Means are provided to sense the variations in the amplitude of the microwave field in the linear accelerator and to control the frequency of the magnetron so as to maintain the amplitude of the accelerating field at a reference value representative of the expected maximum amplitude value at resonance. Means are also provided to sense the variations in the temperature of the linear accelerator and to control the frequency of the magnetron so as to compensate for the variations in the resonant frequency of the accelerator that result from temperature induced changes the length thereof. They disguise their purchase as a obvious player in the petro industry to get much needed technology for nuking. Needless to say, DOE is interested. My own suspicions arose out of the fact that I lived in Calgary, the petro capital of the north.
Good shielding seems contrarian.
Because neutrons are electrically neutral, they cannot ionize the gas in standard Geiger counters very well. Detection is indirect, usually by collision with a nucleus whose secondary particle emission includes charged particles which then CAN be detected. And using a plastic shield to moderate high-energy neutrons down to thermal levels so that an efficient gas proportional detector can be used. A wire in the center of the detector tube conducts the resulting charge to the logging tool's electrical circuitry, where the neutron pulse is counted. Obviously these can be pelletized to smaller sizes for more localized effects.