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Notes: A MIVOC system as it has been applied to several electron cyclotron resonance ion sources has been used to load a room temperature electron beam ion trap with a selection of different metals. X-ray measurements have demonstrated the ability of this method to produce highly charged ions for a large number of elements in a simple way and at low costs, which is favored by the low consumption rate of the used substances and operation of the ion trap at room temperature. The analysis of x-ray spectra measured with a Si(Li) semiconductor detector which is based on atomic structure calculations indicate the production of Mn23+, Fe25+, Ge30+, and Sn44+ ions. © 2000 American Institute of Physics.

Notes: The injection of an additional strong focused electron beam from a special designed electron gun into a magnetic electron cyclotron resonance (ECR) confinement field is studied. The electron gun uses a cathode with a long lifetime and resistiveness providing high emission current densities with electron currents up to 50 mA and voltages up to 4 keV. A sequence of aluminum foils is used to investigate the trajectories of the electrons in the magnetic field without plasma. The high density electron beam passes through the foils, welds them, and prints its image into the foils. Details of this technique are described in Ref. 1. Using this technique we see that before the electrons enter the sextupole region the beam moves along the magnetic straight lines preserving its structure. Only a central beam passes through the sextupole region, thereby changing its form due to the interaction with radial components of the magnetic field. A new operation method at our 14.5 GHz ECR ion source is based on so-called reflection mode electrons (RMEs) analogous to a known electron beam ion source operation regime.2 The basic idea is that electrons, which traveling from the cathode in a strong axial field, meet an anticathode potential, are reflected from it, move back to the cathode, and will be reflected again and so on. It can be supposed that the electrons will make reflections up to the moment when the anode aperture of the gun is fulfilled and the electrons will be collected on the anode electrode. Investigations are performed extracting nitrogen ions using the RME beam. As a result we got a clear increase in the beam current of the extracted ions (e.g., at 10 mA electron injection an increase of the current of N5+ ions up to 400%) and a shift of the measured ion charge state distribution to higher mean ionization stages. Measured x-ray spectra from a neon loaded plasma show for the case of RME operation increasing energy shifts to the high energy side of the spectra, i.e., the mean ionization degree of the ions in the plasma increases. They also increase the intensity of the neon K x rays (more than 100% increase for RME injection of Ee=4 keV and Ie=10 mA) indicating that for the same operation parameters the mean density of energetic electrons rises at RME injection, i.e., there are more electrons with energies high enough to ionize K-shell electrons in neon. © 2000 American Institute of Physics.

Notes: A compact electron beam ion trap (WEBIT) working at room temperature without any cryogenic components is described and experimentally investigated. The trap design is based on permanent magnet technology. For the formation of the electron beam a Pierce electron gun equipped with a cathode of high emissivity is used. The ion trap is created by a compressed electron beam passing through a drift tube system consisting of three sections with corresponding electrical trap potentials. X-ray spectra measured with a Si(Li) semiconductor detector indicate the production of Kr34+, Xe44+, Ce48+, Ir64+, and Hg66+ ions. © 2000 American Institute of Physics.

Notes: Ion charge states of 3d metal ions in the electron beam of the Dresden electron beam ion trap (EBIT), a room-temperature EBIT, are determined by x-ray spectroscopy. It is shown that ions of highest charge states as bare nuclei and hydrogen- and helium-like ions can be produced with ion densities of about 105 cm−3 up to 108 cm−3 in the trap. The Dresden EBIT operates at a typical working gas pressure region of 10−8 mbar down to 10−10 mbar. Thus the influence of the realized working gas pressure on the derived ion charge state distribution is investigated by model calculations. © 2002 American Institute of Physics.

Notes: The Dresden electron-beam ion trap (EBIT) is a long-term stable room-temperature EBIT working without any cryogenic techniques. Spectroscopic investigations have shown that in the Dresden EBIT bare nuclei at least up to nickel can be produced as well as helium-like ions from elements such as krypton or germanium and neon-like ions from elements such as xenon or iridium. The output of quantum radiation from highly charged ions trapped in the Dresden EBIT is high enough that wavelength-dispersive spectroscopic investigations are possible. Up to now, two devices (Dresden EBIT I and Dresden EBIT II) have been built up. Results derived on Dresden EBIT II demonstrate that it is possible to produce the described apparatus in any number. Thus, it opens up a way also for small laboratories to employ highly charged ions in their investigations. © 2002 American Institute of Physics.

Notes: Abstract: Irq+ ( 41≤q≤64) ions with open-shell configurations have been produced in the electron beam of the room-temperature Dresden Electron Beam Ion Trap (Dresden EBIT) at electron excitation energies from 2 keV to 13 keV. X-ray emission from direct excitation processes and radiative capture in krypton-like to aluminium-like iridium ions is measured with an energy dispersive Si(Li) detector. The detected X-ray lines are analyzed and compared with results from multiconfigurational Dirac-Fock (MCDF) atomic structure calculations. This allows to determine dominant produced ion charge states at different electron energies. The analysis shows that at the realized working gas pressure of 5×10-9mbar for higher charged ions the maximum ion charge state is not preferently determined by the chosen electron beam energy needed for ionization of certain atomic substates, but by the balance between ionization and charge state reducing processes as charge exchange and radiative recombination. This behaviour is also discussed on the basis of model calculations for the resulting ion charge state distribution.