Scattering cell employing electrostatic means for supporting a particle

Claim 2

A scattering cell for receiving charged particles for intersection with a beam of light and including a levitator for suspending charged particles within the scattering celL, including a pair of parallel plate electrodes and an insulating wall member forming an included space and including an entrance area for a beam of light, a third pin electrode extending through and insulated from one of the parallel plate electrodes, first means for introducing charged particles into the enclosed space, second means for providing a beam of light through the entrance area of the wall member and past a position adjacent to the third pin electrode, third means for supplying an electrical potential between the pair of parallel plate electrodes to produce a first electric field in a first direction, and fourth means for supplying an electrical potential between the pin electrode and the pair of parallel plate electrodes to produce a second electric field in a second direction opposite to the direction of the first electric field to form a composite field between the pair of plate electrodes to balance forces operating on any charged particles located between the pair of plate electrodes and to produce a third radial electric field to pull any charged particles located between the pair of plate electrodes toward a position adjacent the pin electrode.

Claim 3

The scattering cell of claim 1 wherein the first means for introducing charged particles into the enclosed space includes a nebulizer.

Claim 4

The scattering cell of claim 1 additionally including a bellows assembly for pneumatically controlling the movement of the charged particles in the enclosed space.

Claim 5

The scattering cell of claim 1 additionally including controls for adjusting the magnitude and polarity of the electrical potentials applied to the electrodes.

Claim 6

The levitator of claim 1 additionally including means detecting the position of a charged particle located between the electrodes and for providing an error signal representing the difference between the actual position of the charged particle and a desired position for the charged particle and for adjusting the potential applied to the electrodes to adjust the position of the charged particle.

Claim 7

The levitator of claim 1 wherein the enclosed space is pneumatically isolated from any external changes in pressure.

Claim 8

A scattering cell for receiving microparticles and including a levitator for suspending a microparticle in a fixed location to be intercepted by a beam of light, including an electrode structure including a pair of electrodes spaced from each other and supplied with an electrical potential between the pair of electrodes to produce a first electric field on a microparticle located between the pair of electrodes and including a third pin electrode extending through and insulated from one of the first pair of electrodes and supplied with an electrical potential between the third electrode and the pair of electrodes to produce a second electric field to oppose the first electrical field on the microparticle located between the pair of electrodes to balance the microparticle and to produce a radial electric field to pull the microparticle to a position adjacent to and on the axis of the third pin electrode, first means for introducing microparticles between the pair of electrodes, and second means for producing a beam of light to pass through the position adjacent to the third pin electrode to intercept microparticles at such position.

Claim 9

A scattering cell for receiving microparticles and including a levitator for suspending a microparticle in a fixed location to be intercepted by a beam of light, including an electrode structure including a pair of electrodes spaced from each other and supplied with an electrical potential between the pair of electrodes to produce a first electric field on a microparticle located between the pair of electrodes and including a third pin electrode extending through and insulated from one of the first pair of electrodes and supplied with an electrical potential between the third electrode and the pair of electrodes to produce a second electric field to oppose the first electrical field on the microparticle located between the pair of electrodes to balance the microparticle and to produce a radial electric field to pull the microparticle to a position adjacent to and on the axis of the third pin electrode, first means for introducing microparticles between the pair of electrodes, and second means for producing a beam of light to pass through the position adjacent to the third pin electrode to intercept microparticles at such position.

Claim 10

The scattering cell of claim 7 wherein the first means for introducing microparticles between the pair of electrodes includes a nebulizer.

Claim 11

The scattering cell of claim 7 additionally including a bellows assembly for controlling the movement of the microparticles between the pair of electrodes.

Claim 12

The scattering cell of claim 7 additionally including controls for adjusting the magnitude and polarity of the electrical potentials applied to the electrodes.

Claim 13

The levitator of claim 7 additionally including means detecting the position of a microparticle located between the pair of electrodes and for providing an error signal representing the difference between the actual position of the microparticle and a desired position for the microparticle and for adjusting the potential applied to the electrodes to adjust the position of the microparticle.

Claim 14

The levitator of claim 7 wherein the electrodes structure forms an enclosed space and wherein the enclosed space is pneumatically isolated from any changes in external pressure.

Claim 15

A scattering cell for receiving charged particles for intersection with a beam of light and including a levitator for suspending charged particles within the scattering cell, including a pair of parallel plate electrodes and an insulating wall member forming an included space and including an entrance area for a beam of light, a detection area for observing scattered light at different angular positions relative to the charged particles, and a beveled port for observing a portion of the scattered light, a third pin electrode extending through and insulated from one of the pairs of parallel plate electrodes, first means for introducing charged particles into the enclosed space, second means for providing a beam of light through the entrance area of the wall member and past a position adjacent to the third pin electrode, third means for supplying an electrical potential between the pair of parallel plate electrodes to produce a first electric field in a first direction, fourth means for supplying an electrical potential between the pin electrode and the pair of parallel plate electrodes to produce a second electric field in a second direction opposite to the direction of the first electric field to form a composite field between the pair of plate electrodes to balance forces operating on any charged particles located between the pair of plate electrodes and to produce a third radial electric field to pull any charged particles located between the pair of plate electrodes toward a position adjacent the pin electrode, and fifth means for detecting the portion of the scattered light passing through the beveled port and for providing an error signal representing the difference between the actual position of the charged particle and a desired position for the charged particle and for adjusting the potential applied to the electrodes to adjust the position of the charged particle.

Claim 16

A scattering cell for receiving charged particles for intersection with a beam of light and including a levitator for suspending charged particles within the scattering cell, including a pair of parallel plate electrodes and an insulating wall member forming an included space and including an entrance area for a beam of light, a detection area for observing scattered light at different angular positions relative to the charged particles, and a beveled port for observing a portion of the scattered light, a third pin electrode extending through and insulated from one of the pairs of parallel plate electrodes, first means for introducing charged particles into the enclosed space, second means for providing a beam of light through the entrance area of the wall member and past a position adjacent to the third pin electrode, third means for supplying an electrical potential between the pair of parallel plate electrodes to produce a first electric field in a first direction, fourth means for supplying an electrical potential between the pin electrode and the pair of parallel plate electrodes to produce a second electric field in a second direction opposite to the direction of the first electric field to form a composite field between the pair of plate electrodes to balance forces operating on any charged particles located between the pair of plate electrodes and to produce a third radial electric field to pull any charged particles located between the pair of plate electrodes toward a position adjacent the pin electrode, and fifth means for detecting the portion of the scattered light passing through the beveled port and for providing an error signal representing the difference between the actual position of the charged particle and a desired position for the charged particle and for adjusting the potential applied to the electrodes to adjust the position of the charged particle.

Claim 17

The scattering cell of claim 13 wherein the fifth means includes a beam splitter for directing the scattered light to a pair of light detecting devices and with the difference between the output from the light detecting devices providing the error signal.