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Angular distributions for the inelastic scattering of 13.0 MeV deuterons on 104;106;108;110Pd were measured with the Sao Paulo Pelletron-Enge-Spectrograph facility in the range of 12(0) < thetalab < 64(0). A Coulomb-Nuclear Interference analysis, employing the Distorted Wave Born Approximation with the Deformed Optical Model as transition potential, under well established global optical parameters, was applied to the first quadrupolar excitations. The values of C = / , the ratio of charge to isoscalar deformation lengths, and of ()² were extracted through the comparison of experimental and predicted cross section angular distributions. The ratios of reduced charge to isoscalar transition probabilities, B(EL) to B(ISL) respectively, are related to the square of the parameter C and were thus obtained with the advantage of scale uncertainties cancellation. For 104Pd, and preliminary for 108Pd, the respective values of C = 1.18(3) and C = 1.13(4) reveal an enhanced contribution of the protons relative to the neutrons to the excitation, while a smaller effect is found for 106Pd, C = 1.06(3) and for 110Pd, C = 1.07(3), in comparison with the value C = 1.00 expected for homogenous collective excitations.

One neutron stripping and pick-up results obtained in Sao Paulo with good energy resolution show that levels interpreted in previous works as two-phonon and three-phonon states in 100Ru are excited with considerable intensity through predominantly direct one-step single neutron transfers. Furthermore, a comparative analysis of excitation energy values obtained in recent experiments, including the present results, with previous ones shows that there are at least 4 spurious levels in the adopted 100Ru level scheme below 2.5 MeV. Several levels seen in recent gamma work are here confirmed and three new ones indicated below 3.2 MeV of excitation energy.

É discutida a conceituação de objetos com estrutura fractal, tendo em vista sua utilização em experiências motivadoras no laboratório didático. Foram estudadas bolas de pão amassado, que podem ser empregadas como contraponto não fractal (D ~ 3,0) às bolas de papel amassado, as quais apresentam dimensão fractal (D ~ 3,0), salientando a necessidade de um cálculo correto de incertezas. Três tipos de pão foram investigados: dois brancos, de forma e italiano, e um preto denso, do tipo alemão de três grãos. Desses, apenas o pão branco italiano demonstrou possível estrutura fractal, após o amassamento, caracterizada pela dimensão fractal D = 2,81 ± 0,06, enquanto os resultados obtidos para os pães preto e de forma, D = 2,95 ± 0,06 e D = 2,98 ± 0,04 respectivamente, não os tipificam como fractais. São analisados os problemas conceituais que resultaram em dimensão fractal 2,08 ± 0,25 para o pão, em informação encontrada na literatura de escopo didático. The concept of objects with a fractal structure is discussed, in the context of their use in motivating activities for the didactic Laboratory. Spheres of squashed bread, which may be employed as non-fractal counter example (D ~ 3,0) to the fractal crumpled paper balls (D ~ 2,5), were analysed and the need for correct computation of the uncertainties is stressed. Three kinds of bread were investigated: two white ones, an usual sandwich and an italian type, and one very heavy three grain german dark bread. Only the white italian bread showed a possible fractal structure after the squashing procedure, characterized by the dimension 2.81 ± 0.06, while the results for the others, respectively D = 2.95 ± 0.06 and D = 2.98 ± 0.04, for the dark and white sandwich breads, do not typify them as fractals. The conceptual problems, which resulted in a fractal dimension of D = 2.08 ± 0.25 for bread, found in an article in the literature, are analysed.

Information collected in the present high resolution study of 104Pd(d,t)103Pd is interpreted within the systematics of the A ~ 100 region. The paper complements data previously presented by the S.Paulo Group, which were taken with the Pelletron-Enge-Spectrograph facility. A one-to-one correspondence to gamma ray results for 103Pd, collected by the Nuclear Data Sheets (NDS), was achieved and at least four open questions were settled. More reliable spectroscopic strengths were extracted in the present study.

Low-lying levels of 103Pd have been investigated through the (d,t) reaction on 104Pd, at an incident deuteron energy of 15.0 MeV. Outgoing particles were momentum analyzed by an Enge magnetic spectrograph and detected in nuclear emulsion plates, with an energy resolution of 8 keV. Previous (d,t) work suffered from a much worse resolution than that here achieved. A partial analysis of the data obtained is reported, referring to six out of the fourteen scattering angles for which data were obtained. Angular distributions associated with eight of the thirteen levels seen up to 1.1 MeV of excitation have been compared to DWBA one-neutron pick-up predictions. Both, the attributed excitation energy values and the transferred angular momenta are in excellent agreement with the results of other kind of experiments, as tabulated by the Nuclear Data Sheets. Some peculiar structure characteristics, associated with the yrast 5/2+, 3/2+ and 7/2+ states found in the Ru chain could be recognized also in 103Pd, pointing to the possibility of a more global understanding of this transitional mass region.

Background: Resonances around $x\ensuremath{\alpha}$ thresholds in light nuclei are recognized to be important in basic aspects of nuclear structure. However, there is scarce experimental information associated with them.Purpose: We study the $\ensuremath{\alpha}$-clustering phenomenon in resonant states around the $4\ensuremath{\alpha}$ threshold (14.44 MeV) in the ${}^{16}\text{O}$ nucleus.Method: The ${}^{12}\text{C}{(}^{6}\text{Li},d){}^{16}\mathrm{O}$ reaction was investigated with an unprecedented resolution at a bombarding energy of 25.5 MeV by employing the S\~ao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion technique.Results: Several narrow resonances were populated and the energy resolution of 15 keV allows for the separation of doublet states that were not resolved previously. The upper limits for the resonance widths in this region were extracted. The angular distributions of the absolute differential cross section associated with four natural parity quasibound states are presented and compared to distorted wave Born approximation predictions.Conclusions: Narrow resonances not previously reported in the literature were observed. This indicates that the $\ensuremath{\alpha}$-cluster structure information in this region should be revised.

The 9Be(6Li,d)13C and 12,13C(6Li,d)16,17O reactions were measured at the Sao Paulo Pelletron-Enge-Spectrograph facility at 25.5 MeV incident energy. The nuclear emulsion detection technique was applied. Several narrow resonances were populated up to approximately 17 MeV of excitation energy. An excellent energy resolution was obtained: 40 keV for 13C and 15-30 keV for 16O. The upper limit for the resonance widths were determined. Recently, d-a angular correlations were measured at θd = 0° with incident energy of 25 MeV using the LNS Tandem-MAGNEX Spectrometer facility.

Several narrow alpha resonant 16O states were detected through the 12C(6Li,d) reaction, in the range of 13.5 to 17.5 MeV of excitation energy. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion technique. Experimental angular distributions associated with natural parity quasi-bound states around the 4α threshold are presented and compared to DWBA predictions. The upper limit for the resonance widths obtained is near the energy resolution (15 keV).

Taking {sup 94}Mo(d,d{sup {prime}}){sup 94}Mo(2{sub 1}{sup +}) at 13.2 MeV incident energy as an example, a discussion is made about the influence of known experimental uncertainties in the primary data on the precision of the B(E2) and B(IS2) values, extracted in Coulomb-nuclear interference (CNI) measurements in a correlated way. The reflexes of judicious variations of three optical model parameters (around the global prescription) on the extracted values are also examined. The good quality of the data obtained with the S. Paulo Pelletron-Enge-Spectrograph facility is shown to allow for a 2{endash}3{percent} statistical uncertainty level for these quantities, within a distorted-wave Born approximation-deformed optical model approach. The accuracy of relative values of the ratio B(E2)/B(IS2), which may be linked to the ratio of proton to neutron quadrupole moments, is argued to be of similar order. {copyright} {ital 1997} {ital The American Physical Society}

Coulomb-nuclear interference data for incident energies between 9 and 17 MeV were obtained in the form of elastic and inelastic (to the ${2}_{1}^{+}$ states) excitation functions of backscattered (\ensuremath{\theta}\ensuremath{\simeq}172.8\ifmmode^\circ\else\textdegree\fi{}) alpha particles on $^{100,102,104}\mathrm{Ru}$. The analysis was done in a distorted-wave Born approximation within a deformed optical model approach. B(E2) values, obtained from the charge deformation lengths ${\mathrm{\ensuremath{\delta}}}^{\mathit{C}}$ extracted from the low energy data, are compatible for the three isotopes within \ensuremath{\sim} 2\ensuremath{\sigma} with published values. The nuclear quadrupolar deformation lengths ${\mathrm{\ensuremath{\delta}}}^{\mathit{N}}$, obtained from the analysis of the interference region of the excitation functions, and also of one angular distribution at 22 MeV measured for $^{100}\mathrm{Ru}$ are generally lower than the corresponding charge deformation lengths, the difference increasing with increasing A of the isotope, ${\mathrm{\ensuremath{\delta}}}^{\mathit{N}}$ being 18% lower than ${\mathrm{\ensuremath{\delta}}}^{\mathit{C}}$ for $^{104}\mathrm{Ru}$ (${2}_{1}^{+}$). Nuclear deformation lengths associated with the ${3}_{1}^{\mathrm{\ensuremath{-}}}$ states of $^{100,102,104}\mathrm{Ru}$ and with the ${4}_{2}^{+}$ state of $^{100}\mathrm{Ru}$ at 2.367 MeV were also obtained as a by-product of the present work. \textcopyright{} 1996 The American Physical Society.

The 9Be(6Li,d)13C reaction was used to investigate alpha resonant states in 13C up to 15 MeV of excitation. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron‐Enge‐Spectrograph facility and the nuclear emulsion detection technique. An energy resolution of 50 keV was obtained. Several narrow alpha resonant states not previously measured were detected, in particular the one at the (3α+n) threshold populated by an L = 2 transfer, revealing a 9Be+α component for the 1/2− cluster state candidate at this threshold. Experimental angular distributions are presented in comparison with DWBA predictions.

Alpha resonant states in 13 C up to 15 MeV were excited by the 9 Be (6 Li , d )13 C reaction. The data were taken at a bombarding energy of 25.5 MeV employing the São Paulo-Pelletron-Enge Split Pole facility and the nuclear emulsion technique. The resolution of 50 keV allowed for the separation of the resonant contributions to the known 7/2- and (5/2-) states near the 9 Be + α threshold both associated with an L = 4 transfer. Several narrow alpha resonant states not previously measured were detected, in particular the one at the 3α + n threshold populated by an L = 2 transfer, revealing a 9Be + α component for the 1/2- cluster state candidate at this threshold.

The 9Be(6Li,d)13C reaction was used to investigate alpha resonant states in 13C up to 13 MeV of excitation. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron‐Enge‐Spectrograph facility and the nuclear emulsion detection technique. The resolution of 50 keV allowed for the separation of the resonant contributions to the known 7/2− at 10.753 MeV and (5/2−) at 10.818 MeV 13C states. The alpha resonance seen at the (3α+n) threshold was not previously reported. The experimental angular distributions are presented in comparison with DWBA predictions.

Angular distribution for the inelastic scattering of 28 MeV 6Li on 76Ge was measured using the Sao Paulo PelletronEngeSplit-pole Spectrograph facility. The coulomb-nuclear interference (CNI) analysis was applied to the first quadrupole state transition. The values of CL = δCL/δNL, the ratio of charge to isoscalardeformation lengths, and of (δNL02 were extracted through the comparison of experimental and DWBA-DOMP predicted cross section. The ratio of reduced charge to isoscalartransition probabilities, B(EL) to B(ISL) respectively, are related to the square of the parameter CL and were thus obtained with the advantage of scale uncertainties cancellation. The value of C2 = 1.10(2) obtained indicate a slight predominance of the protons relative to the neutrons for 76Ge.

Ratios of $B(E2)$ to $B(IS2)$, that is, of the reduced quadrupole transition probabilities related, respectively, to charge and mass were extracted through Coulomb-nuclear interference (CNI) for the excitation of the ${2}_{1}^{+}$ states in $^{70,72,74}\mathrm{Ge}$, with a relative accuracy of less than 4%. For this purpose, the CNI angular distributions associated with the inelastic scattering of 28-MeV incident $^{6}\mathrm{Li}$ ions accelerated by the S\~ao Paulo Pelletron, and momentum analyzed by the Enge magnetic spectrograph were interpreted within the DWBA-DOMP approach (distorted wave approximation for the scattering process and deformed optical model for the structure representation) with global $^{6}\mathrm{Li}$ optical parameters. The present CNI results demonstrate an abrupt change in the $B(E2)/B(IS2)$ ratio for $^{74}\mathrm{Ge}$: although for $^{70,72}\mathrm{Ge}$, values of the order of 1.0 or slightly higher were obtained, this ratio is 0.66 (7) for $^{74}\mathrm{Ge}$. The heavier Ge isotope is thus one of the few nuclei that, so far, have been shown to present clear mixed symmetry components in their ground-state band.

The study of the odd 99;101Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in 100;102;104Ru. Angular distributions for the 99;101Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb-Nuclar Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of Jpi= 5=2+, 7=2+ and 9=2+. Through the comparison of experimental and predicted cross section angular distributions, the values of ()² and of the ratio C = / were obtained.

A systematic, high resolution (6--8 keV) study of ([ital d],[ital t]) reactions on [sup 100,102,104]Ru is reported. Spectroscopic factors were extracted by comparison of experimental angular distributions with distorted wave Born approximation predictions. All of the information for [sup 99]Ru and, for excitation energies above 0.9 MeV, for [sup 103]Ru is new. Most of the strength expected for the 50--82 neutron shell was found. The strength distributions are discussed, also in comparison with the corresponding stripping reactions. Special attention is focused on extremely low and relatively intense [ital l]=3 excitations and on the [ital l]=4 transfer pattern observed.

The /sup 91/Zr(d,d')/sup 91/Zr( reaction has been investigated at 17 MeV incident energy. Up to 4.8 MeV excitation, 73 levels, some of them new, were identified. Angular distributions associated to approx.40 levels were attributed to pure L = 2, 3, or 5 excitations, concentrated in energy regions where the /sup 90/Zr core exhibits 2/sup +/, 3/sup -/, and 5/sup -/ states. The partial deformation parameters ..beta../sub L//sup prime/ obtained show agreement with those from low energy proton scattering for L = 2, but there is a systematic difference for L = 3 and L = 5, which is discussed. Attention is drawn to the high excitation probability of the first excited state of /sup 91/Zr, as measured by the ..beta../sub 2/approx. =0.18 value obtained, a factor of approx.2 above all other values for nuclei with A = 90 +- 2.

Levels in /sup 92/Zr were studied by a high resolution (d,p) reaction on /sup 91/Zr. Outgoing particles were momentum analyzed in a split-pole spectrograph and detected in nuclear emulsion plates. A total of 64 levels was identified up to about 5.4 MeV of excitation, several of them not previously reported. Experimental angular distributions were compared to distorted-wave Born-approximation predictions and reduced spectroscopic factors obtained. Energies of centers of gravity of each shell-model orbital were deduced and effective (d/sub 5/2/)/sup 2/ and (s/sub 1/2/d/sub 5/2/) neutron-neutron two-body diagonal matrix elements were estimated.

Energy levels of /sup 101/Ru have been studied by the /sup 100/Ru(d,p)/sup 101/Ru reaction at an incident deuteron energy of 12 MeV. Outgoing particles were momentum analyzed by a magnetic spectrograph and detected in nuclear emulsion plates, with an energy resolution of 7.5 keV. A total of 68 levels up to 3.2 MeV excitation energy was identified, about two-thirds of them reported for the first time. Experimental angular distributions were compared to distorted-wave Born approximation predictions and reduced spectroscopic factors obtained. The total l = 2 and 75% of l = 0, 4, and 5 spectroscopic strengths were located. Attention is drawn to transitions to low-lying states in /sup 101/Ru (below E/sub exc/ = 0.75 MeV) with l = 3 and l = 1 character.

Attention is drawn to the strong collective {ital L}=4 direct excitation of the state at 2.367 MeV in {sup 100}Ru by inelastic scattering of 16 MeV protons characterized by a deformation parameter {beta}{sub 4}=0.10, one of the highest reported for any region of the mass table.