What are the methods of positron production? Please don't use mathematical formulas in the explanation.
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2$\begingroup$ Maybe you want to tell us what you already know about positron production, first, and then we can fill in the details? $\endgroup$– CuriousOneDec 24, 2014 at 17:42
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$\begingroup$ I do not want the positron production reason, But the method of positron production, For example, gamma irradiation to the nucleus $\endgroup$– hadiDec 24, 2014 at 17:49
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1$\begingroup$ How many ways are there to catch chickens? Do you consider that a legitimate question? $\endgroup$– CuriousOneDec 24, 2014 at 17:52
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$\begingroup$ How are Positron from The pair of electrons produced? $\endgroup$– hadiDec 24, 2014 at 17:57
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1$\begingroup$ I did. You were the one who said that I shouldn't use mathematical formulas. That's pretty much all one can say without getting out the math. Throw a small charged ball hard enough against another charged ball and two more charged balls will come out, one with the opposite charge... $\endgroup$– CuriousOneDec 24, 2014 at 18:11
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2 Answers
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You can easily find the answer in Wikipedia, http://en.wikipedia.org/wiki/Positron_emission.
One source of positrons are nuclear reactions. I just quote from there: "In 1934 Frédéric and Irène Joliot-Curie bombarded Aluminium with alpha particles to effect the nuclear reaction
$$\ _2^4He + _{13}^{27}Al \to _{15}^{30}P + _0^1n,$$
and observed that the product isotope $ _{15}^{30}P$ emits a positron identical to those found in cosmic rays by Carl David Anderson in 1932. This was the first example of β+ decay (positron emission). . . "
In general the positron is produced if we force a proton to decay as
$$ _1^1p → -0^1n + e^+ + \nu _e$$
This decay doesn't occur spontaneously, because the proton is a stable particle. The procedure is to produce, by a nuclear reaction, a nuclide rich in protons which for reaching a more stable configuration emits a positron for passing to more neutrons.
You can see in Wikipedia a list of unstable nuclides that, if produced, would emit positrons:
$ _6^{11}C, \ _7^{13}N, \ _8^{15}O, \ _9^{18}F, \ _{11}^{22}Na,$ etc.
See for comparison the stable isotopes of these isotopes
$ _6^{12}C, \ _7^{14}N, \ _8^{16}O, \ _9^{19}F, \ _{11}^{23}Na. $
All the nuclides in the preceding list need one more neutron for acquiring stability, but since they don't have that neutron, they produce it by positron decay passing to nuclides that have fewer protons.
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There are basically three methods:
Bombardment, decay, decay following bombardment.
But really all positron emitters that exist on earth in practical quantities are man made: it always starts with bombardment of nuclei with protons, deuterons or alpha particles. Usually the "thing" that is made is the unstable nucleus - the actual production of the positron is the product of the decay of that nucleus.