Tracerlab TGC-1 and TGC-2 End Window GM Tubes

The TGC-1 and TGC-2 are glass walled end window GM tubes designed for beta counting. They were the first GM tubes produced by Tracerlab, Inc.  The earliest references I have for them are June 1948, while the last reference is 1958.  TGC, as might be expected, stands for Tracerlab Geiger Counter.

The key difference between the two tubes is that the TGC-1 has a 3-4 mg/cm2 mica window while the window of the TGC-2 is < 2 mg/cm2.  Due to its thinner window, the TGC-2 was capable of alpha detection and had a better efficiency for low energy betas. Both employed helium as the fill gas together with an organic quench gas.

Size:     3.75 long and 1.5 inner diameter

Window Thickness:    TGC-1             3 4 mg/cm2

                                    TGC-2             ca. 1.5 mg/cm2

Wall:                            glass,    > 300 mg/cm2, aquadagged on inside

Anode:       Tungsten central wire.

Operating voltage:      1400 V

Plateau length:   300 volts

Fill gas:   helium

Fill gas pressure:     720 mm Hg

Dead time:  ca. 200 us

Base:     four prong ceramic base:

Price:    TGC-1  $50 in 1948, $43.50 in 1952

              TGC-2  $75 in 1948, $53.50 in 1952

References:

Nucleonics June 1948 p 80

Nucleonics June 1948 p 103   

AEC Radiation Instrument Catalog, page date May 1, 1950

Tracerlog No. 11  June 1948

Tracerlab Inc, Catalog E, March 1958

GM Detectors             Museum Directory

Last updated: 07/25/07
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