Talk:Rutherford backscattering spectrometry

Latest comment: 8 years ago by Shovalzo in topic A better starting paragraph

Geiger Marsden diagram - plum pudding misleading

edit

Hi, I think the first part of the diagram is misleading. If the positively charged nuclear particles were evenly distributed throughout the plum pudding then that model predicts there would be a "significant" proportion of the "projected" alpha particles deflected from a straight path. So on the receiving surface one would see light flashes scattered over a "significant" area - the angle of deflection dependent on how close the alpha particles came to the positively charged nuclear particles (I can't remember if protons were named at that time or if neutrons had been proposed). Anyway, what Rutherford's assistants saw was that most of the light flashes were on a path that indicated there was no deflection of the alpha particles by the atoms. Hence the deduction was the gold(?) atoms were mainly "empty space". The clincher for a mainly empty space but with concentrated nucleus was the detection of a few "bounced back" alpha particles. Hence the interpretation of the highly concentrated positive nucleus. Most people when they tell the story concentrate on the "bounced back" "shell at tissue paper" part of the interpretation , but the lack of deflection of the alpha particles is just as significant in providing evidence of the nuclear model. Now ..... my point about the entry is .... the first part of the diagram (plum pudding) should show a "significant" proportion of the paths of the alphas particles being deflected by the positive particles in the nucleus - not passing straight through as in the current version of the picture. Apart from that, I like the way the diagram is drawn and put together the compare and contras the plum pudding and nuclear models. Clive long 07:58, 17 October 2007 (UTC) Clive LongReply

Factor missing

edit

The differential cross-section of the backscattering is missing the prefactor   .. and don't tell me it's in atomic units, as there would be no   then. --MarsmanRom —Preceding unsigned comment added by 141.20.43.124 (talk) 09:55, 7 February 2008 (UTC)Reply

Please check

edit

I have reverted an edit which changed a formula because the person who changed it has only three edits and the other two were obviously bad. I have not looked at the formula itself to determine what is actually correct. Somebody who has access to the referenced material should check this. Here is the diff of my revert: [1]. --DanielRigal (talk) 00:02, 13 June 2009 (UTC)Reply

Spectroscopy or Spectrometry?

edit

I find three names for this technique, "Rutherford backscattering spectroscopy", "Rutherford backscattering spectrometry", and "Rutherford backscattering". Chu [2], Burrow [3], and Young [4] says "spectrometry". Kimura [5], Metzner [6], and Cherniak [7] says "spectroscopy".

Many others say simply "Rutherford backscattering" without the third word. Anybody have any comment on this? Are these all equally valid? Personally, I tend to find "spectro-" a little odd, because the technique is not related to optics. --朝彦 (Asahiko) (talk) 08:06, 4 February 2010 (UTC)Reply

@Asahiko: There doesn't seem to be a "canonical name" for RBS, and spectroscopy and spectrometry are both used fairly frequently. I prefer spectrometry as it's somewhat more appropriate for an experimental technique (see the definitions in Spectroscopy), but really there's no reason not to use either.

I also see your point on using "spectro-" in a non-light related context, but condensed-matter physics often refers to "spectroscopy" in any context where some kind of energy spectrum is produced even when the incident particles are not photons. This argument is weaker for RBS than for most others, I think, but the name is still common in the literature. ajdecon (talk) 15:43, 14 February 2011 (UTC)Reply

First use of "spectrum" (from the Latin, specere, to see) in this sense is by Newton in 1671 in his Optics paper (Phil.Trans.6, 3075-3087), and he meant "quantum phaenomenon made visible with a dispersive mechanism", as opposed to "phantom" or "apparition" which is how the word was used previously. We have kept this special usage whenever a dispersive mechanism is used to make any phaenomenon visible. Hence "spectrometry". It is the visibility (=observability) and the dispersion that are important, not the photons. C.jeynes (talk) 09:47, 22 August 2011 (UTC)Reply

Spectrometry and spectroscopy are used interchangeably - the usage is covered by convention not logic. Hence "RBS" is usually expanded "spectrometry" (following Chu et al, 1978), but XPS is "spectroscopy", for no very good reason. In principle "spectroscopy" is what you see and "spectrometry" is what you measure. So the Hubble red-shift is a "spectroscopy" since you are depending on recognising the red-shifted pattern, whereas an RBS spectrum has to be unfolded to be understood. But its all a bit fluid, honestly. C.jeynes (talk) —Preceding undated comment added 09:54, 22 August 2011 (UTC).Reply

External links content to be put into article prose?

edit

Stacey (talk) 16:25, 26 December 2015 (UTC)Reply

A better starting paragraph

edit

The first paragraph should at least have one line explaining what can be gained from RBS. If I'm checking if this method can help me get, say, the doping profile, I should be able to get the information quickly, without reading in depth the entire article. It is not clear at all what is being measured and what info is gained. — Preceding unsigned comment added by Shovalzo (talkcontribs) 06:51, 11 September 2016 (UTC)Reply