X-ray and particle shield for improved vacuum conductivity

Patent metadata

Field	Value
Publication number	US-10748740-B2
Application number	US-201816106914-A
Country	US
Kind code	B2
Filing date	Aug 21, 2018
Priority date	Aug 21, 2018
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

An x-ray shield for improved vacuum conductivity is disclosed herein. An example x-ray shield includes at least one elongate member formed from high atomic weight material shaped into a twist with at least 180° of twist.

First claim

What is claimed is:

1. An apparatus comprising:
an elongate x-ray shield formed from high atomic weight material shaped into a twist with at least 180° of twist, the elongate x-ray shield disposed within at least a portion of a vacuum tube coupled to a vacuum chamber to prevent at least a portion of x-rays from escaping the vacuum chamber.

2. The apparatus of claim 1 , wherein the elongate x-ray shield has 210° of twist.

3. The apparatus of claim 1 , wherein the high atomic weight material is lead.

4. The apparatus of claim 1 , wherein the high atomic weight material is formed from a material including sintered tungsten particles.

5. The apparatus of claim 1 , wherein the elongate x-ray shield is coated in a layer of low atomic weight material.

6. The apparatus of claim 5 , wherein the low-z material is aluminum.

7. The apparatus of claim 1 , wherein the elongate x-ray shield is biased positively or negatively.

8. The apparatus of claim 1 , wherein the elongate x-ray shield is cooled.

9. The apparatus of claim 1 , wherein the elongate x-ray shield has a length and a width.

10. The apparatus of claim 9 , wherein the width and length are based on an inner diameter and a portion of length of a vacuum tube, the vacuum tube coupling a high vacuum chamber with a vacuum pump.

11. The apparatus of claim 1 , further comprising a second elongate x-ray shield arranged perpendicular to the elongate x-ray shield, the second elongate x-ray shield formed from high atomic weight material shaped into a twist.

12. A system comprising:
a vacuum chamber;
a vacuum pump coupled to the vacuum chamber by a vacuum tube; and
an elongate x-ray shield disposed within at least a portion of the vacuum tube, the elongate x-ray shield formed from high atomic weight material shaped into a twist.

13. The system of claim 12 , wherein the elongate x-rays shield has at least 180° of twist.

14. The system of claim 12 , wherein the elongate x-rays shield has at least 210° of twist.

15. The system of claim 12 , wherein the high atomic weight material is lead.

16. The system of claim 12 , wherein the high atomic weight material is formed from a material including sintered tungsten particles.

17. The system of claim 12 , wherein the elongate x-ray shield is coated in a layer of low atomic weight material.

18. The system of claim 17 , wherein the low-z material is aluminum.

19. The system of claim 12 , wherein the elongate x-ray shield is biased positively or negatively.

20. The system of claim 12 , wherein the elongate x-ray shield is cooled.

21. The system of claim 12 , wherein the elongate x-ray shield has a length and a width.

22. The system of claim 12 , wherein the vacuum chamber is part of a charged particle microscope.

Assignees

• Fei Co

Inventors

• De Groot Rients Jan
• Smit Casper

Classifications

• G21F1/125

  comprising metals · CPC title

• G21F3/00 Primary

  Shielding characterised by its physical form, e.g. granules, or shape of the material · CPC title

• H01J37/165 Primary

  Means associated with the vessel for preventing the generation of or for shielding unwanted radiation, e.g. X-rays · CPC title

• G21F1/085

  Heavy metals or alloys · CPC title

• H01J37/026

  Means for avoiding or neutralising unwanted electrical charges on tube components · CPC title