from http://www.bubbletech.ca/radiation_detectors_files/bubble_detectors.html
"Bubble Detectors are the most sensitive, accurate, neutron dosimeters available. Used for over 15 years by nuclear facilities, research institutes, military personnel, and the medical community, Bubble Detectors provide instant visible detection and measurement of neutron dose. Inside the detector, tiny droplets of superheated liquid are dispersed throughout a clear polymer. When a neutron strikes a droplet, the droplet immediately vaporizes, forming a visible gas bubble trapped in the gel. The number of droplets provides a direct measurement of the tissue-equivalent neutron dose. The Bubble Detector is the only neutron dosimeter where the response is independent of dose rate and energy, with zero sensitivity to gamma radiation. Bubble Detectors are so compact, lightweight, and rugged, that they can be clipped to a coat or shirt pocket, placed in areas with limited access, or used in close proximity to a neutron source for a quick assessment. With an isotropic angular response, neutron dose can be accurately measured regardless of the direction of neutrons relative to the detector. Bubble Detectors are ideal for ALARA programs, providing the user with an immediate measurement of neutron hazards." Harry
