| Schematic of the electron-impact ion source used in our experiment. The electrons were liberated from a copper cathode by a laser beam (photo-electric effect) in a cold environment. : Parameters of the photo-cathode experiment. |
| (left) Dependence of anode drain current and \textsuperscript{84}Kr ion current on the anode voltage for different settings of the target magnet at a laser power and center wavelength of \SI{8(1)}{\milli\watt} and \SI{215}{\nano\meter}, respectively. Connecting lines were added to guide the eye. (right) Time structure of electron, laser and ion pulses. A photo-diode was used to assess the laser time structure. Laser and electron pulse shape were estimated by measurement of the voltage drop over a \SI{50}{\ohm} resistor. The curve shapes were redrawn from an oscilloscope photograph. The offset between electron and laser pulses was not measured. The ion time structure was obtained with a MagneToF detector and is given relative to the laser pulse. |
| Dependence of anode drain current and \textsuperscript{84}Kr ion current on laser power for different anode voltages and magnet currents. The electron current measurement does not differentiate between electrons impinging on the grid and electrons entering the anode volume. The ion currents for \SI{500}{\volt} and \SI{200}{\volt} at \SI{0}{\ampere} magnet current were indistinguishable, and only the data for \SI{500}{\volt} are shown. |
| Dependence of anode drain current and \textsuperscript{84}Kr ion current on laser power for different anode voltages and magnet currents. The electron current measurement does not differentiate between electrons impinging on the grid and electrons entering the anode volume. The ion currents for \SI{500}{\volt} and \SI{200}{\volt} at \SI{0}{\ampere} magnet current were indistinguishable, and only the data for \SI{500}{\volt} are shown. |
| Mass scan obtained with the photo-cathode ion source obtained at an anode voltage of \SI{200}{\volt} in comparison to a mass scan obtained with a standard VADIS (VD7, thermionic electron emission) operated at \SI{120}{\volt}. Both sources were supplied with krypton. In addition, the standard VADIS was supplied with carbon monoxide gas and residual xenon was present from previous tests. The scales have been adjusted to show a similar level of sensitivity. Negative ion currents for the photo-cathode source have been trimmed to \SI{1e-14}{\ampere}. |
| : Figure caption for first of two sided figures. : Caption not extractedFigure caption for a narrow figure where the caption is put at the side of the figure. |