A mass spectrometer that includes an MCP detector selects and analyzes a calibrant compound that has a first isotope and a second isotope with a known abundance ratio. The mass spectrometer measures the intensity of the first isotope that produces multiple-ion strikes at the MCP detector and the intensity of the second isotope that produces single-ion strikes at the MCP detector while the bias voltage of the MCP detector is stepped through a sequence of one or more different voltages. At each step, the ratio of the measured intensities is compared to the known abundance ratio for the two isotopes. When the measured ratio is within a predetermined threshold of the known abundance ratio, an optimum voltage for the MCP detector is calculated using one or more measured ratios calculated for voltages of the sequence of voltages.

A mass spectrometer that includes an MCP detector selects and analyzes a calibrant compound that has a first isotope and a second isotope with a known abundance ratio. The mass spectrometer measures the intensity of the first isotope that produces multiple-ion strikes at the MCP detector and the intensity of the second isotope that produces single-ion strikes at the MCP detector while the bias voltage of the MCP detector is stepped through a sequence of one or more different voltages. At each step, the ratio of the measured intensities is compared to the known abundance ratio for the two isotopes. When the measured ratio is within a predetermined threshold of the known abundance ratio, an optimum voltage for the MCP detector is calculated using one or more measured ratios calculated for voltages of the sequence of voltages.

The present invention relates to electron multipliers as used in ion detection apparatus such as mass spectrometers. The multiplier comprises a voltage stabilizing component or system, and is configured to reduce a negative effect of voltage fluctuations within and/or electromagnetic radiation emitted by the voltage stabilizing component or system during operation on an output signal of the electron multiplier. The multiplier may be configured so as to decouple the voltage fluctuations within and/or the electromagnetic radiation emitted by the voltage stabilizing component or system from its output signal.

The present invention relates to electron multipliers as used in ion detection apparatus such as mass spectrometers. The multiplier comprises a voltage stabilizing component or system, and is configured to reduce a negative effect of voltage fluctuations within and/or electromagnetic radiation emitted by the voltage stabilizing component or system during operation on an output signal of the electron multiplier. The multiplier may be configured so as to decouple the voltage fluctuations within and/or the electromagnetic radiation emitted by the voltage stabilizing component or system from its output signal.

The invention relates to a class of RF Timer based electron and photon vacuum recorders, particularly to single electron and photon sensitive recorders with picosecond time resolution. The RF Timer features a vacuum container housing an electron gun with a photocathode, an electron-transparent accelerating electrode, and an electrostatic lens for electron focusing. A deflecting electrode guides photoelectrons in a circular and spiral path, and a position-sensitive detector system records their positions with nanosecond electronic signals processed in real-time. The objective is to achieve single electron and photon recording with a time resolution of 10 picoseconds or better at speeds reaching several MHz and stability better than 0.2 picoseconds/h.

The invention relates to a class of RF Timer based electron and photon vacuum recorders, particularly to single electron and photon sensitive recorders with picosecond time resolution. The RF Timer features a vacuum container housing an electron gun with a photocathode, an electron-transparent accelerating electrode, and an electrostatic lens for electron focusing. A deflecting electrode guides photoelectrons in a circular and spiral path, and a position-sensitive detector system records their positions with nanosecond electronic signals processed in real-time. The objective is to achieve single electron and photon recording with a time resolution of 10 picoseconds or better at speeds reaching several MHz and stability better than 0.2 picoseconds/h.

An ion detector includes: a first electron multiplier for detecting first ions having a first polarity; a second electron multiplier for detecting second ions having a second polarity different from the first polarity; a first anode for capturing electrons emitted from the first electron multiplier; a second anode for capturing electrons emitted from the second electron multiplier; and a switching circuit including a first input terminal electrically connected to the first anode, a second input terminal electrically connected to the second anode, and an output terminal, the switching circuit selectively connecting one of the first input terminal and the second input terminal to the output terminal.

An ion detector includes: a first electron multiplier for detecting first ions having a first polarity; a second electron multiplier for detecting second ions having a second polarity different from the first polarity; a first anode for capturing electrons emitted from the first electron multiplier; a second anode for capturing electrons emitted from the second electron multiplier; and a switching circuit including a first input terminal electrically connected to the first anode, a second input terminal electrically connected to the second anode, and an output terminal, the switching circuit selectively connecting one of the first input terminal and the second input terminal to the output terminal.

In a photoelectric conversion device, the potential control unit controls electric potentials applied to the meta-surface. The meta-surface includes a plurality of patterns which are space away from each other. The plurality of patterns include an antenna portion and at least one bias portion. The antenna portion extends in a predetermined direction and emits the electron in response to incidence of the electromagnetic wave. The potential control unit switches a first state and a second state by controlling the electric potentials applied to the plurality of patterns. In the first state, a component of an electric field from the bias portion toward the antenna portion in a predetermined direction is positive. In the second state, a component of an electric field from the bias portion toward the antenna portion in the predetermined direction is negative.

In a photoelectric conversion device, the potential control unit controls electric potentials applied to the meta-surface. The meta-surface includes a plurality of patterns which are space away from each other. The plurality of patterns include an antenna portion and at least one bias portion. The antenna portion extends in a predetermined direction and emits the electron in response to incidence of the electromagnetic wave. The potential control unit switches a first state and a second state by controlling the electric potentials applied to the plurality of patterns. In the first state, a component of an electric field from the bias portion toward the antenna portion in a predetermined direction is positive. In the second state, a component of an electric field from the bias portion toward the antenna portion in the predetermined direction is negative.