Magnetic tape digital recording for nuclear research

Abstract

The paper describes two magnetic tape digital recording techniques developed for nuclear physics research. Both 1 in. 16-track and ? in. 4-track systems are used with maximum bit packing densities of 200 and 400/in, respectively. The tape writing and reading technique uses a return to zero method chosen to facilitate ?drop out? detection; a ?0? is written by a short duration current pulse of one polarity and a ?1? but a similar pulse of reverse polarity. The absence of a pulse on any track during reading indicates a ?drop out? and the particular event is then rejected. This error check permits the use of tape systems with overall drop out performance as bad as 1 in 160 bits.