Electronics progress report, March 1--31, 1949

With the completion of tests of the prototype cathode-follower, it was decided to produce three more models. These have been constructed and pass the same pulse as that of the prototype. Drawings are being made of these units. By the time these units had been completed, the amplifier of the scaler was modified so that its frequency response was essentially flat up to 4.5 megacycles. Using this amplifier and the cathode-follower, a study of the pulse shapes was made and four different pulse shapes were found to be obtainable. A band pass network between the B-wall tube and the input of the cathode-follower provided a very substantial improvement over the shunt peaking network with a band pass of 1.8 to 6.5 megacycles and provided clean, uniform pulses. Plans are being made to experiment with a filter of narrower band pass, which, if satisfactory, will produce greater amplitude. When the final band pass has been determined, a combination of shunt peaking and band pass networks should provide a net gain of 30% in amplitude. The result of this research is to provide an immediate improvement in resolution loss and a possibility of realizing a still lower minimum resolving time when the other components in the counting system have been improved. With the amplitude obtained and the use of pass bands of frequencies, it may be possible to develop a B-wall amplifier using one stage of amplification