Determination of half value layer (hvl) lead (Pb) of used batteries for radiation protection using digital radiography at the medical physics laboratory UNNES

X-rays are electromagnetic waves that have a short wavelength of about 1 Ǻ (10-8 cm), so they can be used to diagnose human diseases. Apart from being beneficial, X-rays also have a negative impact on human health. Currently, film-based conventional radiography (RK) systems have begun to be replaced with digital radiography (RD) systems. One example of a modified radiography from a conventional radiography system to a digital radiography system is the radiography system located at the UNNES Medical Physics Laboratory. However, the X-ray plane has one important parameter that must be controlled, namely the quality of the X-ray beam. The quality of the X-ray beam can be measured using the half value layer (HVL), that is, the thickness of the material needed to reduce the intensity of the X-ray by half its initial value. The type of material used in this study is used lead plate with various thicknesses. The results showed that the intensity value could be reduced by increasing the thickness of the lead plate. The decrease in the intensity value shows that there is a difference in the gray level of each step on the lead stepwedge. The HVL of lead obtained was 1.96 cm; 2.13 cm; 2.59 cm; 2.72 cm; 3.17 cm; and 3.44 cm at voltages of 40 kV, 50 kV, 60 kV, 70 kV, 80 kV, and 90 kV, respectively. Based on the amount of voltage used and the HVL value obtained, the HVL value obtained is proportional to the magnitude of the X-ray voltage. The greater the X-ray voltage used, the greater the HVL value obtained.