[TA]JonB 2009-11-17 13:06:25 | • Muon1 modified to find closed orbits from 12GeV stepping downwards • Existing genetic algorithm search for largest energy range with stable optics I was able to glean a small amount of usable information from that article. Good to see the two entries on Page 9. Muon 1 data is being useful. |
[TA]JonB 2009-11-17 13:09:30 | and again in the huge poster: FODO Cell Lattice The Muon1 code was used to track protons through a cell with its 4th order Runge-Kutta algorithm with some extra code logic added to find closed orbits and optics. The existing genetic algorithm optimiser could then be run to improve the figure of merit derived for the entire cell, starting off with random designs within the allowed range and recombining or mutating the best of these repeatedly to increase the overall score. For each cell being tested, closed orbits are searched for at energies starting at 12GeV and decreasing by 5% steps, with linear transfer matrices (and optical stability) determined at each stage. A `FODO' cell with two drifts each at least long enough to hold two RF cavities was tried first and optimisation reached a design with stable optics down to a low energy of 3.46GeV. |
[TA]JonB 2009-11-17 13:32:41 | and my curiosity about FFAGs (because I didn't see an acronym breakdown) led me to this article in CERN space: http://cerncourier.com/cws/article/cern/29119 |
Stephen Brooks 2009-11-18 17:34:44 | Yes, that's a correct reference for FFAGs. They are somewhere half way between synchrotrons like at CERN and the filled-in/wide aperture, fixed magnetic field cyclotrons. In some applications making the magnetic field non-variable has technical advantages, though you pay for it in complexity of the magnetic fields and orbits and often with a larger aperture. |