Measurement of the mass and charge of charged particles
AssigneeXerox Corporation
InventorsArmand P. Neukermans, Dale R. Ims
Life of this patent
Estimating the term…
Abstract
Disclosed is a method for the measurement of the mass and/or charge of a charged particle. The method involves injecting the particle into a sampling device made up of a tube comprising a Faraday cage with a region of a grounded conductive material on either end of it. The particle flows through the tube in a stream of gas and as it passes through the Faraday cage it induces a charge on the cage wall. By measuring the magnitude of the induced charge or its duration in the cage, the magnitude of the charge on the particle or the mass of the particle can be determined.
Claims8
A method of measuring the mass of a charged particle which comprises:
- a. providing a tubular member having a first region which comprises a grounded conductive material and a second region which is in the form of a Faraday cage, said first and second regions being separated by an insulator;
- b. introducing the charged particle into the first region of said tube while causing a stream of gas to flow through the tube in a direction away from the first region and toward the second region to and through the second region and induce a charge on the wall of the second region;
- c. measuring the time the particle spends in the second region by measuring the duration of the induced charge;
- and
- d. obtaining the mass of the charged particle by determining the mass of the particle as a function of the time it takes to pass through the second region by comparing the time the particle spends in the second region with the time particles of known mass spend in the region under similar conditions.
A method for measuring the charge of a charged particle which comprises:
- a. providing a tubular member having a first region of a grounded conductive material and a second region in the form of a Faraday cage, said first and second regions being separated by an insulator;
- b. introducing the charged particle into the first region of said tube while causing a stream of gas to flow through the tube in a direction away from the first region and toward the second region to thereby cause the particle to be carried from the first region to and through the second region and induce a charge on the wall of the second region;
- c. measuring the magnitude of the charge induced on the wall of the second region;
- and
- d. obtaining the magnitude of the charge of the charged particle by determining the magnitude of the charge induced on the wall of the second region by the use of a peak detector which measures the magnitude of the charge induced on the wall of the second region and feeds this data to a pulse light analyzer which has been calibrated by observing its response to a known charge.
Dependencies are inferred from the claim text.