US2479201A

US2479201A - Geiger-muller counter

Info

Publication number: US2479201A
Application number: US520482A
Authority: US
Inventors: Bleeksma Jan
Original assignee: Philips Laboratories Inc
Current assignee: Philips Laboratories Inc
Priority date: 1944-01-31
Filing date: 1944-01-31
Publication date: 1949-08-16
Anticipated expiration: 1966-08-16

Description

1949' J. BLEEKSMA 2,479,201

GEIGER-MULLER COUNTER Filed Jan. 31, 1944 JAN BLEEKSMA IN VEN TOR.

ATTORNEY Patented Aug. 16, 1949 UNITED STATES 2,479,201 Galena-MULLER comma Jan Bleeksma, Mount Vernon,

N. Y., asslgnor, by

mesne assignments, to Philips Laboratories, Inc., Irvington on Hudson, N. Y., a corporation of Delaware Application January 31, 1944, Serial No. 520,482

2 Claims. 1

My invention relates to measuring instruments, and more particularly to Geiger-Muller counters as used in the measurement of corpuscular as well as electromagnetic radiation.

It is an object of the present invention to provide a Geiger-Muller counter of simplified construction so as to facilitate, expedite and reduce the cost of manufacture thereof.

It is a further object of this invention to provide a Geiger-Muller counter with improved structural and functional characteristics.

Another object of my invention is to provide an improved Geiger-Muller counter characterized by a long life and a high degree of electrical stability.

Other objects, and the manner in which the same are attained, will appear from the following description:

Geiger-Muller counters as heretofore proposed and used comprised a tubular glass envelope containing a wire extending in the center of the envelope and forming the anode, and a tubular metallic cathode surrounding this wire at a distance therefrom and likewise spaced from the inner wall of the envelope, This construction requires a separate lead-in conductor for the cathode as well as supports for the cathode in the surrounding envelope. Moreover, the concentric placement of the cathode with respect to the anode wire frequently met with difficulties,

The present invention simplifies the construction of a Geiger-Muller counter, and obviates the aforenoted drawbacks inherent in the prior art devices by eliminating the envelope-contained cathode member and the main body portion of the tubular glass envelope, and providing instead a tubular metallic member joined to end portions of glass and forming the main body portion of a partly metallic envelope, while at the same time serving as cathode with respect to the centrally arranged anode wire.

By means of the foregoing expedient the con-- struction of the Geiger-Muller counter is simplified and at the same time the life of the counter and its electrical stability are improved.

In the drawing forming part of the specification one embodiment of the invention is illustrated by way of example.

In the drawing,

Figure 1 shows, somewhat diagrammatically, a longitudinal section of a Geiger-Muller counter according to the invention; while Fig. 2 is a transverse section taken along the line 11-11 of Fig. 1. I

Referring now to the drawing, the Geiger- Muller counter shown comprises an anode wire I and a tubular metallic cathode member 2 surrounding the anode. According to the basic concept of the invention, the tubular member 2. apart from its acting as cathode, also forms the main body portion of the envelope, and has fused or joined thereto a tubular front portion 3 of glass or similar material closed by a Lindeman window 4. The portion 3 is further provided with a small glass tube 5 by means of which the counter may be exhausted and subsequently filled with an ionizing and quenching filling, for

\ example a mixture of a rare gas such as krypton or argon with a small amount of petroleum ether or alcohol vapor. The other end of the member 2 is provided with a tubular-portion 6 of glass or similar material which portion is fused to and closed by a lead-through support I for the anode wire I which wire is welded, brazed or otherwise secured in the position shown.

As shown at III, the edges of the member 2 are preferably tapered to facilitate fusing thereto of the

end portions

3 and 6. 4

External electrical connection to anode l is provided by a wire conductor 8 having one end embedded in the lead-through conductor 1 and its other end suitably threaded to receive terminal nuts 99; electrical connection to the cathode member 2 being provided by a metal band I I surrounding the cathode.

The novel Geiger-Muller counter according to the invention is easily assembled and adjusted thereby making it possible to produce counters of uniform electrical perfection. Furthermore, in view of the accurate centric adjustment of the anode with respect to the cathode which may be realized, as well as the elimination of a separate lead-in conductor for the cathode, the counter is free from field distortions of any kind. An important advantage realized by the construction in accordance with the invention is the long life and electrical stability achieved. More particularly, only the effective surface of the cathode is exposed to the filling of the counter. By reason of this fact the amount of the quenching medium, 1. e. alcohol vapor, adsorbed. on the cathode surface in the form of a sheath and which is required for preventing secondary electron emission from the cathode surface is considerably reduced relative to the amount of the quenching medium available in the counter. Therefore a greater supply of the quenching medium is available for replacement of the oathode sheet. Furthermore, since the exposed area of the cathode is reduced to the absolute miniaerator mum, the consumption of the quenching medium is similarly reduced to a minimum. Since the life of the counter is a function of the quantity of the quenching medium and the stability of the counter is a, function of the proportion of the quenching medium in the filling and the amount available for covering the cathode surface, it will be seen that the construction above described which minimizes changes in the constituents of the counter filling, brings about a counter of substantial life and stability.

The counter is conveniently mounted in an insulated clamp or the like attached to the metallic main portion of the envelope, the metallic character of this portion reducing breakage so as to increase the life of the instrument.

I wish it to be understood that I do not desire to be limited to the exact details 01' construction or design shown and described, as numerous modifications within the scope of the appended claims will suggest themselves to a person skilled in the art.

What I claim is:

1. A Geiger-Muller counter, comprising a central anode, a tubular envelope comprising a central metallic portion in the form 01 a cylindrical sleeve having tapered ends serving as a cathode,

glass end portions, and a filling in said envelopecomprising a mixture of an ionizing medium and a quenching medium.

2. A Geiger-Muller counter, comprising a central anode, a tubular envelope comprising a central metallic portion in the form of a cylindrical 'd sleeve having tapered ends, two cup-shaped glass end portions fused to the tapered ends of said central portion and extending from the ends at said central portion and surrounding with clearance the ends of said anode, a reentrant bottom part in one of said cup-shaped portions, a metallic member fused to said reentrant bottom part and extending therethrough for supporting said anode, a connecting terminal for said cathode se- ,cured to the outer wall of said central portion, a.

radiation permeable window enclosing the other for said glass end portions, and a filling in said envelope comprising a gas selected from the group krypton and argon with the addition of alcohol.

- JAN BLEEKSMA.

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

UNITED STATES PATENTS Number Name Date 1,679,332 Bucky July 31, 1928 1,949,347 Bouwers Feb. 27, 1934 2,217,421 Scott Oct. 8, 1940 2,222,450 Trost Nov. 19, 1940 2,275,456 Neufeld Mar. 10, 1942 2,332,426 Atlee Oct. 19, 1943 2,405,572 Friedman Aug. 13, 1946 OTHER REFERENCES