RESIDUAL INJURY CAUSED BY IRRADIATION WITH FAST NEUTRONS
Abstract
The LD50 of C3H female mice for fission-spectrum neutrons was 274.5 4.2 rad. The previously reported value in the same mice for 250 kvp X-ray was 632 rad, giving an RBE of 2.30. Conditioning exposure of the mice to a total neutron dose of 482.3 7.2 rad over an interval of 8-10 weeks resulted in lowering the LD50 for neutrons by 41.8 5.9 rad, or 8.67 11.23 of the total conditioning dose. The previously reported value in the same mice for 250 kvp X-ray was 9.58% of the conditioning dose. Continued exposure of the mice to 166 rad doses of neutrons at intervals of 4-5 weeks gave a median survival time of 22 weeks. This was greater than that produced by exposure to 420 rad and less than that produced by exposure to 280 rad of 250 kvp X-ray given at the same time. The RBE of the mice for residual radiation injury and the RBE for chronic radiation tolerance over short time intervals are described as the same as that for acute injury tolerance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 26, 1962
- Accession Number
- AD0273633
Entities
People
- J.s. Krebs
- R.w. Brauer
Organizations
- Naval Radiological Defense Laboratory