Many industries use sealed neutron sources for several purposes (mainly to estimate the water content in materials like coal, sands, rocks, etc.) determining a not negligible neutron dose for the personnel operating with, even if the source is inside its shielding (i.e. in the storage condition). As a consequence a dosimetric control of these workers is requested, usually performed by LiF thermoluminescence dosemeters (TLDs), a technique giving a good response for X and gamma rays in an enough simple way. These dosemeters are used to evaluate the neutron dose taking advantage of the different neutron thermal cross section of 6Li and 7Li and implicitly assuming that in these applications the thermal neutrons dose can reasonably be related to the total neutron dose. The neutron energy spectrum near some types of industrial neutron sources frequently used (typically 241Am-Be with an activity of the order of some GBq) and the total and thermal neutron dose delivered to an operator walking in proximity of it, have been calculated by a Monte Carlo simulations. The experimental results were obtained with a dosemeter based on commercial thermoluminescence crystals GR-206A and GR-207A developed for personal dosimetry in mixed fields, very frequent in the industry.
LiF Neutron Dosimetry in Industrial Applications: Reliability and Drawback
CIOLINI, RICCARDO;
2004-01-01
Abstract
Many industries use sealed neutron sources for several purposes (mainly to estimate the water content in materials like coal, sands, rocks, etc.) determining a not negligible neutron dose for the personnel operating with, even if the source is inside its shielding (i.e. in the storage condition). As a consequence a dosimetric control of these workers is requested, usually performed by LiF thermoluminescence dosemeters (TLDs), a technique giving a good response for X and gamma rays in an enough simple way. These dosemeters are used to evaluate the neutron dose taking advantage of the different neutron thermal cross section of 6Li and 7Li and implicitly assuming that in these applications the thermal neutrons dose can reasonably be related to the total neutron dose. The neutron energy spectrum near some types of industrial neutron sources frequently used (typically 241Am-Be with an activity of the order of some GBq) and the total and thermal neutron dose delivered to an operator walking in proximity of it, have been calculated by a Monte Carlo simulations. The experimental results were obtained with a dosemeter based on commercial thermoluminescence crystals GR-206A and GR-207A developed for personal dosimetry in mixed fields, very frequent in the industry.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
