Talk:Bragg peak

From Wikipedia, the free encyclopedia

WikiProject Physics This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.
Stub This article has been rated as Stub-Class on the assessment scale.
??? This article has not yet received an importance rating within physics.

Help with this template This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.
This article has been automatically assessed as Stub-Class by WikiProject Physics because it uses a stub template.
  • If you agree with the assessment, please remove {{Physics}}'s auto=yes parameter from this talk page.
  • If you disagree with the assessment, please change it by editing the class parameter of the {{Physics}} template, removing {{Physics}}'s auto=yes parameter from this talk page, and removing the stub template from the article.

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. The Bragg peaks, and the depth-dose profiles of different energy photons, electrons, protons, pi-mesons etc are all exploited in the clinical situation.Jellytussle 18:43, 30 December 2005 (UTC)

Photon maxima are caused by the build up effect - this is totally unrelated to the Bragg Peak. Electron maxima are caused principally by increased obliquity with depth (a Bragg Peak type effect does contribute, but is less significant). The Bragg Peak description of radiotherapy depth dose curves really only applies to light ions (Protons up to Neon). I believe the Bragg Peak description is correct (I just tweaked it a bit). Andybuckle 14:04, 16 May 2006 (UTC)


Does this image illustrate a bragg peak of air ionization? --Deglr6328 23:47, 31 August 2006 (UTC)

No.Jellytussle 10:50, 1 September 2006 (UTC)

That wasn't very convincing. care to elaborate?--Deglr6328 22:36, 1 September 2006 (UTC)
The current image (in the text of the article) represents the Bragg peak in a uniformly dense medium, though the length scale will change depending on what uniformly dense medium you choose due to associated cross-sections changing. For things like auroral physics, where ionisation is created by electrons and protons coming in and striking atmospheric particles, you start off with a low density material (which stretches the initial tail) and then get a very sudden peak as you hit higher energy stuff, which brings the Bragg peak closer to the Chapman function, which is the much different photon version. Although the image here does show something, it would need to be closer in to show the actual peak. At present it shows emission, but not in enough detail to show there's a lead up to the brightest bit and then a sudden cut-off. If it did, it would be good, its just its so far out at the moment, the bright bit could be due to the beam spreading. MilleauRekiir 22:39, 5 December 2006 (UTC)

Bragg peaks are evident in depth-ionization curves and depth-dose curves. The figure and discussion currently relate principally to Bragg peaks of dose in water. The article may benefit from being split into "pure physics" and a "medical applications". Andybuckle 15:09, 13 December 2006 (UTC)