QUANTITATIVE EVALUATION OF TRANSVERSE PHASE SPACE TOMOGRAPHY

Effects of energy distribution of objective beams on the transverse phase space tomography have been evaluated by numerical calculations. As the result, for a beam with a rectangle-shaped energy distribution, the error in the emittance derived from the reconstructed transverse phase space image is found to be as acceptably low as less than 15 % when the energy spread is less than 15 %. However, for a realistic beam by a thermionic rf gun of our interest which has a low energy tail, the reconstructed image is found severely distorted even with a extremely low energy spread of 0.5 % of the main beam component. On that beam by applying a 70 % energy cut-off with respect to the peak energy, the image is reconstructed well enough in terms of both the emittance and the phase space distribution