2. The quantum of the electromagnetic field that manifests itself by absorption or emission only in multiple quantum units of energy.
3. A unique massless particle that carries electromagnetic force.
Bone densitometry is a method of determining the density of bone by use of radiographic techniques. The use of dual photon absorptiometry will provide density data of the axial skeleton with a precision of 97 percent to 98 percent. It is used in testing for the degree of osteoporosis.
2. A quantum of electromagnetic energy that can be considered as a particle with no mass, no charge, and traveling at the speed of light.
As "packets" of light they can be individually counted and used to build up a picture of; for example, a distant galaxy.
This detector is a four-stage, magnetically-focused image intensifier, coupled via a lens to a plumbicon television camera tube.
A plumbicon is the development of the vidicon television camera tube in which the photosensitive material is lead oxide.
A plumbicon is a registered trademark of Philips for its Lead Oxide (PbO) target vidicons or camera tubes in which a charge-density patterns are formed by photoconduction and stored on photoconductor surfaces that are scanned by electron beams; usually, of low-velocity electrons; used chiefly in industrial television cameras.