محمدی, سعید

دانشگاه پیام نور تهران

[ 1 ] - محاسبات مصرف سوخت و پارامترهای نوترونیک مربوط به رآکتورهای آب سنگین تحقیقاتی با سوخت اورانیوم- توریوم توسط کد MCNPX

One of the main characteristics of heavy water research reactors is their high production of plutonium. This work demonstrates the possibility of reduction of plutonium production and other actinides in heavy water research reactors. Among the many ways for reducing plutonium production in a heavy water reactor, in this research, changing the fuel from natural uranium to thorium-uranium mixed f...

[ 2 ] - شبیه‌ساز تومور فعال سازی شده توسط نقره و برآورد بهبود دز در فوتون درمانی

Treatment of radio-sensitized tumor is one of the promising modalities in radiotherapy. Since the different parameters and physical conditions vary in the treatments, the use of simulation models is easier, less costly and faster than practical methods for forecasting the solutions designed to optimize treatment. Therefore in this study, Monte Carlo simulations are applied to investigate the do...

[ 3 ] - بهینه‌سازی مکان چشمه‌های براکی تراپی در دو و سه بعد با کاربست الگوریتم ژنتیک

Optimization in radiotherapy is one of an important and attractive topic in Medical Physics. In this study, we have written a computer code base on genetic algorithm using MATLAB software, to optimize the best places of brachytherapy sources with optimal value of a parameter which is determined by weight. The weight parameter is related to the activity of each seed implant brachytherapy sources...

[ 4 ] - عامل شکل اخترفیزیکی واکنش گیراندازی تابشی (_4^7)Be (α,γ) (_6^11)C

در این کار به علت اهمیت واکنش گیراندازی(_4^7)Be (α,γ) (_6^11)C در فیزیک هسته ای و اخترفیزیک ضمن معرفی این واکنش به محاسبه ی پتانسیل‌های مربوط به آن، سطح مقطع و آهنگ واکنش پرداخته و در نهایت پس از معرفی و محاسبه‌ی فاکتور اخترفیزیکی S(E)کمیتی با وابستگی کمتر انرژی نسبت به سطح مقطع در رنج انرژی‌های پایین مربوط به نوکلئوسنتزاولیه، فاکتور اخترفیزیکی را برای این واکنش در رنج انرژی MeV10- MeV 0 در حدو...

[ 5 ] - Compton scattering as a probe for materials investigation

This article investigates into the feasibility of using gamma radiation Compton backscatter spectra as a means of material characterization, with the view to developing a portable, hand held probe for investigative purposes such as searching for illicit substances hidden in wall or car door cavities.

[ 6 ] - Effect of Dental Filling Materials on Electron Beam Radiotherapy Dose Distribution in Head Region: a Monte Carlo Study by FLUKA and MCNPX Codes

Introduction: Radiation therapy is regarded as the mainstay treatment for head or neck cancer patients. In this method, the backscattered radiation of dental composites can damage the surrounding tissue. Material and Methods: The current study compared the effects of electron beam radiation on healthy teeth with the tooth filled with material...

[ 7 ] - Using PSO algorithm optimization for planning 103Pd seeds brachytherapy positions

Radiation therapy, is one of the treatments for cancer. Brachytherapy is a radiotherapeutic technique that a sealed radiation source is placed inside or next to the tissue and has become a mainstream treatment option for cancer. Achieving maximum dose to the gland as well as minimum injury to the adjacent tissues is a basic principle in radiation therapy. Sources configuration must be designed ...