Nonadditivity effects during the passage of protons through multilayer targets

Abstract

A theoretical approach is proposed for describing the effect of the number and sequence of surface layers of different compositions on the distribution of radiation defects over the depth of the screened material. It is shown that the energy losses of fast protons penetrating through the tungsten-carbon media depend not only on the thickness and chemical composition of the media but also on the sequence and the number of the layers. Results of calculations using GEANT4 and SRIM programs agree well with each other and show that proton loses a larger amount of energy during the passage through the bilayer W/C target than through the C/W one. An increase in the number of layers leads to a decrease in the influence of the target structure on the distribution of the absorbed energy. This effect is explained by the difference in the stopping powers of neighboring layers.

KEYWORDS:

• Multilayer target
• ion deposited energy
• ion induced defect
• displacement per atom

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

N. V. Novikov

N.V. Novikov is working as an Senior Researcher in the Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia. He specializes in the area of ion cross sections for loss and capture of one or several electrons in gaseous and solid targets and ion energy losses in various inelastic processes, etc. He has published more than 110 research articles in journals and conferences.

N. G. Chechenin

N.G. Chechenin is working as an Head of department in the Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia. He specializes in the area of composite materials based on oriented carbon nanotubes, giant magnetoresistance loops in spin valves, simulation of total ionizing dose effects, single event upset rate in radiation environments, etc. He has published more than 230 research articles in journals and conferences.

A. A. Shirokova

A.A. Shirokova is working as an Researcher in the Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia. She specializes in the area of composition and energy of nuclear reactions fragments, isometric cross-section ratios, etc. She has published more than 50 research articles in journals.