Radiant energy – Invisible radiant energy responsive electric signalling – Including a radiant energy responsive gas discharge device
Patent
1996-08-19
1998-04-21
Glick, Edward J.
Radiant energy
Invisible radiant energy responsive electric signalling
Including a radiant energy responsive gas discharge device
250374, H01J 4706, G01T 118
Patent
active
057420610
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a gas detector making it possible to detect ionizing radiation, such as .alpha., .beta., .gamma., x or ultraviolet radiation from a plurality of proportional microcounters assembled so as to form a proportional counter.
Such a detector has numerous applications in the fields of medical imaging, biology, particle physics or crystallography and in numerous fields requiring nondestructive testing.
2. Discussion of the Background
The detector according to the invention is of the type in which the primary electrons resulting from the ionization of radiation by the gas are multiplied under the effect of a high local intensity electric field in a gas. Several types of such gas detectors are at present known and used by the expert.
The most widely known of such detectors is the parallel plate detector. It has a counter obtained by means of two parallel grids spaced from one another by a few millimeters and between which the electrons are multiplied. This zone located between the two parallel grids is called the "multiplication zone". Thus, the multiplication zone of such a detector is in the form of a single volume defined by the two grids. Due to the fact that it constitutes a single volume of a relatively large size, such a counter suffers from the disadvantage of being very breakdown sensitive. Moreover, the counters of such parallel plate detectors can only have a limited spatial resolution and due to the plate/grid thickness cannot be arranged in such a way as to form detectors having varied shapes.
Another type of gas detector is the wire detector, which has a plurality of equidistant wires held taut in one plane. On either side of said plane are placed two taut grids forming cathodes. Electron multiplication takes place in the vicinity of the wires, because at this location there is a high electric field. However, the multiplication zone of such a detector cannot be isotropic. It also does not permit the detector to have varied shapes.
A further, more recent gas detector type is the microstrip detector. In the microstrip detector, the counter consists of coplanar electrodes etched on an insulating support. Such a microstrip detector is described in French patent FR-A-2 602 058. The major disadvantage of this detector is its relatively low gain limited essentially to 5,000, because it does not permit the superimposing of several counters. In addition, like the counters of parallel plate detectors described hereinbefore, the counters of these microstrip detectors have anisotropic multiplication zones localized on very thin tracks (approximately 10 .mu.m), which makes them very sensitive to breakdown. These detectors also suffer from the disadvantage of being relatively fragile.
SUMMARY OF THE INVENTION
The object of the invention is to obviate the disadvantages of the aforementioned detectors. To this end, it proposes a gas detector incorporating a counter constituted by a plurality of independent, proportional microcounters.
More specifically, the invention relates to an ionizing radiation detector having an enclosure filled with a gaseous mixture and which can e.g. incorporate a rare gas and within which is placed a proportional counter defining between itself and the upper wall of the enclosure, a zone in which the ionization of the gas takes place by radiation absorption. This proportional counter also has at least one lower electrode and at least one upper electrode, which are parallel to one another and separated from one another by an insulating material layer and are raised to different potentials. The upper electrode and the insulating material layer have at least one opening in which there is a substantially uniform electric field and constituting a multiplication zone for the electrons resulting from radiation ionization.
Each portion of the counter incorporating an upper electrode portion and an insulating layer portion, which are perforated, as well as a lower electrode portion constitutes an independent mi
REFERENCES:
patent: 3930162 (1975-12-01), Reiss
patent: 4264816 (1981-04-01), Walenta
patent: 4686369 (1987-08-01), McDaniel et al.
patent: 4965861 (1990-10-01), Filthuth
patent: 5569699 (1996-10-01), Barthe et al.
patent: 5614722 (1997-03-01), Solberg et al.
van Beek et al., "A Position Sensitive Detector System Consisting of an Array of Mini-Proportional Counters", IEEE Transactions on Nuclear Science, vol. NS-31, No. 1, Feb. 1984.
Bartol Fran.cedilla.ois
Bordessoule Michel
Bucaille Thierry Claude
Charlet Joel Robert
Lemonnier Marc
Centre National de la Recherche Scientifique
Glick Edward J.
LandOfFree
Ionizing radiation detector having proportional microcounters does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ionizing radiation detector having proportional microcounters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ionizing radiation detector having proportional microcounters will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2060238