Monte Carlo calculation of beam quality correction for solid-state detectors and phantom scatter correction at 137Cs energy

Beam quality correction k QQo (r) , which reflects the absorbed energy dependence of the detector, is calculated for solid state detector materials diamond, LiF, Li 2 B 4 O 7 and Al 2 O 3 for the 137 Cs RTR brachytherapy source using the Monte Carlo-based EGSnrc code system. The study also includes calculation of detector-specific phantom scatter corrections k phant (r)  for solid phantoms such as PMMA, polystyrene, RW1, solid water, virtual water and plastic water. Above corrections are calculated as a function of distance r along the transverse axis of the source. k QQo (r) is about unity for the Li 2 B 4 O 7 detector. LiF detector shows a gradual decrease in k QQo (r) with r (decrease is about 2% over the distance range of 1 – 15 cm). Diamond detector shows a gradual increase in k QQo (r) with r (about 3% larger than unity at 15 cm). In the case of Al 2 O 3 detector, k QQo (r) decreases with r steeply (about 14% over the distance range of 1 – 15 cm). The study shows that some solid state detectors demonstrate distance-dependent k phant (r) values, but the degree deviation from unity depends on the type of solid phantom and the detector.