Use of optical receiver circuit design techniques in a transimpedance preamplifier for high performance mass spectrometry

A transimpedance amplifier is a common preamplifier solution for a capacitive charge/current detector, and is widely used in optical communication. The concept is ideal for a mass spectrometry (MS) system, in particular the Fourier-Transform Ion Cyclotron Resonance (FT-ICR) MS, the MS with the highest resolution and the highest mass accuracy. To push the performance toward a prospective goal of single-ion detection, a novel T Feedback Network was designed and tested in two transimpedance preamplifiers. At a given transimpedance, the T Feedback Network can reduce the feedback resistance by ~100 fold, thus reducing the thermal noise voltage due to this resistor by ~10 fold, whilst preserving more bandwidth. Each of the elements in the T Feedback Network reported here can be any complex impedance, which allows adaptation of this novel feedback system to other frequency and transimpedance characteristics for applications not only in other mass spectrometers, such as the Orbitrap, time-of-flight, and ion trap systems, but also in other charge/current detecting systems such as optical communication, spectroscopy/microscopy systems, or charge-coupled devices (CCDs), etc.