ABSTRACT
The graph has quite an unusual shape. It reaches a peak thickness with the super corona ring around 12cm from the corona point of the gun. Either side of this point the powder layer is much thinner. As the ring distance increases the gun behaves more like a normal corona gun. Graph S shows the average powder thickness plots using a SOkV gun voltage. The. graph has a clear peak in thickness around the 14-I Scm region. This time the powder layer continues to become thinner as the ring moves away from the lScmregion.
