Dear Michael and all,
I want to use broad-band impedance model for ring tracking. I set BROAD_BAND=1 in ZTRANSVERSE command and specified the resonators but I couldn't realize how to determine the plane (x/y) they belong to. Also, how can I figure out the appropriate bin size in this case?
Any help would be appreciated.
Regards,
Mina
Tracking with Broad-band Impedances
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Re: Tracking with Broad-band Impedances
Mina,
By default, ZTRANSVERSE applies the same impedance in both planes. You can change this using the XFACTOR and YFACTOR parameters. E.g., if you set YFACTOR=0, then the impedance will only apply in the horizontal plane.
The number of bins nBins should be a power of 2. The bin width binSize must be such that nBins*binSize>2*(fullBunchDuration). The frequency spacing is computed as df = 1/(nBins*binSize). Setting the number of bins and the bin size is a bit of an art. In particular, you'll want enough bins to resolve the resonance (df<<fRes/Q) but not so many that you have excessive binning noise.
Here's my suggestion:
--Michael
By default, ZTRANSVERSE applies the same impedance in both planes. You can change this using the XFACTOR and YFACTOR parameters. E.g., if you set YFACTOR=0, then the impedance will only apply in the horizontal plane.
The number of bins nBins should be a power of 2. The bin width binSize must be such that nBins*binSize>2*(fullBunchDuration). The frequency spacing is computed as df = 1/(nBins*binSize). Setting the number of bins and the bin size is a bit of an art. In particular, you'll want enough bins to resolve the resonance (df<<fRes/Q) but not so many that you have excessive binning noise.
Here's my suggestion:
- Compute df = fRes/Q/M, with M~10 so that the resonance is well resolved.
- Compute binSize = fullBunchDuration/N, with N~50 so that the bunch distribution is well resolved. Use the nearest power of 2.
- Compute nBins = 1/(df*binSize)
- Choose number of particles np = P*nBins, with P~100.
--Michael