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v3.3.3-pre
Participants:
Foteini Asvesta, Lili Celine Blondel, Michele Carla’, Ozgur Etisken, Gianni Iadarola, Leandro Intelisano, Nikos Karastathis, Sofia Kostouglou, Parthena Stefania Papadopoulou, Yannis Papaphilippou, Axel Poyet, Tirsi Prebibaj, Adriana Rossi, Kyriacos Skoufaris, Guido Sterbini, Natalia Triantafyllou, Michail Zampetakis.
Guido opened the meeting by reporting the follow-up list of the previous BB meeting (see https://indico.cern.ch/event/797108/).
Axel presented the status of the wire simulations in LHC. The first goal of this simulation campaign is to benchmark the simulation results with the MD results (in particular the MD#3 results, where the wire collimators were at 5.5 sigma_coll, dipolar configurations, the octupoles were off, the chromaticity was 15 and the tunes were the nominal ones (0.31,0.32)).
The present simulations show an overall beneficial effect of the wires but the wires in IP1 seems more effective of the one in IP5 (in contradiction with the experiments). Hence, the needs for a detailed scrutiny of the simulation input.
Axel showed the series of tests and sanity checks for the MADX input. The sanity checks for the MADX-SIXTRACK is not yet completed.
For the MADX test the python package cpymad was used. Axel stressed that this package was very handy and useful to carry out the test. He prepared and commented few python notebooks with examples how to use it.
The BEAMBEAM element in MADX was tested and is consistent with expectation (particular emphasis was given to the direction of the strong beam: to compensate (wire mode) the strong beam has to be opposite in charge (electron) and direction with respect to the weak beam (proton)).
In order to check the wire side and polarity, the wire dipolar and quadrupolar effect (in open loop) was compared to the analytical expectations. The results are consistent for all wires.
In addition, the MADX footprints of the single wires were analyzed. They qualitatively agree with expectation. A quantitative analysis in under study.
An in-depth scrutiny of the MAD-X quadrupolar feed-forward was carried out.
Yannis suggested investigating possible problem on the MADX-SIXTRACK by using the FMA tools of SIXTRACK (Sofia) and correlate them with MADX.
Adriana asked if how the wire is modeled in MADX and SIXTRACK. Axel answered that in MADX the wire is modeled with a BEAMBEAM element. In SIXTRACK one can chose to use a BEAMBEAM element or a solid wire. In the simulation presented, Axel is using a BEAMBEAM also in SIXTRACK. Past simulations from Kyriacos showed that, in the usual parameters space, the wire and BEAMBEAM elements in SIXTRACK are equivalent.
AOB
Axel asked if the communication about the HTCondor user in the section/group can be improved. Gianni suggested, as best forum, to share howtos/pitfalls in the ABP computing working group wiki (https://twiki.cern.ch/twiki/bin/view/ABPComputing/WebHome). In particular everyone can/should contribute in the section https://twiki.cern.ch/twiki/bin/view/ABPComputing/RecommendationsAndUsefulInformation.
For technical problem solving, Gianni suggested not to hesitate to use the help-desk.
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