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Author Arwui, C. C. ♦ Deatanyah, P. ♦ Wotorchi-Gordon, S. ♦ Ankaah, J. ♦ Emi-Reynolds, G. ♦ Amoako, J. K. ♦ Adu, S. ♦ Hasford, F. ♦ Lawluvi, H. ♦ Kpeglo, D. O. ♦ Sosu, E. K.
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Icru Slab Phantom ♦ Tld Calibration ♦ Radiation Survey Meter ♦ Constructed Lead Block Collimator ♦ Panoramic Beam ♦ Lead Door ♦ Biological Shield ♦ Dose Rate ♦ Backscatter Condition ♦ Secondary Standard Dosimetry Laboratory ♦ Panoramic Isotropic Emission ♦ Tld Badge ♦ Transmission Dose Rate Measurement ♦ Personnel Dosimeter ♦ Human Body ♦ Lead Block Mould ♦ Thermoluminescent Dosimeter ♦ Percentage Distribution ♦ Narrow Beam Geometry ♦ Survey Meter ♦ Ghana Atomic Energy Commission ♦ Effective Reduction ♦ Panoramic Bench ♦ Designed Block ♦ Specified Distance ♦ Panoramic Cs-137 Source ♦ Dose Measurement ♦ Standardized Icru Slab Phantom ♦ Scatter Radiation ♦ National Nuclear Research Institute
Abstract The objective of calibrating TLD badges and radiation survey meters demand that accurate dose gets to the TLDs and radiation survey meters. A lead block mould and an ICRU slab phantom had been designed and constructed to collimate the panoramic Cs-137 source at the secondary standards dosimetry laboratory (SSDL) by experts at the National Nuclear Research Institute (NNRI) workshop of the Ghana Atomic Energy Commission according to required specifications. This is to concentrate the panoramic isotropic emission into narrow beam geometry to enhance the calibration of personnel dosimeters and radiation survey meters and further reduces scattered radiations due to backscatter and transmission through the biological shield. The designed block was tested by a series of dose measurement of 1mSv using thermoluminescent dosimeters (TLDs) placed on a standardized ICRU slab phantom to cater for backscatter conditions of the human body at specified distances of 1, 2 and 3 meters with and without the collimation. The transmission dose rates measurements through the biological shield were taken by a survey meter. The results show percentage distribution of an effective reduction of transmitted dose rate to the laboratories and offices. However, the lead door recorded very high transmitted dose rates. It was finally concluded that further collimation will be necessary to completely eliminate scatter radiations introduced by the panoramic bench and transmission through the lead door.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study