A Thomson parabola ion imaging spectrometer designed to probe relativistic intensity ionization dynamics of nanoclusters

Abstract

Conventional techniques of probing ionization dynamics at relativistic intensities for extended target systems such as clusters are difficult both due to problems of achieving good charge resolution and signal integration over the focal volume. Simultaneous measurement of arrival time, necessary for these systems, has normally involved complicated methods. We designed and developed a Thomson parabola imaging spectrometer that overcomes these problems. Intensity sampling method evolved in this report is proved to be mandatory for probing ionization dynamics of clusters at relativistic intensities. We use this method to measure charge resolved kinetic energy spectra of argon nanoclusters at intensities of 4 × 10(18) W cm(-2).

Anisotropic negative-ion emission from cluster nanoplasmas

“…The experimental system used in these measurements has been described in detail in some of our recent papers [17,19]. A schematic of the apparatus is given in Fig.…”

“…Ion energies are measured with a Thomson parabola imaging spectrometer (TPS) [17] that samples the ions through a pair of movable slits followed by a 250-μm aperture. A chevron-type microchannel plate (MCP) detector coupled to a phosphor screen anode is used to obtain the ion images.…”

“…It was found that while the ion energies change very little, the ion charge states, as observed in Thompson parabola spectrometry [17], are reduced to an anomalously low value [12]. The unusually large charge-transfer rate that occurs in the transit of the supersonic jet could not be explained by the normal charge-transfer reactions or the electron recombination processes.…”

Decrypting the charge-resolved kinetic-energy spectrum in the Coulomb explosion of argon clusters

“…The experimental system for the cluster generation and characterization and TOF measurements is described in detail elsewhere [9,13,14]. Th inset of Fig.…”

“…Our recent success in developing a Thomson parabola spectrometer (TPS) [9] for clusters, leads to high-accuracy measurements that can be compared to simulations. In this paper we present charge-resolved kinetic-energy spectra (CRKES) of all the ions emitted when Ar n (n 36 000) is exposed to 7×10 15 W cm −2 .…”