4. Nuclear Physics (CSN3)

Ionization and radiative electron capture processes (REC) in ion-atom collisions at MeV/u energy range and Ion Beam Analysis (IBA) techniques, applied to different types of materials

by Adela Consuela Scafes




The presentation will begin with a brief overview of the research activity carried out at the Horia-Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest, Romania The seminar topic will focus mainly on the processes occurring in the rapid collisions of heavy-light ions such as 12C, 16O, 32S and 35Cl with thin (self-supporting) solid targets. The ionization and X-ray (characteristic and radiative electron capture-REC) cross sections from integral measurements of K and L X-ray yields have been determined. The measurements were performed at 9 MV FN Pelletron Tandem Accelerator of IFIN-HH. The measured X-ray cross-sections are useful in developing and testing theoretical models (such as PWBA + ECPSSR, SCA, geometric model, Stobbe formula for REC) and complements the existing database for atomic ionization cross-sections. They can have an important role in applied physics, such as elemental PIXE (Particle Induced X-ray Emission) analysis with heavy ions, heavier than proton. Within the last section of the seminar, I will discuss the PIXE method, along with other IBA techniques, which are used to characterize different type of materials. Thus, PIXE along with PIGE (particle-induced gamma-ray emission) and RBS (Rutherford backscattering spectrometry), are one of the "Total IBA" techniques, simultaneously applied in order to determine elemental concentrations and depth profiling of the thin films and various biological samples, with applications in materials physics and medicine. Certain measurements, on certain samples (such as antlers) have been obtained for the first time through the “total IBA”-type method, using the 3 MV Tandetron Accelerator of IFIN-HH, which is mainly inferred into applied physics experiments.