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The Bragg peak is a pronounced peak on the Bragg curve which plots the energy loss of ionizing radiation during its travel through matter. For protons , α-rays , and other ion rays , the peak occurs immediately before the particles come to rest.
Bragg curve of 5.49 MeV alpha particles in air. The force usually increases toward the end of range and reaches a maximum, the Bragg peak, shortly before the energy drops to zero. The curve that describes the force as function of the material depth is called the Bragg curve. This is of great practical importance for radiation therapy.
Hence the dose increases with increasing thickness up to the Bragg peak that occurs near the end of the particle's range. Beyond the Bragg peak, the dose drops to zero (for protons) or almost zero (for heavier ions). The advantage of this energy deposition profile is that less energy is deposited into the healthy tissue surrounding the target ...
Usually, the energy loss per unit distance increases while the particle slows down. The curve describing this fact is called the Bragg curve. Shortly before the end, the energy loss passes through a maximum, the Bragg Peak, and then drops to zero (see the figures in Bragg Peak and in stopping power).
In order to achieve diffraction conditions, the sample under study must be precisely aligned. The contrast observed strongly depends on the exact position of the angular working point on the rocking curve of the sample, i.e. on the angular distance between the actual sample rotation position and the theoretical position of the Bragg peak.
ultra: from Latin, meaning beyond; micro and scopic: from ancient Greek, meaning small looking, referring to the fineness of particulates; silico-: from Latin, silicon; volcano: from Latin, referring to volcano; coni: from ancient Greek (κόνις, kónis) which means dust-osis: from ancient Greek, suffix to indicate a medical condition
Is this definition of Bragg Peak strictly correct? The Bragg peak, as applied to clinical radiotherapy is the peak of maximum energy deposition in the depth-dose curve of ANY absorbed radiation (photons as well as electrons.) The Bragg peak does not describe the surface dose or the tail of the curve.
In medicine, proton therapy, or proton radiotherapy, is a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often to treat cancer.The chief advantage of proton therapy over other types of external beam radiotherapy is that the dose of protons is deposited over a narrow range of depth; hence in minimal entry, exit, or scattered radiation dose to healthy ...