The Directional Gamma Tool, is a Tungsten-collimated version of the gamma tool.
These tools aresometimes referred to as “focused” or “shielded” gamma tools.
In thisdesign a 65° “window” is machined along the length of the Tungsten shield thatsurrounds the crystal/phototube detector.
Only gamma ray entering fromthe formation through this window can be detected and counted. Whenaligned with the tool face or other physical reference,
It is same overall length and diameter. Becauseof the required thickness of the Tungsten shield, the Nal(TI) scintillatorcrystal is of a smaller diameter.
The length is increased to 6.0” however,to deliver an equivalent volume of crystal material as in the FR-T to providemaximum sensitivity.