This section is concerned with the transmission of information from a detector (ionization or fission chamber) inside a reactor vessel to the electronic equipment outside the vessel.

At the present time, coaxial cable is used for this purpose; hence, the transmission of information through a coaxial cable is considered. Three modes of information transmission are studied:

a. The conventional mean-value system of instrumentation. This mode uses only the

d-c component of the current from the detector. For this system, only a theoretical treatment of the transmission of direct current is considered. • .

. • b. The counting system of instrumentation. This mode uses each individual pulse

generated by the detector. For this system, the transmission of pulses is studied theoretically, the theoretical pulse transmission data are compared with experimental data, the experimental frequency response and transient pulse characteristics of two. of the in-core cables are studied, and experimental temperature and radiation effects

are discussed.

c. The Campbell system of instrumentation. This mode uses the a-c component of cur­rent from the detector. Here the transmission of alternating current is considered.