NCT Treatment Room Dose Determinations Using the Monte Carlo Adjoint Shielding (MASH) Method

2001 ◽  
pp. 629-633
Author(s):  
R. A. Rydin ◽  
T. R. Hubbard ◽  
R. U. Mulder
Keyword(s):  
Monte Carlo ◽  
Treatment Room

Evaluation of Stability using Monte Carlo Simulation in 2 People Isolation Treatment Room of Radiation Iodine

2016 ◽  
Vol 39 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Dong-Gun Jang ◽  
◽  
Sung-Jin Ko ◽  
Chang-Soo Kim ◽  
Jung-Hoon Kim
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Treatment Room

SU-F-T-217: A Comprehensive Monte-Carlo Study of Out-Of-Field Secondary Neutron Spectra in a Scanned-Beam Proton Therapy Treatment Room

2016 ◽  
Vol 43 (6Part16) ◽  
pp. 3512-3512
Author(s):  
F Englbrecht ◽  
S Trinkl ◽  
V Mares ◽  
W Ruehm ◽  
M Wielunski ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Monte Carlo Study ◽  
Secondary Neutron ◽  
Neutron Spectra ◽  
Treatment Room ◽  
Beam Proton ◽  
Therapy Treatment

Monte Carlo estimation of photoneutrons contamination from high-energy X-ray medical accelerators in treatment room and maze: a simplified model

2009 ◽  
Vol 135 (1) ◽  
pp. 21-32 ◽  
Author(s):  
M. Zabihzadeh ◽  
M. R. Ay ◽  
M. Allahverdi ◽  
A. Mesbahi ◽  
S. R. Mahdavi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Energy ◽  
Simplified Model ◽  
X Ray ◽  
Treatment Room ◽  
Monte Carlo Estimation

scholarly journals Monte Carlo Simulations of Neutron Ambient Dose Equivalent in a Novel Proton Therapy Facility Design

2020 ◽  
Vol 6 (4) ◽  
pp. 29-37
Author(s):  
Uwe Titt ◽  
Enzo Pera ◽  
Michael T. Gillin
Keyword(s):  
Monte Carlo ◽  
Radiation Protection ◽  
Proton Therapy ◽  
Facility Design ◽  
Dose Equivalent ◽  
Treatment Room ◽  
Dose Limits ◽  
Ambient Dose Equivalent ◽  
Ambient Dose ◽  
Proton Therapy Facility

Abstract Purpose The neutron shielding properties of the concrete structures of a proposed proton therapy facility were evaluated with help of the Monte Carlo technique. The planned facility's design omits the typical maze-structured entrances to the treatment rooms to facilitate more efficient access and, instead, proposes the use of massive concrete/steel doors. Furthermore, straight conduits in the treatment room walls were used in the design of the facility, necessitating a detailed investigation of the neutron radiation outside the rooms to determine if the design can be applied without violating existing radiation protection regulations. This study was performed to investigate whether the operation of a proton therapy unit using such a facility design will be in compliance with radiation protection requirements. Methods A detailed model of the planned proton therapy expansion project of the University of Texas, M. D. Anderson Cancer Center in Houston, Texas, was produced to simulate secondary neutron production from clinical proton beams using the MCNPX Monte Carlo radiation transport code. Neutron spectral fluences were collected at locations of interest and converted to ambient dose equivalents using an in-house code based on fluence to dose-conversion factors provided by the International Commission on Radiological Protection. Results and Conclusions At all investigated locations of interest, the ambient dose equivalent values were below the occupational dose limits and the dose limits for individual members of the public. The impact of straight conduits was negligible because their location and orientation were such that no line of sight to the neutron sources (ie, the isocenter locations) was established. Finally, the treatment room doors were specially designed to provide spatial efficiency and, compared with traditional maze designs, showed that while it would be possible to achieve a lower neutron ambient dose equivalent with a maze, the increased spatial (and financial) requirements may offset this advantage.

Monte Carlo study of neutron-ambient dose equivalent to patient in treatment room

2016 ◽  
Vol 118 ◽  
pp. 140-148 ◽  
Author(s):  
A. Mohammadi ◽  
H. Afarideh ◽  
F. Abbasi Davani ◽  
M. Ghergherehchi ◽  
A. Arbabi
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Study ◽  
Dose Equivalent ◽  
Treatment Room ◽  
Ambient Dose Equivalent ◽  
Ambient Dose

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

Monte Carlo Algorithms for Moments of Transition Arrays

1988 ◽  
Vol 102 ◽  
pp. 79-81
Author(s):  
A. Goldberg ◽  
S.D. Bloom
Keyword(s):  
Monte Carlo ◽  
State Vector ◽  
Basis Vector ◽  
Collective State ◽  
Dispersion Characteristics ◽  
Dipole Strength ◽  
The Third ◽  
Monte Carlo Algorithms ◽  
Third Moment ◽  
Very High

AbstractClosed expressions for the first, second, and (in some cases) the third moment of atomic transition arrays now exist. Recently a method has been developed for getting to very high moments (up to the 12th and beyond) in cases where a “collective” state-vector (i.e. a state-vector containing the entire electric dipole strength) can be created from each eigenstate in the parent configuration. Both of these approaches give exact results. Herein we describe astatistical(or Monte Carlo) approach which requires onlyonerepresentative state-vector |RV> for the entire parent manifold to get estimates of transition moments of high order. The representation is achieved through the random amplitudes associated with each basis vector making up |RV>. This also gives rise to the dispersion characterizing the method, which has been applied to a system (in the M shell) with≈250,000 lines where we have calculated up to the 5th moment. It turns out that the dispersion in the moments decreases with the size of the manifold, making its application to very big systems statistically advantageous. A discussion of the method and these dispersion characteristics will be presented.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

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