Talk:Positron emission

message: This article claims (as does Beta decay), that a positron is also called a 'beta plus particle'. Why is this, seeing as a positron is positively charged? Can someone confirm this?
----
Answer: Historical reasons. The electron, when ejected from a radioactive nucleus, was called a beta particle. When it was realized that beta particles were just electrons, the term "beta-minus decay" was used. Thus, by analogy, positron emission is therefore "beta-plus decay".
--24.80.110.173 04:30, 5 August 2005 (UTC)
thread_title: Untitled

message: Positron emission is another term for beta plus decay. This page is too small to be a separate article. I'd like to suggest merging this with beta decay, which already contains information about beta plus decay.<BR />
- SkyLined (talk) 16:48, 22 March 2008 (UTC)
replies: text: Good idea. -Lone Deranger (talk) 22:44, 24 March 2008 (UTC)

text: I'd say merging them is a bad idea. They are two totally separate decay types with separate products. --The High Fin Sperm Whale 17:46, 3 May 2010 (UTC)
thread_title:  Merger proposal 

message: Shouldn't the energy be on the other side of the equation? Positron emission requires an input of energy as the neutron is heavier than the proton. 138.38.148.5 (talk) 21:34, 14 April 2008 (UTC)
replies: text: If the energy were on the other side, the decay would not occur! Only exothermic decays happen.  Other reactions are possible but require energy inputs as in an "atom smasher" or other collision initiator such as a cosmic ray interaction. I believe the key here is that Carbon 11 is unstable because of the unpaired neutron, but the decay energy depends on the whole ensemble of protons and neutrons present and should not be viewed as "decay" of a proton into a neutron, which, as you noted, is energetically impossible. Even in ordinary (non-nuclear) chemistry, reactions and are often driven by the combinations of atoms that occur on either side of the reaction equation, because bonds can be stronger or weaker depending on the combinations that occur. Carrionluggage (talk) 15:10, 15 April 2008 (UTC)
thread_title:  Error? 

message: Someone has listed a change from 0.45 to 0.96 MeV but it does not show (in my browser - I still see 0.45)
The 0.96 MeV value is the total energy released, positron and neutrino.  The latter is very hard to detect so this number is not of much practical use.  It is the endpoint of the positron spectrum - unattainable in practice.  The value 0.45 MeV is the mean positron energy - useful in medical applications etc.
Why can't I see the change except in the history? Carrionluggage (talk) 21:59, 22 April 2008 (UTC)
thread_title:  change of energy released 

message: I think a section discussing when such positron-emitting isotopes were discovered and or predicted would be of interest.  — Preceding unsigned comment added by 69.164.56.1 (talk) 03:08, 11 March 2012 (UTC)
thread_title:  History? 

message: "Positron emission occurs only very rarely naturally on earth, when induced by a cosmic rayor from one in a hundred thousand decays of potassium-40, a rare isotope, 0.012% of that element on earth." But there is also lanthanum-138, which has a probability of 66.4% for beta-plus decay (which means that it has a shorter partial half-life for beta-plus decay than potassium-40). 129.104.241.25 (talk) 12:43, 1 October 2023 (UTC)
thread_title:  Occurrence of positron emission 

message: It means positron emission + electron capture for most isotopes, but only position emission for 40K, 59Ni, 91Nb, 91m1Nb, 140Pr, 143Pm, 144Pm, 140Eu, 142Eu, 152Eu, 140Gd, 142Gd, 142Tb, 142Dy and 201Pb. Of course there is actually no confusion caused because when β+ and EC appear at the same time, we know that the former refers only to positron emission. 129.104.241.214 (talk) 14:42, 28 December 2023 (UTC)
thread_title:  The symbol β<sup>+</sup> in the tables of isotopes is ambiguous