The Dresden EBIS-A is an electron beam ion source able to produce ions of high charge states of practically all elements of the periodic table. It delivers beams of protons, alpha-particles, various highly charged ion species, as well as molecular fragments.
The functional principle of the ion source is based on a cathode of high electron emissivity generating a strong electron beam which is magnetically compressed to achieve high electron beam densities. The operation principle of the ion source allows for generation of pulsed ion beams as well as DC beams (leaky mode).
Particle injection into the Dresden EBIS-A can be realized by different injection methods such as direct gas inlet, metal ion introduction via the gas inlet using volatile compounds (MIVoC), or by injection of low charged ions produced by Liquid Metal Ion Sources (LMIS) or other primary ion sources (charge breeding).
The length of the extracted ion pulses has a range from 20 ns up to 100 µs. The pulse shape can be varied from Gaussian up to flat-top shapes by an additional electronic system controlling the ramping of the trap voltages during ion extraction.
Next to its use as a source for ion extraction, the trapped ions interacting with the electron beam inside the machine are a useful source of x-rays observable through optional spectroscopic ports.
Figure 1 and Figure 2 represent two examples of extracted ion spectra from the Dresden EBIS-A. Figure 1 is an ion spectrum of the intermediate-weight element argon showing that up to fully ionized Ar18+ can be produced. The other spectrum, Figure 2, presents extracted gold charge states of up to Au60+. Furthermore, the following table gives an overview of ion currents which can be extracted from the source.
|Ion Species||Ions / s (DC)||Ions / pulse|
|H+ (fully ionized)||2 · 1010||1 · 108 at 100 Hz|
|H2+||2 · 1010|
|He2+ (fully ionized)||6 · 108|
|C4+ (He-like)||6 · 108 at 2 Hz|
|C6+ (fully ionized)||6 · 107 at 2 Hz|
|Ar+||2 · 109|
|Ar8+ (Ne-like)||2 · 108||1 · 107 at 10 Hz|
|Ar16+ (He-like)||7 · 106 at 1 Hz|
|Ar18+ (fully ionized)||1 · 105 at 1 Hz|
|Fe16+ (Ne-like)||3 · 106 at 17 Hz|
|Fe24+ (He-like)||6 · 105 at 0.3 Hz|
|Fe26+ (fully ionized)||1 · 105 at 0.3 Hz|
|Kr26+ (Ne-like)||2 · 106|
|Xe44+ (Ne-like)||3 · 105 at 0.2 Hz|
|Au51+ (Ni-like)||5 · 105 at 1.4 Hz|
|Au60+||1 · 104 at 0.4 Hz|
Please note: The ion output depends strongly on the ion source parameters. To achieve the highest possible ion output the source parameters need to be optimized for each ion species individually.
|max. electron current||200 mA|
|max. electron energy||20 keV|
|magnet system||bakeable NdFeB permanent magnets|
|magnetic induction on axis||600 mT|
|trap length||60 mm|
|beam emittance||< 10 mm mrad|
|ion pulse width||50 ns up to 100 µs|
|ionization factor||> 1e+22 e/cm²|
|dimensions (length x width x height)||ca. 640 mm x 400 mm x 605 mm|
|weight||125 kg (275 lbs) with magnets|
|cooling water||one circuit, 1.5 l / min at 3 bar|
|vacuum conditions||UHV, 1e-8 mbar and better|
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