A low-energy compact Shanghai-Wuhan electron beam ion trap for extraction of highly charged ions

TL;DR

This paper introduces a compact, low-energy superconducting electron beam ion trap (SW-EBIT) designed for efficient extraction and analysis of highly charged ions, demonstrating its capabilities with tungsten ions and charge-state measurements.

Contribution

The development of a low-energy, superconducting, compact EBIT with integrated ion extraction and charge-state analysis for highly charged ions.

Findings

Produced and analyzed tungsten ions below charge state 15

Measured charge-state distributions and spectra of tungsten ions

Preliminary identification of spectral lines from specific tungsten charge states

Abstract

A low-energy, compact and superconducting electron beam ion trap (the Shanghai-Wuhan EBIT or SW-EBIT) for extraction of highly charged ions is presented. The magnetic field in the central drift tube of the SW-EBIT is approximately 0.21 T produced by a pair of high-temperature superconducting coils. The electron-beam energy of the SW-EBIT is in the range of 30-4000 eV, and the maximum electron-beam current is up to 9 mA. Acting as a source of highly charged ions, the ion-beam optics for extraction is integrated, including an ion extractor and an einzel lens. A Wien filter is then used to measure the charge-state distribution of the extracted ions. In this work, the tungsten ions below the charge state of 15 have been produced, extracted, and analyzed. The charge-state distributions and spectra in the range of 530-580 nm of tungsten ions have been measured simultaneously with the electron-beam energy of 279 eV and 300 eV, which preliminarily indicates that the 549.9 nm line comes from $W^{14+}$.