|
Date: |
|
Description: | This is one of five demonstration tubes cellotaped to a piece of card bearing the legend "UNDER HARD VACUUM BUBBLE WINDOW GEIGER, 1948 (MAZE TYPE) BUBBLE WINDOWS (THIN GLASS COUNTER WINDOWS- J.Sci. Inst., 26, p. 106 (1949) < 0.25 mg/cm2 (written in J.T. Lloyds hand. The legend was cut from the card and put in the object history file, the remainder of the card was disposed of) DES CURRAN,Samuel,Crowe,Sir. circa 1948 Glasgow University, Glasgow Scotland MANU LLOYD,John,Traverse.,B.Sc.,F.Inst.S.T. 1948 Glasgow University, Glasgow Scotland DES after GEIGER,Hans,Wilhelm,Professor and MULLER,Walther. 1928 Keil University, Germany A glass window for a Maze type of Geiger-Muller counting tube made as a demonstration of the glass and other thin film fixing technique used by most contemporary tubes in comparison to the bubble window type. The films were set in place with a variety of fixatives this one may be araldite or even polye4ster. Early tubes were filled with an argon-alcohol mix. The anodes in this type of tube were tungsten and the cathodes were an aquadag coating. See "Counting Tubes Theory and Applications", S.C. Curran and J.D. Craggs,1949. Also J.T. Lloyd, J. sci. Instrum., 26, 1949, p. 126. The window was formed by placing a semi molten thin sheet of glass in the end of the tube then pumping down the tube to form the bubble before the glass cooled. When the glass had hardened the vacuum was increased to the operating pressure normally about 10-11 cm of mercury. The tube used is 125mm dia and a crudley cut sheet of glass has been fixed over the open end. There is a pumping stem at one side of the tube but it has not been sealed. In a working tube the glass window would be very much thinner for alpha particle detection. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
|
|