Published June 1970
by Intl Commission on Radiation .
Written in English
|The Physical Object|
In dosimetry, linear energy transfer (LET) is the amount of energy that an ionizing particle transfers to the material traversed per unit distance. It describes the action of radiation into matter.. It is identical to the retarding force acting on a charged ionizing particle travelling through the matter. By definition, LET is a positive quantity. LET depends on the nature of the radiation as. Linear energy transfer.. [International Commission on Radiation Units and Measurements.] Book: All Authors / Contributors: International Commission on Radiation Units and Measurements. viii, 51 pages 28 cm. Series Title: ICRU report, Reviews. User-contributed reviews. Tags. Add tags for "Linear energy transfer.". Be the first. Linear energy transfer or LET is generally measured in units of keV μm −1. The ICRU recommends when a restricted form of LET is desired, that the energy cut-off form of LET be applied because this can be evaluated using restricted stopping-power formulae (Taylor et al., ). Spectrometry of linear energy transfer and its use in high-energy particle beams Article (PDF Available) in Physics of Particles and Nuclei Letters 5(6) November with Reads.
ICRU report 51 defines linear energy transfer as synonymous to linear collision stopping power, both of them unrestricted. It notes that "a more general concept of linear energy transfer involves an energy cutoff. For the present report, however, the simpler definition of the 'unrestricted' energy transfer, as given above, is adequate.". The quality of the radiation can be related to the linear energy transfer spectra or the lineal energy spectra. Lineal energy spectra for different types of radiation are described and the expectation values: frequency mean lineal energy and dose mean lineal energy for neutrons of different energies are compared. ICRU Report Condensed-phase effects are included in the liquid version (MC4L) by means of the dielectric functions which, essentially, substitute the oscillator-strength used in the vapour version (MC4V). The results in the form of radial dose distributions and spatially restricted linear energy transfer are presented and compared with the literature. With the definition of the restricted linear energy transfer,L Δ, given in ICRU Rep the approximation remains imperfect. This study deals with the resulting need for a modified definition ofL Δ, as proposed in a draft report of ICRU. Essential differences .
The force usually increases toward the end of range and reaches a maximum, the Bragg peak, shortly before the energy drops to curve that describes the force as function of the material depth is called the Bragg is of great practical importance for radiation therapy.. The equation above defines the linear stopping power which in the international system is expressed in N but. The kinetic energy of an electron, E, is obtained from the relation of the energy versus the range for electrons in water which is cited from ICRU Report 16 . The residual range of the electron at position X is given by R- x, where R is the range of the electron with initial energy Ei, and x the distance between position X and the parent. ICRU 16; Linear Energy Transfer () ICRU 17; Radiation Dosimetry: X Rays Generated at Potentials of 5 to kV () ICRU 18; Specification of High Activity Gamma-Ray sources () ICRU 19* Radiation Quantities and Units () ICRU 19S* Dose Equivalent [supplement to ICRU Report 19] () ICRU The ICRU report on proton therapy also emphasizes the sharp relative increments in the RBE on the distal edge and the therefore increased effective range. Currently, due to lack of biological input parameters, our ability to predict RBE for all tissues in treatment planning is very limited and thus the continuous use of a generic RBE was.