Monica ZECIU-DOLHA^1,a, Alida TIMAR-GABOR^1,a, Andrada CAMENIŢĂ¹,Dan COSTIN¹ & Constantin COSMA^1
1Babes-Bolyai University, Faculty of Environmental Science and Engineering, Fantanele 30, 400294,
Cluj Napoca, Romania,
^aCorresponding autor e-mail: monica.zeciu@ubbcluj.ro, alida.timar@ubbcluj.ro

GAMMA BACKGROUND MEASUREMENTS BY TL METHOD: APPLICATIONS IN LOCATIONS WITH VARIED GEOLOGICAL CONTEXT

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The aim of this study was to establish whether the thermoluminescence (TL) method is suitable for natural gamma dose monitoring with the ultimate goal to apply this method in the project “Radon map for Center, West and North West regions from Romania” that has the additional aim of establishing a high resolution database for natural gamma dose rates. Seven locations with varied geological context have been selected (Arad, Cluj-Napoca, Bologa, Miercurea-Ciuc, Predeal, Belis, Sinaia). Ultrasensitive TL dosimeters, LiF:Mg,Cu,P were used in order to quantify the gamma doses. The calibration was performed using a gamma ⁶⁰Co source. The dose response was linear, with a determination coefficient of R²= 0.96 for MCP-N detectors and 0.99 for MCP-7 type. For MCP-N dosimeters, the sensitivity was 0.375±0.040 μC/mGy, while for MCP-7 dosimeters the determined sensitivity was 0.363±0.018 μC/mGy for our dosimetric system (Harshaw 3500 TLD Reader). For Beliş location, gamma dose rate was found to be 133±16 nGy/h for MCP-N detectors and 158±8 nGy/h for MCP-7, higher than in the other locations (Arad:93±10 nGy/h and 115±7 nGy/h; Cluj:102±12 nGy/h respectively 110±7 nGy/h; Bologa:102±11nGy/h and 114±8 nGy/h; Miercurea-Ciuc:105±12 nGy/h respectively 116±6 nGy/h; Predeal:95±10 nGy/h and 111±7 nGy/h; Sinaia:87±10 nGy/h and 99±5 nGy/h). The results can be explained by the existent geological substrate in this area, a granitic one, with rocks rich in ²³⁵U and ⁴⁰K. The feasibility test of the investigated method will successfully serve for obtaining realistic input data for the effective dose received by the population.