Accession Number : ADA203974
Title : Millimeter Wave Ocular Effects
Descriptive Note : Annual rept. Jan-Dec 1986
Corporate Author : UNIVERSITY OF WESTERN ONTARIO LONDON
Personal Author(s) : Trevithick, John R.
Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA203974
Report Date : 20 FEB 1987
Pagination or Media Count : 55
Abstract : Techniques were developed for irradiation of rabbit eyes with 35 GHz millimeter waves to determine cellular damage mechanisms and thresholds. The irradiation was performed using anesthetized 2.5 kg New Zealand white rabbits exposed to 35 GHz pulsed and continuous wave (CW) irradiation delivered by a special focusing antenna to a spot approximately 1.3 cm diameter in which the rabbit eye was placed. The peak specific absorption rate (SAR) (1.4 mW/g per 1 mW/sq. cm of incident power) was determined with the aid of a thermographic camera which gave a map of the local corneal surface temperatures; the SAR assumed the values of thermal conductivity and specific heat for water since the cornea contains so much water. The damage observed has been divided into four categories which are progressively increased, by SEM and TEM evaluation. The unirradiated left cornea appears to serve as an appropriate control. This damage appears to increase (1) as the irradiation is modulated by pulsing at the same average power. (2) Damage increases as the same total energy is delivered over a short period (15 min vs 0.2 sec), perhaps as a result of higher temperature values attained. (3) the lowest dose rate at which damage has been detected in preliminary experiments should be continued to permit further data to be gathered, since the threshold value implicit in the results above is rather close to the safety threshold, when the safety factor of 10 is taken into account. Keywords: Nonionizing radiation, Radiation effects.
Descriptors : *MILLIMETER WAVES , *EYE , *RADIATION EFFECTS , WATER , THRESHOLD EFFECTS , RATES , SHORT RANGE(TIME) , RADIATION ABSORPTION , THERMAL CONDUCTIVITY , ANTENNAS , CAMERAS , SAFETY , FOCUSING , VALUE , IRRADIATION , SURFACE TEMPERATURE , DOSE RATE , SPECIFIC HEAT , THERMOGRAPHY , IONIZING RADIATION , RABBITS , CYTOLOGY , DAMAGE , CORNEA , PEAK VALUES , TEMPERATURE
Subject Categories : RADIOBIOLOGY
Distribution Statement : APPROVED FOR PUBLIC RELEASE