Charles W Price

US Patent:

52296105, Jul 20, 1993

Filed:

Feb 6, 1992

Appl. No.:

7/833434

Inventors:

James A. McNeil - Boulder CO
David S. Oakley - Lake Oswego OR
Charles E. Price - Boulder CO

Assignee:

Colorado School of Mines - Golden CO

International Classification:

G01N 2300

US Classification:

250308

Abstract:

A low-cost detector of hydrogen-containing compounds in gas or thin-film samples is disclosed. The device preferably includes an alpha particle source, an energy degrading medium, a charged particle detector (e. g. a solid state diode detector), and amplification, threshold, counting, logic, timing circuits, humidity correction apparatus, and alarm/display. The invention relies upon the use of the energy degrading foil to pass selectively certain particles. Energetic alpha particles from a radioactive source enter the sample and hydrogen nuclei, or protons, elastically scattered by alpha particles, are able to penetrate the energy degrading foil which is thick enough to stop the alpha particles. The protons are detected and a suitable output signal can be produced to provide an accurate measure of the quantity of hydrogen in the gas or thin-film sample. The hydrogen detector can be combined with a smoke detector to produce an apparatus capable of detecting both smoke and hydrogen.