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Beams from Super-FRS / Status Storage Rings Helmut Weick EXL / R3B / ELISe collaboration meeting

Beams from Super-FRS / Status Storage Rings Helmut Weick EXL / R3B / ELISe collaboration meeting Göteborg, 14. Oct 2008. The High Intensity Target Spot Size and Separation Spot Size and Transmission Separation Status of Ring Buildings. The Ring-Branch. MF9. MF9. 20 Tm. RIBs.

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Beams from Super-FRS / Status Storage Rings Helmut Weick EXL / R3B / ELISe collaboration meeting

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  1. Beams from Super-FRS /Status Storage RingsHelmut Weick EXL / R3B / ELISe collaboration meeting Göteborg, 14. Oct 2008 • The High Intensity Target • Spot Size and Separation • Spot Size and Transmission • Separation • Status of Ring Buildings

  2. The Ring-Branch MF9 MF9 20 Tm RIBs antiprotons 740 MeV/u HI primary beams Rings used by NUSTAR, PANDA, SPARC+FLAIR

  3. Performance of the Production Target Hydro-dynamical calculation Liquid Lithium jet may be worse than graphite. Less energy density but low spall strength of liquid. Lithium will splash at high velocity. It will reshape, but the amount splashed is large. An. Tauschwitz et al., NIM A (2008) Ø= 45 cm Graphite target wheel may stand 5x1011 uranium ions in one pulse with enlarged spot size of sx = 4mm times sy =6 mm. Comparable energy densities (~1 kJ/g) have been reached in test experiment S334 on small spot size. The amplitude of pressure waves and thereby themaximum tensile forces are similar as the distance to the target boundary is similar (P = 30 MPa). d = 0.5 – 4.3 cm graphite sample Ø=1 cm Laser 238U Doppler Vibrometer Larger spot size does reduce the resolution and can reduce transmission !

  4. Spot Size at Exit Slit (MF7) Size increases with initial spot size, 1500 MeV/u 238U -> 12C target 4 g/cm2 132Sn slowed down and separated with degraders to 740 MeV/u.

  5. X-Spot Size at Exit Slit (MF7) x x Size increases depends on energy-loss straggling as one limit and magnification including factor from wedge shaped degraders. Transmission does not depend so critically on sx.

  6. Y-Spot Size and Transmission Large spot required for high intensity uranium beams, used for fission, example again 132Sn. Enlarged spot size in vertical direction reduces transmission into the CR. But reduction is only to 54% for spot size 1x2 mm2 to 4x6 mm2 (factor 12). sx = 2 mm sx = 2 mm sx = 4 mm

  7. Separation with Enlarged Beam Spot (1) Rates per incident ion at MF7 Difficult separation of fission fragments due to broad initial momentum distribution (Br cut) 132Sn from 238U beam at 1500 MeV/u, slowed down and separated in degraders to 740 MeV/u. Transmission of fission fragments around the selected 132Sn. for different sx x sy at target. Separation got worse but rate increase is moderate (linear scale).

  8. Separation with Enlarged Beam Spot (2) Rates per incident ion at MF7 Example: 104Sn from 124Xe beam at 1500 MeV/u, slowed down and separated in degraders to 740 MeV/u. Lower dE/dx, spot size needn’t be enlarged so much. No big difference in yield after separation (linear scale).

  9. m/q - Separation in Rings Transmission through Super-FRS Stochastic cooling is amass selective RF filter. D(m/q)/(m/q) ~ 10-3 cools down to Dp/p ~ 10-4 • slits in rings can be used. Still Super-FRS must separate nuclides with D(m/q)/(m/q)< 10-3. For 132Sn next critical ones 124Agand140I (<10-3) are separated. Problems only with m/q = 2, 2.5 After electron cooling even possibility for separation with D(m/q)/(m/q) < 10-4 but needs more development. CR cut 104Sn m/q = 2.08

  10. Problem of Charge States No tracking of ions possible to help in suppression of charge states. Isobaric contamination by ions with electrons possible. These contaminants can come with much higher cross section. Must be separated in Super-FRS, as m/q difference is only the difference in mass excess (requires Dm/m = 10-5) e.g. 132Sn50+ and 132Sb50+ or 132Te50+. Best way for suppression is to use a series of many strippers at high energy. Example, 132Sn setting shown before:132Te and 132I are transmitted (both with 1 electron at the end). But 132Te with 2 electrons or 132I with 3 electrons would be critical. After stripping three times, ratio 132Sb to 132Sn = 10-4.

  11. Ring Scheme Super-FRS: Production, Separation CR: Bunch rotation Stochastic cooling at 740 MeV/u also for separation Direct transfer line from SIS-18 or Super-FRS to NESR in phase A RESR: Deceleration if needed down to 100 MeV/u NESR: Cooling, accumulation, measuring

  12. Beam Parameters 0.5 mm 0.8 mm 1.3 mm ~5 mm

  13. Simulation of Fragment Beams for Storage Rings • Simulation package for beam intensity in EXL or ELISe includes • Primary beam intensity from FAIR parameter list • Production in Super-FRS target (formula for opt. target), • Transmission through Super-FRS in CR (approximation to many MOCADI simulations, different for fission or lighter nuclei) • Beam energy and degrader thickness from energy loss by ATIMA • Reaction losses and charge exchange in degraders. • Cooling times in CR or NESR as input. • Cross section for electron capture in target or electron cooler. • Calculation of beam lifetime in the rings. • Formula for average luminosity in mode with optimized cycle of accumulation, cooling, (bunching), measuring • All combined in PERL script, runs fast. • Luminosity tables are available as spreadsheets. H. Weick, H. Simon, V. Volkov

  14. NESR, Building 8 8b 8 8a

  15. NESR Floor Plan layout to be revised byarchitects Detectors, electronics Clean room DAQ, electronics Others 150 m2 work places 100 m2 electronics racks 40 m2 meeting room 70 m2 storage place 420 m2 in total + 1/3 with second floor

  16. New Detector in ESRpocket built at KVI

  17. Summary • For full intensity U-beam liquid Lithium target will spall. • Solid graphite or CC-composite target wheel will last with enlarged beam spot. • Graphite test experiment done with same temperature rise and pressure as at Super-FRS. Reproducible in simulation. • Enlarged Spot reduces resolving power, but losses in resolution can be mostly compensated by separation in storage rings (only exception m/q=2.5) Rate of ions injected into CR is slightly increased. • Transmission into CR for 12 times enlarged beam spot area at target still 54% of small spot value. • Simulation package for luminosities of RIBs. Review (5+6th May 2008),defended the present design.Costs should be reduced but only without losing much performance (specified as acceptance). Still some input needed for NESR building.

  18. Time Schedule for FAIR Time pressure for Super-FRS old 3 stages -> Phases A + B The order should stay (say STI, ISC) We know that the start is delayed.

  19. Detailed Room Plan Specifications for buildings in 2006/7 load lists (electrical power, cooling water, cryopower, temperature) 2008 room book, with area and type of room in NESR building, much more detailed. Prepared by FAIR-CC but they require a lot of input (5 page catalog). We still need information for each room, from WGs. Temperature, humidity, limits, on what time scale? Transport concept and sizes, Weight on floor or wall, Floor covering, raised floors, electr. conductivity, Cooling water (type, how many adapters?), drinking water, Compressed air (pressure?), detector gases supplies, Cryo supply (no central liquid He anymore, no SC magnets) Clean room classification, Number of people working Electrical power (no. of sockets), clean ground, Control systems (gases, cooling, etc.) LAN, WLAN, phone, video, Type of furniture

  20. Forward Spectrometer We had a bit confusion in names: - Forward spectrometer, - In-ring spectrometer, - Heavy-ion spectrometer, - Heavy-ion detectors. Is it really a spectrometer, spectrograph, or tagging? No precise momentum measurement planned anymore. Two working groups: * Heavy Ions *Neutrons and forward protons

  21. Change of NESR Lattice Shown 1/8 of NESR More space for insertions also for detectors, on the cost of slightly lower acceptance.

  22. Dynamic Aperture Dp/p=-1.5% Dp/p=+1.5% EXL: Dp/p only ±0.3%, but narrow aperture for vacuum separation Ions starting at what region of the aperture are still stored? Dynamic aperture is defined only by the shape of the magnetic fields disregarding the geometric aperture. Nonlinearities reduce dynamic aperture, require correction. Dynamic aperture should be larger than geometric aperture,even with a safety margin as we have only simulations so far. NESR61(64)Diego Obrador Campos In case ofNESR60 no dynamic acceptane for shifted momentum.

  23. Positions for Heavy Ion Detectors - ELISe, AIC NESR P33 Det-1 NESR bypass-1 by Petr Shatunov for AIC Det-2 +ELISe,adjustment to latest NESR still to be done Det-3 Det-4 H. Weick

  24. Spot size on Detector after Annihilation (AIC) extended target -> larger spot in projection 72Ni at 740 MeV/u Beam spot on detectors

  25. Spot Size on Detector - ELISe Fission Fission of 238U at 740 MeV/u to 132Sn at Det.1

  26. Detectors between dipoles Mounting of detector pockets can be difficult. Suggestion: one vacuum chamber over two or three dipoles. zoom

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