Electrodeless discharges in coaxial tubes, capable of holding a laser crystal in the center, have been studied to obtain a measure of the energy coupled into the tube, to understand the dynamical processes, and to quantitatively determine the radiation emitted by the tube. The energy coupling and emitted radiation have been found to depend on the voltage stored on the capacitor, the primary coil dimensions, the fill gas and fill‐gas pressure, and the tube dimensions. The dominant dynamical processes are those due to strong cylindrically imploding shock waves. Radiation emitted is found to be due to particles liberated from tube walls as well as that of the fill gas. Curves of radiation intensity vs wavelength, as well as spectral pictures and calculations of spectral matching coefficients, indicate the possibility of pumping very high powers into ruby crystals.