CERN Accelerating science

Sketch of the hybrid single photon detector (image not to scale).

The resistive MM by discrete elements. (a) Sketch illustrating the principle by the exploded view of the PCB layers: the blue pad is the anode electrode of the MM; the red pad is embedded in the PCB and the signal is transferred from the blue to the red pad by capacitive coupling. (b) The principle is illustrated by the electrical scheme: the top elements of the capacitors are the pad forming the MM anode (blue pad in (a)), the bottom elements of the capacitors (red pad in (a)) are connected to the front-end electronics. (c) Picture of the MM anode PCB, front view. (d) Picture of the MM anode PCB, rear view, detail: the connectors serving 48 pads are grouped together; the signal connectors and the resistor arrays connectors can be seen.

Picture, taken during the detector construction, of two MM units arranged in a detector.

Picture, taken during the detector construction, of two THGEMs arranged in a detector. The 12 physical segments of each THGEM are visible.

Scheme of the voltage distribution to six THGEM segments of the top (bottom) face.

Spark rate versus beam intensity for the 16 sectors of the four chambers.