Anonymous
Anonymous asked in Science & MathematicsPhysics · 9 years ago

# What is the shortest wavelength of gamma ray ever been observed?

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5.5 trillionths of an inch! It sounds very infinitesimal, but gamma rays of the electromagnetic spectrum have wavelengths of that size and shorter. The lengths range from 10-10 meters to 10-15 meters or shorter. There is no absolute lower limit to the extent of the shortest wavelength because it has not yet been reached.

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Source(s): JML
• Gamma radiation, also known as gamma rays (denoted as γ), is electromagnetic radiation of high frequency (very short wavelength). They are produced by sub-atomic particle interactions such as electron-positron annihilation, neutral pion decay, radioactive decay (including isomeric transition which involves an inhibited gamma decay), fusion, fission or inverse Compton scattering in astrophysical processes. Gamma rays have frequencies above 10 exahertz (10^19 Hz), and therefore have energies above 100 keV and wavelength less than 10 picometers, often smaller than an atom. Gamma rays from radioactive decay commonly have energies of a few hundred keV, and almost always less than 10 MeV. The upper limit for such energies is about 20 MeV, and there is effectively no lower limit (they are sometimes classed as X-rays if their frequencies are lower than 10^19 Hz). Because gamma rays are a form of ionizing radiation, they pose a health hazard.

20 MeV is equivalent to 3.2e-12 Joules

f = E/h = 4.9e21 Hz

λ = c/f = 6e-14 meters

this is 60 fm (femto meters)

E = hf, where h = Plank's constant 6.626e-34 Js

E = hc/λ

E is the energy of the particle in Joules

f is frequency, λ is wavelength in meters

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Source(s): wikipedia
• Dunno, but the shortest length of anything according to string theory is about 10^-35 m. [See source.] This is called a Planck Length.

As a gamma photon is a manifestation of how a single string vibrates, we can rationalize that gamma photons will not have shorter wave lengths than a single string.

EM spectra charts show 10^-15 m wave lengths for the upper range of gamma rays. This is 20 orders of magnitude longer than the Planck Length. How far up this chart gamma rays have been measured is unknown.

Source(s): "The Elegant Universe" by Brian Greene.
• Anonymous
9 years ago

1900000000000 electrons

Source(s): masters in physics