csrImpedance & ZLONGIT
Posted: 26 Feb 2020, 11:25
Dear All
I am trying to show the effects of the CSR on e-beam in an Arc. I used the "csrImpedance" and made the steady-state CSR impedance. And then by "ZLONGIT" I added this Impedance to the code. After each bending I use this Impedance.
for example, for each bending, I have :
"CSRSH_AR1":ZLONGIT,zreal="csr_AR1.sdds=f+ZReal", zimag="csr_AR1.sdds=f+ZImag",interpolate=1,bin_size=0
"AR1_B1S01B": CSRCSBEND,L=4.001828,ANGLE=-0.05235986879,E2=-0.05235987756, &
TILT=1.570796327,HGAP=0.01905, n_kicks=15,nonlinear=1,derbenev_criterion_mode="evaluate", &
INTEGRATION_ORDER=4,BINS="nbins_csr",SG_HALFWIDTH=1,SGDERIV_HALFWIDTH=1, &
ISR=1,CSR=1,HIGH_FREQUENCY_CUTOFF0=0.25,HIGH_FREQUENCY_CUTOFF1=0.3
"AR1_B1S01": LINE=(AR1_B1S01B, CSRSH_AR1)
----------
In arc, I have 8 bending magnets, so I did same fore each one. I attached the lattice file.
The "csr_AR1.sdds" was made by csrImpedance.
I hope, I am going in correct direction.
I want to ask about csrImpedance.
1- filter
When I changed the cutoff1,cutoff2 in filter I had different results. I don't know how I select these values. When I removed the filter, I found good result.
I was wondering, if I could ignore this filter in csrImpedance.
2- maximum frequency
The bunch length is 333 fs, as it was suggested in manual I considered maximum frequency much greater than 1∕(2πσt), but it made a problem. I had following errors:
"If using broad-band impedance, you should increase the number of bins (or use auto-scaling) and rerun" (Actually it is auto-scaling and increasing nbin did not remove the error )
"If using file-based impedance, you should increase the number of data points or decrease the frequency resolution." (I did it but no change)
and this error:
"error: impedance spectrum has non-zero imaginary DC term (ZLONGIT)"
and following warning:
" Using 1-D CSR formalism but Derbenev criterion not satisfied (1.120180e-01 > 0.1)."
I appreciate any help you can give me with these errors and cutoff1,cutoff2 in filter .
Best regards,
Najmeh
I am trying to show the effects of the CSR on e-beam in an Arc. I used the "csrImpedance" and made the steady-state CSR impedance. And then by "ZLONGIT" I added this Impedance to the code. After each bending I use this Impedance.
for example, for each bending, I have :
"CSRSH_AR1":ZLONGIT,zreal="csr_AR1.sdds=f+ZReal", zimag="csr_AR1.sdds=f+ZImag",interpolate=1,bin_size=0
"AR1_B1S01B": CSRCSBEND,L=4.001828,ANGLE=-0.05235986879,E2=-0.05235987756, &
TILT=1.570796327,HGAP=0.01905, n_kicks=15,nonlinear=1,derbenev_criterion_mode="evaluate", &
INTEGRATION_ORDER=4,BINS="nbins_csr",SG_HALFWIDTH=1,SGDERIV_HALFWIDTH=1, &
ISR=1,CSR=1,HIGH_FREQUENCY_CUTOFF0=0.25,HIGH_FREQUENCY_CUTOFF1=0.3
"AR1_B1S01": LINE=(AR1_B1S01B, CSRSH_AR1)
----------
In arc, I have 8 bending magnets, so I did same fore each one. I attached the lattice file.
The "csr_AR1.sdds" was made by csrImpedance.
I hope, I am going in correct direction.
I want to ask about csrImpedance.
1- filter
When I changed the cutoff1,cutoff2 in filter I had different results. I don't know how I select these values. When I removed the filter, I found good result.
I was wondering, if I could ignore this filter in csrImpedance.
2- maximum frequency
The bunch length is 333 fs, as it was suggested in manual I considered maximum frequency much greater than 1∕(2πσt), but it made a problem. I had following errors:
"If using broad-band impedance, you should increase the number of bins (or use auto-scaling) and rerun" (Actually it is auto-scaling and increasing nbin did not remove the error )
"If using file-based impedance, you should increase the number of data points or decrease the frequency resolution." (I did it but no change)
and this error:
"error: impedance spectrum has non-zero imaginary DC term (ZLONGIT)"
and following warning:
" Using 1-D CSR formalism but Derbenev criterion not satisfied (1.120180e-01 > 0.1)."
I appreciate any help you can give me with these errors and cutoff1,cutoff2 in filter .
Best regards,
Najmeh