Beam Stop Phantom

Beam Stop Array for X-Ray Scatter Measurements.

The Phantom consists of a regular array of lead cylinders embedded in a polymethylmethacrylate (PMMA) plate. Under the assumption that the lead blockers offer an attenuation length sufficient to prevent primary radiation from reaching the detector, QRM-BeamStop is a convenient means to experimentally determine the x-ray scatter-to-primary ratio for a given measurement setup for analog and digital radiography.
The beam stop array is placed between the object and the x-ray source or between object and detector.
A measurement of the signal level behind each blocker gives the scatter intensity, whereas a measurement without the beam stop array represents the total intensity (scatter and primary signal). Dividing both values results in the scatter fraction.