Magnetically Insulated Shock Tube

Experiments were carried out in a small (1 in. diameter) electrically driven shock tube with a homogeneous longitudinal magnetic field of up to 20 000 gauss in both the discharge and expansion chambers. A 1600-joule capacitor bank was used with deuterium pressures of 150 μ Hg or more, giving shock velocities of up to 8 cm/μsec. At magnetic field strengths of 7500 gauss and higher, several effects were found. The shock velocity was substantially increased. An interface, such as seen in diaphragm-type shock tubes was clearly defined in the wave-speed photographs. The reflected shock velocities were abnormally high, indicating a γ of more than 5/3. The shock fronts were observed to be convex.