Schematic of the top view of the DPP source. Two rotating disk electrodes are covered with liquid Sn. First, a negative voltage is applied to the cathode followed by a laser pulse evaporating the liquid Sn in between the electrodes and initiating the discharge.
The gating pulse for time delay is shown together with the laser pulse and the time derivative of the discharge current . The pinch is taken as zero on the time scale.
The time-resolved pinhole image is recorded simultaneously with the FC signal. The distance of the detectors to the discharge plasma is chosen to be equal to 88 cm. For the MCP detector an aperture of 0.25 mm and for the FC an 8 mm aperture are placed. An optional magnetic field can be applied perpendicular to the path of the ion beam.
(a) The CCD images for different time delays between the discharge and the gating pulse. The position of the electrodes is marked by dotted lines. (b) Oscilloscope pictures of the FC signal measured simultaneously with the gating MCP pulse from the images of (a). (c) CCD images with a magnetic field of 35 mT applied perpendicular to the particles’ trajectory. From the downwards shift of the spot it can be concluded that ions are being captured with the MCP.
A schematic presentation of the model used to calculate the deflection at the MCP position at a distance behind a perpendicular applied magnetic field . A positive ion with speed entering the magnetic field of length will exit the field under angle .
The mass-to-charge ratio calculated with Eq. (2) as a function of the lateral deflection distance from the bright spots in Fig. 4(c).
Time-resolved pinhole images of the high-energy ion beam emitted by single discharge pulses. The spots are the result of the collection of Sn ions with TOF equal to during a time interval of 200 ns. These ions have kinetic energies of 45 keV and may originate from the cathode region (f), the middle of the discharge gap [(c), (g), and (i)], as well as the anode region [(a), (b), (d), and (e)].
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