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A large acceptance dipole magnet for the R 3 B set-up

A large acceptance dipole magnet for the R 3 B set-up. R 3 B : R eactions with R elativistic R adioactive B eams. The R 3 B collaboration. 136 physicists 41 institutes 14 countries . R 3 B in the FAIR project.

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A large acceptance dipole magnet for the R 3 B set-up

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  1. A large acceptance dipolemagnet for the R3B set-up R3B: Reactions with Relativistic Radioactive Beams - Jean-Eric Ducret - R3B - GLAD magnet

  2. The R3B collaboration 136 physicists 41 institutes 14 countries - Jean-Eric Ducret - R3B - GLAD magnet

  3. R3B in the FAIR project R3B: The high energy branch of the nuclear physics with exotic heavy-ion beams (NUSTAR) Physics program for R3B: Halos and neutron skins in exotic nuclei Evolution of the shell structure Collective excitations (possibly new) Nuclei beyond the drip-line Correlations Astrophysics Excited nuclei for nuclear matter properties - Jean-Eric Ducret - R3B - GLAD magnet

  4. R3B experiments Experimental methods common to the R3B experiments Scattering with heavy ions at energies of a few hundreds of MeV per nucleon Probing the structure of exotic ions by scattering them on either heavy targets (in the Coulomb field of the target nucleus) or on very light targets (e.g. proton) and looking at their decay channels Measuring in coincidence the (many) fragments of de-excitation in order to cover the final-statephase space as completely as possible and to reconstruct the excited nuclear system prior to de-excitation - Jean-Eric Ducret - R3B - GLAD magnet

  5. R3B experiments Advantages of using high-energy beams Maximize forward focusing from the scattering-system center-of-mass frame (where the physical processes occur) to the lab frame (where the detection stands), especially for light-target & heavy-ion reactions Simplify the description of the reaction mechanisms leading to the excitation of the projectile extract accurate nuclear-structure information Gain on available luminosity on the target because of a higher transmission inside the fragment separator between the exotic-beam production target and the secondary target used for physics studies Use of fully stripped ions possible use of thick targets to compensate for low luminosities (very exotic beams) experiments become possible with ~ 1 ion/s beams - Jean-Eric Ducret - R3B - GLAD magnet

  6. R3B experimental set-up Principle of an experiment @ R3B Identification and, if necessary for spectrometry, cooling of the beam Measurement of the final state as exclusively as possible- identification of the charged fragments at the target or after a momentum analysis in the large acceptance magnet (in particular for the mass reconstruction)- measurement of the neutral particles with dedicated detectors (γ/n) - Jean-Eric Ducret - R3B - GLAD magnet

  7. R3B large acceptance magnet Superconductinglarge-acceptance magnet • Bending angle: 18 deg for 132Sn @ 1 A.GeV • Angular opening: +/- 80 mr for neutrons and charged fragments, in both H & V planes • Fringe field: B < 0.02 T around the target point, ~ 1 m upstream of the magnet entrance - Jean-Eric Ducret - R3B - GLAD magnet

  8. R3B large acceptance magnet Magnetic field integral: ~ 4.8 T.m Choices for the design of the magnet Superconducting magnet Full linearity of the field with the current Lower operational cost (lower electrical power consumption) Active shielding technique: B  0 rapidly outside the magnet Blue: B < 0.02 T Red: B > 5 T - Jean-Eric Ducret - R3B - GLAD magnet

  9. R3B large acceptance magnet Grading of the coils Goal: To decrease as much as possible the stored energy inside the magnet (dimensioning parameter for a superconducting magnet and main variable governing the price of the object)  be as efficient as possible for the active volume design (i.e. as close as possible to the particle trajectories) While: Keeping as flat as possible the field profile along the symmetry axis of the magnet B (T) 2.0 1.0 Entrance Exit Z (mm) - Jean-Eric Ducret - R3B - GLAD magnet

  10. Magnet transport calculations Goal of the study Check of the kinematics reconstruction performances at the target from coordinates measurements at the exit of the magnet Method Track different kinds of particles in the field map of the magnet generated by the TOSCA-OPERA calculation Fit the relationships between the downstream coordinates and the kinematical variables at the target reaction point (polynomial parameterization) Extract the most significant components by a main component analysis Introduce a pseudo-resolution in the detectors at the exit of the magnet to measure its influence on the reconstruction - Jean-Eric Ducret - R3B - GLAD magnet

  11. Magnet transport calculations Different particles Each type of particles samples a particular part of the magnetic field map and with its own sensitivity given by its magnetic rigidity:- The heavy ions probe the most central part of the field map with a large rigidity, thus a relatively small sensitivity- The alphas with a comparable rigidity probe a much larger part of the field map- The protons, with the smaller rigidity (i.e. more sensitivity to the field profile), probe the whole magnetic volume and are thus sensitive to non-dipolar components of the fields, particularly important on the edges of the active volume Protons: Δp/p  [-10,10] (%), v & h  [-80,80] (mr) Alphas: Δp/p  [-5,5] (%), v & h  [-80,80] (mr) Heavy ions: Δp/p  [-1,1] (%), v & h  [-10,10] (mr) - Jean-Eric Ducret - R3B - GLAD magnet

  12. Magnet transport calculations RMS = 0.15 % (Δp/p) (%) Preliminaryfield map -0.4 -0.2 0 0.2 0.4 Protons RMS = 0.2 mr h (mr) -1.5 -1 -0.5 0 0.5 1 1.5 - Jean-Eric Ducret - R3B - GLAD magnet

  13. Magnet transport calculations RMS < 0.1 % (Δp/p) (%) Preliminaryfield map -0.4 -0.2 0 0.2 0.4 0.6 Alphas RMS = 0.1 mr h (mr) -0.3 -0.2 -0.1 0 0.1 0.2 0.3 - Jean-Eric Ducret - R3B - GLAD magnet

  14. Magnet transport calculations RMS < 0.1 % (Δp/p) (%) Preliminaryfield map -0.1 -0.05 0 0.05 0.1 0.15 0.2 Heavy ions RMS < 0.1 mr h (mr) -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 - Jean-Eric Ducret - R3B - GLAD magnet

  15. Magnet transport calculations Xf (mr) (Δp/p) (%) Uncertainties- heavy ions OK !! f (mr) φf (mr) - Jean-Eric Ducret - R3B - GLAD magnet

  16. Magnet transport calculations Xf (mr) (Δp/p) (%) Uncertainties- protons Effect of non-dipolar comp.on the sides ofthe centralvolume Tracking will have to be carefully calibrated f (mr) φf (mr) - Jean-Eric Ducret - R3B - GLAD magnet

  17. R3B large acceptance magnet A few numbers characterizing the magnet Field integral: ~ 4.8 T.m Stored energy: in between 22 & 24 MJ Central field: ~ 2.7 T Maximum field on the conductor: ~ 7.5 T Current density: < 80 A/mm2 Total current: ~ 2500 A Conductor cross-section: 7.5 x 5 mm2 Cold mass temperature: ~ 4 K Mechanical effort on the conductor: ~ 300 – 400 t/m - Jean-Eric Ducret - R3B - GLAD magnet

  18. R3B large acceptance magnet Specific technical difficulties of the project Original magnet design (open magnetic volume, shape of the active volume) Very constrained fringe field (especially in the target direction) Flat profile vs large acceptance with two symmetries Peak field on the conductor & current density Mechanical efforts (~ accelerator magnets) Thermo-siphon with little slope for the lHe flow Stability of the conductor Current leads from room temperature to 4 K - Jean-Eric Ducret - R3B - GLAD magnet

  19. R3B large acceptance magnet Risk analysis of the project Degradation of conductor performances at fabrication Sample tests in advance, detailed quality insurance at production Degradation of conductor performances at winding  Detailed winding control Bad mechanical behavior of the cold mass Material properties tests at 4 K Insufficient pre-stress on coils Detailed planning for the construction Bad thermo-siphon cooling Back-up system Quench detection failure Re-enforce quench detection Shortcuts in coil insulation Detailed winding control - Jean-Eric Ducret - R3B - GLAD magnet

  20. R3B magnet project organization • Insurance quality organization • Documented procedures • Defined relationships & organization within the project team & between the project team and the “R. of the W.” • Detailed planning & deliverables • Deputy in charge of the quality - Jean-Eric Ducret - R3B - GLAD magnet

  21. R3B magnet product breakdown 0000 Magnet 1000 Cold mass 2000 Cryostat 3000 Protection 4000 Electrical power 5000 Cryogenic 6000 Vacuum 7000 Instrumentation & control 8000 Installation 9000 Tests - Jean-Eric Ducret - R3B - GLAD magnet

  22. R3B magnet construction planning Detailed technical design: Q4-2005 to Q2-2006 Superconductor definition & industrial offers:  S2-2006 Mechanical design of the magnet: Q3-2006 to Q4-2007 Test at reception of the superconductor: Q1 to Q4 2007 Winding & first integration of coil # 1: Q2 2007 Winding & first integration of other coils:  Q2 2008 Construction of the mechanical structure: 2008 Second integration (full magnet): S2 2008 Instrumentation & tests of the control systems: S2 2008 Complete instrumentation of the magnet & tests in Saclay:Q1 2009 Shipping to GSI & installation in R3B hall: Q3 2009 (Q = quarter, S = semester) - Jean-Eric Ducret - R3B - GLAD magnet

  23. R3B magnet detailed planning - Jean-Eric Ducret - R3B - GLAD magnet

  24. R3B magnet project First goals to be achieved Magnetic calculations Reduce the peak field on the conductor Improve the field distribution to a flatter shape Superconductor Definition of the conductor parameters (on the conservative side) Investigate already existing cables in order to ensure a good quality and a low price Compute discharge effects and optimize V/I Quality control Definition of controls and procedure for the cable and conductor fabrication - Jean-Eric Ducret - R3B - GLAD magnet

  25. R3B magnet deliverables Q3 2006: End of technical design Detailed technical design report Q2 2009: End of tests in Saclay Report on tests of the magnet Q3 2009: Delivery in GSI & installation R3B magnet & final report - Jean-Eric Ducret - R3B - GLAD magnet

  26. Conclusions The R3B large acceptance dipole magnet A central part of the R3B set-up for the “high-energy” nuclear physics program @ FAIR with exotic beams An innovative design with technology known by Saclay(with quite innovative high-temperature superconducting current leads) The project team The project team is formed by people used to work together With a close connection to physics requirements and to the R3B collaboration The final design is on the way and the construction will start within the framework of the experienced big-project management of Saclay (LHC) - Jean-Eric Ducret - R3B - GLAD magnet

  27. R3B magnet project Mechanical studies Support the mechanical efforts of 300 – 400 t/m Interactions with the magnetic calculations Cold mass: interactions with thermal & thermodynamic calculations Pre-stress of the coils to support the efforts Definition of the necessary mechanical tests Design of the magnet support structure and the links between the 4K pieces and the room temperature Include in the whole design the necessity of shipping the device from Saclay to GSI !! - Jean-Eric Ducret - R3B - GLAD magnet

  28. R3B magnet project Cryogenic studies Thermo-siphon Insure the homogeneity of the cooling Thermal calculation of the system Cryostat design Definition of the conductor parameters (on the conservative side) Thermal calculations of the current leads Coupling with the lN2 and lHe supply in the R3B hall Definition of the data for the control system - Jean-Eric Ducret - R3B - GLAD magnet

  29. - Jean-Eric Ducret - R3B - GLAD magnet

  30. - Jean-Eric Ducret - R3B - GLAD magnet

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