What is the wavelength of the photons produced in electron positron pair annihilation?

1.2132 picometer
The photon must have higher energy than the sum of the rest mass energies of an electron and positron (2 ⋅ 511 keV = 1.022 MeV, resulting in a photon-wavelength of 1.2132 picometer) for the production to occur.

What is the wavelength of a photon of minimum energy that can produce an electron hole pair?

For photon energies below 2m0c^2, the process cannot occur; in other words, 1.02 MeV is the threshold energy for pair production. For photon energies above the threshold, a photon has more than enough energy to create a particle pair and the surplus energy appears as kinetic energy of the two particles.

What is the result of the annihilation of an electron and a positron?

In particle physics, annihilation is the process that occurs when a subatomic particle collides with its respective antiparticle to produce other particles, such as an electron colliding with a positron to produce two photons.

What photon is produced from annihilation?

gamma photons
If a positron interacts with an electron, it annihilates, which in turn generates two gamma photons (rays) in opposite directions ( ).

What is the wavelength of a positron?

Despite the fact that the DeBroglie wavelength of a positron at 300K is an order of magnitude larger than typical inter-core spacings, the positron has a relatively high probability of becoming localized or trapped in vacancies. In fact, the threshold defect density for positron trapping is typically of order 1 ppm.

What is minimum energy photon?

The minimum energy required to eject an electron from the surface is called the photoelectric work function. The threshold for this element corresponds to a wavelength of 683 nm. Using this wavelength in the Planck relationship gives a photon energy of 1.82 eV.

What is the annihilation peak how it is produced?

It is synthetically produced by neutron activation of cobalt-59 in nuclear reactors. Cobalt-60 is a common calibration source found in many laboratories. The gamma spectrum has two significant peaks, one at 1173.2 keV and another at 1332.5 keV.

How is a positron produced?

Positrons are the antiparticles of electrons. The major difference from electrons is their positive charge. Positrons are formed during decay of nuclides that have an excess of protons in their nucleus compared to the number of neutrons. When decaying takes place, these radionuclides emit a positron and a neutrino.