Recent Articles

Search for evidence of antineutrino decays

John R. Morton, III and Leland M. Richards

Phys. Rev. C 9, 1668 (1974) - Published 1 April, 1974

Show Abstract

An attempt was made to observe the decay of antineutrinos into a form of energy observable within a NaI crystal. Antineutrinos produced by fission in a nuclear device were incident on a 14-cm cube of NaI. No effect was observed, and minimum observable energy is given per fission.

[NUCLEAR REACTIONS, FISSION ${}^{235}U (n, f)$ ; searched for evidence of $\bar{ν} \to x$ from nuclear explosion. Negative result.]

${}^{3}H ({}^{3}{He}, n) {}^{5}{Li}$ reaction from 14 to 26 MeV

C. C. Chang and E. Ventura

Phys. Rev. C 9, 1671 (1974) - Published 1 April, 1974

Show Abstract

The excitation function for the ${}^{3}H ({}^{3}{He}, n) {}^{5}{Li}$ reaction is obtained for $E_{τ} = 14 - 26$ MeV at $θ_{lab} = 20^{\circ}$ . The result shows a broad resonance at $E_{τ} = 20.5 \pm 0.8$ MeV. The existence of such a resonance is consistent with a resonance found in the ${}^{3}H ({}^{3}{He}, γ_{1}) {}^{6}{Li}$ capture reaction.

[NUCLEAR REACTIONS ${}^{3}H ({}^{3}{He}, n) {}^{5}{Li}$ , $E = 14 - 26$ MeV; measured $σ (E, θ)$ ; ${}^{6}{Li}$ deduced resonance; adsorbed ${}^{3}H$ target.]

Erratum: Spectroscopy of ${}^{10}B$ levels from the ${}^{9}{Be} (d, n) {}^{10}B$ reaction

Yong Sook Park, A. Niiler, and R. A. Lindgren

Phys. Rev. C 9, 1673 (1974) - Published 1 April, 1974

Erratum: Neutron resonance spectroscopy. VII. Ti, Fe, and Ni

J. B. Garg, J. Rainwater, and W. W. Havens, Jr.

Phys. Rev. C 9, 1673 (1974) - Published 1 April, 1974

Erratum: $γ - γ$ directional correlation measurements in ${}^{106}{Pd}$

F. T. Avignone, III and J. E. Pinkerton

Phys. Rev. C 9, 1673 (1974) - Published 1 April, 1974

Erratum: Rules for spin and parity assignments based on $log ft$ values

S. Raman and N. B. Gove

Phys. Rev. C 9, 1674 (1974) - Published 1 April, 1974

Elastic scattering of 60-MeV alpha particles by the even nickel isotopes

D. G. Madland, P. Schwandt, W. T. Sloan, P. Shapiro, and P. P. Singh

Phys. Rev. C 9, 1002 (1974) - Published 1 March, 1974

Show Abstract

An optical-model analysis of the scattering of 60-MeV $α$ particles by ${}^{58}{Ni}$ , ${}^{60}{Ni}$ , ${}^{62}{Ni}$ , and ${}^{64}{Ni}$ has been performed with particular emphasis placed on (1) the significance of the backward-angle data with respect to removal of potential ambiguities and (2) the extent to which $α$ elastic scattering at this energy is sensitive to the interior detail of the potential. In the ${}^{58}{Ni}$ case, six equivalent potentials are found to fit the diffraction scattering region ( $θ < 70^{\circ}$ ), but only two of these simultaneously provide acceptable fits in the backward-angle region. It is shown that the detailed form of the real potential significantly affects the scattering only at distances beyond ∼4 fm. The 60-MeV $α$ probe is not sensitive to the detail of the total potential inside of ∼3 fm in any way that affects the elastic cross section.

[NUCLEAR REACTIONS ${}^{58, 60, 62, 64}{Ni} (α, α)$ , $E = 60$ MeV; ${}^{60}{Ni} (α, α)$ , $E = 75$ MeV; measured $σ (θ)$ ; $θ = 12 - 160^{\circ}$ , enriched targets. Optical-model analysis.]

Limitation to complete fusion during a collision between two complex nuclei

J. Galin, D. Guerreau, M. Lefort, and X. Tarrago

Phys. Rev. C 9, 1018 (1974) - Published 1 March, 1974

Show Abstract

Experimental results on the limits observed for complete fusion between heavy nuclei are discussed. It is shown that there is no critical angular momentum independent of the bombarding energy and of the entrance channel. Excitation energy and total angular momentum of the compound system do not appear as good parameters for determining the complete fusion cross section. All the available results can be presented in terms of a critical distance of approach $R_{cr}$ . Such a distance is obtained when the kinetic energy of incoming nucleons equals the interaction potential and is related to the nuclear-matter density of both nuclei. For very heavy partners, a fusion barrier occurs, in addition to the interaction barrier.

[NUCLEAR REACTIONS Heavy-ion complete fusion; calculated critical distance of approach, $R_{cr} = (1.0 \pm 0.07) (A_{1}^{\frac{1}{3}} + A_{2}^{\frac{1}{3}})$ .]

High-resolution comparison of ( $p, p^{'}$ ) and ( $d, d^{'}$ ) reactions

B. L. Cohen, J. E. Holden, and G. R. Rao

Phys. Rev. C 9, 1025 (1974) - Published 1 March, 1974

Show Abstract

A comparison is made between the strengths with which each nuclear state up to 5.3 MeV excitation in ${}^{124}{Sn}$ , 7.3 MeV in ${}^{64}{Ni}$ , and 7.6 MeV in ${}^{58}{Ni}$ is excited in ( $p, p^{'}$ ) and ( $d, d^{'}$ ) reactions. A very strong correlation is found, indicating that direct-reaction processes are dominant in both reactions. The fraction of these direct reactions resulting in excitation of the lowest energy $2^{+}$ and $3^{-}$ collective states is determined and in each case is less than 20%.

[NUCLEAR REACTIONS ${}^{58}{Ni}$ , ${}^{64}{Ni}$ , ${}^{124}{Sn} (d, d^{'})$ , ( $p, p^{'}$ ); $E = 17, 12$ MeV; compared cross sections for exciting same levels in the two reactions.]

Lifetime measurements and $E 2$ effective charges for nuclei in the $1 f_{\frac{7}{2}}$ shell

B. A. Brown, D. B. Fossan, J. M. McDonald, and K. A. Snover

Phys. Rev. C 9, 1033 (1974) - Published 1 March, 1974

Show Abstract

Lifetimes for a number of levels in nuclei with $40 < A < 56$ have been measured using the recoil-distance technique. The experimental results for the mean lifetimes are $45_{- 7}^{+ 10}$ psec for the 1491-keV $3^{+}$ and 57 ± 10 psec for the 1511-keV $5^{+}$ levels in ${}^{42}{Sc}$ ; 8.1 ± 1.1 psec for the 2987-keV ${\frac{15}{2}}^{-}$ level in ${}^{43}{Sc}$ ; 19.6 ± 1.7 psec for the 3285-keV $6^{+}$ level in ${}^{44}{Ca}$ ; 12.8 ± 1.2 psec for the 3334-keV $6^{+}$ level in ${}^{48}{Ti}$ ; 5.1 ± 1.0 psec for the 1021-keV ${\frac{11}{2}}^{-}$ level in ${}^{49}V$ ; 12.6 ± 2.1 psec for the 783-keV $2^{+}$ level in ${}^{50}{Cr}$ ; 20.4 ± 3.3 psec for the 238-keV ${\frac{7}{2}}^{-}$ level in ${}^{51}{Mn}$ ; ${13.7}_{- 2.3}^{+ 3.6}$ psec for the 2369-keV $4_{1}^{+}$ , 59.5 ± 3.3 psec for the 3114-keV $6^{+}$ , and 10.4 ± 1.2 psec for the 3469-keV ( $3^{\pm}$ , $5^{-}$ ) levels in ${}^{52}{Cr}$ ; 15.5 ± 1.8 psec for the 2563-keV ${\frac{13}{2}}^{-}$ and 3.9 ± 0.6 psec for the 2693-keV ${\frac{15}{2}}^{-}$ levels in ${}^{53}{Mn}$ ; and 5.7 ± 1.2 psec for the 2538-keV $4^{+}$ level in ${}^{54}{Fe}$ . Lifetime limits were found for eight additional levels in these nuclei. In addition, an improved value $τ = 68.3 \pm 3.1$ psec was obtained for 937-keV $3^{+}$ level in ${}^{18}F$ . The $B (E 2)$ strengths for transitions in nuclei with $42 \leq A \leq 44$ are collected and interpreted in terms of isospin-dependent effective charges using wave functions for the ${(1 f_{\frac{7}{2}})}^{n}$ , and ${(fp)}^{n}$ , and ${(fp)}^{n + m} {(sd)}^{- m}$ model spaces. The core-polarization charges obtained from an analysis using ${(fp)}^{2} + {(fp)}^{4} {(sd)}^{- 2}$ wave functions are $e_{p} = 1.16 \pm 0.16$ and $e_{n} = 0.45 \pm 0.03$ . Core-deformation effects are found to enhance the isoscalar but not the isovector effective charges for states with low spin. The $B (E 2)$ strengths for transitions in the isotones with 28 neutrons are also collected and interpreted using ${(1 f_{\frac{7}{2}})}^{n}$ wave functions. The effective proton charge is found to be approximately constant for all transitions with $e_{p} = 1.8 - 2.0$ . Estimates of effective proton charges for these nuclei resulting from the use of larger model spaces are discussed allowing an approximate comparison for the whole $40 < A < 56$ region.

[NUCLEAR REACTIONS ${}^{39}K (α, n) E = 10.4$ MeV, ${}^{40}{Ca} ({}^{3}{He}, p) E = 10.5$ MeV, ${}^{16}O ({}^{3}{He}, p) E = 10.5$ MeV, ${}^{40}{Ca} (α, p) E = 14.0$ MeV, ${}^{41}K (α, p) E = 14.0$ MeV, ${}^{45}{Sc} (α, p) E = 10.0$ MeV, ${}^{46}{Ti} (α, p) E = 11.0$ MeV, ${}^{40}{Ca} ({}^{16}O, α 2 p) E = 47$ MeV, ${}^{49}{Ti} (α, n) E = 14.5$ MeV, ${}^{40}{Ca} ({}^{16}O, 3 p) E = 47$ MeV, ${}^{40}{Ca} ({}^{16}O, 2 p) E = 47$ MeV; measured recoil distance. Deduced $T_{\frac{1}{2}}$ , $B (E 2)$ . Deduced $40 < A < 56$ effective charges. Natural and enriched targets, Ge(Li) detector.]

Influence of the exchange potential on the neutron radius of ${}^{208}{Pb}$ extracted from sub-Coulomb pickup

J. W. Negele

Phys. Rev. C 9, 1054 (1974) - Published 1 March, 1974

Show Abstract

Analysis of sub-Coulomb pickup using the realistic nonlocality arising from the exchange term in Hartree-Fock theory is shown to yield a point-nucleon rms radius for the excess neutrons in ${}^{208}{Pb}$ of 6.21 fm, a value of 0.22 fm larger than previously obtained using local potentials. A simple schematic calculation is presented to elucidate the effect of nonlocality and arguments are presented to substantiate the reliability of a more realistic calculation. The implications of this result concerning the Coulomb energy anomaly are briefly discussed.

[NUCLEAR STRUCTURE ${}^{208}{pb} (p, d)$ , ( $d, t$ ) calculated in Hartree-Fock theory; relation to Coulomb displacement energy.]

Search for closed-shell effects on the $\frac{E 2}{M 1}$ mixing of transitions in ${}^{116}{Sn}$

G. Garcia-Bermudez, S. L. Gupta, N. C. Singhal, A. V. Ramayya, J. Lange, J. H. Hamilton, and N. R. Johnson

Phys. Rev. C 9, 1060 (1974) - Published 1 March, 1974

Show Abstract

Directional-correlation measurements of several cascades in ${}^{116}{Sn}$ have been made with a NaI-Ge(Li) detector system. Of particular interest in the 819-keV, $2^{+'}$ → $2^{+}$ transition which was classified earlier as 90% $E 2$ and almost pure $M 1$ by two different groups. The $γ - γ (θ)$ measurements of the $2^{+'}$ (819-keV) → $2^{+}$ (1293-keV) → $0^{+}$ cascade yield $A_{2}$ and $A_{4}$ coefficients of 0.31(2) and 0.27(5), respectively. From these data a $δ (\frac{E 2}{M 1})$ of $- 1.8 (2)$ is obtained for the 819-keV transition, which corresponds to 76.4 ± 3.7% $E 2$ radiation. The $γ$ - ray intensities were measured more precisely.

[RADIOACTIVITY ${}^{116}{In}^{m}$ ; measured $γ - γ (θ)$ , $I_{γ}$ ; deduced $δ$ . NaI-Ge(Li) detectors.]

Comparison of ${}^{3}{He}$ -, ${}^{4}{He}$ -, and ${}^{12}C$ -induced nuclear reactions in heavy-mass targets at medium excitation energies. I. Experimental cross sections

J. D. Stickler and K. J. Hofstetter

Phys. Rev. C 9, 1064 (1974) - Published 1 March, 1974

Show Abstract

The excitation functions for the ${}^{197}{Au} {({}^{12}C, x n)}^{209 - x}$ At, ${}^{209}{Bi} {({}^{3}{He}, x n)}^{212 - x}$ At, ${}^{209}{Bi} {(α, x n)}^{213 - x}$ At, ${}^{187}{Re} {({}^{3}{He}, x n)}^{190 - x} Ir$ , ${}^{187}{Re} {(α, x n)}^{191 - x} Ir$ , and ${}^{197}{Au} {({}^{3}{He}, x n)}^{200 - x} Tl$ reactions were obtained by the activation method employing the stacked-foil technique. The maximum laboratory kinetic energies were 70-MeV ${}^{3}{He}$ , 80-MeV ${}^{4}{He}$ , and 120-MeV ${}^{12}C$ ions. The radiations accompanying the decay of the induced radioisotopes were detected by a calibrated Ge(Li) detector and the cross sections were deduced by the activation method.

[NUCLEAR REACTIONS ${}^{197}{Au} ({}^{3}{He}, x n)$ , ${}^{209}{Bi} ({}^{3}{He}, x n)$ , ${}^{187}{Re} ({}^{3}{He}, x n)$ , $x = 2, 6$ , $E = 20 to 70$ MeV, ${}^{209}{Bi} (α, x n)$ , ${}^{187}{Re} (α, x n)$ , $x = 2, 6$ , $E = 20 to 80$ MeV, ${}^{197}{Au} ({}^{12}C, x n)$ , $x = 3, 6$ , $E = 60 to 120$ MeV; measured $σ (E)$ .]

Comparison of ${}^{3}{He}$ -, ${}^{4}{He}$ -, and ${}^{12}C$ -induced nuclear reactions in heavy-mass targets at medium excitation energies. II. Reaction model calculations

K. J. Hofstetter and J. D. Stickler

Phys. Rev. C 9, 1072 (1974) - Published 1 March, 1974

Show Abstract

The excitation functions for neutron emission following fusion of ${}^{3}{He}$ , ${}^{4}{He}$ , and ${}^{12}C$ ions with a variety of heavy target nuclei, as determined in the previous communication, are compared to the statistical, exciton, and hybrid reaction model predictions. An initial exciton number of 5 is determined for $α$ -particle-induced reactions by the simple exciton model. The initial exciton number of 7 is consistent with the ${}^{3}{He}$ -induced reactions by the exciton model. The hybrid-model predictions are found to be consistent with the ${}^{3}{He}$ - and ${}^{4}{He}$ -induced reactions using the initial exciton numbers of 3 and 4, respectively. The initial pre-equilibrium exciton states are assumed to be $2 p - 1 n$ and $2 p - 2 n$ pure particle states, respectively. The models permitting pre-equilibrium particle emission are not consistent with the data on ${}^{12}C$ -induced reactions; however, a statistical model calculation with level density parameter $a = \frac{A}{20}$ yields reasonable agreement with the cross sections. Angular momentum effects are discussed in terms of the model predictions and the isomer ratio for helion population of ${}^{186}{Ir}^{g}$ and ${}^{186}{Ir}^{m}$ are determined.

[NUCLEAR REACTIONS ${}^{197}{Au} ({}^{12}C, x n)$ , ${}^{209}{Bi} ({}^{3}{He}, x n)$ , ${}^{209}{Bi} (α, x n)$ , ${}^{187}{Re} ({}^{3}{He}, x n)$ , ${}^{187}{Re} (α, x n)$ , ${}^{197}{Au} ({}^{3}{He}, x n)$ statistical model, exciton model, hybrid model, optical model, angular momentum; predict $σ (E)$ for ( $xn$ ) reactions.]

Exponential dependence of the nuclear moment of inertia on pairing correlation and the pairing stretch model for nuclear rotation

Chin W. Ma and John O. Rasmussen

Phys. Rev. C 9, 1083 (1974) - Published 1 March, 1974

Show Abstract

Nuclear moments of inertia calculated from the cranking model show the dependence on pairing correlation to be nearly exponential over most of the region of physical interest. Furthermore, the uncorrelated wave functions yield moments of inertia deviating in some cases considerably from rigid-body values. The exponential relation is applied to the calculations of rotational energies in a pairing stretch model. With two adjustable parameters the energy fits are quite good.

[NUCLEAR STRUCTURE deformed even-even rare earth nuclei; calculated moments of inertia, energies. Cranking model. Coriolis antipairing effect.]

New neutron-deficient Pb and Bi nuclides produced in cross bombardments with heavy ions

Y. Le Beyec, M. Lefort, J. Livet, N. T. Porile, and A. Siivola

Phys. Rev. C 9, 1091 (1974) - Published 1 March, 1974

Show Abstract

New $α$ -emitting bismuth nuclides ranging in mass number from 189 to 197 and lead nuclides ranging from 186 to 192 have been produced in the following reactions: ${}^{203}{Tl} {({}^{3}{He}, x n)}^{206 - x} Bi$ , ${}^{187}{Re} {({}^{16}O, x n)}^{205 - x} Bi$ , ${}^{185}{Re} {({}^{16}O, x n)}^{203 - x} Bi$ , ${}^{181}{Ta} {({}^{20}{Ne}, x n)}^{201 - x} Bi$ , ${}^{159}{Tb} {({}^{40}{Ar}, x n)}^{199 - x} Bi$ , ${}^{181}{Ta} {({}^{19}F, x n)}^{200 - x} Pb$ , ${}^{182}W {({}^{16}O, x n)}^{198 - x} Pb$ and ${}^{155}{Gd} {({}^{40}{Ar}, x n)}^{195 - x} Pb$ . Assignments were made on the basis of excitation function measurements and comparison with similar reactions leading to the formation of the analogous well-known Po nuclides. The following assignments were made, where for each nuclide the two listed numbers are the $α$ -ray energy in MeV and half-life: ${}^{197}{Bi}^{m}$ —5.77, 10 min; ${}^{195}{Bi}$ -5.43, 170 sec; ${}^{195}{Bi}^{m}$ —6.11, 90 sec; ${}^{194}{Bi}$ -5.61, 105 sec; ${}^{193}{Bi}$ -5.90, 64 sec; ${}^{193}{Bi}^{m}$ —6.18; ${}^{192}{Bi}$ -6.06, 42 sec; ${}^{191}{Bi}$ -6.32, 13 sec; ${}^{191}{Bi}^{m}$ —6.63; ${}^{191}{Bi}^{m}$ —6.86; ${}^{190}{Bi}$ -6.45, 5.4 sec; ${}^{189}{Bi}$ -6.67, <2 sec; ${}^{192}{Pb}$ -5.06, 2.3 min; ${}^{191}{Pb}$ -5.29, 1.3 min; ${}^{190}{Pb}$ -5.58, 1.2 min; ${}^{189}{Pb}$ -5.72, 51 sec; ${}^{188}{Pb}$ -5.98, 26 sec; ${}^{187}{Pb}$ -6.08, 17 sec; and ${}^{186}{Pb}$ -6.32, 8 sec. Estimates of $α$ branching ratios are also presented.

[RADIOACTIVITY new nuclides ${}^{197}{Bi}^{m}$ , ${}^{195}{Bi}$ , ${}^{195}{Bi}^{m}$ , ${}^{194}{Bi}$ , ${}^{913}{Bi}^{m}$ , ${}^{192}{Bi}$ , ${}^{191}{Bi}$ , ${}^{191}{Bi}^{m}$ , ${}^{190}{Bi}$ , ${}^{189}{Bi}$ , ${}^{192}{Pb}$ , ${}^{191}{Pb}$ , ${}^{190}{Pb}$ , ${}^{189}{Pb}$ , ${}^{188}{Pb}$ , ${}^{187}{Pb}$ , ${}^{186}{Pb}$ ; nuclides produced in various ( $HI, x n$ ) reactions; measured $E_{α}$ , $t_{\frac{1}{2}}$ , $α$ branching ratios.]

Coulomb excitation of ground bands in ${}^{160, 162, 164}{Dy}$ with ${}^{20}{Ne}$ and ${}^{35}{Cl}$ ions

R. O. Sayer, E. Eichler, Noah R. Johnson, D. C. Hensley, and L. L. Riedinger

Phys. Rev. C 9, 1103 (1974) - Published 1 March, 1974

Show Abstract

Multiple Coulomb excitation of states up to $J^{π} = 12^{+}$ in the ground band was measured to test the rigid-rotor prediction for intraband $B (E 2)$ ratios. The deexcitation $γ$ rays were observed in singles and in the particle- $γ$ coincident mode following excitation by ${}^{20}{Ne}$ or ${}^{35}{Cl}$ ions from the Oak Ridge isochronous cyclotron. $B (E 2)$ values were extracted by comparing experimental excitation probabilities with theoretical values calculated with the Winther- de Boer computer code. An unexpected result is that the $B (E 2; 4 \to 6)$ values for ${}^{162, 164}{Dy}$ are 15±5% smaller than the rotational values. However, the most striking variation of $B (E 2)$ with spin occurs for ${}^{160}{Dy}$ . We find $\frac{{B (E 2)}_{\exp}}{{B (E 2)}_{rotational}} = 0.77 \pm 0.05$ , 0.94±0.06, and 1.29±0.14 for the 4→6, 6→8, and 8→10 transitions, respectively. The 10→8 transition in ${}^{160}{Dy}$ is significantly faster than rotational even when our approximate quantal correction of 6% is not included in the analysis.

[NUCLEAR REACTIONS ${}^{160, 162, 164}{Dy}$ ( ${}^{35}{Cl}$ , ${}^{35}{Cl}$ ′), $E = 125$ MeV; ( ${}^{20}{Ne}$ , ${}^{20}{Ne}$ ′), $E = 72$ MeV; measured Coulomb excitation yields. ${}^{160, 162, 164}{Dy}$ levels, deduced $E_{γ}$ , $B (E 2)$ .]

Study of charged particles emitted from ${}^{117}{Te}$ compound nuclei. I. Argon-induced reactions

J. Galin, B. Gatty, D. Guerreau, C. Rousset, U. C. Schlottauer-Voos, and X. Tarrago

Phys. Rev. C 9, 1113 (1974) - Published 1 March, 1974

Show Abstract

The compound nucleus ${}^{117}{Te}$ was formed with ${}^{40}{Ar}$ + ${}^{77}{Se}$ at 71- and 107-MeV excitation energies; the maximum relative angular momenta in the entrance channels are about $70 ℏ$ and $110 ℏ$ . The deexcitation by protons, deuterons, tritons, $α$ particles, and lithium was studied, measuring absolute cross sections, energy spectra, and angular distributions. The experimental results, especially the strong anisotropies of the $α$ -particle angular distributions and the dependence of the average energy on the emission angle, are discussed in terms of the statistical theory and the influence of very high angular momentum on the evaporation mechanism. The angular distributions of the elastic scattering have been measured simultaneously and are described by a strongly absorbing optical potential.

[NUCLEAR REACTIONS ${}^{nat}{Se}$ ( ${}^{40}{Ar}$ , ${}^{40}{Ar}$ ); $E = 146, 201$ MeV; measured $σ (θ)$ ; optical-model analysis; ${}^{nat, 77}{Se} ({}^{40}{Ar}, p)$ , ( ${}^{40}{Ar}, d$ ), ( ${}^{40}{Ar}, t$ ), ( ${}^{40}{Ar}, α$ ), ( ${}^{40}{Ar}, Li$ ); $E = 146, 201$ MeV; measured $σ (E, E_{particle})$ , $σ (E_{particle}, θ)$ , $σ_{particle}$ ; discussion with regard to statistical model.]

Study of charged particles emitted from ${}^{117}{Te}$ compound nuclei. II. Comparison between ${}^{40}{Ar}$ + ${}^{77}{Se}$ and ${}^{14}N$ + ${}^{103}{Rh}$ reactions and determination of critical angular momenta

J. Galin, B. Gatty, D. Guerreau, C. Rousset, U. C. Schlotthauer-Voos, and X. Tarrago

Phys. Rev. C 9, 1126 (1974) - Published 1 March, 1974

Show Abstract

The compound nucleus ${}^{117}{Te}$ was formed with ${}^{14}N$ + ${}^{103}{Rh}$ at 71- and 107-MeV excitation energies. The deexcitation by protons, deuterons, tritons, and $α$ particles was studied and compared to the deexcitation of the same compound nucleus ${}^{117}{Te}$ issued from ${}^{40}{Ar}$ + ${}^{77}{Se}$ at the same excitation energies. The influence of angular momentum on the evaporation mechanism (angular distributions and cross sections of charged particles) have allowed to determine different values of critical angular momenta limiting compound-nucleus formation. These values are discussed with respect to different models.

[NUCLEAR REACTIONS ${}^{103}{Rh}$ ( ${}^{14}N$ , ${}^{14}N$ ); $E = 81, 121$ MeV; measured $σ (θ)$ ; optical-model analysis ${}^{103}{Rh} ({}^{14}N, p)$ , ( ${}^{14}N, d$ ), ( ${}^{14}N, t$ ), ( ${}^{14}N, α$ ); $E = 81, 121$ MeV measured $σ (E, E_{particle})$ , $σ (E_{particle}, θ)$ , $σ_{particle}$ ; discussion with regard to statistical model; comparison with Ar-induced reactions; deduced critical angular momenta.]

Interaction of 300-GeV protons with uranium

S. K. Chang and Nathan Sugarman

Phys. Rev. C 9, 1138 (1974) - Published 1 March, 1974

Show Abstract

The cross sections and thick-target recoil properties of 30 nuclides produced in the interaction of 300-GeV protons with a ${}^{238}U$ target have been measured. The cross sections were determined relative to the monitor reaction ${}^{27}{Al} (p, 3 pn) {}^{24}{Na}$ , whose cross section was assumed to be constant above 10 GeV. The average cross section of all products is found to be ∼10% lower at 300 GeV than at 11.5 GeV. The recoil ranges of observed nuclides are ∼8% shorter than at lower proton energy and $\frac{F}{B}$ values are closer to unity. A preliminary study of the effect of secondary particles is presented.

[NUCLEAR REACTIONS ${}^{238}U (p, f, and spallation)$ , $E = 300$ GeV; measured $σ$ and thick-target recoil properties of 30 product nuclides.]

Select page:

Physical Review C

Recent Articles

Filter

Recent Issues

Search for evidence of antineutrino decays

${}^{3}H ({}^{3}{He}, n) {}^{5}{Li}$ reaction from 14 to 26 MeV

Erratum: Spectroscopy of ${}^{10}B$ levels from the ${}^{9}{Be} (d, n) {}^{10}B$ reaction

Erratum: Neutron resonance spectroscopy. VII. Ti, Fe, and Ni

Erratum: $γ - γ$ directional correlation measurements in ${}^{106}{Pd}$

Erratum: Rules for spin and parity assignments based on $log ft$ values

Elastic scattering of 60-MeV alpha particles by the even nickel isotopes

Limitation to complete fusion during a collision between two complex nuclei

High-resolution comparison of ( $p, p^{'}$ ) and ( $d, d^{'}$ ) reactions

Lifetime measurements and $E 2$ effective charges for nuclei in the $1 f_{\frac{7}{2}}$ shell

Influence of the exchange potential on the neutron radius of ${}^{208}{Pb}$ extracted from sub-Coulomb pickup

Search for closed-shell effects on the $\frac{E 2}{M 1}$ mixing of transitions in ${}^{116}{Sn}$

Comparison of ${}^{3}{He}$ -, ${}^{4}{He}$ -, and ${}^{12}C$ -induced nuclear reactions in heavy-mass targets at medium excitation energies. I. Experimental cross sections

Comparison of ${}^{3}{He}$ -, ${}^{4}{He}$ -, and ${}^{12}C$ -induced nuclear reactions in heavy-mass targets at medium excitation energies. II. Reaction model calculations

Exponential dependence of the nuclear moment of inertia on pairing correlation and the pairing stretch model for nuclear rotation

New neutron-deficient Pb and Bi nuclides produced in cross bombardments with heavy ions

Coulomb excitation of ground bands in ${}^{160, 162, 164}{Dy}$ with ${}^{20}{Ne}$ and ${}^{35}{Cl}$ ions

Study of charged particles emitted from ${}^{117}{Te}$ compound nuclei. I. Argon-induced reactions

Study of charged particles emitted from ${}^{117}{Te}$ compound nuclei. II. Comparison between ${}^{40}{Ar}$ + ${}^{77}{Se}$ and ${}^{14}N$ + ${}^{103}{Rh}$ reactions and determination of critical angular momenta

Interaction of 300-GeV protons with uranium

Filter

Recent Issues

Filter

Article Lookup

Enter a citation