Journal of Medical Physics
TECHNICAL NOTE
Year
: 2008  |  Volume : 33  |  Issue : 2  |  Page : 78--81

Evaluation of dose distributions in gamma chamber using glass plate detector


Pradeep Narayan, SG Vaijapurkar, PK Bhatnagar 
 Defence Laboratory, Ratanada Palace, Jodhpur, Rajasthan, India

Correspondence Address:
Pradeep Narayan
Defence Laboratory, Ratanada Palace, Jodhpur - 342 011, Rajasthan
India

A commercial glass plate of thickness 1.75 mm has been utilized for evaluation of dose distributions inside the irradiation volume of gamma chamber using optical densitometry technique. The glass plate showed linear response in the dose range 0.10 Kilo Gray (kGy) to 10 kGy of cobalt-60 gamma radiation with optical sensitivity 0.04 Optical Density (OD) /kGy. The change in the optical density at each identified spatial dose matrix on the glass plate in relation to the position in the irradiation volume has been presented as dose distributions inside the gamma chamber. The optical density changes have been graphically plotted in the form of surface diagram of color washes for different percentage dose rate levels as isodose distributions in gamma chamber. The variation in dose distribution inside the gamma chamber unit, GC 900, BRIT India make, using this technique has been observed within 15%. This technique can be used for routine quality assurances and dose distribution validation of any gamma chamber during commissioning and source replacement. The application of commercial glass plate for dose mapping in gamma chambers has been found very promising due to its wider dose linearity, quick measurement, and lesser expertise requirement in application of the technique.


How to cite this article:
Narayan P, Vaijapurkar S G, Bhatnagar P K. Evaluation of dose distributions in gamma chamber using glass plate detector.J Med Phys 2008;33:78-81


How to cite this URL:
Narayan P, Vaijapurkar S G, Bhatnagar P K. Evaluation of dose distributions in gamma chamber using glass plate detector. J Med Phys [serial online] 2008 [cited 2020 Mar 30 ];33:78-81
Available from: http://www.jmp.org.in/article.asp?issn=0971-6203;year=2008;volume=33;issue=2;spage=78;epage=81;aulast=Narayan;type=0