RCL Mark 1 Model 5 Probe Counter  (late 1940s)

This tube, manufactured by Radiation Counter Laboratories of Chicago Illinois, is identified on the label as the Model 1 Mark 5.  Unfortunately, I have no literature that refers to this particular model. Its outward appearance is identical to the Mark 1 Model 100 and so the best I can do is provide the following information for the Model 100.  The Mark 1 Model 100 was described in the October 1948 issue of Nucleonics as follows:  "This thin-walled probe counter has been developed for inserting into small recesses  or into regions of high flux density. The diameter is 7 mm and the thin wall section is 15 mm. The gas volume extends up to the handle of the counter and a tubulation permits easy refilling." 
 The AEC Radiation Instrument Catalog of 1950 described the Model 100 as a "miniature thin wall Geiger counter tube suitable for internal medical studies."  

Size:   17 cm long,  7 mm diameter

Quench Gas:  organic (Model 100)

Wall: glass,  thickness 30 mg/cm(Model 100)

Cathode: Clear metallic coating (tin?) 

Operating voltage:  850 volts (Model 100)


References for Model 100:

Atomic Energy Commission Radiation Instrument Catalog No. 2 Part 1. 1950, page BG-2A8A, page date June 1, 1949.

Nucleonics October 1948 page 83.

Nucleonics May 1952, page 89.


Donated by the Atomic Energy of Canada Limited at Chalk River.

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Last updated: 07/25/07
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