ -transfer assignments and spectroscopic factors were deduced from comparison with distorted-wave Born-approximation calculations for the levels up to 4.52 MeV in ${}^{51}{Mn}$ and up to 6 MeV excitation in ${}^{53}{Mn}$ . A number of new $l = 0, 1$ values were assigned in both Mn isotopes on the basis of better small-angle data. For $l = 1$ , systematic differences between known $p_{\frac{1}{2}}$ and $p_{\frac{3}{2}}$ transitions were noted at angles below 10°. Distorted-wave Born approximation calculations with familiar spin orbit potentials fail to reproduce these differences.

NUCLEAR REACTIONS ${}^{50, 52}{Cr}$ ( ${}^{3}{He}$ , $d$ ) ${}^{51, 53}{Mn}$ , $E_{{}^{3}{He}} = 18$ MeV; measured $σ (E_{d}, θ)$ , resolution ∼ 13 keV. DWBA analysis, deduced $l$ , $π$ , spectroscopic factors, small angle $l = 1$ $j$ dependence.

Mechanism of ${}^{14}N$ ( $t$ , $p$ ) to the ground state quadruplet in ${}^{16}N$

H. T. Fortune, O. M. Bilaniuk, G. Stephans, and R. Middleton

Phys. Rev. C 19, 5 (1979) - Published 1 January, 1979

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Complete angular distributions (8°-168°) have been measured for the ${}^{14}N$ ( $t$ , $p$ ) ${}^{16}N$ reaction, at a bombarding energy of 15 MeV, leading to the lowest four levels of ${}^{16}N$ . Results have been analyzed using distorted-wave Born approximation and microscopic wave functions. The approximate magnitude of the compound-nucleus component has been extracted.

NUCLEAR REACTION ${}^{14}N$ ( $t$ , $p$ ), $E = 15$ MeV; ${}^{16}N$ levels, deduced reaction mechanism and tested shell-model wave functions. DWBA analysis.

Coincidence studies of heavy fragments in deeply inelastic collisions between heavy ions: Sequential fission probability in reactions of 730-MeV ${}^{86}{Kr}$ with Au

M. Rajagopalan, L. Kowalski, D. Logan, M. Kaplan, J. M. Alexander, M. S. Zisman, and J. M. Miller

Phys. Rev. C 19, 54 (1979) - Published 1 January, 1979

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Angular correlations have been measured between heavy fragments in ${}^{86}K$ R + ${}^{197}{Au}$ reactions using two gas telescopes. The data have been analyzed to yield a separation of two-body from multibody events. The assumption that sequential fission accounts for all multibody breakup allows the determination of sequential fission probability as a function of inelastic energy transfer. Comparison to fission excitation functions for similar heavy compound nuclei provides insight into the deposition of energy and angular momentum. For $- Q$ of ≈ 200 MeV or E* ≈ 140 MeV typical spin values of $30 - 40 ℏ$ can be estimated for the heavy (Aulike) fragments.

NUCLEAR REACTIONS ${}^{197}{Au}$ ( ${}^{86}{Kr}$ , $X$ ), $E = 730$ -MeV, deeply inelastic collisions, measured fragment-fragment coincidences and correlations using two gas telescopes. Derived sequential fission probability as a function of inelastic energy transfer.

Comparison of the ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{12}C$ ) ${}^{32}S$ and ${}^{28}{Si}$ ( ${}^{18}O$ , ${}^{14}C$ ) ${}^{32}S$ reactions at 60 MeV incident energy

G. P. A. Berg, M. A. G. Fernandes, K. Nagatani, J. C. Peng, B. Berthier, J. P. Fouan, J. Gastebois, J. P. Le Fèvre, and M. -C. Lemaire

Phys. Rev. C 19, 62 (1979) - Published 1 January, 1979

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Cross-section angular distributions of the ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{12}C$ ) ${}^{32}S$ and the ${}^{28}{Si}$ ( ${}^{18}O$ , ${}^{14}C$ ) ${}^{32}S$ reactions leading to lowlying states in ${}^{32}S$ and the ${}^{18}O$ + ${}^{28}{Si}$ elastic scattering have been measured at 60 MeV incident energy. Optical model parameters were obtained by the analysis of the measured ${}^{18}O$ + ${}^{28}{Si}$ elastic scattering and the analysis of existing ${}^{16}O$ + ${}^{28}{Si}$ elastic scattering data. The exact finite-range distorted-wave Born approximation analysis of the ( ${}^{16}O$ , ${}^{12}C$ ) reaction data showed that the transfer data could only be reproduced using a surface-transparent set of optical model parameters. On the contrary no optical model parameters could be found which provide simultaneously good fits of the ${}^{18}O$ + ${}^{28}{Si}$ elastic scattering and the ( ${}^{18}O$ , ${}^{14}C$ ) transfer data. The transfer data could be reproduced however, using optical model parameters which do not describe elastic scattering data. Relative spectroscopic factors were extracted for both transfer reactions and are compared with previous results of ( ${}^{16}O$ , ${}^{12}O$ ) and ( ${}^{6}{Li}$ , $d$ ) reaction studies. In addition we determined spectroscopic factors of the ${}^{28}{Si}$ ( ${}^{12}C$ , ${}^{8}{Be}$ ) ${}^{32}S$ reaction by reanalyzing existing data. The comparision suggests the conclusion that the ( ${}^{16}O$ , ${}^{12}C$ ) and ( ${}^{18}O$ , ${}^{14}C$ ) reactions proceed through different reaction mechanisms.

NUCLEAR REACTIONS ${}^{28}{Si}$ ( ${}^{18}O$ , ${}^{14}C$ ) ${}^{32}S$ ; ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{12}C$ ) ${}^{32}{Si}$ ; ${}^{28}{Si}$ ( ${}^{18}O$ , ${}^{18}O$ ); $E_{lab} = 60$ MeV; measured $σ (θ)$ ; $θ_{lab} = 4 ° - 20 °$ for ( ${}^{18}O$ , ${}^{14}C$ ), ( ${}^{16}O$ , ${}^{12}C$ ), and $θ_{lab} = 4 ° - 47 °$ for ( ${}^{18}O$ , ${}^{18}O$ ), $Δ θ_{lab} = 1 °$ , enriched target; deduced OM parameters; EFR-DWBA analysis, deduced relative spectroscopic factors.

States in ${}^{106}{Cd}$ populated by heavy-ion ( $xn$ ) reactions interpreted by a two-quasiparticle-plusrotor model

L. E. Samuelson, J. A. Grau, S. I. Popik, F. A. Rickey, and P. C. Simms

Phys. Rev. C 19, 73 (1979) - Published 1 January, 1979

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Levels in ${}^{106}{Cd}$ were studied using (heavy-ion, $xn γ$ ) reactions. The experiments included $γ$ -ray yields as a function of bombarding energy, $γ$ -ray angular distributions, $γ$ -ray linear polarizations, and $γ - γ$ coincidence measurements. The decay scheme, which includes 85 $γ$ -ray transitions, is similar to those reported for ${}^{108}{Cd}$ and ${}^{102, 104, 106}{Pd}$ . In addition to the ground-state band, there appear two negative-parity collective bands built on two quasineutron states. The yrast positive-parity states appear dominated by intruder states at $8^{+}$ , 3044.23 keV (two-quasiproton), $10^{+}$ , 4435.08 keV (two-quasineutron), and $12^{+}$ , 4659.81 keV (four-quasiparticle). The results are compared to calculations from a two-quasiparticle plus slightly deformed rotor model which utilizes a variable moment of inertia.

NUCLEAR STRUCTURE ${}^{96}{Mo}$ ( ${}^{13}C$ , $3 n γ$ ) at 45 MeV; ${}^{97}{Mo}$ ( ${}^{12}C$ , $3 n γ$ ) at 45 MeV, ${}^{94}{Zr}$ ( ${}^{16}O$ , $4 n γ$ ) at 63 MeV: measured $I_{γ} (E ({}^{13}C))$ , $I_{γ} (E ({}^{16}O))$ , $I_{γ} (θ) {}^{13}C$ , ${}^{16}O$ , $P_{γ} [{}^{16}O]$ , $γ - γ$ coin [ ${}^{12}C$ , ${}^{16}O$ ], $γ - γ$ DCO [ ${}^{12}C$ ]. ${}^{106}{Cd}$ deduced levels, $J$ , $π$ , $γ$ multipolarity. Rotational model calculations. Enriched targets, Ge(Li) detectors.

( ${}^{3}{He}$ , $t$ ) reaction mechanism via the ${}^{38}{Ar}$ ( ${}^{3}{He}$ , $t$ ) ${}^{38}K$ reaction at 40 MeV

G. Bruge, M. S. Zisman, A. D. Bacher, R. Schaeffer, C. J. Zeippen, and J. M. Loiseaux

Phys. Rev. C 19, 9 (1979) - Published 1 January, 1979

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The ${}^{38}{Ar}$ ( ${}^{3}{He}$ , $t$ ) ${}^{38}K$ reaction has been studied using a 40 MeV ${}^{3}{He}$ beam. Angular distributions for 26 levels are presented and theoretical analysis of the results has been carried out. Firstly, the conclusions of a macroscopic study of the ${}^{38}K$ level spectrum are presented. Secondly, the difficulties encountered using a onestep microscopic model to describe the five lowest states of ${}^{38}K$ are discussed. Thirdly, the improvements obtained by including two-step contributions in our microscopic model are shown and the importance of the transitions occuring via the [ $({}^{3}{He}, α) + (α, t)$ ] channel is emphasized.

NUCLEAR REACTIONS ${}^{38}{Ar}$ ( ${}^{3}{He}$ , $t$ ), $E = 40$ MeV; measured $σ (θ)$ ; resolution 75 keV. Microscopic DWBA analysis; coupled-channel analysis; deduced $L$ transfers; deduced strengths of microscopic ( ${}^{3}{He}$ , $t$ ) effective force.

$l = 1$ transfer reaction ${}^{28}{Si}$ ( ${}^{10}B$ , ${}^{9}{Be}$ ) ${}^{29}P_{g . s .}$ ( $\frac{1}{2^{+}}$ )

W. Treu, C. W. Towsley, K. G. Nair, and H. Voit

Phys. Rev. C 19, 96 (1979) - Published 1 January, 1979

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The $l = 1$ single-nucleon transfer reaction ${}^{28}{Si}$ ( ${}^{10}B$ , ${}^{9}{Be}$ ) ${}^{29}P_{g . s .}$ ( $\frac{1}{2^{+}}$ ) has been investigated at incident energies of 59, 75, and 132 MeV. In addition, the transfer to the first ( $\frac{3}{2^{+}}$ ) and second ( $\frac{5}{2^{+}}$ ) excited states was observed. The data were analyzed using exact finite range distorted wave Born approximation calculations. The agreement between experimental data and calculations is rather good for all transitions.

NUCLEAR REACTIONS ${}^{28}{Si}$ ( ${}^{10}B$ , ${}^{9}{Be}$ ), $E = 59, 75, 132$ MeV (lab); measured $σ (θ)$ , DWBA analysis, spectroscopic factors.

Intermediate structures in ${}^{12}C$ + ${}^{16}O$ system through alpha-induced reactions on ${}^{24}{Mg}$

F. Soga, J. Schimizu, H. Kamitsubo, N. Takahashi, K. Takimoto, R. Wada, T. Fujisawa, and T. Wada

Phys. Rev. C 18, 2457 (1978) - Published 1 December, 1978

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Intermediate resonance have been studied in the ${}^{24}{Mg} (α, {}^{12}C)$ ${}^{16}O$ and ${}^{24}{Mg} (α, α^{'}) {}^{24}{Mg}$ reactions. The excitation functions were measured in the energy range between 22 and 26 MeV. Significant anomalies have been found at $E_{c . m .} (in {}^{12}C + {}^{16}O system) = 12.73, 13.7, 14.0, 14.35, and 14.76$ MeV. Angular distributions of ${}^{12}C$ nuceli have been measured at these energies. The spins and parities of these intermediate resonance states are assigned as $7^{-}$ , 8+, $9^{-}$ (8+), $9^{-}$ , and $9^{-}$ , respectively. Angular distributions of the elastic and inelastic scattering have been measured at these energies.

NUCLEAR REACTIONS ${}^{24}{Mg} (α, {}^{12}C)$ , ${}^{24}{Mg} (α, α^{'})$ , $22 <~ E_{α} <~ 26$ MeV; measured $σ (E_{α}) θ_{lab} = 7 °, 16 °$ , $E_{α} = 22.77, 24.25, 24.65, 24.86, 25.13, 25.38$ MeV; measured $σ (θ)$ deduced $J^{π}$ , enriched target.

Role of low-energy two-body virtual states in three-particle scattering situations

J. A. Lock

Phys. Rev. C 18, 2465 (1978) - Published 1 December, 1978

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A model three-particle scattering situation consisting of a projectile incident on a target bound to a residual core was considered under the assumptions that there was a low-energy virtual state in the projectile-target channel, that the projectile and core did not interact, and that the projectile-target and target-core interactions were $s$ -wave separable interactions. When the appropriate Faddeev equations were solved by inversion, an enhancement was found in the three-body elastic cross section for virtual state energies less than or comparable to the target-core binding energy. This enhancement was determined to be kinematical in origin.

NUCLEAR REACTIONS Three-body scattering theory, subsystem virtual states. Enhancements in three-body elastic cross section.

Structure of negative parity high-spin states in ${}^{34}{Cl}$

P. Baumann, A. M. Bergdolt, G. Bergdolt, A. Huck, and G. Walter

Phys. Rev. C 18, 2470 (1978) - Published 1 December, 1978

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The ${}^{31}P (α, n)$ ${}^{34}{Cl}$ reaction at 13.0 and 14.6 MeV $α$ energies was used to investigate ${}^{34}{Cl}$ levels at 4743 keV ( $J^{π} = 6^{-}$ ), 3632 keV ( $J^{π} = 5^{-}$ ), and 3600 keV ( $J^{π} = 4^{-}$ ) excitation energy. Angular distribution measurements and lifetime determinations by the recoil distance method were performed. Lifetimes of 7±3, 280±60, and 23±5 ps were obtained for the 4743, 3632, and 3600 keV levels, respectively. The value of the lifetime for the 4743 keV level yields a negative parity assignment for this state. Strong $E 2$ and $E 3$ deduced transition strengths are related to the transition strengths deexciting quadrupole and octupole vibrations in the core nucleus ${}^{32}S$ .

NUCLEAR REACTIONS ${}^{31}P (α, n)$ , $E_{α} = 13.0 and 14.6$ MeV; measured $σ (E_{γ}, θ)$ and RDM, deduced $δ$ , $τ$ , and $π$ . Natural targets. Ge(Li) detectors.

Inner hole states in ${}^{207}{Pb}$ via the ${}^{208}{Pb} ({}^{3}{He}, α)$ ${}^{207}{Pb}$ reaction at 70 MeV

S. Gales, G. M. Crawley, D. Weber, and B. Zwieglinki

Phys. Rev. C 18, 2475 (1978) - Published 1 December, 1978

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The ${}^{208}{Pb} ({}^{3}{He}, α) {}^{207}{Pb}$ reaction at 70 MeV incident energy was used to populate hole states up to 28 MeV excitation energy in ${}^{207}{Pb}$ . A split-pole spectrometer was used for particle analysis and detection. For the excitation energy range between 0 to 4.5 MeV, about eleven well resolved states are excited. These levels contain the main part of the spectroscopic strengths of the $3 p_{\frac{1}{2}}$ , $2 f_{\frac{5}{2}}$ , $3 p_{\frac{3}{2}}$ , $2 f_{\frac{7}{2}}$ , $1 i_{\frac{13}{2}}$ , and $1 h_{\frac{9}{2}}$ neutron subshells. Three additional regions of enhanced cross sections, centered at 5.5, 8.5, and 14 MeV excitation energy in ${}^{207}{Pb}$ , are also observed. The 65 keV energy resolution of the present study revealed fine structure in the peak previously observed around 8.5 MeV in ${}^{207}{Pb}$ . About fifteen levels or groups of levels are populated between 4.5 and 10.5 MeV, and angular distributions have been extracted for each individual peak as well as for the gross structures. A distorted-wave Born-approximation analysis of the data was carried out and shows that the missing $l = 3 and 5$ strengths in ${}^{207}{Pb}$ are located in some strong peaks at 5.13, 5.62, and 6.37 MeV. Thus the full sum rule is obtained for the neutron subshells between $N = 126$ and $N = 82$ . The highly fragmented peak located at 8.5 MeV excitation energy is shown to arise from $1 h_{\frac{11}{2}}$ neutron pickup. Finally, the large structure, 5 MeV wide and centered around 14 MeV, observed for the first time in this work is tentatively interpreted as arising from neutron pickup from the $1 g_{\frac{9}{2}}$ inner shell. The $T_{>}$ components of the deeply-bound state are also observed between 20 to 24 MeV in ${}^{207}{Pb}$ and therefore from the sum-rule analysis, centroid energies and total strengths for each inner subshell are deduced.

NUCLEAR REACTION ${}^{208}{Pb} ({}^{3}{He}, α)$ , $E = 70$ MeV; measured $σ (E, θ)$ . ${}^{207}{Pb}$ deduced levels, $E_{x}$ , $l$ , ( $J$ ), $π$ , $C^{2} S$ ; inner shell spectroscopic factors; enriched target, magnetic spectrometer.

${}^{208}{Pb} (p, α) {}^{205}{Tl}$ reaction

P. A. Smith, G. M. Crawley, R. G. Markham, and D. Weber

Phys. Rev. C 18, 2486 (1978) - Published 1 December, 1978

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The ${}^{208}{Pb} (p, α) {}^{205}{Tl}$ reaction has been studied at $E_{p} = 35$ MeV. Excitation energies and angular distributions have been obtained for many new states in ${}^{205}{Tl}$ . Cluster model distorted-wave Born approximation calculations are shown to produce excellent fits to the angular distributions. Among the new states, four are given ${(\frac{15}{2}, \frac{17}{2})}^{+}$ assignments and one is assigned as ${(\frac{19}{2}, \frac{21}{2})}^{+}$ on the basis of the distorted-wave Born approximation fits.

NUCLEAR REACTIONS ${}^{208}{Pb} (p, α)$ , $E_{p} = 35$ MeV; measured $σ (θ)$ ; ${}^{205}{Tl}$ deduced levels; enriched target, DWBA analysis; compared with weak coupling model.

Magnetic moment of the first excited state of ${}^{99}{Mo}$

T. V. Ragland, R. J. Mitchell, R. P. Scharenberg, R. E. Holland, and F. J. Lynch

Phys. Rev. C 18, 2494 (1978) - Published 1 December, 1978

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We have measured the $g$ factor of the $\frac{5}{2^{+}}$ first-excited state of ${}^{99}{Mo}$ . We obtained for this state, which has an excitation energy of 98 keV and a mean life of 24.5 μs, a value $g = - 0.310 \pm 0.002$ . This result is consistent with the $g$ factor observed for the $d_{\frac{5}{2}}$ level in neighboring odd neutron nuclei, and in approximate agreement with theoretical calculations.

NUCLEAR REACTIONS ${}^{96}{Zr} (α, n) {}^{99}{Mo}$ , $E_{α} = 20$ MeV, ${}^{98}{Mo} (d, p)$ ${}^{99}{Mo}$ , $E_{d} = 10$ MeV. Pulsed beam, measured $I_{γ} (θ, β, t)$ for $E_{γ} = 98$ keV; deduce $g$ , relaxation time.

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Systematic nuclear-structure dependence of analyzing powers for ( $\vec{p}$ , $t$ ) reactions on mediummass vibrational nuclei

Ambiguities in the inference of precompound emission from excitation function analysis

Search for band crossing in ${}^{44}{Ti}$ through the ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{4}{He}$ ) ${}^{40}{Ca}$ reaction

Search for $α α^{*}$ rotational levels in ${}^{8}{Be}$

Erratum: Semiempirical nuclear level density formula with shell effects

Nuclear excitation of ${}^{115}{In}$ by positron annihilation with $K$ -shell electrons

Fragmentation of a previously reported $g_{\frac{9}{2}}$ analog state in ${}^{63}{Cu}$

Small-angle cross sections for ${}^{50, 52}{Cr}$ ( ${}^{3}{He}$ , $d$ ) ${}^{51, 53}{Mn}$ at 18 MeV

Mechanism of ${}^{14}N$ ( $t$ , $p$ ) to the ground state quadruplet in ${}^{16}N$

Coincidence studies of heavy fragments in deeply inelastic collisions between heavy ions: Sequential fission probability in reactions of 730-MeV ${}^{86}{Kr}$ with Au

Comparison of the ${}^{28}{Si}$ ( ${}^{16}O$ , ${}^{12}C$ ) ${}^{32}S$ and ${}^{28}{Si}$ ( ${}^{18}O$ , ${}^{14}C$ ) ${}^{32}S$ reactions at 60 MeV incident energy

States in ${}^{106}{Cd}$ populated by heavy-ion ( $xn$ ) reactions interpreted by a two-quasiparticle-plusrotor model

( ${}^{3}{He}$ , $t$ ) reaction mechanism via the ${}^{38}{Ar}$ ( ${}^{3}{He}$ , $t$ ) ${}^{38}K$ reaction at 40 MeV

$l = 1$ transfer reaction ${}^{28}{Si}$ ( ${}^{10}B$ , ${}^{9}{Be}$ ) ${}^{29}P_{g . s .}$ ( $\frac{1}{2^{+}}$ )

Intermediate structures in ${}^{12}C$ + ${}^{16}O$ system through alpha-induced reactions on ${}^{24}{Mg}$

Role of low-energy two-body virtual states in three-particle scattering situations

Structure of negative parity high-spin states in ${}^{34}{Cl}$

Inner hole states in ${}^{207}{Pb}$ via the ${}^{208}{Pb} ({}^{3}{He}, α)$ ${}^{207}{Pb}$ reaction at 70 MeV

${}^{208}{Pb} (p, α) {}^{205}{Tl}$ reaction

Magnetic moment of the first excited state of ${}^{99}{Mo}$

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