The neutron tubes developed at our lab were remodeled by improving the vacuum to 2×10

-6

Pa

increasing magnetic field intensity of ion source terminal to 0.33 T

and optimizing thickness（2.2μm） of the target coating based on experiments.In this way

a yield of 10

9

/s can be achieved with theΦ50 mm neutron tube

and working at a yield of5×10

7

/s

the life can be over 4000 h

with a stability of better than 2%.