Peter has the right idea. If you are an adroit electronics guy and are willing to do a bit of work, the Russian tubes can and have been turned to good purpose in neutron counting. After the right voltages are applied and the charge amps made, it is a matter of biasing properly to avoid the tube just becoming a fancy x-ray/gamma detector and not a neutron, specific, counter.
This usually means having a significant gamma source on hand to find the bias point by adjusting out the moderate energy gamma counts, first with the correct bias and then, if needed, a windowing module to set a threshold to avoid higher energy gamma counts.
It must be remembered that just because a tube is called a neutron detector tube it is not going to count only neutrons. It is up to you to make it count only neutrons via electronic wizardy and careful attention to force it not to count all the other stuff it is quite capable of counting other than neutrons.
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.