E Nojikawa

An overview of the Tokyo electron beam ion trap

A new Electron Beam Ion Trap has recently been completed in Tokyo. The general features of the apparatus, design and operation are given. This paper also surveys the planned and ongoing experimental program.

The present status of the Tokyo electron beam ion trap

Recent progress of the Tokyo electron beam ion trap (Tokyo-EBIT) project is described. The Tokyo-EBIT is of an original design and construction with several features different from other EBITs in the world. The maximum energy and current of the electron beam are designed to be 340 keV and 300 mA with a magnetic field of 4.5 T. The ongoing and planned physics experiments are described and the results for the initial stage of operation of the Tokyo-EBIT are given.

High-resolution x-ray spectromicroscopy with the Tokyo electron beam ion trap

A high-resolution x-ray spectrometer with a spherically bent quartz crystal and an x-ray sensitive charge coupled device (CCD) have been applied to the observation of highly charged ions produced and trapped in the Tokyo electron beam ion trap (EBIT). The spectrometer made it possible to measure the spatial distribution and wavelength of the radiation at the same time. A simple, but lower energy resolution method was also used, by taking advantage of the intrinsic energy resolution of the CCD. The possibility to apply such techniques to diagnostics of an EBIT is discussed.

Detector systems for use with an electron beam ion trap

This article describes two data systems, primarily for use with x-ray detectors in conjunction with an Electron Beam Ion Trap (EBIT). Both systems are designed from a common viewpoint that useful information should be presented in real-time whilst as much information as possible should be stored for subsequent off-line analysis.

X-ray spectroscopy at the Tokyo electron beam ion trap

We have observed x-ray signals from He-like Ba and Ne-like W ions trapped in an Electron Beam Ion Trap (EBIT) at an electron beam energy of 19.9 keV. In the spectra, several transitions in Ne-like Ba and W ions and radiative recombination processes (RR) to n ≥ 2 levels were observed. These atoms were seeded by the cathode and were ionized in the trap region by electron impact. We have observed dielectronic recombination processes (DR) in Ne-like Xe.

Extraction of trapped ions from the Tokyo electron beam ion trap

A beam line for transporting highly charged ions extracted from the Tokyo Electron Beam Ion Trap is being constructed in order to study ion-surface interactions and to inject into secondary ion traps for atomic physics experiments. A basic idea for the design and a computer modeling for the extraction system are described. The results of a test experiment to detect the total number of ions extracted from the EBIT are also reported.

Control system of the Tokyo electron beam ion trap

We introduce the control and power supply system of the Electron Beam Ion Trap at the University of Electro-Communications, Tokyo.

A new method for nondestructively monitoring the position of a charged particle beam in real time

The design and construction of a simple new device for nondestructively monitoring the position of an electron beam is described. By modulating a small portion of the electron-beam current, changes in the amounts of charge induced on the monitor electrodes are detected as currents. These currents are related to the location of the “center of charge” of the electron beam. Calculations and experimental results which illustrate the performance of the device are reported. This device is primarily intended for use in electron-beam ion sources and traps, although it could be applied to other situations where the beam current can be modulated.