Dino Posted May 25, 2017 Posted May 25, 2017 Dear reader of this topic, I was wondering what would happen if a photon gives his energy to a proton or a neutron in a atom. (Imagine that a photon would come across a single atom in space for example and he would miss the elektrons) Would the balance of the protons and neutrons disturb and what would happen next ? (Please correct me if I am saying anything wrong)
Strange Posted May 25, 2017 Posted May 25, 2017 There is a good summary of the ways a gamma photon can interact with an atom here: http://www.physics.rutgers.edu/ugrad/205/manuals/matter.pdf (pages 5 & 6) I don't think lower energy photons will interact with the nucleus at all.
swansont Posted May 25, 2017 Posted May 25, 2017 The balance of neutrons and protons will affect whether the photon is absorbed, since that dictates the energy level structure of the nucleus. So you could cause a nuclear excitation. It is possible that a photon of sufficient energy could eject a neutron or proton. 1
Dino Posted May 25, 2017 Author Posted May 25, 2017 So does that mean that if a photon with sufficient energy to eject a proton of a element that it would change into another element ? So for example: From Helium to Hydrogen ? Is this correct ?
swansont Posted May 25, 2017 Posted May 25, 2017 So does that mean that if a photon with sufficient energy to eject a proton of a element that it would change into another element ? So for example: From Helium to Hydrogen ? Is this correct ? Yes. Or change isotope, if a neutron were ejected.
Dino Posted May 27, 2017 Author Posted May 27, 2017 (edited) So does that mean that if technology is able to create a photon with sufficient energy and to let him move in the right direction to hit a proton we could change for example Helium into Hydrogen, this would be a great way to "change" all sorts of elements without the fear of extinction of them on this planet. Edited May 27, 2017 by Dino
swansont Posted May 27, 2017 Posted May 27, 2017 So does that mean that if technology is able to create a photon with sufficient energy and to let him move in the right direction to hit a proton we could change for example Helium into Hydrogen, this would be a great way to "change" all sorts of elements without the fear of extinction of them on this planet. Energy-wise this is a very inefficient way of transmuting elements.
Dino Posted May 27, 2017 Author Posted May 27, 2017 (edited) So for example: a Helium-4 isotope to a Hydrogen-3 isotope taking 1 proton away would take if my calculations are correct: Helium-4 has 2 protons and 2 neutrons, 2 * 1,007276466812 = 2,014552934 u and 2 * 1,00866491600 = 2,017329832 2,014552934 + 2,017329832 = 4,031882766 u Helium - 4 mass = 4,002603 4,031882766 - 4,002603 = 0,029279766 u 1 u = 931,494061 MeV 0,02927976 * 931,494061 = 27,27392814 MeV 27,27392814 / 4 = 6,818482034 MeV So does that mean that if I have calculated it correctly it takes 6,818482034 MeV to remove a proton of the nucleus from a Helium-4 isotope ? Edited May 27, 2017 by Dino
Sensei Posted May 27, 2017 Posted May 27, 2017 (edited) So for example: a Helium-4 isotope to a Hydrogen-3 isotope taking 1 proton away would take if my calculations are correct: Helium-4 has 2 protons and 2 neutrons, 2 * 1,007276466812 = 2,014552934 u and 2 * 1,00866491600 = 2,017329832 2,014552934 + 2,017329832 = 4,031882766 u Helium - 4 mass = 4,002603 4,031882766 - 4,002603 = 0,029279766 u 1 u = 931,494061 MeV 0,02927976 * 931,494061 = 27,27392814 MeV 27,27392814 / 4 = 6,818482034 MeV So does that mean that if I have calculated it correctly it takes 6,818482034 MeV to remove a proton of the nucleus of a Helium-4 isotope ? Not really. [math]^4_2He + 19.82 MeV \rightarrow ^3_1H + p^+[/math] Take mass of Helium-4 4.0026 u multiply by 931.494 MeV/u subtract 2 electrons 0.511 MeV each, you will receive 3727.38 MeV Repeat the same with Hydrogen-3 3.01605 u you will receive 2808.92 MeV. 3727.38 MeV + 19.82 MeV = 2808.92 MeV + 938.272 MeV (without taking into account momentum) Helium-4 has one of the largest energies needed to eject proton or neutron, from the all isotopes. Edited May 27, 2017 by Sensei 1
Dino Posted May 28, 2017 Author Posted May 28, 2017 (edited) So for example: to go from Fluorine to Oxygen-18 isotope, Fluorine = 18,99840 u 18,99840 * 931,494 = 17696,89561 MeV 17696,89561 - (9 * 0,511) = 17692,30 MeV Oxygen-18 isotope = 17,99916 u 17,99916 * 931,494 = 16766,11 MeV 16766,11 - (8 * 0,511) = 16762,02 MeV 17692,30 MeV + ? = 16762,02 MeV + 938,272 MeV 17692,30 MeV + 7,99 MeV = 16762,02 MeV + 938,272 MeV Are these calculations corrrect ? Edited May 28, 2017 by Dino
Sensei Posted May 28, 2017 Posted May 28, 2017 Are these calculations corrrect ? Yes. My app is showing 7.99485 MeV as well. 1
Dino Posted May 28, 2017 Author Posted May 28, 2017 (edited) So to eject a proton from a Fluorine nucleus there is a photon needed with 7,99485 MeV of energy going in the right direction to get absorbed by a proton of a Fluorine nucleus ? To calculate the wavelength of the photon there is this equation: [latex] {E}=\frac{\ hc}{\lambda } [/latex] or [latex] {\lambda}=\frac{\ hc}{E } [/latex] [latex] {\lambda(\mu m)}=\frac{\ 1,24}{7994850 } [/latex] which brings up to a wavelenght of 1,550998455 * 10^-07 micrometer, multiplied by a 1000 to give nanometers it is 1,550998455 * 10^-04 nanometer which is 0,0001550998455 nanometer. Is this correct ? (Please correct me if I am saying anthing wrong) Edited May 28, 2017 by Dino
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