Proton emission

Short description: Type of radioactive decay

"Proton radioactivity" redirects here. For hypothetical decay of protons into subatomic particles, see Proton decay.

File:Zerfallsschema.svgThe decay of a proton rich nucleus A populates excited states of a daughter nucleus B by β+ emission or electron capture (EC). Those excited states that lie below the separation energy for protons (Sp) decay by γ emission towards the ground state of daughter B. For the higher excited states a competitive decay channel of proton emission to the granddaughter C exists, called β-delayed proton emission. Nuclear physics

Nucleus * Nucleons (p, n) * Nuclear matter * Nuclear force * Nuclear structure * Nuclear reaction

Models of the nucleus

Liquid drop * Nuclear shell model * Interacting boson model * Ab initio

Nuclides' classification

Stable * Magic * Even/odd * Halo&nbsp;(Borromean)

Nuclear stability

Binding energy * p–n ratio * Drip line * Island of stability * Valley of stability * Stable nuclide

Radioactive decay

Alpha α * Beta β (2β, β+) * K/L capture * Isomeric (Gamma γ * Internal conversion) * Spontaneous fission * Cluster decay * Neutron emission * Proton emission

Nuclear fission

Spontaneous * Products (pair breaking) * Photofission

Capturing processes

electron (2×) * neutron (s * r) * proton (p * rp)

High-energy processes

Spallation (by cosmic ray) * Photodisintegration

Nucleosynthesis and
nuclear astrophysics

Nuclear fusion
Processes: Stellar * Big Bang * Supernova
Nuclides: Primordial * Cosmogenic * Artificial

High-energy nuclear physics

Quark–gluon plasma * RHIC * LHC

* v
* t
* e

Proton emission (also known as proton radioactivity) is a rare type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state (or a low-lying isomer) of very proton-rich nuclei, in which case the process is very similar to alpha decay. For a proton to escape a nucleus, the proton separation energy must be negative (Sp < 0)—the proton is therefore unbound, and tunnels out of the nucleus in a finite time. The rate of proton emission is governed by the nuclear, Coulomb, and centrifugal potentials of the nucleus, where centrifugal potential affects a large part of the rate of proton emission. The half-life of a nucleus with respect to proton emission is affected by the proton energy and its orbital angular momentum.[1] Proton emission is not seen in naturally occurring isotopes; proton emitters can be produced via nuclear reactions, usually using linear particle accelerators.

Although prompt (i.e. not beta-delayed) proton emission was observed from an isomer in cobalt-53 as early as 1969, no other proton-emitting states were found until 1981, when the proton radioactive ground states of lutetium-151 and thulium-147 were observed at experiments at the GSI in West Germany.[2] Research in the field flourished after this breakthrough, and to date more than 25 isotopes have been found to exhibit proton emission. The study of proton emission has aided the understanding of nuclear deformation, masses, and structure, and it is a pure example of quantum tunneling.

In 2002, the simultaneous emission of two protons was observed from the nucleus iron-45 in experiments at GSI and GANIL (Grand Accélérateur National d'Ions Lourds at Caen).[3] In 2005 it was experimentally determined (at the same facility) that zinc-54 can also undergo double proton decay.[4]

## See also

* Nuclear drip line
* Diproton (a particle possibly involved in double proton decay)
* Free neutron
* Neutron emission
* Photodisintegration

## References

1. ↑ Poenaru, Dorin N., ed (2001) (in English). Nuclei Far from Stability and Astrophysics. Dordrecht: Springer Netherlands. pp. 79–81. doi:10.1007/978-94-010-0708-5. ISBN 978-0-7923-6937-0. http://link.springer.com/10.1007/978-94-010-0708-5.
2. ↑ S. Hofmann (1996). "Chapter 3: Proton radioactivity". in Dorin N. Poseru. Nuclear Decay Modes. Bristol: Institute of Physics Publishing. pp. 143–203. ISBN 0-7503-0338-7.
3. ↑ Armand, Dominique (June 6, 2002). "A new mode of radioactive decay". http://www.cnrs.fr/cw/en/pres/compress/radioactDecay.htm.
4. ↑ Blank, Bertram; Ploszajczak, Marek (December 17, 2013). "Two-proton radioactivity". Reports on Progress in Physics 71 (4). doi:10.1088/0034-4885/71/4/046301.

## External links

* File:Queryensdf.jpg Nuclear Structure and Decay Data - IAEA with query on Proton Separation Energy

* v
* t
* e

Nuclear processes

Radioactive
decay

* Alpha decay
* Beta decay
* Gamma radiation
* Cluster decay
* Double beta decay
* Double electron capture
* Internal conversion
* Isomeric transition
* Neutron emission
* Positron emission
* Proton emission
* Spontaneous fission

Stellar
nucleosynthesis

* Deuterium fusion
* Lithium burning
* pp-chain
* CNO cycle
* α process
* Triple-α
* C burning
* Ne burning
* O burning
* Si burning
* r-process
* s-process
* p-process
* rp-process

Other
processes

* Photodisintegration
* Photofission

Capture

* Electron capture
* Neutron capture
* Proton capture

|

Exchange

* (n-p) reaction

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Proton emission. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Physics:Proton_emission&oldid=4108491"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template