Inactivation of Bacteriophage T6 in an Aqueous System by High Energy Protons

Summary

T6 bacteriophages were irradiated in water by a 218 mev proton beam, LET of which covers a range from 4·3 to 30 mev/g cm⁻² as the beam traverses a stack of samples and absorbers. The total phage inactivation including both immediate and delayed effects was dose-dependent and independent of LET. A separate measurement of the delayed inactivation showed that 240 mev protons have the same after-effect coefficient as that of 250 kvp x-rays. For the direct phage inactivation in a broth suspension, 240 mev protons also showed the same efficiency as 250 kvp x-rays.