Analysis of potenciality for the use of compounds based on MgSO4 and MgB4O7 for beta radiation monitoring

Abstract

The thermoluminescent dosimeters have a crucial paper in radiation measurement in these types of procedures. Sulfates, such as dosimetric material, has been used for more than 20 years. The phosphor which has been investigated for dosimetry is magnesium sulfate. The objective of this study was to present some results of development of dosimeters based on magnesium sulfate for beta dosimetry (The literature presents results for materials stimulated with gamma radiation, x-ray, etc.). The composites studied were : MgSO4: Dy ;MgSO4: Tm and MgB4O7: Dy. Samples of MgSO4: Tm and MgB4O7: Dy were produced through an adaptation of the crystal growth method described by yamashita in 1971, and the MgSO4: Dy was produced through a new method called recrystallization, replacing the acid with water. After the crystals growth, the materials suffer thermal treatment at 900 ° C for 5 hours for magnesium sulfate and 400 ° C for two hours for magnesium tetraborate, and then were submitted to irradiation with beta source 90Sr +90 Y, with doses from 1 to 40 Gy. Finaly, were obtained the thermoluminescent response curves. Through the results obtained, it can be concluded that the material presented has potential for measuring beta radiation. The TL emission curves presented emission peaks between 70 ° C and 350 ° C, which is a temperature range suitable for dosimetry.