An ion detector includes a microchannel plate configured to generate secondary electrons upon reception of ions incident thereon and multiply and output the generated secondary electrons; a plurality of electron impact-type diodes configured to have effective regions narrower than an effective region of the microchannel plate on an electron incident surface facing the microchannel plate side, receive the incident secondary electrons output from the microchannel plate, and multiply and detect the incident secondary electrons; and a focus electrode configured to be disposed between the microchannel plate and the electron impact-type diodes and focus the secondary electrons toward the electron impact-type diode.

A method and apparatus for detection of charged particles in spectroscopy. Charged particles, received from an energy dispersive spectroscopic analyser as a charged particle beam, are accelerated towards a detector. The accelerated charged particles are received at an array of detecting pixels, the array of detecting pixels forming the detector. The charged particles arriving at the detector have a spread in the energy dispersive direction.

A high-voltage power supply system for a mass spectrometer comprises a ground-referenced power supply with a first transformer having a primary winding and a secondary winding, the primary winding is electrically coupled to a first source of AC power, and a floated bias voltage power supply with a second transformer having a primary winding and a secondary winding, the primary winding of the second transformer is electrically coupled to a second source of AC power. A return electrical path of the floated bias voltage power supply is electrically coupled to the ground-referenced power supply to bias an output voltage of the ground-referenced power supply. A floating shield is around the floating bias voltage power supply, and at least one resistive element is in the return electrical path of the floated bias voltage power supply to reduce noise coupled from the floated bias voltage power supply to the ground-referenced power supply.

The invention relates to a method for, in an ion guide (10), modulating a stream of ions according to a modulation function, wherein the stream of ions includes at least N different ion species, wherein N is at least 1. This ion guide (10) forms an ion guide path, wherein the ions of the stream of ions are conveyed along the ion guide path in a conveying direction to form the stream of ions. The ion guide (10) includes an ion gate (12) arranged at an ion gate position on the ion guide path, wherein the ion gate (12) is adapted to provide an open state for allowing the ions passing the ion gate position when being conveyed along the ion guide path and a closed state for preventing the ions from passing the ion gate position. The ion guide (10) further includes a first arrangement (13) of conveying electrodes (230) arranged along the ion guide path, the first arrangement (13) of conveying electrodes (230) extending over a first section of the ion guide path, wherein the first section of the ion guide path reaches from at least the ion gate position downstream to at least a transition position on the ion guide path, wherein the first arrangement (13) of conveying electrodes (230) is adapted for generating first travelling waves having a first travelling wave amplitude and travelling along the first section of the ion guide path at a first travelling wave velocity for conveying the ions along the first section of the ion guide path. Furthermore, the ion guide (10) includes a second arrangement (14) of conveying electrodes (240) arranged along the ion guide path, the second arrangement (14) of conveying electrodes (240) extending over a second section of the ion guide path, wherein the second section of the ion guide path reaches from the transition position downstream, wherein the second arrangement (14) of conveying electrodes (240) is adapted for generating second travelling waves having a second travelling wave amplitude and travelling along the second section of the ion guide path at a second travelling wave velocity for conveying the ions along the second section of the ion guide path. According to the method, the stream of ions is modulated with the ion gate (12) according to the modulation function and AC voltages are applied to the first arrangement (13) of conveying electrodes (230) for generating the first travelling waves and to the second arrangement (14) of conveying electrodes (240) for generating the second travelling waves for conveying the ions downstream of the ion gate (12<