RFDF basic question
Posted: 14 Nov 2018, 21:15
Hi,
I'm implementing a RFDF element in a diagnostics section beamline. For optimization purposes the structure was divided into two pieces (of half the total length each) in order to put a marker in between. Now, when I simulate a typical time calibration that one would perform experimentally with a LOLA type structure to get the streak parameter and the time resolution, I got different results if I use a single piece of length L or two consecutive pieces of length L/2 (in the second case I get a streak twice as large as in the first case).
My understanding is that this shouldn't make any difference - unless the thin-lens approximation for the RFDF is used. So I am not sure if I am defining the element properly or if I am missing any parameter that could change the behavior of the cavity... Below the definition in the lattice file:
a) divided into two pieces
"TDS.U": RFDF, L=0.4, TILT=1.570796326794897, FREQUENCY=11988000000, N_KICKS=101, VOLTAGE=27000000
"TDS-C": MARK, FITPOINT=1
"TDS.D": RFDF, L=0.4, TILT=1.570796326794897, FREQUENCY=11988000000, N_KICKS=101, VOLTAGE=27000000
b) one single piece:
"TDS": RFDF, L=0.8, TILT=1.570796326794897, FREQUENCY=11988000000, N_KICKS=101, VOLTAGE=27000000
Thanks a lot in advance for your help!
Best regards,
Pau
I'm implementing a RFDF element in a diagnostics section beamline. For optimization purposes the structure was divided into two pieces (of half the total length each) in order to put a marker in between. Now, when I simulate a typical time calibration that one would perform experimentally with a LOLA type structure to get the streak parameter and the time resolution, I got different results if I use a single piece of length L or two consecutive pieces of length L/2 (in the second case I get a streak twice as large as in the first case).
My understanding is that this shouldn't make any difference - unless the thin-lens approximation for the RFDF is used. So I am not sure if I am defining the element properly or if I am missing any parameter that could change the behavior of the cavity... Below the definition in the lattice file:
a) divided into two pieces
"TDS.U": RFDF, L=0.4, TILT=1.570796326794897, FREQUENCY=11988000000, N_KICKS=101, VOLTAGE=27000000
"TDS-C": MARK, FITPOINT=1
"TDS.D": RFDF, L=0.4, TILT=1.570796326794897, FREQUENCY=11988000000, N_KICKS=101, VOLTAGE=27000000
b) one single piece:
"TDS": RFDF, L=0.8, TILT=1.570796326794897, FREQUENCY=11988000000, N_KICKS=101, VOLTAGE=27000000
Thanks a lot in advance for your help!
Best regards,
Pau