Corrosion-resistant, strong x-ray window

Patent metadata

Field	Value
Publication number	US-9502206-B2
Application number	US-201514597955-A
Country	US
Kind code	B2
Filing date	Jan 15, 2015
Priority date	Jun 5, 2012
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

The invention is an x-ray window with a stack of thin film layers including aluminum layer(s), corrosion-barrier layer(s), and/or polymer layer(s). Aluminum layer(s) can provide improved gas impermeability. Polymer layer(s) can increase structural strength. The x-ray window can be substantially transmissive to x-rays but also substantially block visible light and infrared light. The x-ray window can have minimal deflection.

First claim

What is claimed is:

1. An x-ray window comprising:
a. a stack of thin film layers including a first aluminum layer, a second aluminum layer, a polyimide layer, and a corrosion-barrier layer;
b. the corrosion-barrier layer comprises a material selected from the list consisting of amorphous carbon and hexamethyldisilazane;
c. an order of the stack of thin film layers is the corrosion-barrier layer, the first aluminum layer, the polyimide layer, then the second aluminum layer;
d. an enclosure having a hollow center and an opening;
e. the stack of thin film layers is hermetically sealed to the opening of the enclosure;
f. the corrosion-barrier layer is disposed as the farthest layer away from the hollow center;
g. the stack of thin film layers having:
i. a transmissivity of greater than 60% for x-rays having an energy of 1.74 keV;
ii. a transmissivity of less than 10% for visible light at a wavelength of 550 nanometers; and
iii. a transmissivity of less than 10% for infrared light at a wavelength of 800 nanometers.

2. The x-ray window of claim 1 , wherein the stack of thin film layers have a deflection distance of less than 300 micrometers with one atmosphere differential pressure across the stack of thin film layers.

3. The x-ray window of claim 1 , wherein the stack of thin film layers have:
a. a deflection distance of less than 200 micrometers with one atmosphere differential pressure across the stack of thin film layers;
b. a transmissivity of greater than 70% for an x-ray energy of 1.74 keV;
c. a transmissivity of less than 3% for visible light at a wavelength of 550 nanometers; and
d. a transmissivity of less than 4% for infrared light at a wavelength of 800 nanometers.

4. The x-ray window of claim 1 , wherein the enclosure comprises titanium.

5. The x-ray window of claim 1 , wherein:
a. the polyimide layer has a thickness of between 150 to 400 nanometers;
b. the first aluminum layer has a thickness of between 10 to 30 nanometers;
c. the second aluminum layer has a thickness of between 10 to 30 nanometers; and
d. the corrosion-barrier layer has a thickness of between 5 to 25 nanometers.

6. An x-ray window comprising:
a. a stack of thin film layers including an aluminum layer, a polymer layer, and a corrosion-barrier layer;
b. the corrosion-barrier layer comprises a material selected from the list consisting of amorphous carbon and hexamethyldisilazane;
c. the stack of thin film layers having:
i. a transmissivity of greater than 60% for x-rays having an energy of 1.74 keV;
ii. a transmissivity of less than 10% for visible light at a wavelength of 550 nanometers; and
iii. a transmissivity of less than 10% for infrared light at a wavelength of 800 nanometers.

7. The x-ray window of claim 6 , wherein the stack of thin film layers have a deflection distance of less than 300 micrometers with one atmosphere differential pressure across the stack of thin film layers.

8. The x-ray window of claim 6 , wherein the stack of thin film layers have:
a. a deflection distance of less than 200 micrometers with one atmosphere differential pressure across the stack of thin film layers;
b. a transmissivity of greater than 70% for an x-ray energy of 1.74 keV;
c. a transmissivity of less than 3% for visible light at a wavelength of 550 nanometers; and
d. a transmissivity of less than 4% for infrared light at a wavelength of 800 nanometers.

9. The x-ray window of claim 6 , wherein the corrosion-barrier layer comprises amorphous carbon with hybridization of carbon that is:
a. less than 25% sp3 hybridization; and
b. greater than 75% sp2 hybridization.

10. The x-ray window of claim 6 , wherein the corrosion-barrier layer comprises hydrogenated amorphous carbon with an atomic percent of hydrogen between 1% and 10%.

11. The x-ray window of claim 6 , wherein the polymer is a polyimide.

12. The x-ray window of claim 6 , wherein:
a. a mass percent of aluminum in the aluminum layer is at least 95%;
b. a mass percent of polymer in the polymer layer is at least 95%;
c. a mass percent of carbon and hydrogen in the corrosion-barrier layer is at least 95%.

13. The x-ray window of claim 6 , wherein an order of the layers in the stack of thin film layers is the polymer layer, the aluminum layer, then the corrosion-barrier layer.

14. The x-ray window of claim 6 , wherein:
a. the polymer layer has a thickness of between 150 to 400 nanometers;
b. the corrosion-barrier layer has a thickness of between 5 to 25 nanometers; and
c. the aluminum layer has a thickness of between 10 to 30 nanometers.

15. The x-ray window of claim 6 , further comprising an enclosure having a hollow center and an opening, the enclosure comprising titanium, and wherein the stack of thin film layers is hermetically sealed to the opening of the enclosure.

16. The x-ray window of claim 15 , wherein the corrosion-barrier layer is the farthest layer away from the hollow center.

17. The x-ray window of claim 15 , wherein:
a. the aluminum layer comprises a first aluminum layer and a second aluminum layer; and
b. an order of the stack of thin film layers is the first aluminum layer, the polymer layer, the second aluminum layer, then the corrosion-barrier layer.

18. An x-ray window comprising:
a. a stack of thin film layers including an aluminum layer disposed between a first corrosion-barrier layer and a second corrosion-barrier layer;
b. the first corrosion-barrier layer and the second corrosion-barrier layer comprise a material selected from the list consisting of amorphous carbon and hexamethyldisilazane;
c. the stack of thin film layers having:
i. a transmissivity of greater than 60% for an x-ray energy of 1.74 keV;
ii. a transmissivity of less than 10% for visible light at a wavelength of 550 nanometers; and
iii. a transmissivity of less than 10% for infrared light at a wavelength of 800 nanometers.

19. The x-ray window of claim 18 , wherein the stack of thin film layers have:
a. a deflection distance of less than 200 micrometers with one atmosphere differential pressure across the stack of thin film layers;
b. a transmissivity of greater than 70% for an x-ray energy of 1.74 key;
c. a transmissivity of less than 3% for visible light at a wavelength of 550 nanometers; and
d. a transmissivity of less than 4% for infrared light at a wavelength of 800 nanometers.

20. The x-ray window of claim 18 , wherein:
a. the first corrosion-barrier layer has a thickness of between 1 to 25 nanometers;
b. the aluminum layer has a thickness of between 10 to 60 nanometers; and
c. the second corrosion-barrier layer has a thickness of between 1 to 25 nanometers.

Assignees

• Univ Brigham Young
• Moxtek Inc

Inventors

• Harker Mallorie
• Liddiard Steven D
• Abbott Jonathan
• Davis Robert
• Vanfleet Richard
• Pei Lei

Classifications

• H04R1/00

  Details of transducers, {loudspeakers or microphones} · CPC title

• H01J5/18 Primary

  Windows permeable to X-rays, gamma-rays, or particles · CPC title

• H04R19/005

  using semiconductor materials · CPC title

• H04R19/04

  Microphones (H04R19/01 takes precedence) · CPC title

• B81B3/0078

  Constitution or structural means for improving mechanical properties not provided for in B81B3/007 - B81B3/0075 · CPC title