Small diameter radiation sensor cable

1. A method of manufacturing a radiation sensor cable for medical radiation therapy, comprising the steps of:

a. cutting a scintillation fiber to a predetermined scintillation fiber length;

b. inserting said scintillation fiber into an opaque fiber cap having a length and an interior hollow and an open end and a closed end, wherein the predetermined scintillation fiber length is less than said length of said fiber cap;

c. inserting a first end of an optical fiber into said cap behind said scintillation fiber;

d. pushing said optical fiber until it contacts said scintillation fiber so that said optical fiber directly abuts said scintillation fiber without adhesive therebetween to make a first detector assembly; and

e. adding a data adaptor to a second end of said optical fiber to form a radiation sensor cable.

2. The method of claim 1 , further comprising adding a drop of adhesive to said open end of said cap.

3. The method of claim 1 , wherein said scintillation fiber and said optical fiber are each cut with a hot knife prior to insertion into said cap.

4. The method of claim 1 , further comprising inserting said first detector assembly into heat shrinkable tubing and heat shrinking to fit.

5. The method of claim 1 , further comprising the steps of adding a second detector assembly made according to steps a-e to said radiation sensor cable.

6. The method of claim 1 , further comprising the steps of adding a second detector assembly made according to steps a-e to said radiation sensor cable, but proximal to said first detector assembly, and inserting said first and second detector assemblies inside heat shrinkable tubing and shrinking to fit.

7. The method of claim 1 , wherein said fiber cap is made from a hard polymer of durometer less than 45 Shore D.

8. The method of claim 1 , wherein fiber cap is made only of a hard opaque plastic of durometer 30-40 Shore D by injection molding, and said interior hollow is sized to closely fit a plastic scintillation fiber abutted against a plastic optical fiber.

9. The method of claim 1 , where said radiation sensor cable has a diameter of less than 5 mm.

10. A method of manufacturing a radiation sensor cable for medical radiation therapy, comprising the steps of:

a. obtaining a fiber cap of opaque plastic, said fiber cap having a length and an interior hollow and an open end and a closed end,

b. cutting a bare scintillation fiber with a hot knife to a predetermined scintillation fiber length;

c. inserting said bare scintillation fiber into said fiber cap and wherein the predetermined scintillation fiber length is less than said length of said fiber cap and wherein said interior hollow has a diameter to closely fit said scintillation fiber;

d. inserting a bare end of an optical fiber into said cap behind said scintillation fiber;

e. pushing said optical fiber until it directly abuts said bare scintillation fiber without adhesive therebetween to make a first detector assembly;

f. inserting said first detector assembly into opaque heat shrinkable tubing and heat shrinking to fit; and

g. adding a data adaptor to a second end of said optical fiber to form a radiation sensor cable.

11. The method of claim 10 , further comprising the steps of adding a second detector assembly made according to steps a-g to said radiation sensor cable.

12. The method of claim 10 , further comprising the steps of adding a second detector assembly made according to steps a-g to said radiation sensor cable, but proximal to said first detector assembly, and inserting said first and second detector assemblies inside said heat shrinkable tubing and shrinking to fit.

13. The method of claim 10 , wherein said radiation sensor cable has a diameter of less than 5 mm.

14. The method of claim 10 , further comprising inserting a fiducial marker into said fiber cap before inserting said bare scintillation fiber.

15. The method of claim 10 , further comprising adding a fiducial marker onto an outer tip of said fiber cap.