Signal detection mechanism from electron multiplier
US4335304A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1980 |
| Grant date | Jun 15, 1982 |
| Priority date | — |
| Expiry date | Jul 31, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electron multiplier, including an excitation means and collector, disposed in a high vacuum chamber and adapted to be coupled at its input to a charged particle analyzer is coupled through the vacuum chamber wall by a plurality of electrical feedthrough devices such that the excitation means is coupled to a high voltage power supply disposed outside the high vacuum chamber and the collector is coupled simultaneously through a capacitance coupling means and a resistance coupling means, both disposed within the high vacuum chamber, to an amplifier-discriminator and floating operational amplifier, respectively, both disposed outside the high vacuum chamber. The impedance offered by the capacitance coupling means is substantially lower than that offered by the resistance coupling to 10 nanosecond current pulses originating from single electron events. In the electron counting mode of operation the pulse signal from the amplifier-discriminator provides a measure of the input electron flux, but when the pulse count rate becomes extremely high, signal distortion due to pulse overlap occurs and a voltage-to-frequency converter driven by the operational amplifier means and an input-to-ou…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.