Alpha particles at energies of 10 MeV to 1 TeV: conversion coefficients for fluence-to-absorbed dose, effective dose, and gray equivalent, calculated using Monte Carlo radiation transport code MCNPX 2.7.A

2009 ◽  
Vol 138 (4) ◽  
pp. 310-319 ◽  
Author(s):  
K. Copeland ◽  
D. E. Parker ◽  
W. Friedberg
Keyword(s):  
Monte Carlo ◽  
Effective Dose ◽  
Radiation Transport ◽  
Absorbed Dose ◽  
Alpha Particles ◽  
Transport Code ◽  
Conversion Coefficients

scholarly journals Radiation Risks in Cis-Lunar Space for a Solar Particle Event Similar to the February 1956 Event

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Fahad A. Zaman ◽  
Lawrence W. Townsend
Keyword(s):  
Effective Dose ◽  
Energy Transport ◽  
Radiation Transport ◽  
Organ Doses ◽  
Solar Particle Events ◽  
Solar Particle ◽  
Transport Code ◽  
On Line ◽  
Critical Organ ◽  
In Cis

Solar particle events (SPEs) can pose serious threats for future crewed missions to the Moon. Historically, there have been several extreme SPEs that could have been dangerous for astronauts, and thus analyzing their potential risk on humans is an important step towards space exploration. In this work, we study the effects of a well-known SPE that occurred on 23 February 1956 on a mission in cis-Lunar space. Estimates of the proton fluence spectra of the February 1956 event were obtained from three different parameterized models published within the past 12 years. The studied geometry consists of a female phantom in the center of spherical spacecraft shielded by aluminum area densities ranging from 0.4 to 40 g cm−2. The effective dose, along with lens, skin, blood forming organs, heart, and central nervous system doses, were tallied using the On Line Tool for the Assessment of Radiation In Space (OLTARIS), which utilizes the High Z and Energy TRansport code (HZETRN), a deterministic radiation transport code. Based on the parameterized models, the results herein show that thicknesses comparable to a spacesuit might not protect against severe health consequences from a February 1956 category event. They also show that a minimum aluminum shielding of around 20 g cm−2 is sufficient to keep the effective dose and critical organ doses below NASA’s permissible limits for such event. In addition, except for very thin shielding, the input models produced results that were within good agreement, where the doses obtained from the three proton fluence spectra tended to converge with slight differences as the shielding thickness increases.

scholarly journals MONTE CARLO SIMULATION IN INTERNAL RADIOTHERAPY OF THYROID CANCER

2020 ◽  
Vol 3 (9) ◽  
pp. 16-24 ◽  
Author(s):  
Hammam Oktajianto ◽  
Evi Setiawati
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Thyroid Cancer ◽  
Monte Carlo Method ◽  
Effective Dose ◽  
Radiation Effect ◽  
Cervical Vertebrae ◽  
Absorbed Dose ◽  
Particle Track ◽  
Internal Radiotherapy

Thyroid radiotherapy is a cancer therapy that is treated by giving radioactive I-131 in Thyroid gland. This cancer is at the ninth from ten of common malignant cancer. A man has higher risk to get Thyroid cancer than a woman has. This organ is lain near human neck. This research aim was to simulate particle track of radiation I-131 and determine an absorbed dose and effective dose in Thyroid and other organs around Thyroid such as Brain, Lung and Cervical vertebrae. The simulation and calculation used Monte Carlo method operated by MCNPX software. Geometry of Thyroid and other organs used ORNL MIRD phantom geometry. From the results, it shown that particle track of radiation was distributed at Thyroid while several particles radiated other organs. The absorbed dose in Thyroid and other organs increased every rising activity of I-131 used, but the absorbed dose in other organs was less than in Thyroid. Radiation effect for damage cancer in Thyroid was shown by an effective dose which it increased every rising activity of I-131 used and the maximum effective dose was at 200 mCi activity of I-131. Although the effective dose in Thyroid increased, the effective dose in other organs like Brain, Lung and Cervical vertebrae was still less than in Thyroid so that the use of I-131 each activity did not really influence other organs around Thyroid.  

Proton Dose Conversion Coefficients Based on Chinese Reference Adult Woman Voxel Phantom

2013 ◽  
Author(s):  
Fangfang Liu ◽  
Mingqi Shen ◽  
Taosheng Li ◽  
Chunyu Liu
Keyword(s):  
Effective Dose ◽  
Reference Data ◽  
Absorbed Dose ◽  
The Body ◽  
Adult Woman ◽  
Voxel Model ◽  
Conversion Coefficients ◽  
Computational Phantoms ◽  
Posterior Anterior ◽  
Anterior Posterior

In order to calculate the dose conversion coefficients for proton, the voxel model of Chinese Reference Adult Woman (CRAW) was established by the Monte Carlo transport code FLUKA according to the Chinese reference data and the Asian reference data. Compared with the reference data, the deviations of the mass for organs or tissues of CRAW is less than ±5%. Calculations have been performed for 14 incident monoenergetic protons energies from 0.02GeV to 10TeV at the irradiation incident of anterior-posterior (AP) and posterior-anterior (PA). The results of fluence-to-effective dose conversion coefficients are compared with data from the different models such as an anthropomorphic mathematical model, ICRP reference adult voxel model, the voxel-based visible Chinese human (VCH). Anatomical differences among various computational phantoms and the spatial geometric positions of the organs or tissues lead to the discrepancies of the effective dose conversion coefficients in the ranging from a negligible level to 107% at proton energies below 0.2GeV. The deviations of the coefficients, above 0.2GeV, are mostly within 10%. The results of fluence-to-organ absorbed dose conversion coefficients are compared with the data of VCH. The deviations of the coefficients, below and above 0.2GeV, are within 150% and 20%, respectively. The primary factors of the deviations for the coefficients should be due to the differences of the organ mass and the size of the body shape.

Integrating Circuit Level Simulation and Monte-Carlo Radiation Transport Code for Single Event Upset Analysis in SEU Hardened Circuitry

2008 ◽  
Vol 55 (6) ◽  
pp. 2886-2894 ◽  
Author(s):  
Kevin M. Warren ◽  
Andrew L. Sternberg ◽  
Robert A. Weller ◽  
Mark P. Baze ◽  
Lloyd W. Massengill ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Radiation Transport ◽  
Single Event Upset ◽  
Single Event ◽  
Transport Code
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