Sceptre IIIA

The toroidal discharge apparatus Sceptre III has been modified and is now known as Sceptre III A; the modification included new magneticfield coils and improved measurement facilities. The paper reviews the experimental results which have been obtained with Sceptre III A. The evidence of many of the measurements suggests that the large electron-energy loss associated with this type of discharge is caused by an electron-particle loss to the tube walls. If this is correct, the observed Doppler broadening and Doppler shift of the ion spectral lines have simple explanations. A mechanism is suggested for the electron-particle loss.