Model of Magnetsin the Decay Ring E. Bouquerel & FLUKA Team, CERN (EN-STI-EET) EUROnu, 3rd WP4 - Beta Beam - Task Meeting 25th November 2009, Grenoble
Reminder(EURISOL DS FP6…) Magnet studies achieved on the Straight Section of the Decay Ring (where Collimation occurs) Average Power deposited due to collimation approaches: 74 kW (55% of the injected 9x10126He2+ particles) 230 kW (80% of 4.26x1012 particles for the 18Ne10+) Use of superconducting magnets NOT possible due to high intensity to collimate (quenching issues) use of warm dipoles/quadrupoles
Tracking Simulations Losses due to collimation generated with ACCSIM code (F. Jones; P. Delahaye): To perform the first stages of modeling the trajectory of the ions (from their injection to the collimation process) Generation of an output file containing: Turn number, Element number, Particle number, Even type, Longitudinal position (coordinates), Event and transverse coordinates. ACCSIM output file used as a source file for FLUKA simulations + implementation with a 3D geometry of one of the Straight Section of the DR components and physics models for ion interactions in matter
Geometry Implementation (FLUKA) Dipol. Qdrupol. Collim. Vertical axis (cm) beam Beam pipe 2nd Bump tunnel Straight Section, beam axis (cm)
Geometry Implementation (FLUKA)Dipoles Implementation of 5 warm dipoles in the Straight Section + in the 2nd bump
Geometry Implementation (FLUKA)Dipoles Only abritrary model for warm dipoles needed for collimation studies (FP6) L=12m 600m 20 mrad y z x 500 300 1000 Cu 85 500 z Fe 100 Inspired from C-shaped magnet Diamond and SESAME storage rings 200 y
Geometry Implementation (FLUKA)Quadrupoles Cu Implementation of 25 standard warm quadrupoles in the Straight Section and the 2nd bump Fe 2m long 30cm 90mm aperture
Power Deposited / Doses Absorbed(FLUKA) Coordinate along the straight axis (cm) GeV/cm3/prim. lost Between 18-20% of the incoming power deposited along the Straight Section, mainly on the quadrupoles/dipoles located after each collimator
Power Deposited / Doses Absorbed(FLUKA) Quadrupoles • average power deposited: acceptable • dose absorbed by the coils: NOT acceptable Dose limitation for warm elements: 10 MGy Absorbers needed Dipoles
Power Deposited / Doses Absorbed • Five carbon absorbers added in FLUKA: • 100 cm long • 50 cm diameter • 8.3 cm diameter aperture (SimpleGeo view)
Doses Absorbed (FLUKA) Quadrupoles no abs. Dose absorbed decreased by factor 3 to 5 with abs. Dipoles no abs. Dose absorbed decreased by factor ~4 with abs.
Doses Absorbed (FLUKA) Quadrupoles no abs. Dose absorbed decreased by factor 3 to 5 with abs. • Dose absorbed still too high: • can stand a 3-year-operation of the DR before changing them addition of more absorbers? Dipoles no abs. Dose absorbed decreased by factor ~4 with abs. Preliminary values!!
Next Steps/Possibilities Coupling ACCSIM/FLUKA to get a better accuracy in the patterns of the collimated ions at each turn achieved in the DR ISOCIM/FLUKA being successfully tested SPS Scrapers (V. Vlachoudis, F. Cerutti, CERN) Addition of absorbers to avoid magnet changes after 3-year-operation (reach a total dose absorbed < 10 MGy) Quadrupoles/Dipoles more detailed in FLUKA (assumptions for materials): Yoke: could equally be steel Cu windings: with water cooling and epoxy resin/ glass cloth Could change significantly the pattern of the absorbed dose by the magnets! • Increase the aperture of the quadrupoles • Any suggestion welcome!
References • F.W. Jones, G.H. Mackenzie, and H. Schonauer, “ACCSIM – A Program to Simulate the Accumulation of Intense Proton Beams,” 14th Int. Conf. on H. E. Accelerators, Tsukuba, Japan, 1989, in Particle Accelerators 31:199 (1990). • "The FLUKA code: Description and benchmarking“ G. Battistoni, S. Muraro, P.R. Sala, F. Cerutti, A. Ferrari, S. Roesler, A. Fasso`, J. Ranft, Proceedings of the Hadronic Shower Simulation Workshop 2006, Fermilab 6--8 September 2006, M. Albrow, R. Raja eds., AIP Conference Proceeding 896, 31-49, (2007) "FLUKA: a multi-particle transport code“ A. Fasso`, A. Ferrari, J. Ranft, and P.R. Sala, CERN-2005-10 (2005), INFN/TC_05/11, SLAC-R-773 • SimpleGeo, Theis C., Buchegger K.H., Brugger M., Forkel-Wirth D., Roesler S., Vincke H., "Interactive three dimensional visualization and creation of geometries for Monte Carlo calculations", Nuclear Instruments and Methods in Physics Research A 562, pp. 827-829 (2006).