Summary Notes of the MAD-X meeting held on 20 March 2006


Present :
H.Burkhardt, M.Giovannozzi, W.Herr, V.Kapin, A.Koschik, R.de Maria, T.Risselada, F.Schmidt, P.Skowronski, F.Zimmermann


1) New support policy for MAD-X (FS)
Frank explained that he will have less time available (at most 10 %) for MAD-X support. It has been decided that he will devote most of his time to on-line modeling of the LHC. The frequency of the MAD-X meetings will be reduced.

2.a) Recent developments: matching (RdM)

  • Riccardo presented recent progress with the matching module (slides in pdf).
    User defined penalty functions are foreseen.

    2.b) Recent developments: PTC (PS)
    Piotr presented the following improvements:

  • 1. Support for TWCAVITY in MADX-PTC interface. PTC_TWISS was modified accordingly. New command PTC_TRACKCAVS was implemented that enables particle tracking with TPC taking to the account acceleration in cavities. PTC_TRACK was not changed.
  • 2. PTC_SELECT command, that allows to instruct PTC_TWISS to store given coefficient of the tracked polinomial in a user specified table/column. It enables matching of these coefficients, i.e. matching of any order nonlinear terms, (to be implemented by Riccardo, work in progress)
  • 3. PTC_SCRIPT, command requested by Etienne Forest. It runs a PTC script of which the path is passed as a parameter. It will enable additional powerfull functionality of PTC for MAD-X users, e.g. sequences can be arranged into delay loops or recirculators.
  • 4. PTC_INTSTATE, sets the internal state switches of PTC
  • 5. PTC_DAMPMAPS, dumps a linear part of a map for each element (i.e. matrix) into a user specified file.

    3) Plans for PTC modules (VK) (slides in ppt)

    4) Tracking module (AK) (slides in pdf)
    The treatment of off momentum closed orbits is yet to be finalized.

    5) Cleaning up examples and documentation
    All documentation has now been updated and cleaned up. Testing the examples with the special strict test version revealed weaknesses in the code (square roots of negative numbers, divisions by zero, indices exceeding array limits, etc.), and these have been corrected.

    The current module keepers are listed here.

    6) A.O.B.

  • a new version is coming out soon (but too early to include AK's final tracking module)
  • WH wants the default maximum mechanical aperture (maxaper in "run" command) in tracking to be clarified
  • the "refer=entry" and "refer=exit" options (bug reported by WH) contain bugs and will be suppressed in the sequence command


    T.R.