Components of scientific analytical equipment. More particularly, ion detectors of the type which incorporate electron multipliers and modifications thereto for extending the operational lifetime or otherwise improving performance. The ion detector may be embodied in the form of a particle detector having one or more electron emissive surfaces and/or an electron collector surface therein, the particle detector being configured such that in operation the environment about the electron emissive surface(s) and/or the electron collector surface is/are different to the environment immediately external to the detector.

The present invention relates to generally to components of scientific analytical equipment. More particularly, the invention relates to ion detectors of the type which incorporate electron multipliers and modifications thereto for extending the operational lifetime or otherwise improving performance. The invention may be embodied in the form of a particle detector having one or more electron emissive surfaces and/or an electron collector surface therein, the particle detector being configured such that in operation the environment about the electron emissive surface(s) and/or the electron collector surface is/are different to the environment immediately external to the detector.

The present invention relates to generally to components of scientific analytical equipment. More particularly, the invention relates to ion detectors of the type which incorporate electron multipliers and modifications thereto for extending the operational lifetime or otherwise improving performance. The invention may be embodied in the form of a particle detector having one or more electron emissive surfaces and/or an electron collector surface therein, the particle detector being configured such that in operation the environment about the electron emissive surface(s) and/or the electron collector surface is/are different to the environment immediately external to the detector.

Ion detectors of the type used in scientific instrumentation, such as mass spectrometers. More particularly, a self-contained particle detector includes an enclosure formed in part by a transmission mode secondary electron emissive element, the enclosure defining an internal environment and an external environment, wherein the transmission mode secondary electron emissive element has an externally facing surface and an internally facing surface and is configured such that impact of a particle on the externally facing surface causes emission of one or more secondary electrons from the internally facing surface.

Ion detectors of the type used in scientific instrumentation, such as mass spectrometers. More particularly, a self-contained particle detector includes an enclosure formed in part by a transmission mode secondary electron emissive element, the enclosure defining an internal environment and an external environment, wherein the transmission mode secondary electron emissive element has an externally facing surface and an internally facing surface and is configured such that impact of a particle on the externally facing surface causes emission of one or more secondary electrons from the internally facing surface.

Conversion dynodes (CDs) 31 and 32 are respectively provided for ion-ejection ports 21a and 22a facing each other across the central axis C of a linear ion trap (LIT) 2. A shield plate 34 having ion-passage openings 34a is provided between LIT and CDs. A voltage slightly lower than the voltage applied to CDs is applied to the shield plate. Ions ejected from LIT by resonant excitation are accelerated by an electric field between LIT and the shield plate, having their trajectories gradually curved, to eventually reach CDs through the ion-passage openings. Upon receiving the ions, CDs emit electrons. Some electrons may initially move toward the shielding plate, but will be repelled to and detected by an electron multiplier tube 33. CDs can be made of aluminum or similar inexpensive materials, which reduces the cost as well as eliminates the loss of the ions and improves detection sensitivity.

Conversion dynodes (CDs) 31 and 32 are respectively provided for ion-ejection ports 21a and 22a facing each other across the central axis C of a linear ion trap (LIT) 2. A shield plate 34 having ion-passage openings 34a is provided between LIT and CDs. A voltage slightly lower than the voltage applied to CDs is applied to the shield plate. Ions ejected from LIT by resonant excitation are accelerated by an electric field between LIT and the shield plate, having their trajectories gradually curved, to eventually reach CDs through the ion-passage openings. Upon receiving the ions, CDs emit electrons. Some electrons may initially move toward the shielding plate, but will be repelled to and detected by an electron multiplier tube 33. CDs can be made of aluminum or similar inexpensive materials, which reduces the cost as well as eliminates the loss of the ions and improves detection sensitivity.

An ion detector includes a first stage dynode configured to receive an ion beam and generate electrons, a photon source arranged to provide photons to the first stage dynode, the photons of sufficient energy to cause the first stage dynode to emit photoelectrons, an electron multiplier configured to receive the electrons or the photoelectrons from the first stage dynode and generate an output proportional to the number of electrons or photoelectrons, and a controller. The controller is configured to receive the output generated in response to the photoelectrons; calculate a gain curve of the detector based on the output; and set a voltage of the electron multiplier or the first stage dynode to achieve a target gain for the ion beam.

An ion detector includes a first stage dynode configured to receive an ion beam and generate electrons, a photon source arranged to provide photons to the first stage dynode, the photons of sufficient energy to cause the first stage dynode to emit photoelectrons, an electron multiplier configured to receive the electrons or the photoelectrons from the first stage dynode and generate an output proportional to the number of electrons or photoelectrons, and a controller. The controller is configured to receive the output generated in response to the photoelectrons; calculate a gain curve of the detector based on the output; and set a voltage of the electron multiplier or the first stage dynode to achieve a target gain for the ion beam.

An ion detector includes a first stage dynode configured to receive an ion beam and generate electrons, a photon source arranged to provide photons to the first stage dynode, the photons of sufficient energy to cause the first stage dynode to emit photoelectrons, an electron multiplier configured to receive the electrons or the photoelectrons from the first stage dynode and generate an output proportional to the number of electrons or photoelectrons, and a controller. The controller is configured to receive the output generated in response to the photoelectrons; calculate a gain curve of the detector based on the output; and set a voltage of the electron multiplier or the first stage dynode to achieve a target gain for the ion beam.