Radiant energy – Invisible radiant energy responsive electric signalling – With or including a luminophor
Patent
1990-06-21
1992-10-13
Howell, Janice A.
Radiant energy
Invisible radiant energy responsive electric signalling
With or including a luminophor
250364, G01T 120
Patent
active
051553643
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a solid-liquid reversible scintillator and a method of using the same. More specifically, the present invention pertains to a scintillator that emits light in response to radiation, particularly a solid-liquid reversible scintillator of such type that it is possible to select either a solid phase or a liquid phase, whichever is desired, by temperature control, and a method of using such a scintillator.
BACKGROUND ART
Recently, biochemistry has been markedly advanced, and analyses of substances that constitute organisms, such as proteins, and research of metabolic functions of substances, including drugs, have been actively pursued. There has been particularly marked progress in the study of molecular biology to clarify biological phenomena on the basis of the structure and function of biopolymers. In this research, analyses of substances that constitute organisms, such as DNA and proteins, are essential requirements.
Tracers are substances which are added to obtain knowledge about the behavior of elements or substances, and experiments that employ tracers are often conducted in the fields of medical science, pharmacology, etc. To trace the behavior of an element or a compound, it is common to employ a labelled compound that contains a radioisotope of the element concerned. In the medical and pharmaceutical fields, tritium (.sup.3 H), carbon (.sup.14 C), etc., which are organismconstituting elements, are the principal radioisotopes used.
In a tracer experiment, information about the behavior of a target element or compound is obtained by tracing the radioactivity of a radioisotope label. Tracer experiments are also widely conducted in the fields of biochemistry, medical science and pharmacology as stated above. It is a common practice in a tracer experiment to artificially add a radioisotope (e.g., a labelled compound) to an object of measurement. Since radioisotopes are also widely distributed in nature in fixed proportions, in the form of radioisotopes produced, for example, by nuclear reactions caused by cosmic rays, it is possible to estimate the age of an organism, by analyzing the proportion of .sup.14 C in the organism. Therefore, radioisotopes are also used in research for age determination.
Scintillation is the phenomenon whereby a fluorescent substance emits light when radiation is applied thereto. Scintillation counters are used to detect -rays, X-rays, .beta.-rays and neutron rays. Scintillation counters are arranged to convert radiation energy into light by means of a fluorescent substance, convert the light into electronic pulses by a photomultiplier tube and count the number of pulses. The above-described tracer experiments are generally conducted by the use of such scintillation counters.
Scintillation counters are capable of detecting and counting any kind of radiation, such as photon (-rays) and neutron rays, in addition to charged particles. Luminescent substances that are used in scintillation counters are called scintillators. The wavelengths of light emitted by scintillators are generally from 3000 to 600 Angstroms. Scintillators are required to have such characteristics that they have no absorption region in the above-described wavelength range, transmit fluorescence life have a short fluorescence lifetime (which sets a limit on the decomposition time).
Scintillators may be divided into the following classes according to the phase in which they are used: solid scintillators, liquid scintillators and gas scintillators. A great variety of such scintillators have heretofore been proposed and used. For example, the invention of thallium-activated sodium iodide [NaI(Tl)], which is crystalline, was the beginning of the gamma spectroscopy. Additional examples of scintillators are thallium-activated cesium iodide [CsI(Tl)], sodium-activated cesium iodide [CsI(Na)] and europium-activated lithium iodide [LiI(Eu)].
Silver-activated zinc sulfide [ZnS(Ag)], europium-activated calcium fluoride [CaF.sub.2 (Eu)], bismuth germanate (BGO, Bi.sub.4 Ge
REFERENCES:
patent: 4562158 (1985-12-01), Schellenberg
Chose et al., "Principles of Radioisotope Methodology", 1967, p. 301.
Hanig Richard
Howell Janice A.
Packard Instrument B.V.
LandOfFree
Solid-liquid reversible scintillator and method of using the sam does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solid-liquid reversible scintillator and method of using the sam, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solid-liquid reversible scintillator and method of using the sam will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1302943