Neutron probe

Neutron probe
Neutron probe (e=neutron emitter -- d=detector -- b=shielding -- c=counter).

A neutron probe is a device used to measure the quantity of water present in soil.

A typical neutron probe contains a pellet of americium-241 and beryllium. The alpha particles emitted by the decay of the americium collide with the light beryllium nuclei, producing fast neutrons. When these fast neutrons collide with hydrogen nuclei present in the soil being studied, they lose much of their energy. The detection of slow neutrons returning to the probe allows an estimate of the amount of hydrogen present. Since water contains two atoms of hydrogen per molecule, this therefore gives a measure of soil moisture.

Farmers use this to determine how much water is in their fields.

See also

References

  • Morgenschweiss, G., Luft, G., 1981. Einrichtung von Bodenfeuchtemesstellen, Kalibrierung einer Neutronensonde am Beispiel der Wallingfordsonde Typ IH11. Deutsche Gewässerkundliche Mitteilungen (DGM) 25, 84-92.



Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • neutron probe — neutroninis zondas statusas T sritis fizika atitikmenys: angl. neutron probe vok. Neutronensonde, f rus. нейтронный зонд, m pranc. sonde à neutrons, f; sonde neutronique, f …   Fizikos terminų žodynas

  • Neutron detection — is the effective detection of neutrons entering a well positioned detector. There are two key aspects to effective neutron detection: hardware and software. Detection hardware refers to the kind of neutron detector used (the most common today is… …   Wikipedia

  • Neutron — This article is about the subatomic particle. For other uses, see Neutron (disambiguation). Neutron The quark structure of the neutron. (The color assignment of individual quarks is not important, only that all three colors are present.)… …   Wikipedia

  • Neutron moisture gauge — A neutron moisture meter is a moisture meter utilizing neutron scattering. The meters are most frequently used to measure the water content in soil or rock. The technique is non destructive, and is sensitive to moisture in the bulk of the target… …   Wikipedia

  • Neutron star — redirects here. For the story by Larry Niven, see Neutron Star (short story). Neutron stars crush half a million times more mass than Earth into a sphere no larger than Manhattan. A neutron star is a type of stellar remnant that can result from… …   Wikipedia

  • Neutron — Représentation schématique de la composition en quarks d un neutron, avec deux quarks d et un quark u. L interaction forte est transmise par des gluons (représentés ici par un tracé sinusoïdal). La couleur des quarks fait référence aux trois… …   Wikipédia en Français

  • Neutron spectroscopy — Neutron scattering is a spectroscopic method that uses neutron scattering to measure atomic and magnetic motions of atoms. Inelastic neutron scattering observes the change in the energy of the neutron as it scatters from a sample and can be used… …   Wikipedia

  • Neutron-star oscillations — Asteroseismology studies the internal structure of our Sun and other stars using oscillations. These can be studied by interpreting the temporal frequency spectrum acquired through observations [cite journal|… …   Wikipedia

  • Neutron-star oscillation — Asteroseismology studies the internal structure of our Sun and other stars using oscillations. These can be studied by interpreting the temporal frequency spectrum acquired through observations[1]. In the same way, the more extreme neutron stars… …   Wikipedia

  • neutron scattering — noun any of several techniques that use the wavelike behaviour of neutrons as a scientific probe …   Wiktionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”