Quasi-elastic scattering angular distribution for the $$94.5\ \hbox {MeV}\ ^{17}\hbox {F}$$ radioactive ion beam on the $$^{208}\hbox {Pb}$$ target has been measured. To describe the experimental quasi-elastic scattering angular distribution and explore the reaction dynamic, firstly, the optical potentials with the double-folding São Paulo and Akyüz Winther potentials for both real and imaginary parts were used to analyze the experimental data. It is observed that both theoretical angular distributions are very similar. The optical model results describe reasonably the experimental data until 100 $$^\circ $$ but underpredict the data for larger angles. Secondly, the continuum discretized coupled channel method (CDCC) was used to study the effect of the breakup channel on the elastic scattering. The double-folding São Paulo and Akyüz Winther potentials were used as nuclear interactions giving again similar results. The agreement with the data is slightly improved at intermediate angles. The sensibility of the CDCC effects upon the nuclear interaction potential was checked. Finally, the influence of inelastic states of both projectile and target, the one-proton, one-neutron, two-neutron and $$\alpha $$ transfer channels on the quasi-elastic scattering angular distribution is analyzed in the frame of the coupled channel and coupled reaction channel methods, respectively. It is observed that the coupling to the first excited state of $$^{17}\hbox {F}$$ is the one that affects more the elastic scattering, although the inelastic channels of the target also influence it when compared with the optical model results. The effect of the transfer channels on the quasi-elastic angular distribution is negligible.

Gamma-ray angular distributions in oriented ^92 Mo produced via the ^6 Li+ ^89 Y reaction were studied in this work. The characteristic γ rays in ^92 Mo were measured by means of the GALILEO array, which is composed of 25 Compton-suppressed HPGe detectors arranged in a nearly 2 π geometry. A detailed analysis of the spin-alignment attenuation factors ( α _2 ) for different excited states in ^92 Mo was performed, by analyzing the measured angular distribution coefficients of several pure- E2 transitions. The relationship between α _2 and the spin was established in ^92 Mo and the 244-keV transition between the 5 ^-_1 and 4 ^+_1 states resulted to have a E 1 + M 2 character with a mixing ratio ( δ ) of -0.05^+0.05_-0.06 , consistent with shell model calculations.

Quasi-elastic scattering angular distribution for the 94 . 5 MeV 17 F radioactive ion beam on the 208 Pb target has been measured. To describe the experimental quasi-elastic scattering angular distribution and explore the reaction dynamic, firstly, the optical potentials with the double-folding São Paulo and Akyüz Winther potentials for both real and imaginary parts were used to analyze the experimental data. It is observed that both

Gamma-ray angular distributions in oriented $$^{92}$$ Mo produced via the $$^{6}$$ Li+ $$^{89}$$ Y reaction were studied in this work. The characteristic $$\gamma $$ rays in $$^{92}$$ Mo were measured by means of the GALILEO array, which is composed of 25 Compton-suppressed HPGe detectors arranged in a nearly 2 $$\pi $$ geometry. A detailed analysis of the spin-alignment attenuation factors ( $$\alpha _2$$ ) for different excited states in $$^{92}$$ Mo was performed, by analyzing the measured angular distribution coefficients of several pure-E2 transitions. The relationship between $$\alpha _2$$ and the spin was established in $$^{92}$$ Mo and the 244-keV transition between the 5 $$^-_1$$ and 4 $$^+_1$$ states resulted to have a E1 + M2 character with a mixing ratio ( $$\delta $$ ) of $$-0.05^{+0.05}_{-0.06}$$ , consistent with shell model calculations.

The β-delayed two-proton emission from 22Al was investigated experimentally through the implantation-decay method. A β-delayed two-proton decay branch from 22Al were identified based on the coincidence of the charged particles and γ-ray signals. The relative momentum (qpp) and the opening angle (θpp) distributions of the two β-delayed protons are measured and a strong peak at qpp∼20MeV/c, as well as a peak at θpp∼30∘ are observed clearly. The β-delayed 2He emission from 22Al with a probability of 29 (13)% by fitting the experimental data with the results of Monte Carlo simulations.

The mass dependence of the transverse flow in the reactions of Ca-40 + Ca-40 at 35 MeV/nucleon has been determined for emitted isotopes with Z = 1 to 9. The observed flow is compared with that calculated using a constrained molecular dynamics (CoMD) simulation. With the application of the appropriate experimental filter, the general trend of the experimental mass-dependent flow is well reproduced by the simulation employing an effective interaction corresponding to a soft equation of state (K = 200 MeV). The CoMD events are further utilized to study the mechanism of generation of the mass-dependent flow. It is found that the mass-dependent flow is generated by the interplay between the thermal and collective motions under a momentum conservation in the fragmenting system. With the help of the collective-thermal-interplay model, the mass-dependent flow scaled by the reduced mass of fragments A/A(sys) is found to be almost independent of the size of the system.

Angular distributions of the differential cross sections for the quasi-elastic scattering from a Pb-nat target by C-10 at 226 and 256 MeV, by C-11 at 222 MeV and 226 MeV, and by B-10 at 173 MeV were measured at the Heavy Ion Research Facility in Lanzhou, Radioactive Ion Beam Line in Lanzhou (HIRFL-RIBLL). Contributions from the inelastic scattering channels to these data are found to be negligibly small with coupled-channel calculations within the angular range covered by this experiment. These data can be well reproduced by optical model calculations with systematic nucleus-nucleus potentials. The reduced total reaction cross sections were compared with other existing data

By using an antisymmetrized molecular dynamics model (AMD), the data of kinematically complete events are compared with the experimental INDRA data through nuclear stopping in Xe + Sn collisions at 10 to 100A MeV. The sensitivity of the nuclear stopping is studied through interactions with different equations of state (EOSs) (soft and stiff) and in-medium NN cross sections in different energy domains. Above 25A MeV, both EOSs and different N N cross sections can affect the nuclear stopping, but none of these parameters used in the AMD model can reproduce the experimental data at 20 to 30A MeV. On the other hand, below 25A MeV, nuclear stopping is not sensitive to both of the EOSs and the N N cross sections because of complete nuclear stopping. This indicates that some important mechanisms may be missing in AMD or that the selection of central collision events may be significantly different between the experiments and the simulations at this energy range.

The elastic scattering of B-8 by a Pb-nat target was measured at an incident energy of 170.3 MeV. Special care was taken with the limited intensity and broad profile of the secondary beam. The measured angular distribution of the differential cross section shows that the Coulomb-nuclear interference peak (CNIP) is not suppressed in this system, in contrast to what was observed in the scattering of neutron halo nuclei by heavy targets at energies around the Coulomb barrier. Analyses of the angular distribution were performed both in terms of the optical model using a single-folding-type potential and the continuum discretized coupled-channels (CDCC) method, which explicitly takes into account the breakup-channel couplings to the elastic scattering. The overall pattern of the differential cross section is well reproduced by the CDCC calculations. The calculations show that the effect of breakup-channel couplings on the elastic scattering is small in the present case.

A telescope array composed of a silicon strip detector and scintillator crystals is dedicated to detect reaction products induced by radioactive ion beams. The silicon strip detector has a thickness of 1000 gm and is divided into 40 x 40 strips with 1 mm resolution. The crystal array consists of 8 x 8 CsI (Tl) crystals with readouts by photo-multiplier tubes. The design and performance of this telescope array are described. (C) 2013 Elsevier B.V. All rights reserved.

The idea of a thermalized non-equilibrated state of matter offers a conceptually new understanding of the strong angular asymmetry. In this compact review we present some clarifications, corrections and further developments of the approach, and provide a brief account of results previously discussed but not reported in the literature. The cross symmetry compound nucleus $S$-matrix correlations are obtained (i) starting from the unitary $S$-matrix representation, (ii) by explicitly taking into account a process of energy equilibration, and (iii) without taking the thermodynamic limit of an infinite number of particles in the thermalized system. It is conjectured that the long phase memory is due to the exponentially small total spin off-diagonal resonance intensity correlations. This manifestly implies that the strong angular asymmetry intimately relates to extremely small deviations of the eigenfunction distribution from Gaussian law. The spin diagonal resonance intensity correlations determine a new time/energy scale for a validity of random matrix theory. Its definition does not involve overlaps of the many-body interacting configurations with shell model non-interacting states and thus is conceptually different from the physical meaning (inverse energy relaxation time) of the spreading widths introduced by Wigner. Exact Gaussian distribution of the resonance wave functions corresponds to the instantaneous phase relaxation. We invite the nuclear reaction community for the competition to describe, as the first challenge, the strong forward peaking in the typically evaporation part of the proton spectra. This is necessary to initiate revealing long-term misconduct in the heavily cross-disciplinary field, also important for nuclear industry applications.

The present discussion rises a number of the questions. For example, is rotational coherence of large molecules necessarily destroyed in the conventionally statistical limit of structureless non-selective continuum (for fixed total spin and parity values) under the conditions of complete intramolecular energy redistribution and vibrational dephasing in the regime of strong ro-vibrational coupling? For the slow cross-symmetry phase relaxation, quantum coherent superpositions of a large number of complex configurations with, e.g., many different total angular momenta produce image of a rotation of macroscopic object with classically fixed (single) total angular momentum. Suppose that the quantum coherent superpositions involving a very large number of different good quantum numbers play a role, in a hidden form, in a formation of macroscopic world. Then why these quantum superpositions are so stable against quick aging/decay of ordered complex structures preventing or slowing down tendencies towards uniform occupation of the available phase space as prescribed by the random matrix theory? And what kind of complex macroscopic phenomena may reveal traces of partially coherent quantum superpositions involving a huge number of quantum-mechanically different integrals of motion behind of what is referred to as conservation laws in classical physics employed for the description of the macroscopic world?

A method is presented for the measurement of differential cross-sections of heavy ion elastic scattering induced by Radioactive Ion Beams (RIBs) on the Radioactive Ion Beam Line in Lanzhou (RIBLL) at the Heavy-Ion Research Facility in Lanzhou (HIRFL). The disadvantages of broad beam profiles and limited intensities of the RIBs were overcome using large area detectors, two Parallel-Plate Avalanche Counters (PPACs), two double-sided silicon strip detector (DSSD) telescopes, incorporated with Monte Carlo simulations. The PPACs were used to determine the direction and position of the beam particles. The DSSD telescopes were used to measure scattered particles. Small corrections for the misalignment of detectors and the data normalization were made by assuming the pure Rutherford scattering at very forward angles. The method is suitable for the measurement of the cross-sections on heavy targets at low and intermediate energies, and it has been successfully applied to measure the angular distribution of elastic scattering of 7Be on Pb target at Elab=17.9MeV/u.

A new methodology is presented to analyze the threshold anomaly and to compare different kinds of reaction systems together. In this methodology, the experimental and theoretical values of the quarter-point angle are compared directly for different reaction systems. A suitable reduction method is employed to minimize the system effects. This new method can be used to evaluate and study the dynamic effects in the reaction systems.

As a prototype of the Shanghai Laser Electron Gamma Source in the Shanghai Synchrotron Radiation Facility, an x-ray source based on laser-Compton scattering (LCS) has been installed at the terminal of the 100 MeV linac of the Shanghai Institute of Applied Physics. LCS x-rays are generated by interactions between Q-switched Nd:yttrium aluminum garnet laser pulses [with wavelength of 1064 nm and pulse width of 21 ns (full width at half maximum)] and electron bunches [with energy of 108 MeV and pulse width of 0.95 ns (rms)] at an angle of 42 degrees between laser and electron beam. In order to measure the energy spectrum of LCS x-rays, a Si(Li) detector along the electron beam line axis is positioned at 9.8 m away from a LCS chamber. After background subtraction, the LCS x-ray spectrum with the peak energy of 29.1+/-4.4|(stat)+/-2.1|(syst) keV and the peak width (rms) of 7.8+/-2.8|(stat)+/-0.4|(syst) keV is observed. Normally the 100 MeV linac operates with the electron macropulse charge of 1.0 nC/pulse, and the electron and laser collision repetition rate of 20 Hz. Therefore, the total LCS x-ray flux of (5.2+/-2.0) x 10(2) Hz can be achieved.

There is great interest in the generation of energy-tunable, bright, short-pulse X/γ-ray sources, which are required in various research fields. Laser–Compton scattering (LCS) is considered to be one of the most promising methods to implement this kind of X/γ-ray source. At the 100-MeV LINAC of the Shanghai Institute of Applied Physics, a 2-J, 8-ns, 1064-nm, Q-switched Nd:YAG laser is brought to a slanting collision at 40° (44°) with an 112-MeV, 0.9-ns (rms) relativistic electron beam. We measured the LCS X-ray energy spectrum with a peak energy of 31.73±0.22stat±1.64syst keV and a peak width (rms) of 0.74±0.26stat±0.03syst keV. This preliminary investigation was carried out to understand the feasibility of developing an energy-tunable X/γ-ray source. Based on this study, the future Shanghai Laser Electron Gamma Source (SLEGS) at the Shanghai Synchrotron Radiation Facility (SSRF) can be constructed to be not only an energy-tunable γ-ray source by guiding the laser incident angle from laser–Compton scattering, but also a high flux (∼1010 photons/s or even higher) γ-ray source by adding a laser super-cavity.

The Shanghai Synchrotron Radiation Facility (SSRF) is a third-generation synchrotron radiation light source and will come into commission in April 2009. The project Shanghai Laser Electron Gamma Source (SLEGS), which is a high intensity γ-ray beamline based on Laser Compton Scattering (LCS) between relativistic electron bunches and a laser, has been proposed at the SSRF. According to our simulations, the SLEGS is expected to generate a polarized γ-ray beam of up to 22 MeV and 109–10 photons/s if using 3.5 GeV, 200–300 mA relativistic electrons and a 500 W CO2 polarized laser. Here we describe the status and the application prospects of SLEGS and its developed prototype.