Fast pressure sensing system

Patent metadata

Field	Value
Publication number	US-2020161109-A1
Application number	US-201916664389-A
Country	US
Kind code	A1
Filing date	Oct 25, 2019
Priority date	Nov 21, 2018
Publication date	May 21, 2020
Grant date	—

Abstract

The disclosure includes an ionization chamber, a first electron multiplier, and a second electron multiplier. The ionization chamber is configured to receive gas molecules from an environment at a pressure. The first electron multiplier is configured to receive a plurality of photons from a photon source, generate a first plurality of electrons from the plurality of photons, and discharge the first plurality of electrons into the ionization chamber to generate a plurality of gas ions from at least a portion of the gas molecules. The second electron multiplier is configured to receive the plurality of gas ions from the ionization chamber and generate a second plurality of electrons from the plurality of gas ions that is proportional to a quantity of the plurality of gas ions. A quantity of electrons of the second plurality of electrons is indicative of the pressure.

First claim

What is claimed is:

1 . A system comprising:
an ionization chamber configured to receive gas molecules from an environment at a pressure; a first electron multiplier configured to:
receive a plurality of photons from a photon source;
generate a first plurality of electrons from the plurality of photons; and
discharge the first plurality of electrons into the ionization chamber to generate a plurality of gas ions from at least a portion of the gas molecules;
a second electron multiplier configured to:
receive the plurality of gas ions from the ionization chamber; and
generate a second plurality of electrons from the plurality of gas ions that is proportional to a quantity of the plurality of gas ions, wherein a quantity of electrons of the second plurality of electrons is indicative of the pressure.

2 . The system of claim 1 , further comprising the photon source configured to emit the plurality of photons.

3 . The system of claim 2 ,
wherein the photon source comprises an ultraviolet (UV) light emitting diode (LED), and wherein the plurality of photons comprises UV photons.

4 . The system of claim 2 , wherein the photon source has a switching time of less than about 1 millisecond.

5 . The system of claim 1 , wherein at least one of the first and second electron multipliers is a microchannel plate.

6 . The system of claim 1 ,
wherein at least one of the first and second electron multipliers is configured to receive electrical signals that adjust a gain of the at least one of the first and second electron multipliers, wherein the gain of the first electron multiplier is representative of a ratio of a quantity of the plurality of photons to a quantity of the first plurality of electrons, and wherein the gain of the second electron multiplier is representative of a ratio of a quantity of the plurality of gas ions to the quantity of the second quantity of electrons.

7 . The system of claim 1 , further comprising an electrode configured to:
receive the second quantity of electrons from the second electron multiplier; generate an electrical signal from the second quantity of electrons that is proportional to the quantity of the second quantity of electrons; and output the electrical signal.

8 . The system of claim 7 , further comprising a computing device configured to:
receive the electrical signal from the electrode; determine the pressure based on the electrical signal and an ionization cross-section of the gas molecules; and output a pressure measurement signal representing the pressure.

9 . The system of claim 7 , wherein a response time between receiving the plurality of photons from the photon source and outputting the electrical signal is less than about 10 milliseconds.

10 . The system of claim 1 , wherein the pressure is between about 10 −2 torr and about 10 −9 torr.

11 . The system of claim 1 ,
wherein the pressure is a first pressure, wherein the plurality of photons is a first plurality of photons, wherein the plurality of gas ions is a first plurality of gas ions, wherein the portion of the gas molecules is a first portion of the gas molecules, wherein the ionization chamber is configured to receive gas molecules from the environment at a second pressure, wherein the first electron multiplier is configured to generate a third plurality of electrons from a second plurality of photons from a photon source, wherein the first electron multiplier is configured to discharge the third plurality of electrons into the ionization chamber to generate a second plurality of gas ions from at least a second portion of the gas molecules, wherein the second electron multiplier is configured to generate a fourth plurality of electrons from the second plurality of gas ions that is proportional to a quantity of the second plurality of gas ions, wherein a quantity of the fourth plurality of electrons is representative of the second pressure, and wherein the system further comprises a computing device is configured to determine a change in pressure based on the quantities of the second plurality of electrons and the fourth plurality of electrons.

12 . A method, comprising:
receiving, by an ionization chamber, gas molecules from an environment at a pressure; generating, by a first electron multiplier, a first plurality of electrons from a plurality of photons from a photon source; discharging, by the first electron multiplier, the first plurality of electrons into the ionization chamber to generate a plurality of gas ions from at least a portion of the gas molecules; generating, by a second electron multiplier, a second plurality of electrons from the plurality of gas ions that is proportional to a quantity of the plurality of gas ions, wherein a quantity of the second plurality of electrons is indicative of the pressure.

13 . The method of claim 12 , further comprising emitting, by the photon source, the plurality of photons.

14 . The method of claim 13 ,
wherein the photon source comprises an ultraviolet (UV) light emitting diode (LED), and wherein the plurality of photons comprises UV photons.

15 . The method of claim 13 , wherein the photon source has a switching time of less than about 1 millisecond.

16 . The method of claim 12 , wherein at least one of the first and second electron multipliers is a microchannel plate.

17 . The method of claim 12 , further comprising receiving, by at least one of the first and second electron multipliers, electrical signals that adjust a gain of the at least one of the first and second electron multipliers,
wherein the gain of the first electron multiplier is representative a ratio of a quantity of the plurality of photons to a quantity of the first plurality of electrons, and wherein the gain of the second electron multiplier is representative of a ratio of a quantity of the plurality of gas ions to the quantity of the second plurality of electrons.

18 . The method of claim 12 , further comprising:
receiving, by an electrode, the second plurality of electrons from the second electron multiplier; generating, by the electrode, an electrical signal from the electrons that is proportional to the quantity of the second plurality of electrons; and outputting, by the electrode, the electrical signal.

19 . The method of claim 18 , further comprising:
receiving, by a computing device, the electrical signal from the electrode; determining, by the computing device, the pressure based on the electrical signal and an ionization cross-section of the gas molecules; and outputting, by the computing device, a pressure measurement signal representing the pressure.

20 . The method of claim 18 , wherein a response time between receiving the plurality of photons from the photon source and outputting the electrical signal is less than 10 milliseconds.

21 . The method of claim 12 , wherein the pressure is a first pressure, wherein the plurality of photons is a first plurality of photons, wherein the plurality of gas ions is a first plurality of gas ions, wherein the portion of the gas molecules is a first portion of the gas molecules, and wherein the method further comprises:
receiving, by the ionization chamber, gas molecules from an environment at a second pressure; generating, by the first electron multiplier, a third plurality of electrons from a second plurality of photons from a photon source; discharging, by the first electron multiplier, the third plurality of electrons int

Assignees

• Stanford Res Inst Int

Inventors

• Chaudhary Ashish
• Short Robert Timothy

Classifications

• G01L21/30 Primary

  by making use of ionisation effects · CPC title

• H01J41/02 Primary

  Discharge tubes for measuring pressure of introduced gas {or for detecting presence of gas} · CPC title

• G01N27/64

  using wave or particle radiation to ionise a gas, e.g. in an ionisation chamber · CPC title

• H01J41/06

  with ionisation by means of cold cathodes · CPC title

• H01J41/04

  with ionisation by means of thermionic cathodes · CPC title