COMPARATIVE STUDY FOR QUARTZ DOPED WITH SOME ACTIVATORS AGAINST STANDARD LiF-100 *
RABIE, N.(1), DIAB, K.M.(1), KHALIL, W.A.(2) and EISSA, H.M.(1)
(1) National Institute of Standards, Ionizing Radiation and Radioactive Materials Lab. and (2) Biophysics Department, Faculty of Science, Cairo University, Egypt.
Key words: Doped quartz, LiF-100, Thermoluminescence dosimeters.
دراسة مقارنة لعينات من الكوارتز المطعم ببعض العناصر النشطة
مقابل عينات الليثيوم فلورايد-100
القياسية
نادية ربيع و حسن دياب و وفاء خليل و هدى عيسى
خلاصـة
تمت هذه الدراسة لمقارنة عينات من الكوارتز المطعم بالليثيوم فلورايد أو كالسيوم فلورايد مع عينات الليثيوم فلورايد-100 القياسية وذلك للتحقق من كفاءة الكوارتز لاستخدامه لقياس الجرعة الإشعاعية بواسطة ظاهرة الوميض الحرارى. تم تشعيع عينات الكوارتز بجرعات من أشعة جاما فى المدى من 0.5 سنتى جراى حتى 180 جراى وبناء عليه، تم دراسة بعض الخواص للكوارتز المصنع مثل الوزن المثالى والتسخين ومعدل التسخين واستنتاج درجة حرارة الخلط للعينات المطعمة. تمت أيضاً دراسة خواص عينات الكوارتز المطعم بالليثيوم فلورايد أو كالسيوم فلورايد وحساب قيمة اللايقين فى النتائج للكواشف المصنوعة من الكوارتز المطعم ومقارنة النتائج بعينات الليثيوم فلورايد-100 القياسية.
ABSTRACT
Comparative
studies were made between the quartz samples doped with
LiF or CaF and the reference dosimeter LiF-100 to satisfy the quality of
quartz as a TL dosimeter. The prepared quartz samples were irradiated for
a wide range of gamma doses from 0.5 cGy up to 180Gy. The characteristics
of the prepared quartz samples such as optimum weight, pre-heating
effects, heating rate and mixing heat for doped samples were investigated.
TL characteristics were studied for the quarts samples doped with
activators (LiF or CaF). The various sources uncertainty of
thermoluminescence technique for the quartz samples doped with LiF or CaF
were calculated.
The expanded and the combined uncertainties were calculated for detector, reader, thermal treatment and over response for the prepared quartz doped with activators (LiF or CaF) and for standard LiF-100. The dosimetric properties for the prepared quartz dosimeters were compared with standard LiF-100 dosimeter.
The data showed that the quartz doped with CaF could be used as
dosimeter because it has a single suitable one peak. Also, it has a wide
linear response range greater than the standard LiF-100, but the only
defect was the fading which highest to 10%. Quartz doped with LiF has a
good dating peak at 400°C and sensitive to low doses in the rage of
environmental dose. Combined uncertainty (UC) for the prepared
quartz doped with LiF or CaF and also the standard
LiF-100 were in compatible within the range.
