Bremsstrahlung induced by proton andHe3-ion bombardments in the 1-4-MeV/amu energy range

Abstract

Continuous x rays from a thin aluminum target produced by proton and 'He-ion bombardments have been measured with a Si(Li) detector over the impact-energy ranges 1 -4 MeV and 3-9 MeV, respectively. The experimental results obtained were compared with theoretical predictions based on the binary-encounter approximation. Agreements are obtained both in the shape of spectra and absolute cross sections without any adjustable parameter over the entire energy range measured, but generally the theoretical calculation predicts smaller cross sections than the experimental results as the photon energy becomes higher and the bombarding energy gets lower. Energy-dependent directional anisotropy of the bremsstrahlung was theoretically estimated and compared with the experimental results measured at directions 45', 90', and 135' with respect to the incident beam, showing qualitative agreement.

PIXE and Its Applications to Elemental Analysis

“…In addition to the characteristic X-rays, continuous X-rays are produced in ion-atom collisions. There are three processes for the production of continuous X-rays: quasi-free electron bremsstrahlung (QFEB) [14], secondary electron bremsstrahlung (SEB) [15], and atomic bremsstrahlung (AB) [16]. QFEB is the target electron bremsstrahlung produced by the Coulomb potential of the projectile and is the main component of the continuous X-ray energy spectrum for values less than m e E/m p .…”

Single-photon emission associated with double electron capture inF9++Ccollisions

“…Soft x rays are emitted in the case of large impact parameters, wh ile hard x rays correspond to small impact parameters. The captured electron in ion-atom collisions can encounter various mechanisms of e-n bremsstrahlung in the vicinity of the projectile such as radiative electron capture to continuum (RECC) [29], radiative ionization (RI) [30,31], and secondary electron bremsstrahlung (SEB) [32].…”

Estudo do espectro contínuo de raios-x induzido pela passagem de prótons de alguns MeV na matéria

“…In the present work, an expression for the SEB DDCS in terms of the exponential integral function is proposed. With this approach, the dimension of the numerical integration is reduced from a 5D integral to a 3D integral and the results are shown to agree with those by Ishii et al (1976).…”

“…Among these processes of bremsstrahlung production, SEB and AB give the greatest contributions. SEB was rst investigated by Folkmann et al (1974), Jakubaßa-Amundsen and Kleber (1975) and Ishii et al (1976). Later work by Yamadera et al (1981) presents a more explicit expression for the SEB DDCS, based on the same formalism by Ishii et al (1976), which reduces the dimension of the nal integral to be performed numerically needed in the previous works.…”

“…The SEB DDCSs implicitly rely on the ionization process, which, in the approach by Ishii et al (1976), has been calculated within the binary encounter approximation (BEA) (Bonsen and Vriens, 1970;Folkmann et al, 1975). These DDCSs for the ejected electron angle and energy are interesting by themselves and are investigated as well in the present work.…”