1. Town Meeting Espoo, 17.-20.9.2007 The objective of this task is to study the feasibility of a new generation of devices with orders of magnitude greater capacity and throughput in order to accumulate, cool, bunch and purify the high intensity radioactive ion beams of EURISOL. + Construction of the prototype for beta-beams (P10: Towards 60 GHz, high-intensity …, by L. Latrasse, LPSC Grenoble) ISOL target1+ ion source 1+  n+ 1+ high-resolution separator A/q separator Accelerator 1+  n+ scenario for ISOL post-accelerators EURISOL Beam Preparation & Layout A. Jokinen Department of Physics, P.O.Box 35 (YFL) FIN-40014 University of Jyväskylä Charge breeder CERN – JYFL – LMU – MSL – INFN – CSNSM - LPSC TASK9

2. Town Meeting Espoo, 17.-20.9.2007 Sub-1: EURISOL-HRS (T. Giles, CERN) Multiple multipolar dipoles CorrectionsLarge dispersion

3. Town Meeting Espoo, 17.-20.9.2007 Sub-2: Ion cooling and bunching in linear Paul traps (D. Lunney)

4. Town Meeting Espoo, 17.-20.9.2007 Present RFQ-devices NameInput BeamInput Emittance Cooler LengthR0R0 RF Voltage, Freq, DCMass Range Axial VoltagePressureOutput Beam Qualities Colette60 keV ISOLDE beam decelerated to ≤ 10 eV ~ 30 π-mm- mrad 504 mm (15 segments, electrically isolated) 7 mmFreq : 450 – 700 kHz--0.25 V/cm0.01 mbar HeReaccelerated to up to 59.99 keV with long. energy spread ~10 eV LPC CoolerSPIRAL type beamsUp to ~ 100 π-mm-mrad 468 mm (26 segments, electrically isolated) 15 mmRF : up to 250 Vp, Freq : 500 kHz – 2.2 MHz -- up to 0.1 mbar-- SHIPTRAP Cooler SHIP type beams 20- 500 keV/A --1140 mm (29 segments, electrically isolated) 3.9 mmRF: 30-200 Vpp, Freq: 800 kHz – 1.2 MHz up to 260 amu Variable: 0.25 – 1 V/cm ~ 5×10-3 mbar He -- JYFL CoolerIGISOL type beam at 40 keV Up to 17 π- mm-mrad 400 mm (16 segmentes) 10 mmRF: 200 Vp, Freq: 300 kHz – 800 kHz --~1 V/cm~0.1 mbar He~3 π-mm-mrad, Energy spread < 4 eV MAFF Cooler30 keV beam decelerated to ~100 eV --450mm30mmRF: 100 –150 Vpp, Freq: 5 MHz --~0.5 V/cm~0.1 mbar Heenergy spread = 5 eV, Emittance @ 30keV: from = 36 π-mm-mrad to eT = 6 π-mm-mrad ORNL Cooler20-60 keV negative RIBs decelerated to <100 eV ~50 π-mm- mrad (@ 20 keV) 400 mm3.5 mmRF: ~400 Vp, Freq: up to 2.7 MHz --up to ±5 kV on tapered rods ~0.01 mbarEnergy spread ~2 eV LEBIT Cooler 5 keV DC beams-- ~1×x10−1 mbar He (high-p sect.) -- ISCOOL60 keV ISOLDE beamup to 20 π- mm-mrad 800 mm (using segmented DC wedge electrodes) 20 mmRF: up to 380 V, Freq: 300 kHz - 3MHz 10-300 amu ~0.1V/cm0,01 - 0,1 mbar He -- ISOLTRAP Cooler 60 keV ISOLDE beam--860 mm (segmented)6 mmRF: ~125 Vp, Freq: ~1 MHz. -- ~2×10-2 mbar He elong ≈ 10 eV us, etrans ≈ 10p mm mrad. TITAN RFCTcontinuous 30–60 keV ISAC beam -- RF: 1000 Vpp, Freq: 300 kHz - 3 MHz -- 6 π-mm-mrad at 5 keV extraction energy TRIMP Cooler TRIMP beams--660 mm (segmented)5 mmRF= 100 Vp, Freq.: up to 1.5 MHz 6 < A < 250 --up to 0.1 mbar-- SPIG Leuven cooler IGISOL Beams--124 mm (sextupole rod structure) 1.5 mmRF= 0-150 Vpp, Freq.: 4.7 MHz -- ~50 kPa HeMass Resolving Power (MRP)= 1450 Argonne CPT cooer -- SLOWRI cooler -- 600 mm (segmented sextuple rod structure) 8 mmRF= 400 Vpp, Freq.: 3.6 MHz -- ~10 mbar He-- Plenty of devices prototyped Similar devices in size and operation parameters Different solutions for the combination of transversally confining RF-field and an axial potential Perform very well Poorly tested with very high intensities !

5. Town Meeting Espoo, 17.-20.9.2007 Next-generation RFQ for EURISOL Technical proposalr by O. Gianfrancesco (in terms of an ion beam/cloud capacity) 10-100-fold increase in the capacity based on the increasing of the pseudopotential depth D Technical challenge to be solved: 20-30 MHz at 10 kV !  10  A beam or cooled bunches of 6x10 9 ions at 100 Hz rate (D. Lunney, Orsay) e.g. A=40; 2x0=7 mm @ 2 MHz; V(q=0.4) = 80 V; D = 8 eV @ 20 MHz; V(q=0.4) = 8000 V; D = 800 eV

6. Town Meeting Espoo, 17.-20.9.2007 O. Gianfrancesco, Ph.D. thesis, McGill University (2005) Radiofrequency: 10 kV beyond 10 MHz

7. Town Meeting Espoo, 17.-20.9.2007 Latest results (August 2007) Full-length cooler assembled 30-keV ion beam injected with an intensity of 1 microA and successfully transmitted (but with no gas cooling) Post-doc (O. Gianfrancesco) resigned… The test bench will be moved to LPC-Caen The tests will continue once an ECR source (with magnetic separation) is set up (fall 2007) Tests (and commissioning?) will be performed in the framework of a Ph.D. thesis (Florian Duval) for use at the SPIRAL-2 facility ISCOOL soon on-line at CERN ! (P6: Hanna Franberg)

8. Sub-3: Charge Breeding: Perspectives for EURISOL EURISOL –Intense beams up to 10 13 ions/s (µA) –Superconducting LINAC (DC beams accepted) –Beam quality and purity EBIS –High performance charge breeder: high charge states, short breeding times and good beam purity –Pulsed mode preferred –Limits in beam total currents ECR –Moderate performance charge breeder: comparatively low charge states, high background –Continuous mode tested, both possible –High currents capabilities (Presentation by O. Kester on Monday)

9. Town Meeting Espoo, 17.-20.9.2007 ECRISEBIS/T Single charge state breeding efficiencies < 20%<30% <70% in principle Beam puritySupport gas and rest gas In between peaks ~0.5-10 nA Rest gas peaks 10-100 pA; In between peaks <<<1 pA (not detectable) Beam particle rate limitations > 1e12/s<1e9/s with pre-bunching <1e11/s with continuous injection Breeding times50 ms10 ms Typical A/qA/Q >5-6A/Q > 2.6 Breakup of moleculesPossible CS optimizationPartially possibleWell suited Energy spread of ionsnegligibleUp to 0.5% for high current devices Ion beam acceptanceLargeSmall Complementary devices !! EURISOL: Comparison EBIS v. ECRIS (O. Kester, GSI)

10. © CERN - European Organization for Nuclear Research / Pekka Suominen ARC-ECRIS (1/2) Conventional ECRIS is based on solenoids + hexapole magnet configuration ARC-ECRIS is based on “yin- yang” or “baseball” type magnets as used in former fusion experiments in 60’s 6.4 GHz prototype already constructed and tested at JYFL  Next step is to make a full scale device operating at 14 GHz or over. First prototype (constructed & tested) Second prototype (under design) (P20: Pekka Suominen)

11. © CERN - European Organization for Nuclear Research / Pekka Suominen ARC-ECRIS (2/2) © LLNL Baseball experiment (P20: Pekka Suominen)

12. Town Meeting Espoo, 17.-20.9.2007 Objectives: - Design a high-intensity pulsed 60 GHz ECR ion source for rapid ionization of light noble gas radioactive ions, especially He and Ne - Realize of a conceptual prototype suitable for the beta-beam project. Realized:  18 - 28 GHz cw and preglow studies performed with PHOENIX V2 fed with 3 He and 22 Ne, extensive studies performed with Ar to understand the nature of Preglow  D8, Bunched efficiency preliminary study - 60 GHz Intermediate report on bunched efficiency  Scientific International Collaboration Program with IAP Nizhny Novgorod (Russia), experiments at 37.5 and 74 GHz in cusp configuration, theoretical interpretation of the preglow performed Preglow Afterglow 18 GHz, 950 W 28 GHz, 3600 W Steady states reached at 3 ms for all charges !! He Ar  -beam ion source (1/3) (T. Lamy)

13. Town Meeting Espoo, 17.-20.9.2007 (Grenoble High Magnetic Field Laboratory + LPSC) Meeting The Ion Source Service activities and objectives have been presented, the 60 GHz program discussed. A collaboration contract agreement will be signed by the end of September. Agreement concerning the construction of an ion source with a magnetic field established by Bitter coils and/or Polyhelix technologies GHMFL will bring its expertise with such technologies, LPSC will perform the design, construction and integration of the prototype Louis Latrasse (EURISOL Engineer) is in charge of this activity (Poster P10) A first prototype will be chosen, designed and built either in an axisymetric MHD stable Cusp configuration either in a Minimum B one: 1.5T Plasma Magnetic profile 6T 3T Bitter Stack Axial and radial magnetic field 60 GHz prototype GHMFL poly helix technology  -beam ion source (2/3)

14. Town Meeting Espoo, 17.-20.9.2007 Test bench for 60 GHz prototype Magnetic field measurements performed at GHMFL with LPSC High acceptance magnetic spectrometer Under design with GANIL, funded by IN2P3, order placed by the end of 2007 First 60 GHz prototype (magnetic field, plasma chamber and extraction) : Fall 2008 Gyrotron 60 GHz CPER (Government, Region, Institutions project contract) accepted and signed Technological Platform Plasmas-SIRCE (Electron Cyclotron Resonance Ion Sources) created 300 k€ allocated by IN2P3 in 2008 1 Gyrotron delivered end 2008  -beam ion source (3/3)

15. Town Meeting Espoo, 17.-20.9.2007 EURISOL LAY-OUT

16. Town Meeting Espoo, 17.-20.9.2007 Requirements from NA Community “C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006” How much beam time can be devoted to nuclear astrophysics experiments (very time-consuming)? ”Nigel Orr, previous Town Meeting”: Essential aspect of facility, but FP5 proposal of sharing using unused charge state(s) from stripping of very little utility. Many VLE and LE/Coulomb barrier expts (0-5MeV/u) require very extended periods of beamtime with same beam (astro’, heavy elements, etc). Dedicated VLE, LE and HE reaccelerator(s) [~0-1, ~1-5 and ~5-150 MeV/u] coupled to separate target-ion source beam preparation systems * …  ie. Beam sharing of driver accelerator beam  ie. Beam sharing of driver accelerator beam

17. Town Meeting Espoo, 17.-20.9.2007 Schematic lay-out Target-ion sources Pre-separators, beam gates Ion cooling and bunching High-resolution separators Charge breeding: EBIS and ECR q/m selection Electrostatic deflection Post-acceleration and Experimental areas Beam preparation lay-out:  Two complete beam preparation chains  Two parallel mass-purified beams for on-line experiments  Two charge breeders:  EBIS (fast, low capacity, low background, narrower charge state distribution, provides intensity also for light elements)  ECR (slow, high capacity, high background, access to intense beams including stable ones)  Modular (easy to expand)  Robust (electrostatic deflectors without moving parts)

18. Town Meeting Espoo, 17.-20.9.2007 Target stations and front-ends New front-end design of 100 kW-target stations (C1: Thierry Stora) Vertical extraction Integration of the pre-separation Body tube MAFF-approach to EURISOL (C2: Yacine Kadi and P32: Cyril Kharoua) Fission target design has been revised Vertical extraction Merging beams to be solved 1 GeV Multiple Extraction Extremely flexible solution Alberto Facco, A1 Rita Paparella, A3

19. Town Meeting Espoo, 17.-20.9.2007 Velocity matching (1/2) Post-accelerator assumes (Task 6) : –Monochromatic beam –Multiply charged (A/q=4-8) –CW beam –Rather low injection energy Low-energy beam transfer (Task 9): –Fixed energy –Pulsed beam –Preferably few tens of keV Variable 1+ energy of the low-energy transfer: - unpractical (low-E transport relies on fixed optical settings & parallel beams affected by the tuning) Bunching cavities just before the RFQ of the LINAC: - typical transmission losses 30 %  radioprotection issue Pulsed charge breeder: - non-CW operation - high peak intensities in the LINAC (for intense beams) - saturation of EBIS

20. Town Meeting Espoo, 17.-20.9.2007 Velocity matching (2/2) RFQ-cooler just before the charge breeder: - cooled and bunched beam for charge breeder - high transmission - low-energy beam transport (60 kV) decoupled from injection to the post- accelerator (5 keV/u, i.e. 20-40 kV if A/q between 4 and 8) - With fast pulsing ”semi-CW” operation and high capacity - Could be combined with a large drift tube section allowing fine-tuning of the V(n+) beam

21. Town Meeting Espoo, 17.-20.9.2007 Summary Steady progress in sub-tasks: Multiple multipolar scheme exists for high-resolution mass selection. Based on the existing ion cooling devices and experience gathered with those, a high-intensity cooler has been proposed. Such a device is under construction in Orsay and wil be moved to LPC-Caen for further development and testing ISCOOL at CERN an important testbench (space-charge). Charge breeding: ECR and EBIS approaches have been developed and compared within EURISOL and EURONS. (Efficiency, capacity, purity, …) A new concept – ARC-ECR - has been proposed (JYFL) An innovative source for beta beam has been proposed and is under construction in LPSC-Grenoble. To fullfill our task, work has to be done: –Solution for the velocity matching (Task 6 and 9) –Lay-out (Task 6,9,10 and 5) –The parameter database, especially efficiencies for safety task for the radiation shielding estimation