Abstract. An external probe with spatial resolution (half width)/(plasma radius) of 0·13 has been developed. It uses the magnetic field deflection method of Lin, Resler and Kantrowitz but quadrupole coils are used to improve the resolution and to minimize self-shielding by the plasma. The theory is discussed and the device is shown to be superior to the r.f. excited probes for moving plasmas. Results are presented for Mach 12 shock waves in argon.

Print publication: Issue 3 (March 1967)
Received 1 September 1966