Peculiar Behavior of Si Cluster Ions in Solid Al

TL;DR

This paper reports a unique behavior of silicon cluster ions in solid aluminum, where rear ions experience reduced deceleration due to wakefield interactions, causing them to catch up with forward ions at high speeds.

Contribution

It reveals a novel wakefield interaction mechanism in Si clusters moving through solid aluminum, highlighting unexpected ion dynamics.

Findings

Rear Si ions experience reduced deceleration.

Rear Si ions can overtake forward ions.

Wakefield effects significantly influence ion motion.

Abstract

A peculiar ion behavior is found in a Si cluster, moving with a speed of ~0.22c (c: speed of light) in a solid Al plasma: the Si ion, moving behind the forward moving Si ion closely in a several angstrom distance in the cluster, feels the wake field generated by the forward Si. The interaction potential on the rear Si may balance the deceleration backward force by itself with the acceleration forward force by the forward Si in the longitudinal moving direction. The forward Si would be decelerated normally. However, the deceleration of the rear Si, moving behind closely, would be reduced significantly, and the rear Si may catch up and overtake the forward moving Si in the cluster during the Si cluster interaction with the high-density Al plasma.