1. A method for assessing an alpha particle emission potential of a metallic material, said method comprising the steps of:
detecting alpha particle emissions from a sample of the metallic material;
determining a concentration of a target parent isotope in the sample of the metallic material from the alpha particle emissions detected in said detecting step and a time which has elapsed between said detecting step and a prior secular equilibrium disruption process; and
determining a possible alpha emission of a target decay isotope of the target parent isotope from the determined concentration of the target parent isotope and the half-life of the target parent isotope.
2. The method of claim 1, wherein the time which has elapsed is an elapsed time between said detecting step and a completion of a prior secular equilibrium disruption process.
3. The method of claim 1, further comprising the additional steps, prior to said detecting step, of:
obtaining a sample of the metallic material; and
heating the sample to diffuse atoms of the target decay isotope within the sample until a uniform concentration of atoms of the target decay isotope is obtained throughout the sample.
4. The method of claim 1, wherein the secular equilibrium disruption process is a process which removes contaminant components from the material.
5. The method of claim 1, wherein the secular equilibrium disruption process comprises at least one process selected from the group consisting of melting, refining, and combinations of the foregoing.
6. The method of claim 1, wherein the secular equilibrium disruption process comprises an electro-refining process.
7. The method of claim 1, wherein the metallic material comprises tin, the target parent isotope is 210Pb, and the target decay isotope is 210Po.
8. The method of claim 1, wherein said step of determining a possible alpha emission of a target decay isotope comprises determining a maximum possible alpha emission of the target decay isotope.
9. The method of claim 1, wherein said step of determining a possible alpha emission of a target decay isotope comprises determining a possible alpha emission of the target decay isotope at at least 300 days from completion of the secular equilibrium disruption process.
10. A method for assessing an alpha particle emission potential of a metallic material, said method comprising the steps of:
subjecting a metallic material to a secular equilibrium disruption process;
obtaining a sample of the metallic material following said subjecting step;
detecting alpha particle emissions from the sample;
determining a concentration of a target parent isotope in the sample from the alpha particle emissions detected in said detecting step and an elapsed time between said subjecting step and said detecting step; and
determining a possible alpha emission of a target decay isotope of the target parent isotope from the determined concentration of the target parent isotope and the half-life of the target parent isotope.
11. The method of claim 10, wherein the elapsed time between said subjecting step and said detecting step is an elapsed time between completion of said subjecting step and said detecting step.
12. The method of claim 10, further comprising the additional step, after said obtaining step and prior to said detecting step, of heating the sample to diffuse atoms of the target decay isotope within the sample until a uniform concentration of atoms of the target decay isotope is obtained throughout the sample.
13. The method of claim 10, wherein said subjecting step further comprises subjecting the metallic material to a process which removes contaminant components from the material.
14. The method of claim 10, wherein said subjecting step further comprises subjecting the metallic material to at least one process selected from the group consisting of melting, refining, and combinations of the foregoing.
15. The method of claim 10, wherein said subjecting step further comprises subjecting the metallic material to an electro-refining process.
16. The method of claim 10, wherein the metallic material comprises tin, the target parent isotope is 210Pb, and the target decay isotope is 210Po.
17. The method of claim 10, wherein said step of determining a possible alpha emission of a target decay isotope comprises determining a maximum possible alpha emission of the target decay isotope.
18. The method of claim 10, wherein said step of determining a possible alpha emission of a target decay isotope comprises determining a possible alpha emission of the target decay isotope at at least 300 days from completion of the secular equilibrium disruption process.
19. The method of claim 10, wherein said step of determining a possible alpha emission of a target decay isotope comprises determining a possible alpha emission of the target decay isotope at 828 days from completion of the secular equilibrium disruption process.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A processing method for a high pressure gas container comprising the step of polishing the inner surface of a high pressure gas container mainly made of iron, which has had a pressure test by hydraulic pressure, by 5 to 100 \u03bcm thickness on average such that the value of dividing the area of the Si2s peak by the area of the Fe2p32 peak in the X-ray photoelectron spectrum of the container inner surface is 0.3 or less.
2. The processing method according to claim 1, wherein at least the final polishing is conducted with a polishing agent having a Si content of 10 wt % or less.
3. A halogen containing gas filled in-a high pressure gas container processed by polishing the inner surface of a high pressure gas container mainly made of iron, which has had a pressure test by hydraulic pressure, by 5 to 100 \u03bcm thickness on average such that the value of dividing the area of the Si2s peak by the area of the Fe2p32 peak in the X-ray photoelectron spectrum of the container inner surface is 0.3 or less.
4. The halogen containing gas filled in a high pressure gas container according to claim 3, wherein the silicon halide content of the gas is 0.3 ppm or less.
5. A method for processing the inner surface of a fluorine containing gas container mainly made of iron, which has had a pressure test by hydraulic pressure, comprising the step of conducting at least the final polishing with a polishing agent having a Si content of 10 wt % or less.