Significance of time-of-flight ion energy spectrum on energy deposition into matter by high-intensity pulsed ion beam

Abstract

Energy deposition by high-intensity pulsed ion beam into a metal target has been studied with time-of-flight (TOF) of ions which can be related to the original ion kinetic energy E0 and the ion mass with $t_{\rm TOF} \propto 1/\sqrt{2E_{0}/m_{i}}$. It is found that the TOF effect has a profound influence on the kinetic energy distribution of implanted ions and subsequent energy deposition process into the target. The HIPIB of mixed H+ and C+ was extracted from a magnetically insulated ion diode at a peak accelerating voltage of 350 kV, leading to an ion current density of 300 A/cm2 at the target. The widespread ion energy spectrum remarkably varied in shape as arriving at the target surface, from the original Gaussian-like of 80-ns duration to a pulse form of a sharp front and a long tail extending to about 140-ns duration. Energy loss of the mixed ions into a Ti target was simulated utilizing a Monte Carlo method. The energy deposition generally showed a shallowing trend and could be divided into two phases proceeded with sequent arrivals of H+ and C+. Note that, the peak value of deposited energy profile appeared at the beginning of mixed ion irradiation phase, other than the phase of firstly arrived H+ with peak kinetic energy and peak ion current. This study indicated that TOF effect of ions greatly affects the HIPIB-matter interaction with a kinetic energy spectrum of impinging ions at the target, noticeably differing from that of original output of the ion source; consequently, the specific energy deposition phenomena of the widespread ion energy can be studied with the TOF correlation of ion energy and ion current, otherwise not obtainable in common cases assuming fixed ion energy distribution in accordance with the original source output.

Trends in heavy ion interaction with plasma

“…The motivations are mainly listed as follows: (1) the energy deposition process of heavy ions in ionized matter is one of the most important processes of heavy-ion-driven high energy density and ICF; (2) Plasma devices could be served as an important accelerator equipment to focus ion beams (socalled plasma lens), and or to strip ion beams (so-called plasma stripper). Beside these applications, such research is also an important fundamental topic to understand the atomic processes in plasma, such as the di-electron recombination process, the radiative electron capture process, and the effective charge in Coulomb interaction process, and so on (Sigmund, 1969;Hoffmann et al, 1990;Dietrich et al, 1992;Jacoby et al, 1995;Golubev et al, 2001;Sharkov, 2001;Bock et al, 2005;Logan et al, 2005;Tahir et al, 2005;Piriz et al, 2006;Zhao et al, 2009;Teske et al, 2010;Tahir et al, 2010;Pikuz et al, 2010;Xin et al, 2010;Zhang et al, 2011).…”

X-ray emission of Xe30+ ion beam impacting on Au target

“…The interaction laser beams or of multi-charged heavy ions with solid targets has drawn considerable interest, not only from fundamental physics, but also from many applications such as material modification, X-ray source devices, ion-wall interaction in magnet confinement fusion, heavy ion driven plasma, fusion energy research, and other areas as well Hoffmann et al, 2005Hoffmann et al, , 2007Tahir et al, 2005;Piriz et al, 2006;Logan et al, 2005;Sharkov, 2001;Golubev, 2001;Sigmund, 1969;Pikuz et al, 2010;Xin et al, 2010;Zavestovskaya, 2010). Accelerator physics and technology has made remarkable progress during recent years.…”