Probing the electron distribution inside the ATA beam pulse
Abstract
Analysis of the Cherenkov light emitted from a single ATA beam pulse provides quantitative information regarding the distribution of beam particles in a four dimensional transverse phase space. Using the techniques described in this report we conclude that the experimentally observed spatial distribution of Cherenkov light implies a parabolic distribution of beam particles. Using the transfer matrix of the magnetic solenoid transport, quantitative values of the emittance, radius, tilt and energy at a position upstream of the Cherenkov foil may be obtained, and the beam brightness as a function of radius within the beam may be calculated. The brightness is defined as the ratio of the beam current within a given radius to the normalized four dimensional volume occupied by particles within that radius. The normalized four volume is the four dimensional volume multiplied by the relativistic parameters β^{2}γ^{2}. We find that the parabolic phase space distribution gives a core brightness three times the edge brightness and agreement with the core brightness measured by the two aperture emittance diagnostic.
 Publication:

Nuclear Instruments and Methods in Physics Research A
 Pub Date:
 January 1991
 DOI:
 10.1016/01689002(91)907175
 Bibcode:
 1991NIMPA.300..137P