Apparatus and methods for detecting, separating, concentrating and measuring electronegative trace vapors

Claim 2

Apparatus for detecting electronegative components of a gas, comprising an electron attachment drift chamber for receiving said gas and having a source of thermal electrons for forMing negative ions from the molecules of said components, means for maintaining the pressure in said chamber at substantially atmospheric pressure, means for collimating said negative ions to form a beam, means for accelerating said beam, said collimating and said accelerating means comprising a series of electrodes with apertures for passing said ion beam, mass spectrometer means for receiving said beam after passage through said electrodes and for passing ions of predetermined mass, and detecting means including means for producing electrons in response to said ions of predetermined mass and means for multiplying said electrons to produce an output.

Claim 3

The apparatus of claim 1, said collimating means being located in a chamber evacuated with respect to said drift chamber, said chambers being connected by an apertured interface.

Claim 4

The apparatus of claim 1, further comprising means for concentrating said components in a sample of said gas and supplying the concentrated sample to said drift chamber.

Claim 5

The apparatus of claim 1, further comprising means for providing a sample of said gas to said drift chamber in proportion to a flow of said gas, means for determining the flow rate of said gas, and means for modifying said output in accordance with said flow rate to produce a readout of the concentration of said components in said gas.

Claim 6

The apparatus of claim 1, sad pressure maintaining means comprising means opening said chamber to the atmosphere.

Claim 7

Apparatus for separating electronegative components from a gas, comprising an envelope, means for introducing said gas into said envelope, means for producing a pulse of low energy electrons at a first region of said envelope to form negative ions of said components at said first region, means applying a drift field to said ions, only after their formation, for causing said ions to drift from said first region toward a second region of said envelope, ion gate means between said regions,means for opening said gate means for a predetermined interval during the application of said drift field to pass ions of predetermined mobility to said second region, means for producing an output in response to the ions at said second region, means for maintaining substantially atmospheric pressure in said envelope in said first region before said gate means, and means located between said gate means and said output means for focusing and accelerating the ions passed by said gate means, said accelerating means comprising a series of electrodes defining successive chambers in said envelope coupled by apertures in said electrodes, said successive chambers having means for forming successively higher vacuums therein.

Claim 8

Apparatus for separating electronegative components from a gas, comprising an envelope, means for introducing said gas into said envelope, means for producing a pulse of low energy electrons at a first region of said envelope to form negative ions of said components at said first region, means applying a drift field to said ions, only after their formation, for causing said ions to drift from said first region toward a second region of said envelope, ion gate means between said regions,means for opening said gate means for a predetermined interval during the application of said drift field to pass ions of predetermined mobility to said second region, means for producing an output in response to the ions at said second region, means for maintaining substantially atmospheric pressure in said envelope in said first region before said gate means, and means located between said gate means and said output means for focusing and accelerating the ions passed by said gate means, said accelerating means comprising a series of electrodes defining successive chambers in said envelope coupled by apertures in said electrodes, said successive chambers having means for forming successively higher vacuums therein.

Claim 11

The method of claim 7, wherein the production of said output comprises forming said last-mentioned ions into a beam and producing an output signal in response to said beam.

Claim 12

The method of claim 7, further comprising varying the time at which opening of said gate is commenced in order to pass ions of different mobility.

Claim 13

Apparatus for separating electronegative components from a gas, comprising an envelope, means for introducing said gas into said envelope, means for producing a pulse of low energy electrons at a first region of said envelope to form Negative ions from said components at said first region, means for maintaining the pressure in said envelope at substantially atmospheric pressure, means applying a drift field to said ions, only after their formation, for causing said ions to drift from said first region toward a second region of said envelope, ion gate means between said regions, and means for opening said gate means for a predetermined interval during the application of said drift field to pass ions of predetermined mobility to said second region.

Claim 14

Apparatus for separating electronegative components from a gas, comprising an envelope, means for introducing said gas into said envelope, means for producing a pulse of low energy electrons at a first region of said envelope to form Negative ions from said components at said first region, means for maintaining the pressure in said envelope at substantially atmospheric pressure, means applying a drift field to said ions, only after their formation, for causing said ions to drift from said first region toward a second region of said envelope, ion gate means between said regions, and means for opening said gate means for a predetermined interval during the application of said drift field to pass ions of predetermined mobility to said second region.

Claim 15

The apparatus of claim 10, said gate means comprising a pair of interdigitated substantially coplanar grids having adjacent elements normally maintained at equal and opposite potential with respect to a reference potential, and said means for opening said gate means comprising means for placing said grids substantially at said reference potential.

Claim 16

The apparatus of claim 10, further comprising means for varying the time between the opening of said gate means and the production of said ions.

Claim 17

The apparatus of claim 10, further comprising means for producing an output in response to the ions at said second region.

Claim 18

The apparatus of claim 13, further comprising means located between said gate means and said output means for focusing and accelerating the ions passed by said gate means.

Claim 19

The apparatus of claim 14, said output means comprising means for producing electrons in response to the last-mentioned ions and means for multiplying the produced electrons.

Claim 20

The apparatus of claim 10, said pressure maintaining means comprising means for opening said envelope to the atmosphere.

Claim 21

Apparatus for separating electronegative components from a gas, comprising an envelope, means for introducing said gas into said envelope, means for producing a pulse of low energy electrons at a first region of said envelope to form negative ions of said components at said first region, means applying a drift field to said ions, only after their formation, for causing said ions to drift from said first region toward a second region of said envelope, ion gate means between said regions, means for opening said gate means for a predetermined interval during the application of said drift field to pass ions of predetermined mobility to said second region, means for producing an output in response to the ions at said second region, and means located between said gate means and said output means for focusing and accelerating the ions passed by said gate means, said accelerating means comprising a series of electrodes defining successive chambers in said envelope coupled by apertures in said electrodes, said successive chambers having means for forming successively higher vacuums therein, said focusing means comprising conical gas-molecule-permeable,negative-ion-reflective grids between said electrodes.

Claim 22

Apparatus for separating electronegative components from a gas, comprising an envelope, means for introducing said gas into said envelope, means for producing a pulse of low energy electrons at a first region of said envelope to form negative ions of said components at said first region, means applying a drift field to said ions, only after their formation, for causing said ions to drift from said first region toward a second region of said envelope, ion gate means between said regions, means for opening said gate means for a predetermined interval during the application of said drift field to pass ions of predetermined mobility to said second region, means for producing an output in response to the ions at said second region, and means located between said gate means and said output means for focusing and accelerating the ions passed by said gate means, said accelerating means comprising a series of electrodes defining successive chambers in said envelope coupled by apertures in said electrodes, said successive chambers having means for forming successively higher vacuums therein, said focusing means comprising conical gas-molecule-permeable,negative-ion-reflective grids between said electrodes.