International Journal of Engineering and Science Applications ISSN 2406-9833 15 IJEScA Determination of the Half-Value Layer by Using Filter Aluminum Sheets for Digital Mammography M. Aswad 1 , B. Abdullah 1 , D. Tahir 1* 1 Health Facilities Hall of Makassar, Makassar 90245 Indonesia 2 Department of Physics, Hasanuddin University, Makassar 90245 Indonesia E-mail: aswadbpfkm@gmail.com bualkarabdullah@gmail.com * dtahir@fmipa.unhas.ac.id ABSTRACT A method of determining the half-value layers (HVL) with or without using an aluminum (Al) filter sheet for digital mammography has been developed. HVL measurements using a single exposure method are performed without the addition of an aluminium filter. This study was conducted to evaluate the accuracy of measurements of HVL values in a single exposure method using a RaySave ion space detector. a standard method with a variation in aluminium filter thickness from 0.110 to 0.980 mm. The HVL measurement values were performed with the distance between the focus of the detector 60.5 cm, and the current 80 mAs at a voltage of 23 kVp, 25 kVp, 27 kVp, 29 kVp and 32 kVp. The HVL value is determined by using the interpolation formula. The results showed that the HVL value using aluminium filter was 0.03 mm higher than the standard method by using multiple exposures for the same thickness of the aluminium filter. Keywords: HVL, Ion chamber, detector, RaySave. Article history: received February, 25 th 2018, received in revised May, 25 th 2018 1. INTRODUCTION Mammography is a special X-Ray examination to assess a person's breast tissue. breast examination process using low-dose X- rays that generally range from 0.7mSv. Mammography is used to detect early or screening in diagnosing breast cancer as early as possible. This tool is able to show abnormalities in the breast in the smallest form less than 5 mm (stadium zero). At this stage, a mammogram may indicate the presence of microcalcification, a lump that can not be felt by the woman himself or even the doctor [1], until a lump is 1 cm or more in size. Therefore, it is important to perform quality control tests (QC) from mammography equipment. QC tests include evaluation of image quality and meaningful dose of the gland that depends on the HVL (the beam quality), breast thickness, and tissue type. In Indonesia, exposure to medical radiation is regulated by the Nuclear Energy Regulatory Agency (BAPETEN), which comes from the Ionizing Radiation Protection Act. Quality assurance requirements (QA) for digital mammography are included in the BAPETEN Standard since October 2011.