THE S-BAND 1.6 CELL RF GUN CORRELATED ENERGYSPREAD DEPENDENCE ON π AND 0 MODE RELATIVEAMPLITUDE

摘要

Theπ mode or accelerating mode in a 1.6 cell rf gun is normally the only modeconsidered in rf gun simulations. However, due to the finite Q there is a small butmeasurable 0 mode present even at steady state. The π mode by definition has a180°phase shift between cells but this phase shift for the total field is several degreesdifferent. This results in a correlated energy spread exiting the gun. A comparison ofsimulation and experiment will be shown.