Recent Articles

Asymptotic normalization of the deuteron $D$ state

R. D. Amado, M. P. Locher, and M. Simonius

Phys. Rev. C 17, 403 (1978) - Published 1 January, 1978

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The ratio of the $D$ -state to $S$ -state asymptotic normalization of the deuteron wave function provides a model independent measure of the deuteron $D$ state. We show how that ratio can be determined directly from experimental data by extrapolating the tensor polarization $T_{2 ν}$ in $p - d$ scattering to the neutron exchange pole.

[NUCLEAR STRUCTURE Method proposed for determining asymptotic strength of deuteron $D$ state.]

Isospin splitting of the one-particle—one-hole excitation in ${}^{4}{He}$

K. Ramavataram and S. Ramavataram

Phys. Rev. C 17, 406 (1978) - Published 1 January, 1978

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The ambiguity regarding the position of the $1^{-}$ , $T = 0$ state in ${}^{4}{He}$ is resolved by comparing the results of the coupled-channels calculations with the recent phase shift analysis of the ${}^{3}H (p, p)$ scattering experiment. The experimental and theoretical evidence definitely suggest that this level occurs around 24 MeV in ${}^{4}{He}$ and that the isospin splitting among the $1^{-}$ states is comparable to that in the $0^{-}$ and $2^{-}$ states belonging to the { ${(1 s)}^{- 1} p$ } configuration.

[NUCLEAR REACTIONS ${}^{3}H (p, p)$ ; $E_{p} = 1 - 10$ MeV. Calculated ${}^{3}P_{1}$ and ${}^{1}P_{1}$ phase shifts and compared with experiment. Deduced the isospin splitting of one-particle—one-hole excitation in ${}^{4}{He}$ .]

$d + d$ four-body breakup reaction at 80 MeV

B. Th. Leeman, H. G. Pugh, N. S. Chant, and C. C. Chang

Phys. Rev. C 17, 410 (1978) - Published 1 January, 1978

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The $d + d$ four-body breakup reaction has been studied in a geometry chosen to emphasize the double spectator process. Data were obtained at a bombarding energy of 80 MeV for the coincident detection of both emitted protons at several equal angle pairs. Comparison with simple plane wave Born approximation calculations suggests that, in addition to the double spectator process, another process, more strongly localized in phase space, is important. It is suggested that such a process is the double spin-flip excitation of both deuterons to the singlet state.

[NUCLEAR REACTIONS $d + d \to 2 p + 2 n$ , $E_{0} = 80$ MeV; measured $\frac{d^{4} σ}{d Ω_{p_{1}} d Ω_{p_{2}} d E_{p_{1}} d E_{p_{2}}} (θ_{p_{1}}, θ_{p_{2}}, E_{p_{1}}, E_{p_{2}})$ ; coplanar geometry; PWBA analysis.]

${}^{13}C (p, γ) {}^{14}N$ study of the 9.13-MeV state in ${}^{14}N$

J. Keinonen, A. Anttila, and R. Hentelä

Phys. Rev. C 17, 414 (1978) - Published 1 January, 1978

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The structure of the midget $E_{p} = 1701$ keV resonance in the ${}^{13}C (p, γ) {}^{14}N$ reaction was restudied with a high-volume Ge(Li) detector. The (82±3)% ground state ( $J^{π} = 1^{+}$ , $T = 0$ ) transition with the angular distribution $W (θ) = 1 + (0.48 \pm 0.03) P_{2} (cos θ) - (0.16 \pm 0.03)$ $P_{4} (cos θ)$ and the new (9±3)% branches to the $6.444 - (J^{π} = 3^{+}, T = 0)$ and 5.832-MeV ( $J^{π} = 3^{-}$ , $T = 0$ ) levels along with the deduced transition strengths lead to the new assignment of $J^{π} = 3^{+}$ , $T = 0$ for the 9.130-MeV state.

[NUCLEAR REACTION ${}^{13}C (p, γ)$ , $E = 1.70$ MeV; measured $σ (E, θ)$ ; deduced branching ratios $ω Γ_{γ}$ , $J$ , $π$ , $T$ , $δ (9.13 \to 0)$ . Ge(Li) detector, enriched target.]

Consistency relations for compound cross sections

A. Frenkel

Phys. Rev. C 17, 418 (1978) - Published 1 January, 1978

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Assuming that the compound cross sections are determined by the transmission matrix alone, we prove consistency relations for the case in which two out of $N$ open channels are equally absorbing. These consistency relations coincide with conjectures of Moldauer and Hofmann et al.

[NUCLEAR REACTIONS Average compound cross sections.]

Neutron resonance spectroscopy: Ta

G. Hacken, R. Werbin, and J. Rainwater

Phys. Rev. C 17, 43 (1978) - Published 1 January, 1978

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Results of high resolution neutron time of flight spectroscopy on natural tantalum (99.988% ${}^{181}{Ta}, I^{π} = \frac{7}{2^{+}}$ ) are presented for $l = 0$ resonances to 2025 eV. Values of $E$ and $g Γ_{n}^{0}$ are presented for 431 resonances, in addition to the three resonances below 15 eV. A Bayes analysis suggests that no $p$ wave levels have been included. The analysis used a multilevel Breit-Wigner shape fitting to the measured transmission curves for three different sample thicknesses. Doppler broadening and potential-resonance interference effects were included, plus some simulation of the experimental resolution effects. The analysis gives $〈 S 〉 = (4.17 \pm 0.04)$ eV for the mean level spacing, and $10^{4} S_{0} = (1.68 \pm 0.11)$ for the $l = 0$ strength function.

[NUCLEAR REACTIONS ${}^{181}{Ta} (n, total)$ , $E = 15 to 2030$ eV; deduced resonance $E$ , $g Γ_{n}^{0}$ , $〈 S 〉$ , $S_{0}$ .]

${}^{83}{Sr}$ with the ${}^{84}{Sr} ({}^{3}{He}, α)$ reaction

L. R. Medsker, S. C. Headley, and H. T. Fortune

Phys. Rev. C 17, 51 (1978) - Published 1 January, 1978

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The ${}^{84}{Sr} ({}^{3}{He}, α) {}^{83}{Sr}$ reaction has been studied at a bombarding energy of 18 MeV with an isotopically enriched ${}^{84}{Sr}$ target. Excitation energies and angular distributions were obtained for 15 levels below 3.4 MeV in ${}^{83}{Sr}$ and for four analog states in the range 8-9 MeV. A distorted-wave analysis was used to determine $l$ values and spectroscopic strengths for the pickup of $1 g_{\frac{9}{2}}$ , $2 p_{\frac{1}{2}}$ , $2 p_{\frac{3}{2}}$ , and $1 f_{\frac{5}{2}}$ neutrons. The present results resolve several discrepancies between previous ${}^{84}{Sr} (d, t)$ and radioactive decay work.

[NUCLEAR REACTIONS ${}^{84}{Sr} ({}^{3}{He}, α)$ , $E = 18$ MeV; enriched target; measured $σ (E_{α}, θ)$ ; deduced ${}^{83}{Sr}$ levels, $l$ , $j$ , $C {}^{2}S$ .]

Giant electric resonances in ${}^{58}{Ni}$ studied by alpha particle capture

L. Meyer-Schützmeister, R. E. Segel, K. Raghunathan, P. T. Debevec, W. R. Wharton, L. L. Rutledge, and T. R. Ophel

Phys. Rev. C 17, 56 (1978) - Published 1 January, 1978

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The reaction ${}^{54}{Fe} (α, γ_{)} {}^{58}{Ni}$ has been studied for $7.6 \geq E_{α} \geq 12.8$ MeV. Seventeen angular distributions have been measured in this energy region making it possible to separate the $E 2$ strength from the $E 1$ strength. The $E 1$ cross section reaches a maximum at about the expected energy. A compact $E 2$ resonance was observed which agrees quite well with the one measured by inelastic $α$ scattering, with a peak cross section at about 16 MeV and a width of ∼ 3 MeV(half width at half maximum). The observed $E 1$ strength equals 0.9% of the isospin allowed $E 1$ sum rule. The measured $E 2$ strength, however, equals 4.3% of the isoscalar $E 2$ sum rule, which is about the same as the fraction of the total $E 1$ strength in ${}^{58}{Ni}$ excited by proton capture. Assuming only statistical processes and applying the Hauser-Feshbach formula to calculate the total $γ$ absorption from the measured particle-capture cross sections leads to the conclusion that the ( $α, γ$ ) reaction exciting the isoscalar giant quadrupole resonance and the ( $p, γ$ ) reaction exciting the giant dipole resonance must have direct components.

[NUCLEAR REACTIONS ${}^{54}{Fe} (α, γ_{0}) {}^{58}{Ni}$ (g.s.). $\frac{d σ}{d Ω} = f (E_{α}, θ)$ for $7.6 <~ E_{α} <~ 12.8$ MeV. Target $\approx 1$ mg rolled ${}^{54}{Fe}$ foil. Deduced $σ (γ, α_{0})$ for GDR and GQR in ${}^{58}{Ni}$ . Concluded from Hauser-Feshbach formalism $σ (γ, α_{0})$ into GQR of ${}^{58}{Ni}$ contains direct reaction components.]

( ${}^{6}{Li}, t$ ) reaction on medium-mass nuclei and the mass and spectrum of ${}^{61}{Zn}$

C. W. Woods, Nelson Stein, and J. W. Sunier

Phys. Rev. C 17, 66 (1978) - Published 1 January, 1978

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The ( ${}^{6}{Li}, t$ ) reaction was studied with a 34-MeV ${}^{6}{Li}$ beam on enriched targets of ${}^{24}{Mg}$ , ${}^{28}{Si}$ , ${}^{54}{Fe}$ , ${}^{56}{Fe}$ , and ${}^{58}{Ni}$ . The tritons were momentum analyzed in a quadrupole-dipole-dipole-dipole magnetic spectrograph and detected with a 1-m helical cathode proportional counter that covered about 4 MeV of excitation. Cross sections for the ( ${}^{6}{Li}, t$ ) reaction to strongly excited states are generally in the range of 1 to 10 μb/sr with exceptions up to 50 μb/sr. Comparisons are made, where possible, between the selectivity of this reaction and other reactions leading to the same final nuclei. A similarity with single-neutron stripping is observed, which suggests a ( ${}^{6}{Li}, t$ ) reaction mechanism involving direct transfer of a proton-pair coupled to a single neutron. The possible two-step process ( ${}^{6}{Li}, d$ ) ( $d, t$ ) is also suggested to account for two cases of $f_{\frac{7}{2}}$ hole states populated in the nickel isotopes. The ${}^{58}{Ni} ({}^{6}{Li}, t) {}^{61}{Zn}$ $Q$ value was measured to be -4736 ± 23 keV giving a mass excess of -56 352±26 keV for ${}^{61}{Zn}$ . This mass excess is believed to be more reliable than previous measurements with other techniques that differ by 500 keV. The triton spectrum for the ${}^{58}{Ni} ({}^{6}{Li}, t) {}^{61}{Zn}$ reaction yields the first measurement of the energy levels of ${}^{61}{Zn}$ .

[NUCLEAR REACTIONS ${}^{24}{Mg} ({}^{6}{Li}, t)$ , ${}^{28}{Si} ({}^{6}{Li}, t)$ , ${}^{54}{Fe} ({}^{6}{Li}, t)$ , ${}^{56}{Fe} ({}^{6}{Li}, t)$ , ${}^{58}{Ni} ({}^{6}{Li}, t)$ , $E_{{}^{6}{Li}} = 34$ MeV; enriched targets, Q3D spectrograph, measured $\frac{d σ}{d Ω}$ , $E_{t}$ , energy levels ${}^{27}{Si}$ , ${}^{31}S$ , ${}^{57}{Ni}$ , ${}^{59}{Ni}$ , ${}^{61}{Zn}$ ; mass ${}^{61}{Zn}$ ; reaction mechanism discussed, correspondence with single-neutron transfer noted.]

$E 2$ and $E 4$ transition moments in ${}^{163}{Dy}$ and ${}^{167}{Er}$

H. J. Wollersheim, Th. W. Elze, and L. D. Tolsma

Phys. Rev. C 17, 75 (1978) - Published 1 January, 1978

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Coulomb excitation by $α$ particles is used to determine reduced $E 2$ and $E 4$ transition matrix elements between ground-band rotational states in ${}^{163}{Dy}$ and ${}^{167}{Er}$ . The following results are obtained for ${}^{163}{Dy}$ : $〈 \frac{7}{2} \frac{5}{2} ∥ M (E 2) ∥ \frac{5}{2} \frac{5}{2} 〉 = 3.83 \pm 0.10 e b$ ; $〈 \frac{9}{2} \frac{5}{2} ∥ M (E 2) ∥ \frac{5}{2} \frac{5}{2} 〉 = 2.31 \pm 0.02 e b$ ; $〈 \frac{11}{2} \frac{5}{2} ∥ M (E 4) ∥ \frac{5}{2} \frac{5}{2} 〉 = {0.60}_{- 0.60}^{+ 0.42} e b^{2}$ , and for ${}^{167}{Er}$ : $〈 \frac{9}{2} \frac{7}{2} ∥ M (E 2) ∥ \frac{7}{2} \frac{7}{2} 〉 = 4.38 \pm 0.08 e b$ ; $〈 \frac{11}{2} \frac{7}{2} ∥ M (E 2) ∥ \frac{7}{2} \frac{7}{2} 〉 = 2.24 \pm 0.01 e b$ ; $〈 \frac{13}{2} \frac{7}{2} ∥ M (E 4) ∥ \frac{7}{2} \frac{7}{2} 〉 = {0.77}_{- 0.51}^{+ 0.39} e b^{2}$ . Quadrupole and hexadecapole moments deduced from these values are compared with those of neighboring even- $A$ nuclei.

[NUCLEAR REACTIONS ${}^{163}{Dy} (α, α^{'})$ , ${}^{167}{Er} (α, α^{'})$ , $E = 12$ MeV, measured $σ (E_{α^{'}}$ , 160°). Deduced $E 2$ and $E 4$ matrix elements.]

Energy dependence of ${}^{16}O ({}^{6}{Li}, d) {}^{20}{Ne}$ from 19.8-32 MeV

L. J. House and K. W. Kemper

Phys. Rev. C 17, 79 (1978) - Published 1 January, 1978

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${}^{16}O ({}^{6}{Li}, d)$ excitation functions have been measured in the laboratory energy range from 19.8 to 32 MeV, in 200 keV steps, for the ${}^{20}{Ne}$ $0^{+}$ (0.0 MeV) and $2^{+}$ (1.62 MeV) states at 7.5° and for the $2^{+}$ (1.62 MeV) and $4^{+}$ (4.25 MeV) states at 17.5°. The fluctuations in the data are less than ±25% over this energy region. At 20, 24, and 28 MeV the cross sections at 165° are at least 5-10 times smaller than at 25°. Comparisons between the data and distorted-wave Born approximation calculations over this energy range show the reaction mechanism to be more complicated than a simple one-step $α$ particle transfer.

[NUCLEAR REACTIONS ${}^{16}O ({}^{6}{Li}, d) {}^{20}{Ne}$ ( $0^{+}, 0.0$ MeV; $2^{+}$ , 1.62 MeV; $4^{+}$ , 4.25 MeV), $E ({}^{6}{Li}) = 19.8 - 32$ MeV, $Δ E = 200$ keV; measured $σ (E)$ at $θ_{lab} = {7.5}^{\circ} and {17.5}^{\circ}$ .]

Is there specific alpha clustering in light nuclei?

N. S. Chant, P. G. Roos, and C. W. Wang

Phys. Rev. C 17, 8 (1978) - Published 1 January, 1978

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The role of the $α$ -core bound state wave function in direct reaction theories of $α$ transfer and knockout reactions is discussed. It is pointed out that for $A \leq 16$ , wave functions with excessive rms radii are needed in order to reproduce predicted $1 p$ shell absolute spectroscopic factors. It is argued that this may indicate considerable specific $α$ clustering in excess of $1 p$ shell estimates.

[NUCLEAR REACTIONS $α$ -transfer and $α$ -knockout reactions, importance of realistic $α$ -core wave function. Possible specific $α$ clustering.]

${}^{16}O$ + ${}^{48}{Ca}$ reaction at 56 MeV. I. Transitions to resolved levels

D. G. Kovar, W. Henning, B. Zeidman, Y. Eisen, J. R. Erskine, H. T. Fortune, T. R. Ophel, P. Sperr, and S. E. Vigdor

Phys. Rev. C 17, 83 (1978) - Published 1 January, 1978

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All direct reaction channels of significant strength ( $σ \geq 50$ μb) in the ${}^{16}O$ + ${}^{48}{Ca}$ reaction at $E_{lab} ({}^{16}O) = 56$ MeV were measured using a $Δ E - E$ time-of-flight telescope system. Excitation spectra with energy resolutions $\approx 200$ keV full width at half maximum were obtained for outgoing ions ${}^{11, 12, 13}B$ , ${}^{12, 13, 14, 15}C$ , ${}^{14, 15, 16, 17}N$ , and ${}^{16, 17, 18, 19}O$ . Angular distributions were obtained for the strongest transitions observed in inelastic scattering, the single-nucleon transfer reactions ( ${}^{16}O$ , ${}^{15}N$ ) and ( ${}^{16}O$ , ${}^{17}O$ ), the two-nucleon transfer reactions ( ${}^{16}O$ , ${}^{14}C$ ), ( ${}^{16}O$ , ${}^{14}N$ ), and ( ${}^{16}O$ , ${}^{18}O$ ), the three-nucleon transfer reactions ( ${}^{16}O$ , ${}^{13}C$ ), and the "exotic" transfers ( ${}^{16}O$ , ${}^{16}N$ ) and ( ${}^{16}O$ , ${}^{15}C$ ). Comparison of distorted-wave Born-approximation calculations for inelastic scattering, and for one- and two-nucleon transfer reactions to experiment suggest that reaction processes more complex than the one-step process are quite important in a majority of the transitions studied.

[NUCLEAR REACTIONS ${}^{48}{Ca}$ ( ${}^{16}O$ , ${}^{16}O$ ), ( ${}^{16}O$ , ${}^{16}O$ ), ( ${}^{16}O$ , ${}^{17, 18}O$ ), ( ${}^{16}O$ , ${}^{14, 15, 16}N$ ), ( ${}^{16}O$ , ${}^{13, 14, 15}C$ ); measured $σ (θ)$ ; $θ = 4^{\circ} - 60^{\circ}$ , $Δ θ = 1 - 3^{\circ}$ , ${}^{48}{Ca}$ ( $^{16}$ , ${}^{19}O$ ), ( ${}^{16}O$ , ${}^{17}N$ ), ( ${}^{16}O$ , ${}^{12}C$ ), ( ${}^{16}O$ , ${}^{11 - 13}B$ ); measured $σ$ . $E_{lab} = 56$ MeV, resolution 250 keV, enriched targets. Optical-model parameters deduced, DWBA calculations compared with data for ( ${}^{16}O$ , ${}^{16}O$ ), ( ${}^{16}O$ , ${}^{17, 18}O$ ) ( ${}^{16}O$ , ${}^{14, 15}N$ ), and ( ${}^{16}O$ , ${}^{13, 14}C$ ).]

Many-body exchange currents and the tri- and four-nucleon charge form factors

D. O. Riska and Mark Radomski

Phys. Rev. C 16, 2105 (1977) - Published 1 December, 1977

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We find that the three-body two-pion-exchange currents lead to an effect very similar to that of the two-body one-pion-exchange currents on the charge form factors of ${}^{3}H$ , ${}^{3}{He}$ , and ${}^{4}{He}$ . Most of this effect is, however, canceled by similar $ρ$ -meson-exchange currents. The four-body three-meson-exchange currents are of negligible importance for the α-particle charge form factor.

NUCLEAR REACTIONS ${}^{3}{He}$ , ${}^{3}H$ , ${}^{4}{He} (e, e)$ ; calculated charge form factors with 2-, 3-, and 4-body meson-exchange operators; pion exchange with/without $ρ$ exchange; simple wave functions; effects of correlations, vertex factors.

Three-body model of ${}^{6}{Li}$ using hyperspherical harmonics

K. K. Fang and E. L. Tomusiak

Phys. Rev. C 16, 2117 (1977) - Published 1 December, 1977

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The method of hyperspherical harmonics (also called $K$ harmonics) is applied to the $α - η - p$ model of ${}^{6}{Li}$ . The ground state ( $J^{π} = 1^{+}$ ) and the $J^{π} = 0^{+}$ excited state at 3.56 MeV are examined. Gaussian type $α$ -nucleon potentials and nucleon-nucleon potentials are used. By expanding the wave functions and the total potential of the system in terms of hyperspherical harmonics, coupled differential equations for the hyperradial part of the wave functions are derived from the Schrödinger equation. Binding energies of the two states, the charge form factor of the ground state, and the magnetic form factor are calculated. Only the grand orbital zero term is used. Comparison with the experimental data is given.

NUCLEAR REACTIONS Three-body model, hyperspherical harmonics, binding energies, form factors.

Search for simple configurations in ${}^{18}{F .}$ I. The ${}^{17}O (p, p) {}^{17}O$ reaction

J. C. Sens, S. M. Refaei, A. Ben Mohamed, and A. Pape

Phys. Rev. C 16, 2129 (1977) - Published 1 December, 1977

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The ${}^{17}O (p, p) {}^{17}O$ reaction has been studied in the energy range $E_{p} = 1.4 - 3.0$ MeV. An $R$ matrix analysis of the elastic scattering excitation functions at four angles leads to $l_{p}$ values for 12 resonances. Some $J^{π}$ assignments have been made. States with large $d_{\frac{5}{2}} d_{\frac{3}{2}}$ configurations have been located at: $7.404 (J^{π} = 1^{+})$ , $7.683 [J^{π} = {(3)}^{+}]$ , and $8.237 (J^{π} = 4^{+})$ MeV.

NUCLEAR REACTION ${}^{17}O (p, p)$ , $E = 1.4 - 3.0$ MeV; measured $σ (E_{p}, θ)$ . ${}^{18}F$ levels deduced $l_{p}$ , $J^{π}$ , $Γ_{p}$ . Enriched target.

Three-body calculation of two-body threshold electrodisintegration of ${}^{3}{He}$ and ${}^{3}{He}$

C. R. Heimbach, D. R. Lehman, and J. S. O'Connell

Phys. Rev. C 16, 2135 (1977) - Published 1 December, 1977

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Threshold two-body electrodisintegration of ${}^{3}{He}$ and ${}^{3}H$ is investigated within the context of exact three-body theory. The calculations performed are based on the formalism of Gibson and Lehman. Careful consideration is given to the singularities of the disintegration Born amplitude for this case, since the momentum transfer is not zero, to assure validity of the numerical methods. Calculated results are compared with all the latest threshold ${}^{3}{He}$ electrodisintegration data which sample a range of scattered-electron angles, $92.6 ° \leq θ_{e} \leq 180 °$ , and incident electron energies, $40 MeV \leq E_{0} \leq 120 MeV$ . Predictions are made for ${}^{3}H$ electrodisintegration for some of the same kinematics. The mechanism for the sharp rise as a function of excitation energy in the ( $e, e^{'}$ ) cross section for $θ_{e} \sim 90 °$ due to the ${}^{2}S \to {}^{2}S$ monopole transition from Coulomb scattering is singled out by examination of the contributions to the Coulomb doublet amplitude. A similar analysis is carried out for the doublet and quartet transverse amplitudes where the ${}^{2}S \to {}^{4}P$ magnetic quadrupole transition dominates for excitation energies less than 20 MeV.

NUCLEAR REACTIONS Electrodisintegration of ${}^{3}{He}$ and ${}^{3}H$ , Faddeev calculation, separable interactions.

Analyzing-power measurements for the ${}^{3}{He} (\vec{t}, d) {}^{4}{He}$ reaction

R. F. Haglund, Jr., G. G. Ohlsen, R. A. Hardekopf, Nelson Jarmie, and Ronald E. Brown

Phys. Rev. C 16, 2151 (1977) - Published 1 December, 1977

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We report analyzing-power angular distributions for the ${}^{3}{He} (\vec{t}, d) {}^{4}{He}$ reaction at bombarding energies of 9.02, 12.86, and 17.02 MeV, and an excitation function at 90° c.m. from 9.02 to 17.27 MeV. The angular distributions show marked deviations from the antisymmetric shape predicted by a simple particle-transfer model incorporating charge symmetry. Reaction mechanisms and violations of charge symmetry which might account for the data are discussed.

NUCLEAR REACTIONS ${}^{3}{He} (\vec{t}, d)$ . Measured $A_{y} (θ)$ , $θ_{c . m .} = 16 ° - 159 °$ , $E = 9.02, 12.86, 17.02$ MeV; $A_{y} (E)$ , $E = 9.02 - 17.27$ MeV, $θ = 90.0 °$ c.m.

High-spin level structure of the five neutron hole nucleus ${}^{203}{Pb}$

S. K. Saha, H. Helppi, P. J. Daly, S. R. Faber, T. L. Khoo, and F. M. Bernthal

Phys. Rev. C 16, 2159 (1977) - Published 1 December, 1977

Show Abstract

A pulsed-beam ${}^{202}{Hg} (α, 3 n γ)$ experiment has revealed a 0.48-s ${}^{203}{Pb}$ isomer, which deexcites through high-spin positive parity levels to the known ${13 / 2}^{+}$ state at 825 keV. Comprehensive ( $γ γ t$ ) coincidence measurements have established the complete isomeric decay scheme, and key transition multipolarities have been deduced from prompt $γ$ -ray angular distribution data and from intensity balance requirements. The results clearly manifest a close structural relationship between the high-spin levels built on the ${}^{203}{Pb}$ ${13 / 2}^{+}$ isomer and previously known states of the ${}^{204}{Pb}$ core nucleus. The 0.48-s isomeric state is assigned $J^{π} = {\frac{29}{2}}^{-}$ , with the dominant neutron hole configuration ${(p_{\frac{1}{2}}^{- 2})}_{0} f_{\frac{5}{2}}^{- 1} {(i_{\frac{13}{2}}^{- 2})}_{12}$ , and the high-spin positive parity levels are interpreted as members of core hole multiplets of the type $i_{\frac{13}{2}}^{- 1} \times 2^{+}$ and $i_{\frac{13}{2}}^{- 1} \times 4^{+}$ .

NUCLEAR REACTIONS ${}^{202}{Hg} (α, 3 n γ)$ , $E = 38.2$ MeV; measured $E_{γ}$ , $I_{γ} (Θ)$ , $γ - γ$ coin, $γ - t$ relationships; ${}^{203}{Pb}$ deduced high spin levels, $J$ , $π$ , $T_{\frac{1}{2}}$ .

Anomalous large hexadecapole charge deformation parameter in ${}^{154}{Gd}$

R. Schormann, H. Fischer, and E. Kuhlmann

Phys. Rev. C 16, 2165 (1977) - Published 1 December, 1977

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By Coulomb excitation with 11.8 MeV $α$ particles the $E 2$ and $E 4$ transition matrix elements in the rotational ground state band of ${}^{154}{Gd}$ have been determined. Assuming a deformed Fermi distribution with diffuse surface, charge deformation parameters could be extracted. As in ${}^{154}{Sm}$ an extremely large hexadecapole deformation $β_{4}^{c}$ is found. The comparison with existing model calculations which give the nuclear distributions reveals striking differences between the charge and the nuclear deformation not found for the neighboring rare-earth nuclei.

NUCLEAR REACTIONS ${}^{154}{Gd} (α, α^{'})$ , $E_{α} = 11.8$ MeV, measured $σ (E_{α}; θ = 160 °, 170 °)$ . Deduced $〈 2^{+} ∥ M (E 2) ∥ 0^{+} 〉$ , $〈 4^{+} ∥ M (E 4) ∥ 0^{+} 〉$ ; extracted $β_{2}^{c}$ , $β_{4}^{c}$ from Fermi charge distribution. Enriched target.

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Physical Review C

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Asymptotic normalization of the deuteron $D$ state

Isospin splitting of the one-particle—one-hole excitation in ${}^{4}{He}$

$d + d$ four-body breakup reaction at 80 MeV

${}^{13}C (p, γ) {}^{14}N$ study of the 9.13-MeV state in ${}^{14}N$

Consistency relations for compound cross sections

Neutron resonance spectroscopy: Ta

${}^{83}{Sr}$ with the ${}^{84}{Sr} ({}^{3}{He}, α)$ reaction

Giant electric resonances in ${}^{58}{Ni}$ studied by alpha particle capture

( ${}^{6}{Li}, t$ ) reaction on medium-mass nuclei and the mass and spectrum of ${}^{61}{Zn}$

$E 2$ and $E 4$ transition moments in ${}^{163}{Dy}$ and ${}^{167}{Er}$

Energy dependence of ${}^{16}O ({}^{6}{Li}, d) {}^{20}{Ne}$ from 19.8-32 MeV

Is there specific alpha clustering in light nuclei?

${}^{16}O$ + ${}^{48}{Ca}$ reaction at 56 MeV. I. Transitions to resolved levels

Many-body exchange currents and the tri- and four-nucleon charge form factors

Three-body model of ${}^{6}{Li}$ using hyperspherical harmonics

Search for simple configurations in ${}^{18}{F .}$ I. The ${}^{17}O (p, p) {}^{17}O$ reaction

Three-body calculation of two-body threshold electrodisintegration of ${}^{3}{He}$ and ${}^{3}{He}$

Analyzing-power measurements for the ${}^{3}{He} (\vec{t}, d) {}^{4}{He}$ reaction

High-spin level structure of the five neutron hole nucleus ${}^{203}{Pb}$

Anomalous large hexadecapole charge deformation parameter in ${}^{154}{Gd}$

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