As it does so, it releases high-energy electrons, which are also known as beta particles
. A semiconductor is then used to capture these electrons, and convert them into low and constant levels of electricity that can then be used to power up a number of devices, depending on needs.
Alpha and beta particles
outside the body are typically not a
Unfired DU munitions are encased in thin metal jackets that seal in alpha and beta particles
and allow only very slight gamma emissions well below regulatory safety limits.
10 Of course, the postulation of the neutrino was not exactly correct: current physics tells us that it is an intermediary particle which is emitted from the nucleus initially, and it is it which decays into a Beta particle
and an antineutrino (though calling the small neutral particle emitted in this process an antineutrino is just as much a change in nomenclature as a change in theory).
Though yttrium-90 has been used successfully on rheumatoid knees in European trials, notes Joe Straus, associate director of clinical research at Mallinckrodt, it sometimes proved too powerful on inflamed fingers and other small joints, causing "radiation burns to the skin overlying those joints." Samarium's less energetic beta particles
should allow the new preparation to be used in a broad range of joints, Straus says--not only the knee but also the finger, elbow, shoulder, and hip.
Examples include ultraviolet, X-rays, and gamma rays from the electromagnetic spectrum and subatomic particles such as alpha particles, beta particles
, and neutrons.
These new detectors can be used for direct, detection and spectrometry of beta particles
and low energy X-rays, or, when coupled with scintillators, for sensing gamma rays and higher energy X-rays.
A beta detector also measures light to determine the presence and concentration of beta particles
. "Both techniques are decades old, but this is the first time they have been used together in this way," noted Bowyer.
The scientists also suggested that other types of radiation, such as beta particles
, might provide a greater margin of safety for treated vessels, nearby healthy tissue, and operating-room staff.
In 1914, however, the English physicist James Chadwick (1891-1974) showed that this was not true of beta particles
. They came off in a continuous range of energies, from a sharply defined maximum down to zero.
To make the new technique effective for therapy calls for devising a way to get the radionuclides to the exact place desired and also to choose a combination whose end products will have sufficiently high levels of beta particles
, Mausner says.
might be fired out of a nucleus with all the energy to be expected from the loss in mass as one nucleus broke down into another.