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Table. 2.

Table. 2.

Energy deposition portions in the paired air slabs for the mammography X-ray beams

Location of the paired air slabs Energy deposition portion (%)


Upper slab
(mm)
Lower slab (mm) Beam code


M20 M23 M25 M28 M30 M35 M40
35–40 30–35 94.39 93.34 92.78 92.11 91.70 90.93 90.35
40–45 25–30 5.56 6.61 7.16 7.82 8.20 8.89 9.34
45–50 20–25 0.02 0.03 0.03 0.05 0.07 0.15 0.25
50–55 15–20 0.01 0.01 0.01 0.01 0.01 0.02 0.04
55–60 10–15 0.01 0.01 0.01 0.01 0.01 0.01 0.01
60–65 5–10 0.00 0.00 0.01 0.00 0.00 0.00 0.00
65–70 0–5 0.00 0.00 0.00 0.00 0.00 0.00 0.00

The air slabs were piled symmetrically with the beam axis plane placed 35-mm-high from the collector electrode as a symmetry plane. The low-energy mammography X-ray beams were incident on the front face of the air box (see Fig. 4). The number appearing in the beam code indicated the high voltage loaded on the X-ray tube with a molybdenum anode. The added filtration was 0.03 mm molybdenum, and the inherent filtration was 1 mm beryllium.

Progress in Medical Physics 2022;33:1-9 https://doi.org/10.14316/pmp.2022.33.1.1
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