AIR CONTAMINATION FROM THE TRITIUM TARGET OF A NEUTRON GENERATOR

Neutron generators are widely used for the production of 14-15 MeV fast neutrons by a ^3H (d, n) ^4He reaction. The activity of tritium contained in a tritium target is about 3.7×10^<11> Bq (10 Ci). In the neutron generator laboratory of Nagasaki University School of medicine, we evaluated tritium concentration in air from that in water exposed to air for 17 hours in a container and thereby measured the air contamination from the tritium target of a neutron generator. The tritium concentration in air was 5.22×10^<-4> Bq/ml and 1.4×10^<-4> Bq/ml in the generator room and reserve room respectively when the air conditioner was operated, and it increased to 69.63×10^<-4> Bq/ml in the generator room when the air conditioner was put off.