Updates to WISE for LHC run II Per Hagen May 2015

2 User interface

3 Optics Imported the optics from /cern.ch/eng/lhc/optics/runII/2015 Initial decision to keep the possibility to able to generate WISE data for both Run 1 and 2 Added an Excel sheet “MAD-X KnL II” to store KnL for all magnets The optics covers thick lens, injection, collision and 19 squeeze scenarios (down to 40 cm in IP1+5, 300 cm in IP8, no squeeze in IP2) The new optics data contain complete scenarios with all magnets (in Run 1 a “copy&paste” of each IR region was needed) The strength of the arc correctors MCS, MSS, MCO, MCD are computed from the average MB b3, a3, b4, b5 per sector and beam The strength of the MQT and MQS (the MQTs not assigned strength in MAD-X) are given by a lookup table in Excel sheet "MAD-X Kn arc corr“ The lookup is a function of beam energy which effectively means function of magnet currents This table is derived from using software made by Stephane F. which uses the MB errors plus the MAD-X Twiss table to compute corrections The same principle is applied to the triplet correctors, but has not been updated for Run II

4 LSA related stuff Extra data needed to imitate LSA is stored in the Excel sheet “LHC ref cycle” It contains E as function of time, FiDeL parameters which are operation dependent to compute b3 decay & snapback, beta* values for squeeze

5 Layout The WISE Excel sheet “LHC ref layout” contains a subset of the info from the official MAD_SEQUENCES view in Oracle. In addition it contains data which is needed for geometry calculations, namely the “markers” for start and end of cryostats, positions of FID points, rotations around vertical axis It is updated by extra macros and Excel This implementations is for historical reasons. It should have used the layout database directly, but rewriting and validating code from scratch is costly Also I forgot to think about backwards compatibility so layout for Run 1 is only available in older versions of WISE (also online)

6 FiDeL data and powering errors The update of FiDeL data for Run 2 is given in a separate presentation The implementation of uncertainty in FiDeL database is given in a separate presentation The FiDeL data has successfully been used to validate the LSA settings for 2015 Pending “to be done” is the decay and snapback scaling of MB b3, and perhaps decay of MQ and MB main field should be added. MB a3 needs updating in LSA and the K values for RSS circuits are different from WISE! All uncertainty for field quality is now driven by FiDeL data. The Excel sheet “Summary” is no longer used (a lot of cleaning-up inside WISE pending) Since most magnets are assigned K-values (but not most of the orbit correctors), uncertainty estimates are available for most magnets The uncertainty is based upon a calibration offset for each magnet family, individual magnet error (“sigma”) in FiDeL as function of current, powering error in the circuit The powering errors are stored in the Excel sheet “Summary” Data originally based upon “LHC Reference” specs, now a recent document is available G:\Projects\WISE\Other\Doc\power-converter-presentation.pdf

7 Geometry data The geometry data has been updated for LHC Run 2 Generate estimates for almost all elements in MADX, like collimators, thanks to SU data Software reviews in 2014 and 2015 revealed 3 inconvenient software bugs due to misunderstandings of coordinate systems The rotation angles in WISE were 1000 smaller than in reality (so always almost 0) The rotation angles in WISE turned out to be identical to MADX The dR radial offset in SU (survey) data points towards LHC centre (like WISE) The uncertainty estimates for geometry has been updated. They are also stored in Excel sheet “Summary” Magnet geometry statistics after WP08 (if missing both magnetic and mechanical axis measurements) Systematic offset mag minus mech axis (if missing magnetic axis measurement) Magnet geometry uncertainty due to ageing and transport into tunnel (spool pieces) Cryostat geometry uncertainty due to positioning in tunnel (if element not measured by SU) And more importantly, guesses of tunnel movements before next re-alignment …

8 SU coordinate system

9 WISE rotation angles = MADX

10 Update of sign issues in MADX geometry script

11 Data ready to use “take-away” for simulations The folder G:\Projects\WISE\Other\Errors\2015 contains simulation data Data for LHC Run 1 is also available, but the mentioned sign issues due to misunderstanding of coordinate systems need reprocessing

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