This study involves the measurement of photoneutron contamination emitted from a Siemens Primus medical linear accelerator by using BD-PND bubble detectors. Various bubble detectors were arranged around the linac head with the interval of I m and at the same height as the isocenter to measure the dose equivalent distribution in the treatment room. The measurements were performed for 15 MV X-ray...

objective: using megavoltage photons generated by medical linear accelerator is a common modality for the treatment of malignant. the crucial problem for using photon beams >8mv is the photoneutron yields that increase the risk of secondary cancer that treated with high-energy photon beams. the contaminated neutrons produced in different components of the accelerator head and rely on many param...

-An absolute measurement of the 235U fission cross section has been carried out using a S4Na-Be photoneutron source with median neutron energy of 964 keV. A symmetric two-foil experiment was set up to measure the fission rate in a low-albedo laboratory, and variations in the sourceto-foil spacing used to determine the room background. Fission fragments passing through a limited solid angle aper...

Photoneutron reactions on 208 Pb in the Giant Dipole Resonance (GDR) energy range have been investigated at γ-ray beam line of NewSUBARU synchrotron radiation facility Japan. Making use quasi-monochromatic laser Compton scattering (LCS) beams and a novel flat-efficiency neutron detection system along with associated neutron-multiplicity sorting method, total partial (γ,xn) photoneutron cross se...

Introduction: GRID therapy is a treatment modality in which a high dose of radiation in a single fraction is given to the tumor. This technique previously was used to treat bulky tumors with orthovoltage beams. Recently, studies have been conducted to suggest that GRID therapy with megavoltage photons can be useful in palliative treatments. On the other hand, there has always ...

CALCULATIONS OF THE GIANT-DIPOLE-RESONANCE PHOTONEUTRONS USING A COUPLED EGS4-MORSE CODE J. C. Liu, W. R. Nelson, K. R. Kase and X. S. Mao Stanford Linear Accelerator Center, P. 0. Box 4349, Stanford, CA 94309 Abstract The production and transport of the photoneutrons from the giant-dipoleresonance reaction have been implemented in a coupled EGS4-MORSE code. The total neutron yield (including b...

Objective: Using Megavoltage photons generated by medical linear accelerator is a common modality for the treatment of malignant. The crucial problem for using photon beams >8MV is the photoneutron yields that increase the risk of secondary cancer that treated with high-energy photon beams. The contaminated neutrons produced in different components of the accelerator head and rely on many param...

Objective: Using Megavoltage photons generated by medical linear accelerator is a common modality for the treatment of malignant. The crucial problem for using photon beams >8MV is the photoneutron yields that increase the risk of secondary cancer that treated with high-energy photon beams. The contaminated neutrons produced in different components of the accelerator head and rely on many param...

Radiotherapy represents the most widely spread technique to control and treat cancer. To increase the treatment efficiency, high energy linacs are used. However, applying high energy photon beams leads to a non-negligible dose of neutrons contaminating therapeutic beams. In addition, using conventional linacs necessitates applying wedge filters in some clinical conditions. However, there is not...

Introduction: The utilization of high-energy photons in the medical linear accelerator can lead to photoneutron production. This study aimed to evaluate the effect of the physical components of the head, including flattening filter (FF) andmultileaf collimator (MLC), as well as the dependence of therapeutic field size on the photoneutron spectrum, dose, and flux. <str...