The time it takes the ion to travel from the sample to the detector depends on the mass number of the ion. Using this principle time-of-flight mass spectrometry detects incoming ions by measuring the time it takes the ion to travel from the ion sources to the detector. Time-of-flight mass spectrometers must have fast response without damped oscillations and must detect ions with high efficiency. MCP detectors meet these requirements due to their high ion sensitivity, subnanosecond response time, and compactness.
Main performance of the manufactured TOF detectors
| Detector type | SEM-7BK-1 TOF detector with a cone-shaped anode | SEM-7BP-1 TOF detector assembled on a printed circuit board |
|---|---|---|
| Gain | 1×107 | 1×107 |
| Single electron pulse height resolution, % | 130 – 140 | 130 – 140 |
| Dark count rate density, s-1cm-2 (max) | 3 | 3 |
| Pulse width (FWHM), ns | 0.85 – 1.0 | 0.75 – 0.85 |
| Pulse leading edge rise time, ns | 0.4 – 0.5 | 0.4 – 0.5 |