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Laurent announced that a MAD-X course is planned for the beginning of March and that places are left.
Rogelio commented for the LHC that it is believed to be possible to correct the significant (8mm) misalignment observed for one empty cryostat without warmup.
The meeting today had three presentations, with slides, all linked to the PS
Preparation for PS commissioning, Alexander Huschauer
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The injectors were upgraded during the shutdown, with new and improved equipment (wire scanners, BGI beam gas ionisation monitor, RF).
The injection energy into the PS was raised (from 1.4 GeV to 2 GeV kinetic energy) to reduce space charge effects.
The PS "Cold Checkout" started 10 days ago. The start with beam is scheduled for the beginning of March.
This will be followed by 6 weeks PS beam commissioning.
The first milestone is beam delivery to the SPS scheduled for mid April.
He also showed the plans to ramp up intensities and brightness during LHC RUN3 to reach the HL-LHC target parameters.
Improved low-energy optics control in the PS, Wietse Van Goethem
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Wietse summarized his work performed during his year as student for his master thesis under supervision of Alex.
He studied the minimization of beta and dispersion beating using optimized algorithms and different sets of quadrupole correctors (LEQ).
He concludes that a noteworthy improvement can be found with a minimal and easily testable modification of the current lattice, and that the flexibility for LHC type beams will increase.
The propagation of optics measurements to wire scanners needs to be reviewed.
3) Combined function magnet modeling, Frank Schmidt
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It has been known since a while, that the chromaticity for the combined function PS appears to be well described by the thick MAD-X lattice in good agreement with PTC, but that this is not well reproduced by the thin MAD-X lattice even when many (like 20) slices are used since the effects of a curved coordinated system is ignored. The same problem occurs both in PTC and SixTrack. Slicing is required to take into account space charge effects.
Symplectic slicing of combined function dipoles has been studied in detail by Malte Tietze and published in PRSTAB 19, 054002 (2016).
Frank Schmidt proposes to use Eq. 34 of Malte to improve the chromaticity of the sliced lattice while being generally symplectic. Eq. 39 could also be used but would result in non-symplectic maps for non-zero orbits. The third option Eq. 38 is generally symplectic but the chromaticity does not agree well with that of the thick version, Eq. 38 is therefore also of little use. Frank also suggests to create a MAD-X module to generate automatically differential algebra maps by transferring the MAD-X 1st and 2nd order (RE, TE) terms. He says that he works with Andrea Latina and Harry Renshall on the implementation of the space charge module and general checks and improvements and expects these to be available before summer.
Rogelio comments that non-symplectic solutions (Eq. 39), even with a warning should be avoided.
Tobias and Helmut remind that MAD-X also allows for thick slicing of dipoles.
Priority of implementing the new thin symplectic combined function magnet in MADX is therefore not the highest. Space charge module should be made available first (Frank estimates that before summer code and documentation should be released). Concerning the calculation of T terms and implementation in MADX, Frank mentions that one of his students might take of it.