Elegant users forum

Halo,

I am working on improving the beam stability and energy spread in ERL and I have a previous calculation for the peak voltage in the RF cavity,
e.x: rfca, l =0.2563 , phase = 46.956 , volt = " 15.813e6 0.2563 * 0.54 *", N_kicks=520
I would like to understand how Elegant calculates these values if I use the RFCA element. Another question, If I used this element RFTMEZ0, how does Elegant calculate the Ez-peak? In the manual, the unit of Ez in V, but isn't it V/m?

For the RFCA element, the voltage is turned into a peak field by dividing by the length Ez=VOLT/L. By default, the calculation is for a traveling wave structure, so the beam sees the indicated field throughout the length. One can also get a standing-wave cavity calculation using STANDING_WAVE=1. In that case, Ez=VOLT/L is the peak field in the standing wave.

For RFTMEZ0, elegant finds the peak value of the Ez(z) data provided via INPUTFILE, then scales to EZ_PEAK. Yes, the units in the manual are incorrect; I'll fix that in the next version.

--Michael