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IBS Calculation Using BETACOOL. He Zhang 2/26/2013 Jlab MEIC R&D Group Meeting. Outline. Formulas for IBS rise time IBS rise time calculation using BETACOOL IBS calculation for MEIC&LEIC. Formulas for IBS rise time calculation. How to derive the formulas?
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IBS Calculation Using BETACOOL He Zhang 2/26/2013 Jlab MEIC R&D Group Meeting
Outline • Formulas for IBS rise time • IBS rise time calculation using BETACOOL • IBS calculation for MEIC&LEIC He Zhang
Formulas for IBS rise time calculation • How to derive the formulas? • IBS is due to the collisions inside the ion bunch • Steps to derive the formulas • In beam frame, two body collision, the change of momentum • In lab frame, the change of emittance • Average over all scattering angles • Average over all particles He Zhang
IBS rise time calculation using BETACOOL How to use BETACOOL: • Set the lattice of the ring • Set ring parameters • Set beam paramters • Choose IBS model • Calculate the growth rate He Zhang
IBS rise time calculation using BETACOOL Set the lattice of the ring Pay attention: He Zhang
IBS rise time calculation using BETACOOL Set ring parameters He Zhang
IBS rise time calculation using BETACOOL Set beam paramters He Zhang
IBS rise time calculation using BETACOOL Choose IBS model • BETACOOL manual suggests: • Use Martini model with numerical integral over z first. For accuracy<1%, mu, nu, and z need to be a few hundred • Then choose “Coulomb logarithm”. Compare the result to find a proper value for Lc. Pay attention: the window value of “Coulomb logarithm” is actually two times “Coulomb logarithm” (2Lc), ~40. He Zhang
IBS rise time calculation using BETACOOL Calculate the growth rate He Zhang
IBS rise time calculation using BETACOOL Calculate the growth rate He Zhang
Discussion about coupling Lijun’s result for MEIC IBS calculation He Zhang
Discussion about coupling He Zhang
Discussion about coupling From the physical manual of BETACOOL: He Zhang
Discussion about coupling From the physical manual of BETACOOL: He Zhang
IBS calculation for MEIC&LEIC Future work • Cooling simualtion • Compare different models and formulas • Get familiar with other functions of BETACOOL This presentation uses the results from the following persons’ work: A. Piwinski, J. Bjorken, S. Mtingwa, M. Monte, M. Martini, A. Sorensen, F. Zimmermann, J. Wei, G. Parzen, etc. Thanks for your time ! He Zhang