Coulomb and nuclear breakup effects in the single neutron removal reaction 197Au(17C,16C gamma)X

We analyze the recently obtained new data on the partial cross sections and parallel momentum distributions for transitions to ground as well as excited states of the 16C core, in the one-neutron removal reaction 197Au(17C,16C gamma)X at the beam energy of 61 MeV/nucleon. The Coulomb and nuclear breakup components of the one-neutron removal cross sections have been calculated within a finite range distorted wave Born approximation theory and an eikonal model, respectively. The nuclear contributions dominate the partial cross sections for the core excited states. By adding the nuclear and Coulomb cross sections together, a reasonable agreement is obtained with the data for these states. The shapes of the experimental parallel momentum distributions of the core states are described well by the theory.Comment: Revtex format, two figures included, to appear in Phys. Rev. C. (Rapid communications

Core excitation in Coulomb breakup reactions

Within the pure Coulomb breakup mechanism, we investigate the one-neutron removal reaction of the type A(a,b$\gamma$)X with $^{11}$Be and $^{19}$C projectiles on a heavy target nucleus $^{208}$Pb at the beam energy of 60 MeV/nucleon. Our intention is to examine the prospective of using these reactions to study the structure of neutron rich nuclei. Integrated partial cross sections and momentum distributions for the ground as well as excited bound states of core nuclei are calculated within the finite range distorted wave Born approximation as well as within the adiabatic model of the Coulomb breakup. Our results are compared with those obtained in the studies of the reactions on a light target where the breakup proceeds via the pure nuclear mechanism. We find that the transitions to excited states of the core are quite weak in the Coulomb dominated process as compared to the pure nuclear breakup.Comment: Revtex format, five postscript figures included, to appear in Phys. Rev.

COMPARATIVE STUDY ON CONTINUOUS STEEL-CONCRETE COMPOSITE BEAMS WITH NORMAL AND STEEL FIBER REINFORCED CONCRETE SLAB

The Thirteenth East Asia-Pacific Conference on Structural Engineering and Construction (EASEC-13), September 11-13, 2013, Sapporo, Japan

Monoclinic-orthorhombic phase transitions in A_2BX_4 single crystals with Sr_2GeS_4-type structure

The structural phase transitions including the monoclinic-orthorhombic transition (α-β transition) in K_2ZnI_4, Rb_2CoI_4 and Rb_2MnI_4 are investigated by means of X-ray diffraction. These compounds take the Sr_2GeS_4-type structure at room temperature. In Rb_2CoI_4 and Rb_2MnI_4, the α-modification is transformed to the β-modification (β-K_2SO_4-type structure) at 515 K and 510 K, respectively. In the β-modification of Rb_2MnI_4, it is found that the transition from the normal phase (space group Pmcn) to incommensurate one (modulation along c^*) takes place at around 520 K. On the other hand, the α-β transition is not observed up to the melting point in K_2ZnI_4. We discuss the α-β transition on the basis of the ratio the ionic radius of A^+ to the average bond length B-X in tetrahedral BX_4^＜2-＞ ion. It is found that the compounds in this family are classified into three types by the ratio

Damage behavior of air-plasma-sprayed thermal barrier coatings under foreign object impact

How do thermal barrier coatings react to the impact of a foreign object? The authors examined the damage done by a projectile to an air‐plasma‐sprayed coating system. Apart from permanent deformation, chipping of the ceramic top coat around the impression sites occurs at impact velocities above 150 m s–1. At increasing impact speed, the cracks in the top coat tend to elongate and result in coating removal (see Figure for a cross‐section)