RFCW Wake field current binning
Posted: 17 Apr 2019, 02:49
Hi,
I try to simulate a passive c band cavity streaking experiment.
The beam has a strongly asymmetric current distribution: Narrow peak in the head (few 10 fs) followed by long tail (few ps) obtained from non-linear compression.
How does auto-binning (N_BINS = 0) calculate the number of bins?
If I set N_BINS to: 300 = (distance of first to last particle) / (point separation in wake file), I get a different result than for N_BINS = 0.
In our case the length of the current peak in the head is in the order of the point separation in the wake file.
Therefore, I expect auto binning is not adequate, as the current peak will not be resolved.
I expect not to get precise results for the wake in the head, as the spacing in the wake file is too large, but I expect a good consistent result for the tail, if the binning approximates the current appropriately.
The result for N_BINS = 300 and 3000 are very similar, whereas N_BINS = 0 gives a very different result.
If I set N_BINS manually I get warnings:
warning: only 0 of 100084 particles where binned (TRWAKE)
consider setting n_bins=0 in TRWAKE definition to invoke autoscaling
warning: only 84350 of 100084 particles were binned (WAKE)
consider setting n_bins=0 in WAKE definition to invoke autoscaling
Thank you very much for you support.
In case you need more information, just let me know.
Best,
Benedikt
I try to simulate a passive c band cavity streaking experiment.
The beam has a strongly asymmetric current distribution: Narrow peak in the head (few 10 fs) followed by long tail (few ps) obtained from non-linear compression.
How does auto-binning (N_BINS = 0) calculate the number of bins?
If I set N_BINS to: 300 = (distance of first to last particle) / (point separation in wake file), I get a different result than for N_BINS = 0.
In our case the length of the current peak in the head is in the order of the point separation in the wake file.
Therefore, I expect auto binning is not adequate, as the current peak will not be resolved.
I expect not to get precise results for the wake in the head, as the spacing in the wake file is too large, but I expect a good consistent result for the tail, if the binning approximates the current appropriately.
The result for N_BINS = 300 and 3000 are very similar, whereas N_BINS = 0 gives a very different result.
If I set N_BINS manually I get warnings:
warning: only 0 of 100084 particles where binned (TRWAKE)
consider setting n_bins=0 in TRWAKE definition to invoke autoscaling
warning: only 84350 of 100084 particles were binned (WAKE)
consider setting n_bins=0 in WAKE definition to invoke autoscaling
Thank you very much for you support.
In case you need more information, just let me know.
Best,
Benedikt