Experimental Configuration
In order to get results as accurate as possible, the experiments must be carried out
with “good geometry”. Good geometry is best achieved by locating the detector as far from
the source as possible and by making the detector and sample small. In these measurements,
the detector-to-source distance is measured as 130.125".
The experimental arrangements and a schematic are given below to illustrate the
geometry.
The 3
He detector, three cadmium collimators, and a boron collimator were aligned
before doing the measurements.
Figure 3.15 shows the close-up of the beam port where the beam is emitted. It keeps
rotating during operating and its center locates 36" above the floor