- Maximum (measured) count rate detectable is 16.8 Mcps (standard CEMs: 5.6 Mcps) per channel.
- Linearity and non-extended dead time behavior up to 10 Mcps true count rate. Up to these count rates no significant deviation from linearity could be observed with the PHOIBOS detection system (CEMs and PCU 300 detection electronics).
The CEM 5 or 9 channeltron detector for the PHOIBOS analyzer is suitable for extremely high count rates without serious degradation.
The PHOIBOS analyzer is equipped with either one, five, or nine single channel electron multipliers (SCD, MCD-5 or MCD-9). These standard detector systems are based on the extended range CEM. This device is a specially formed and treated glass tube which has the effect of multiplying a single electron at the input to a pulse of around 108 electrons at the output. Because of their low resistance, the extended range CEMs are suitable for extremely high count rates. A voltage between 2.5 - 3.5 kV across the cone and the tail-end initiates the electron multiplication. Electron multiplication is produced by the emissive layer along the inner surface of the channel. The gain is governed by the detector voltage and the condition of the emissive layer.