Fundamentals of Radiation Dosimetry

Abstract

The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

High charge carrier storage capacity and wide range X-rays to infrared photon sensing in LiLuGeO4:Bi3+,Ln3+ (Ln = Pr, Tb, or Dy) for anti-counterfeiting and information storage applications

“…The electron tapping depths were roughly estimated by using a variable rate plot, as demonstrated in Fig. 3(g), and the first-order TL-recombination kinetics equation: 47–51 where T m is the temperature (K) of a thermoluminescence glow band maximum, β indicates the utilized heating rate (K s −1 ), E is the trapping depth (eV), k is the Boltzmann constant (8.62 × 10 −5 eV K −1 ), and s is the frequency factor for the compound under study. A linear fitting of the experimentally observed ln( T m 2 / β ) against the 1/ kT m shown in Fig.…”

“…The electron tapping depths were roughly estimated by using a variable rate plot, as demonstrated in Fig. 3(g), and the first-order TL-recombination kinetics equation: [47][48][49][50][51] ln show the RT isothermal decay curves for Bi 3+ and/or Ln 3+ (Ln = Tb) doped LiLuGeO 4 after exposure to X-rays or 254 nm UV light. An afterglow of more than 10 h was measurable in LiLuGeO 4 :0.005Bi 3+ and LiLuGeO 4 :0.005-Bi 3+ ,0.012Tb 3+ after charging with X-rays, as shown in Fig.…”

Autonomous Search of Radioactive Sources through Mobile Robots

“…Assuming that the lost or stolen radioactive source is approximately a point, so only the source activity and spatial location are considered in the study, and the spatial volume is not considered. In homogeneous air, the exposure dose rate of the γ-ray source at distance R is [33]:…”

“…Assuming that the lost or stolen radioactive source is approximately a point, so only the source activity and spatial location are considered in the study, and the spatial volume is not considered. In homogeneous air, the exposure dose rate of the γ-ray source at distance is [ 33 ]: . Among them, is the exposure; and A is the exposure dose rate constant and the activity of the point radiation source, respectively; , where is the source coordinate.…”

Determinación del espectro de energía de un haz de rayos X terapéutico de kilovoltaje a partir de su curva de atenuación

“…Modelamiento Matemático Para un mismo medio material, bajo la condición de equilibrio de partículas cargadas (EPC), la dosis absorbida es equivalente al kerma colisional (Attix, 2008;Ma, 2014). Por tanto, si el medio material es el aire, se tiene que (Bos, 2011), 1donde D ar es la dosis absorbida en aire, K col,ar es el kerma colisional en aire, E max es la energía máxima de los fotones del haz de energía nominal E, Ф(E), es la distribución energética de fluencia, es el coeficiente másico de absorción de energía y ρ es la densidad del material absorbedor.…”