Electron impact inner-shell atomic ionization cross-section measurement

• Grant number: 10/19699-6
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2011
• End date: February 28, 2013
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Vito Roberto Vanin
• Grantee: Vito Roberto Vanin
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The injector for the IFUSP microtron electron accelerator was commissioned and delivers a 1.9 MeV electron beam whose main characteristic is to be CW, which favors all experiments where a constant rate improves the observation of the phenomena, as coincidence or particle production rate measurements. Using this electron beam, we will measure the electron impact inner-shell atomic ionization cross section, using a semiconductor X-ray detector, placing the targets in a target changer inside an irradiation chamber with spectroscopy windows. The electron current will be measured by a faraday cup and monitored by an electron detector placed in a selected angle to observe the electron flux and its energy spectrum; both the energy spectrum in the electron detector and the fraction of charge collected by the faraday cup will be simulated with the PENELOPE program and compared to the corresponding experimental results. The available data were obtained 40 years ago, show discrepancies with the calculated values and the performed experiments were hindered by difficulties that we will overcome. Moreover, in heavy atoms, experimental data in the 2 MeV energy region are scarce, despite the fundamental character of this interaction process. The state-of-the art cross-section calculations are performed in the relativistic Born approximation, either with plane or distorted waves, and are expected to describe this phenomenon with fair accuracy. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MAIDANA, NORA L.; VANIN, VITO R.; JAHNKE, VIKTOR; FERNANDEZ-VAREA, JOSE M.; MARTINS, MARCOS N.; BRUALLA, LORENZO. Efficiency calibration of x-ray HPGe detectors for photons with energies above the Ge K binding energy. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SP, v. 729, p. 371-380, NOV 21 2013. (10/19699-6, 10/52616-7)