Speaker
Description
Summary
10 and 25 micron pores Micro-Channel Plates devices (MCP) have been connected to 50 Ohms transmission lines printed circuit cards and tested using a 408nm laser focused on the window entrance of the MCP. The numbered of amplified photo-electrons is evaluateded using a single photo-electron sensitive photo-multiplier. Once the velocity along the 10cm-long transmission line is determined, the position along the line is derived from the difference in delays between the two ends of the card. Since the two signals originate from the same pulse at the output of the MCP, their shapes are strongly correlated. Waveform analysis using least square fits to a known template waveform allow extracting the time of arrival of the
pulse at the two ends of the line. The differences of these times show a spread of a few picoseconds, depending mainly on the signal to noise ratio, that depends in turn upon the number of incident photo-electrons and the gain of the MCP set by the high voltage applied to the MCP pores.
Results are presented for 18, 50, and 158 Photoelectrons and high voltages values corresponding to signals with amplitudes between 10 and 500 mV. These results are
in good agreement with both simulations, and timing measurements achieved with off-the-shelf Constant Fraction Discriminators and Time to Amplitude converters.
Results obtained from tests at the Advanced Photon Source at the Argonne National Laboratories where the transmission lines are sitting in the vacuum as close as possible to the MCP output, are also presented and compared to detailed simulations. From these results, it is possible to optimize a design where the transmission lines are integrated to the MCP device itself. This design is also briefly discus
