US2485586A

US2485586A - Geiger counter

Info

Publication number: US2485586A
Application number: US725827A
Authority: US
Inventors: Goldstein Ladislas
Original assignee: International Standard Electric Corp
Current assignee: International Standard Electric Corp
Priority date: 1947-02-01
Filing date: 1947-02-01
Publication date: 1949-10-25
Anticipated expiration: 1966-10-25

Description

Oct. 25, 1949.

| GOLDSTEIN GEIGER COUNTER Filed Feb. l, 1947 wash. mbl

IN VEN TOR. A0/.WAS 60.4 srE//V A TTOZPNE'Y' Patented Oct. 25, i1949 GEIGER COUNTER f Ladislas Goldstein, New York, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application February 1, 1947, serial No. 725,827

6 Claims.

This invention relates to devices that detect, and usually give a quantitative indication of, the presence of radioactive substances, atomic particles and radiation, such as cosmic radiation, etc. These devices include those entitled Geiger counters.

An object of the present invention is the provision of an improved device of the type hereinabove described.

Another obj ect is the provision of such a device that is characterized by high sensitivity and thus enables dispensing with additional amplifiers.

A feature of the invention is that it permits the construction of small, light weight portable devices of the type hereinabove referred to.

The above-mentioned and other features and objects of this invention will become more apparent and the invention itself though not necessarily defined by said features and objects will be best understood by reference to the following description of an embodiment of the invention taken in connection with the accompanying drawings, wherein the gure is a schematic side view, partly in cross section, of a device of the type described.

Referring now to the drawing, the apparatus includes an opaque container l which blocks out external light from the apparatus contained therein. Within the container I, there is provided a Geiger-Mueller counter tube 2 which may be provided with the usual wire anode 3 and cylindrical cathode 4 arranged within an envelope 5. Within the envelope 5, a suitable gas or gases 6 are provided, as is well-known to those versed in the art.

In the usual Geiger counter arrangement, a potential is applied between the anode and cathode and when the tube is excited by penetrating rays, such as for example, by gamma rays, to iom'Ze the gas within the envelope 5, current flows in the circuit connecting the anode and cathode and this current is measured or the number of pulses of such current is counted to detect the presence yof the rays and the intensity thereof. 'I'hese pulses have to be considerably amplified before they can operate a counter arrangement. Thus Geiger counters tend to be relatively unportable or bulky because of the amplifiers required.

The present invention operates on a different principle. When the gas 6 in the Geiger-Mueller counter tube is ionized and potentials are applied between the an-odes and cathodes, in addition to pulses of current being produced in the associated circuit, photons are emitted. In accordance with the present invention, the pulses in the circuit associated with the anode and cath- 0de are not measured but the photon emission is. For this purpose, the Geiger-Mueller tube 2 has one portion of its envelope, such as for example, the end l, provided with a wall which permits light radiation to pass through with little absorption thereof. The photo-electric multiplier 8 is arranged adjacent to the Geiger- Mueller tube 2 to receive the light therefrom and to be excited by said light to produce a current response thereto. While the photoelectric multiplier requires'relatively high potentials, it does not use much current particularly at the lower stages thereof. Therefore, if it is desired that the apparatus be portable, a very small power supply unit 9 may be used capable of giving the desired potential without having particularly large capacity. Power supply 9 not only is coupled, as indicated by the lines II), to the photoelectric multiplier to provide current therefor, but also supplies potential to the anode and cathode of the Geiger-Mueller counter tube.

A suitable indicator I I may be provided which has at least the indicating face I2 thereof visible and for this purpose the indicator ll may be mounted on the outside of the container I. The indicator I I is coupled to the output in the photoelectric multiplier and may be of any one of several types. For example, the indicator I I may be a, typical counter used in Geiger counter arrangements which serves to totalize the number of pulses produced. Another form which indicator II may take, is that of a current reading instrument, and may be particularly a current reading instrument which will integrate the current being passed or give an average thereof. The indicator I I may also be a combination of a counter and such a current reading instrument.

As will be appreciated, various photoelectric multipliers provide their maximum response to light at different frequencies. Likewise, it will be appreciated that by the use of different gases 6 within the Geiger-Mueller tube 2, light radiations having their maximum intensity at different frequencies, may be obtained.

It is therefore preferred to select the proper gas 6 with relationship to the maximum response of the photoelectric multiplier 8 so that maximum sensitivity may be obtained. Of course, it is to be understood that the term light radiation is used broadly to cover the entire light range from infra-red to ultra-violet and the term is not intended to be construed narrowly. Furthermore, more broadly, it is to be construed as applying to principles of my invention in connection with;

specific apparatus, it is to be clearly understood that this description is made only by Way of example and not as a limitationaon the scope of my invention.

I claim:

1. A Geigercounter arrangement. comprising.

a Geiger-Mueller counter tube adapted to emit light radiation upon excitation, a source of p0- tential, means for applying said potential to said tube,ay photoelectric device arranged to, be ex+ citedfby llight radiationl iromsaid tube, andmeans associated'with said device and responsiveto the current .ilow therein for indicating the light radiation from said tube;

2. An arrangement according-torclaimd Wherein said device is arranged adjacent saidtube.-l

3. An arrangement according toclaim lwhere-v '4 in said device is arranged adjacent said tube and said tube includes an envelope having a Wall adjacent said tube having low absorption characteristics for said light radiation.

4. An arrangement according to claim 1 further including means for preventing light radiation from any external source from entering said tube and said device.

5. Anvarrangement according to claim 1 further including a light opaque container at least partially surrounding said tube and said device. 6. .An arrangement according to claim 1 Wherein said photoelectric device is a photoelectric multiplier, and means for applying potential from. said.; source: to said multiplier.

LADISLAS GOLDSTEIN.

REFERENCES CITED The following references are of record'in the iile of this patent:

UNITED STATES PATENTS Number Name Datey 651,013 Kitsee June 5, 1900 1,850,467 Nakken Mar. 22, 1932 2,200,722 Pierce et al. May 14, 1940 2,409,498 Keston Oct. 15, 1946l