introduction:  90 sr/ 90 y source  has  been  used  for  the  intravascular  brachytherapy  to  prevent  coronary  restenosis in the patients who have undergone angioplasty. the aim of this research is to determine the  dose distribution of  90 sr/ 90 y source in a water phantom.  materials  and  methods:  in  the  present  work,  mcnp  code  has  been  applied  to  calculate  the  dose  distri...

In this paper, we present a neutron spectrum unfolding technique based on a modification of the least-squares method. The main innovation is the use of a Krylov subspace iteration method to solve the least-squares normal equations. This method was employed because it performs better on ill-conditioned systems of linear equations as compared with standard direct-solution methods. Three different...

Segmented coaxial HPGe (High Purity Germanium) detectors have recently been shown to be feasible for Gamma Emission Tomography (GET). This type of detector allows a combination high efficiency and energy resolution in gamma spectrometry irradiated nuclear fuel. The ultimate aim developing segmented GET measurements is achieve spatial facilitate imaging rod-internal features interrogation smalle...

Anthropometric and anthropomorphic phantoms have been used extensively for characterizing in-vivo measurement systems that determines internally deposited radionuclides. The accuracy in activity determination relies critically on system design, calibration routine, and reproducbility in material composition, geometry configuration, and physical dimensions of the phantoms respect to the actual o...

background: monte carlo and experimental relative dose determination in a water phantom, due to a high dose rate (hdr) 192ir source is presented for real energy spectrum and monochromatic at 356 kev. materials and methods: the dose distribution has been calculated around the 192ir located in the center of 30 cm ×30 cm ×30 cm water phantom using mcnp4c code by monte carlo method. relative dose v...

background: lead-based radiation shields are widely used in radiology departments to protect both workers and patients from any unnecessary exposure to ionizing radiation. recently there has been a great deal of concern expressed about the toxicity of lead. human lead toxicity is well documented. in that light, production of environmentally-friendly lead-free radiation shields with less weight ...

MCNP is the Monte Carlo N-Particle radiation transport code whose history dates back more than half a century to the early days of computing. From a simple beginning, its uses have grown to include fields such as criticality safety, radiation shielding, oil well logging, and medical imaging and diagnostics and an international user community of over 3000 users. This large user community could o...

For the first time, measurements of the time-dependent cross-correlation distributions of plutonium oxide have been made separately for neutrons and gamma rays. Six EJ-309 liquid scintillation detectors with a digital, offline pulse shape discrimination and pulse timing method were used to measure five different samples of varying mass and burnup. The number of (neutron, neutron) correlations w...