Description: Gas proportional counting tube.

Caption: This prototype is one of the first bubble window Maze type counting tubes. It was made as a demonstration of the glass blowing technique. The window was formed by placing a semi-molten thin sheet of glass at the end of the tube then pumping down the tube to form a bubble before the glass cooled.

Introduction: Often simply called a Geiger counter, this component is named for the designers of the first radiation counter the German Physicists Geiger and Muller. Roland Maze later discovered that the heavy metal tube cathodes of the earlier counters could be replaced by thin glass tube covered with aquadag, a water-based graphite coating. This tube has an internal aquadag coating reinforced with an external layer of platinum foil.

Background: This tube was made at Glasgow University by John Lloyd who invented the bubble window process. It provided a very thin glass window through which radiation could pass without much adsorption occurring for radiation counters designed by Charles Samuel Curran.

Reference: Lloyd, John, Travers. "Journal of Scientific Instruments", vol 26, 1949, p. 126

Reference: Curran, Samuel Crowe and Craggs, John Drummond. "Counting Tubes Theory and Applications", 1949

Historical Context: Design of the bubble window - Who: Lloyd, John (Jack) Travers (fl.1948-1981)

Historical Context: Design of the counting tube - Who: Curran, Samuel Crowe, Professor, later Sir (1912-1998) Physicist and first principal of Glasgow's Strathclyde University

Historical Context: Design of the counting tube by Curran - When: 1947

Historical Context: Design of the counting tube by Curran, Kelvin Building, University of Glasgow - Where: University Avenue, Glasgow, Scotland

Historical Context: Invention of the bubble window process by John Lloyd, Kelvin Building, University of Glasgow - Where: University Avenue, Glasgow, Scotland

Historical Context: Invention of the bubble window process by Lloyd - When: 1947

Historical Context: Invention of the gas proportional radiation counting tube by Geiger and Muller - When: 1928

Historical Context: Invention of the gas proportional radiation counting tube by Geiger and Muller, Keil University - Where: Germany

Historical Context: Invention of the proportional gas radiation counter - Who: Muller, Walter, Professor - Who: Geiger, Hans Wilhelm (1882-1945)

Historical Context: Manufacture - Who: Lloyd, John (Jack) Travers (fl.1948-1981)

Historical Context: Manufacture by Jack Lloyd - When: 1947

Historical Context: Manufacture of the tube by John Lloyd, Kelvin Building, University of Glasgow - Where: University Avenue, Glasgow, Scotland

Historical Context: Use of aquadag as a cathode by Maze - When: 1946 - Where: France

Historical Context: Use of auadag as a cathode - Who: Professor Roland Maze French Physicist who discovered cosmic rays in 1938