Long range absorption in the scattering of 6He on 208Pb and 197Au at 27 MeV

Quasi-elastic scattering of 6He at E_lab=27 MeV from 197Au has been measured in the angular range of 6-72 degrees in the laboratory system employing LEDA and LAMP detection systems. These data, along with previously analysed data of 6He + 208Pb at the same energy, are analyzed using Optical Model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for long range absorption mechanisms in 6He induced reactions.Comment: 10 pages, 10 figures, minor corrections. To appear in Nucl. Phys.

alpha-particle production in the scattering of 6He by 208Pb at energies around the Coulomb barrier

New experimental data from the scattering of 6He+208Pb at energies around and below the Coulomb barrier are presented. The yield of breakup products coming from projectile fragmentation is dominated by a strong group of $\alpha$ particles. The energy and angular distributions of this group have been analyzed and compared with theoretical calculations. This analysis indicates that the $\alpha$ particles emitted at backward angles in this reaction are mainly due to two-neutron transfer to weakly bound states of the final nucleus.Comment: 20 pages, 5 figures. Nuclear Physics A792 (2007) 2-1

Investigation of toxic and non-toxic hair trace elements in patients with breast cancer and benign breast diseases

Background: Trace elements are essential for all life forms and play a vital role in human nutrition and biochemical functions. Epidemiologic studies suggest that trace element deficiency may be associated with increased risk of cancer. Materials and Methods: In this study, the levels of a number of the elements in scalp hair samples of 81 people (21 breast cancer patients‌‌, 50 people suffering from benign breast diseases and 10 healthy individuals) were measured by a PIXE analysis. Pellets of hair samples were prepared and bombarded by 2.2 MeV proton beam of a 3 MV Van de Graaff accelerator. Results: The concentrations of S, Cl, K, Ca, Fe and Cu in the hair of healthy individuals are in agreement with those observed in the hair of the benign breast disease and cancer patients within the standard deviations. There was a significant decrease in the mean total of Zn in scalp hair samples of the cancer patients compared to the control group. The average scalp hair concentrations of Pb, Br were higher in the benign breast disease and cancer patients than the healthy control. Conclusion: If the deficiency or excess of a particular trace element can be linked to the cancer of an organ, such studies can be initiated to see whether controlled administering of that elements would check the growth of cancer, which ultimately can pave the way for developing a new drug to be used in chemotherapy for cancer

Scattering of 6He at energies around the Coulomb barrier

6 pages, 5 figures.-- El pdf del artículo es la versión pre-print.-- et al.We have measured elastic cross sections of the scattering of 6 He at E-Lab 14, 16, 17, 18 and 22 MeV on Pb-208 in the angular ranges of 20 degrees-64 degrees and 135 degrees-170 degrees. A significant amount of He-4 events is found at energies well below the Coulomb barrier, that becomes dominant above it. Optical model calculations have been performed including a dynamic polarization potential. Very large imaginary diffuseness parameter is needed in order to describe the experimental distributions.This work has been partially supported by the Spanish Dirección General de Investigación, Ciencia y Tecnología under project numbers FPA2000-1592-C03-02, FPA2002-04181-C04-02/04, the Belgian program P5/07 on interuniversity attraction poles of the Belgian-state Federal Services for Scientific, Technical and Cultural Affairs, and the European Community-Access to Research Infrastructure action of the Improving Human Potential Programme, contract no HPRI-CT-1999-00110. AMSB acknowledges a research grant from the Spanish MCyT.This work has been partially supported by the Spanish Dirección General de Investigación, Ciencia y Tecnología under projects number FPA2000-1592-C03-02, FPA2002-04181-C04-02/04, the Belgian program P5/07 on interuniversity attraction poles of the Belgian-state Federal Services for Scientific, Technical and Cultural Affairs, and the European Community-Access to Research Infrastructure action of the Improving Human Potential Programme, contract Nº HPRI-CT-1999-00110. A.M.S.B. acknowledges a research grant from the Spanish MCyT.Peer reviewe

alpha-particle production in the scattering of He-6 by Pb-208 at energies around the Coulomb barrier

New experimental data from the scattering of 6He+208Pb at energies around and below the Coulomb barrier are presented. The yield of breakup products coming from projectile fragmentation is dominated by a strong group of $\alpha$ particles. The energy and angular distributions of this group have been analyzed and compared with theoretical calculations. This analysis indicates that the $\alpha$ particles emitted at backward angles in this reaction are mainly due to two-neutron transfer to weakly bound states of the final nucleus. Comment: 20 pages, 5 figures. Nuclear Physics A792 (2007) 2-1

Elastic scattering and α-particle production in 6He + 208Pb collisions at 22 MeV

Experimental results of the elastic scattering of 6He on 208Pb at E LAB=22 MeV, measured at the CRC facility (Louvain-la-Neuve, Belgium), are presented, including results on the 4He production channel. These data were taken with full angular coverage and high angular resolution. Both experimental cross sections are compared with continuum discretized coupled channels and distorted-wave Born approximation calculations, where direct breakup and transfer to the continuum processes are considered. The elastic data confirm the absence of the Coulomb rainbow, while the distribution of α particles indicates that such production is mostly generated by transfer to the continuum. © 2011 American Physical Society