IBS Calculation Using BETACOOL
16
IBS Calculation Using BETACOOL He Zhang 2/26/2013 Jlab MEIC R&D Group Meeting
description
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? - PowerPoint PPT Presentation
Transcript of IBS Calculation Using BETACOOL
IBS Calculation Using BETACOOL
He Zhang
2/26/2013 Jlab MEIC R&D Group Meeting
He Zhang ---2---
Outline
• Formulas for IBS rise time
• IBS rise time calculation using BETACOOL
• IBS calculation for MEIC&LEIC
He Zhang ---3---
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 formulas1. In beam frame, two body collision, the change of momentum2. In lab frame, the change of emittance3. Average over all scattering angles4. Average over all particles
He Zhang ---4---
Formulas for IBS rise time calculation
He Zhang ---5---
IBS rise time calculation using BETACOOL
• Set the lattice of the ring• Set ring parameters• Set beam paramters• Choose IBS model• Calculate the growth rate
How to use BETACOOL:
He Zhang ---6---
IBS rise time calculation using BETACOOL
Set the lattice of the ring
Pay attention:
He Zhang ---7---
IBS rise time calculation using BETACOOL
Set ring parameters
He Zhang ---8---
IBS rise time calculation using BETACOOL
Set beam paramters
He Zhang ---9---
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 ---10---
IBS rise time calculation using BETACOOL
Calculate the growth rate
He Zhang ---11---
IBS rise time calculation using BETACOOL
Calculate the growth rate
He Zhang ---12---
Discussion about coupling
Lijun’s result for MEIC IBS calculation
He Zhang ---13---
Discussion about coupling
He Zhang ---14---
Discussion about coupling
From the physical manual of BETACOOL:
He Zhang ---15---
Discussion about coupling
From the physical manual of BETACOOL:
He Zhang ---16---
IBS calculation for MEIC&LEIC
Future work
• Cooling simualtion• Compare different models and formulas• Get familiar with other functions of BETACOOL
Thanks for your time !
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.
