https://repository.auw.edu.bd/handle/123456789/744 2026-06-10T01:01:58Z https://repository.auw.edu.bd/handle/123456789/909 Studies of dose distribution to Lung and Stomach and Estimation of Second Cancer Risk due to Outfi eld Dose in Radiotherapy with 60Co Teletherapy Beam Meaze, AKM Moinul Haque A critical component of the radiation regimen for treating cancer patients is the precise dose delivery to the treatment organ while minimizing the dose to the healthy tissue. This study aims to evaluate in-fi eld organ dose and dose distribution outside the target organs to estimate the excess lifetime risk of second cancer. The study was carried out with a male Alderson Rando Phantom. 20 sets of thermoluminescence dosimeters (MTS-100) were used in this study. The in-fi eld organs absorbed dose was measured by inserting TLDs at diff erent geometrical depths of the left lung, right lung, and stomach, and for peripheral organs skin dose TLDs were placed at the surface of the corresponding organs. Target organs were irradiated at 100 cGy and 200 cGy by a 60Co teletherapy unit, and irradiated TLDs were read out by a RE-2000 TLD reader. For precise dose delivery to the cancerous organs by 60Co teletherapy, the depth dose correction factor for lung cancer treatment is 0.8667 ± 0.01, and for the stomach is 0.7856 ± 0.017. In the case of the treatment for the lung and stomach, the closest organs received signifi cant doses compared to the other distant organs. Thus, the risk of second cancer due to the peripheral dose is obtained. The stomach is at the highest risk when the lung is the target and the liver is at the highest risk when the stomach is the targeted organ. 2023-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/908 Measurements of photoneutron dose rate for 15 MV photon beam from medical linear accelerator using neutron survey meter Meaze, AKM Moinul Haque High-energy medical linear accelerators (>10MV) are increasingly used in the medical field to treat cancer patients depending on the treatment organ and patient physic. Medical linear accelerators (Linacs) operating above 10 MV photon beam produce unwanted neutrons (photoneutron) by means of photonuclear reaction (γ, n) between bremsstrahlung photon beams and constituent materials of Linac head. This study involved the measurement of the neutron dose rate from photon beam of medical linear accelerator (Elekta Synergy) operated at 15 MV photon. For the measurement of dose rate, a neutron survey meter LB 6411 probe was used. Neutron dose rate was obtained as a function of delivered dose, field size and detector position. In the study neutron dose rate was found 13.14 mSv/h at a field size of 10 × 10 cm2 at position (0, 90, 0) cm for 350 cGy and 9.26 mSv/h at 5 × 5 cm2 field size at position (0, 80, 0) cm for 200 cGy photon dose delivery. The dose rate varied with respect to detector position in an irregular manner; 2.95 mSv/h at position (-100, 0, 0) cm -on the side of maze entrance and 4.85 mSv/h at position (100, 0, 0) cm -off side of maze entrance. 2023-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/905 NEUTRON INDUCED 55Mn REACTION IN THE ENERGY RANGE 0.001MeV TO 40MeV Meaze, A. K. M. Moinul Haque Neutron induced 55Mn reactions were evaluated in the energy range 0.001 MeV to 40 MeV using TALYS 1.95 computer code. During this evaluation, local and global parameterisations of Koning and Delaroche were used in nuclear optical model. Comparisons were made with experimental data, collected from EXFOR and other sources. Some optical model parameters (OMP) were needed to be adjusted for better agreement between theoretical calculations and experimental findings. Various evaluated libraries such as ENDF, JENDL etc. were checked and compared with our evaluation. TALYS evaluation showed better agreement when parameters were adjusted. 2023-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/904 Investigation of Some Regular X-ray Imaging Parameters in Suggestive Radiography of Four Hospitals in Bangladesh Meaze, AKM Moinul Haque Analytic radiography is a normal image testing technique which has been utilized for quite a long time. It is recommended by specialists so they can identify any problem in patients' bodies without a cut. Thinking about its wide use, the principle objective of this investigation is to give a top notch picture by keeping the radiation portion as low as conceivable through identifying any variety in quality control (QC) boundaries. In this work, some standard quality control boundaries, for example, voltage exactness, time precision test, tube yield linearity, half value layer (HVL) of x-beam were measured. These quality control (QC) boundaries were estimated by a dosimeter keeping a distance of 100 cm from source. The voltage precision went from 0.31% to 4.67% and the time exactness test went from 0% to 2.29%. The consequences of this investigation show that all the QC boundaries are inside the acceptable level which guarantees the advancement of the low portion conveyed to the patients. 2023-01-01T00:00:00Z