Magnetostrictive and Piezoelectric Readout of Spark Chambers in Magnetic Fields

Some methods by which the applicability of the magnetostrictive delay line readout for wire spark chambers can be extended for use in magnetic field regions are described. For fields up to 20 kG iron-cobalt alloy wires with either a coil or a piezoelectric receive transducer can be used. A different method involving the generation of acoustic pulses in non ferromagnetic wires is described. With a piezoelectric receive transducer this delay line is essentially unaffected by magnetic fields.