Methods and apparatus for geophysical logging

1. A radiation detector comprising:

a photo-detector; and

a scintillator optically coupled to said photo-detector and having a longitudinal axis extending therethrough, said scintillator formed in at least one of a cylindrical segment shape and a truncated frustocylindrical shape comprising an end face that extends obliquely from a radially inner surface to a radially outer surface of said scintillator with respect to said longitudinal axis.

2. A radiation detector in accordance with claim 1 wherein said scintillator is coupled to a single photo-detector.

3. A radiation detector in accordance with claim 1 wherein said scintillator is coupled to a single photo-detector using a lightpipe.

4. A radiation detector in accordance with claim 1 wherein said scintillator is coupled to a single photo-detector using an aspheric lightpipe.

5. A radiation detector in accordance with claim 1 wherein said scintillator comprises a half-cylindrical scintillator, said scintillator coupled to said photo-detector using an aspheric lightpipe.

6. A radiation detector in accordance with claim 1 wherein said scintillator comprises a quarter-cylindrical scintillator coupled to said photo-detector.

7. A radiation detector in accordance with claim 1 wherein said scintillator comprises at least one of an off-axis cylindrical section, a section comprising a concave surface, and a section comprising a convex surface.

8. A radiation detector comprising:

a photo-detector; and

a scintillator optically coupled to said photo-detector using a lightpipe, said scintillator formed in one of a rectangular slab shape and a quarter-cylindrical shape.

9. A radiation detector in accordance with claim 8 wherein said scintillator comprises a plurality of rectangular slab shape scintillators optically coupled to said photo-detector, a longitudinal axis of each of said plurality of rectangular slab shape scintillators is substantially parallel to a longitudinal axis of said radiation detector.

10. A radiation detector in accordance with claim 8 wherein said scintillator is coupled to a single photo-detector.

11. A radiation detector in accordance with claim 8 wherein said scintillator is coupled to a single photo-detector using an aspheric lightpipe.

12. A borehole logging tool comprising:

a housing configured to substantially seal a downhole logging environment from an interior of the housing; and

a survey instrument enclosed within the housing, said survey instrument comprising:

a photo-detector; and

a scintillator optically coupled to said photo-detector, said scintillator formed in a non-right circular cylindrical shape.

13. A borehole logging tool in accordance with claim 12 wherein said scintillator is at least one of a frustocylindrical and a truncated frustocylindrical shape.

14. A borehole logging tool in accordance with claim 12 wherein said scintillator is coupled to a single photo-detector.

15. A borehole logging tool in accordance with claim 12 wherein said scintillator is coupled to a single photo-detector using a lightpipe.

16. A borehole logging tool in accordance with claim 12 wherein said scintillator is coupled to a single photo-detector using an aspheric lightpipe.

17. A borehole logging tool in accordance with claim 12 wherein said scintillator comprises a half-cylindrical scintillator, said scintillator coupled to said photo-detector using an aspheric lightpipe.

18. A borehole logging tool in accordance with claim 12 wherein said scintillator comprises a quarter-cylindrical scintillator coupled to said photo-detector.

19. A borehole logging tool in accordance with claim 12 wherein said scintillator comprises at least one of an off-axis cylindrical section, a section comprising a concave surface, and a section comprising a convex surface.