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MAMI and Beyond

MAMI and Beyond. Electron cooling for high-energy ion beams Igor N. Meshkov JINR, Dubna. Schloss Waldthausen , Mainz March 30 – April 3, 2009. I.Meshkov, HE e-coolers MAMI and Beyond Schloss Waldthausen 30 .03 – 3 .04, 2009. Contents

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MAMI and Beyond

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  1. MAMI and Beyond • Electron cooling for high-energy ion beams • Igor N. Meshkov • JINR, Dubna Schloss Waldthausen, Mainz March 30–April 3, 2009

  2. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 • Contents • Physics of electron cooling and cooler parameters • Engineering problems of electrostatic HE electron coolers • 3. Project of electron cooler at COSY (Budker INP / FZJulich) • 4. NICA project at JINR • 5. Linac-based electron cooler • 6. “Coherent electron cooling” • Conclusion

  3. Physics of Electron Cooling and Cooler Parameters • Two general regimes in storage rings and colliders: • 1) Storage/stacking of ions at cooling     in Particle Rest Frame (Vi) initial  Ve 2) Regime of a pre-cooled ion beam     in PRF (Vi) initial  Ve I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  4. Electron cooling time for two regimes 1) Stacking regime transverse dimension longitudinal dimension 2) Regime of cooled ion beam Cooling time is defined byelectron beamparameters. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 • Physics of Electron Cooling and Cooler Parameters Cooling time is defined by ion beam parameters.

  5. Physics of Electron Cooling and Cooler Parameters IBS Heating and cooling – - competing processes in regime of cooled beam IntraBeam Scattering (IBS) EC in regime of cooled ion beam Ni– ion number per bunch I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 One needs to provide EC  IBS

  6. Physics of Electron Cooling and Cooler Parameters BETACOOL Alexander Smirnov IBS Heating and cooling – - bunch density evolution at electron cooling Under cooling, equilibrium with IBS Before cooling Gaussian distribution Nongaussian distribution dN/dx, arb. units dN/dx, arb. units I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  7. BETACOOL Alexander Smirnov • Physics of Electron Cooling and Cooler Parameters Electron magnetization effect Luminosity evolution at electron cooling: L(t) B [kG] 8 6 4 2 6 Luminosity [cm-2∙s-1] 4 2 0 6 Luminosity [cm-2∙s-1] 4 2 0 6 Luminosity [cm-2∙s-1] 4 2 0 6 Luminosity [cm-2∙s-1] 4 2 0 B [kG] 6 4 2 B [kG] 4 2 B [kG] 2 I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Te = 10 eV Parameters ion beam: 197Au79+ at 3.5 GeV/u, initial =0.5 ∙mm∙mrad, (p/p) = 1∙10-3 electron beam: Ie = 0.5 A, re = 2 mm, Te|| = 5 meV;  = 0.024 (6 m/250 m) Conclusion 1: Electron magnetization is much more preferable

  8. Physics of Electron Cooling and Cooler Parameters IBS Heating and cooling – - competing processes in regime of cooled beam Conclusion 2: Both IBS and EC rates decrease with ion energy as 45 if… x, y, p/p, Je, F… are the same. That is a promising fact. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 However, all this makes the task of collider luminosity achievement and preservation rather complicated.

  9. 2. Engineering problems of electrostatic HE e-coolers What experience do we have? } Our “reference points” I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Electrostatic accelerators and tandems, Electron cooler prototype at Budker INP (1986): 1 MeV x 1 A, several hours continuous operation, Electron cooler of 4.34 MeV at Fermilab.

  10. 2. Engineering problems of electrostatic HE electron coolers Success at Tevatron Collider Peak Luminosity (Run II) 4 3 2 1 0 Luminosity, 10E+32 cm-2s-1 • 2002 2003 2004 2005 2006 2007 2008 2009  • Years I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Mainly owing to application of electron cooler at Recycler! All Tevatron data  Alexandr Schemyakin and Sergei Nagaitsev (Fermilab) Private communication, March 2009

  11. See A.Jankowiak talk as well I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 2. Engineering problems of electrostatic HE electron coolers What do we plan to construct? Electron coolers of 2 MeV at COSY (Budker INP / FZ Jülich) 2 MeV at COSY (Uppsala Univ./ FZ Jülich) 2.5 MeV at NICA (JINR, Dubna) 8.2 MeV at HESR, pp-bar mode (FAIR) 8.2 MeV at HESR, ep mode (FAIR) 54 MeV at RHIC (ii mode, ei mode) See T.Roser talk as well

  12. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 2. Engineering problems of electrostatic HE electron coolers The problems: 2.1. High voltage performance 2.2. Limiting performance of accelerator tubes 2.3. High voltage generators 2.4. Power transmission to accelerator “head” 2.5. Electron current and HV stability 2.6. Electron beam formation, transportation and recovering

  13. 2. Engineering problems of electrostatic HE electron coolers 2.1. High voltage performance I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 SF6 Fermilab experience: 4.4 MV / 80 cm gap E_Opertn = 55 kV/cm at p/p_norm = 6 Conclusion 3: In HE electron coolers E_Opertn ~ 5.5 MV/m Electric strength of SF6 gas!

  14. 2. Engineering problems of electrostatic HE electron coolers 2.2. Limiting performance of accelerator tubes Tandem experience: 1.7 – 2 MV/m But! Small current of accelerated beam  10 A ions Fermilab experience:1.2 MV/m at electron current of accelerated beam (recuperation regime): 0.5 A – tested 0.1 A – operation, 2007-2009 I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Conclusion 4: HE Electron cooler size is defined mainly by accelerator tube size!

  15. 2. Engineering problems of electrostatic HE electron coolers 2.3. High voltage generators Existing options (by voltage increase): 1. “Dynamic machines” 1.1. Cockroft-Walton accelerator – up to 1 MV (practically) 1.2. “Electron-beam Ventil” (ELV, BINP) – a sophisticated version of insulating core transformer  2 MV 1.3. Dynamitron ~ 4 MV max I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 2. Electrostatic machines 2.1. Van de Graaff accelerators 2.2.Pelletron modification “The record-holder” of DC accelerators: Vivitron (Univ. Louis Pasteur, Strasbourg)  35 MV project, 25 MV operation.

  16. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 2. Engineering problems of electrostatic HE electron coolers 2.4. Power transmission to accelerator “head” One needs to place in an electron cooler “head” a few power supplies: 1) Gun cathode filament PS: V ~ 15 V, P  300 W, 2) Gun control electrode PS: V  20 kV, P  2 W, 3) Collector suppressor electrode PS: V  2 kV, P  2 W, 4) Collector receiver PS: V  2 kV, P  3 kW. • Two options of power transmission: • Insulating core transformer – preferable, but  3-4 MV • Rotating rods  complicated, however  up to 25 MV (Vivitron)

  17. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 2. Engineering problems of electrostatic HE electron coolers 2.5. Electron current and HV stability Peculiarity of electron coolers: high reactive power (RP) of electron beam at very low active power (AP) consumption. This is especially well manifested in HE electron coolers. Fermilab experience: RP = 4.34 MV x 0.1 A = 434 kW, AP = 4.34 MV x 1.5 A  7 W, HV stability  V/V  1∙10E-4

  18. Voltage divider HV generator in “Dynamic machines” Measuring devise Capacitive PU electrode Voltage regulator Generating voltmeter (J.C.Maxwell’s invention!) Corona control in electrostatic machines I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 2. Engineering problems of electrostatic HE electron coolers 2.5.Electron current and HV stability (Contnd) HV stability is connected with electron beam losses. HV stabilization methods: a few feed back loops consisting of Measuring devices and voltage regulators:

  19. 2. Engineering problems of electrostatic HE electron coolers 2.6. Electron beam formation, transportation and energy recovering To magnetize or not – that is a question! I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Fermilab experience: Nonmagnetized electron cooling Experience of low and middle energy electron coolers and Numerical simulations at high energy   magnetization is preferable

  20. 3. Project of electron cooler at COSY (BINP/FZJ) V.Parkhomchuk, Report at BINP-JINR-FZJ meeting at Budker INP Novosibirsk, March 17-18, 2009 Main distinguishing characteristics of this HE electron cooler:1. Fast cooling: not hours but minutes  owing to much higher electron beam density – by 50-100 times2. Wide energy range – 24 keV  2 MeV3. Cooling of multicharge ions  recombination suppression by increase of electron transverse temperature Solution: electron magnetization and electron beam compression in the cooling sectionby magnetic field increase from 50-100 G on the gun cathode up to 2.5 – 5.0 kG in the cooling section ! I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  21. 3. Project of electron cooler at COSY (V.Parkhomchuk et al., contnd) HV section of COSY cooler Compressed gas release tubes Turbine Magn. field coils Accelrtng tube Decelertng tube HV PS 30 kV Compressed gas admission tubes Control electronics I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  22. 3. Project of electron cooler at COSY (V.Parkhomchuk et al., contnd) Gas Turbine and Generator Coil I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  23. 3. Project of electron cooler at COSY (V.Parkhomchuk et al., contnd) Electron Cooler for COSY (BINP/FZJ) I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  24. 3. Project of electron cooler at COSY (D.Reistad et al.) Electron Cooler for COSY (Uppsala Univ./FZJ) Pelletron-based concept Magnetized electron beam I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  25. 4. NICA project at JINR Project of Nuclotron-based Ion Collider fAcility (NICA) and MultiPurpose Detector (MPD) at JINR Scientific case: 1. Study of exited nuclear matter in NN, pN and pp interactions and search for the mixed phase of strongly interacting matter in energy range of √s = 4  11 GeV/u i.e. 197Au x 197Au in the kinetic energy range of 1 ÷ 4.5 GeV/u at average luminosity (at 3.5 GeV/u) Laverage = 110E+27 cm-2s-1 2. Study of spin physics in pp and dd collisions in energy range of √s = 10  27 GeV/u (pp) and 4  13 GeV/u (dd) Laverage 110E+30 cm-2s-1 I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  26. 4. NICA project at JINR (Contind) Search for the mixed phase of strongly interacting matter 1 fm/c ~ 3∙10-24 s  Elabs GeV/u 5 3.60 10 4.73 30 7.75 8012.42 RHIC (?) 158 17.36 NA49/61 (SPS) NICA & CBM Barionic chemical potential  [MeV] I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  27. 4. NICA project at JINR (Contind) NICA/ MPD Concept January 2008 Conceptual Design Report in progress, to be completed 2009 Technical Design Report in progress, to be completed May 2009 I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  28. 4. NICA project at JINR (Contind) Booster Krion & Linac Nuclotron Collider C = 251.2 m MPD Spin Physics Detector (SPD) I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 NICA Scheme Existing beam lines (solid target exp-s) Bldng 205

  29. 4. NICA project at JINR (Contind) Vladimir I. Veksler 2.3 m 4.0 m I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Dismounting is in progress presently

  30. 4. NICAproject at JINR (Contind) I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Collider General Parameters

  31. 4. NICA project at JINR (Contind) Beam dump RF MPD RF Spin rotator Spin rotator PU PU Kicker Kicker SPD Beam dump I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Collider Structure Injection channels

  32. 4. NICA project at JINR (Contind) I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Collider beam parameters and luminosity

  33. 4. NICA project at JINR (Contind) “Twin magnets” for NICA collider rings “Twin” quadrupoles “Twin” dipoles (4.5 T) I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  34. 4. NICA project at JINR (Contind) I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Polarized proton beams in NICA

  35. 4. NICA project at JINR (Contind) Longitudinally polarized beams in NICA Yu.Filatov, 2009 Spin rotator “full snake” B B SPD SPD I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  36. 4. NICA project at JINR (Contind) Longitudinally polarized beams in NICA (Contnd) Spin rotator “full snake” B B B SPD SPD I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  37. 4. NICA project at JINR (Contind) 2.5 MeV x 0.5 (1.0?) A SC solenoid 0.2  1.0 T The electron cooler for NICA collider Electron beam 2:Recuperater Electron beam 2:Accelerator HV cascade generator(“Dynamitron” Electron beam 1:Accelerator Electron beam 1:Recuperater Ion beam 1Ion beam 2 Toroidal solenoids Straight and thin toroidal solenoids I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  38. See T.Roser talk as well 5. Linac-based electron cooler Project of electron cooler for RHIC (BNL-Budker INP-JINR) ions e-gun ions electrons Linac 2 Linac 1 electrons Linac 3 Beam dump ions Bunch compressor Linac 4 Bunch stretcher I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009

  39. 5. Linac-based electron cooler (Contnd) FEL MARS  Project at Budker INP (Multipass Accelerator-Recuperator Source) Energy Recovering Linac (ERL) 2 stages  8 + 12 MeV andFEL of  = 50 mcm Electron bunch parameters: Parameters: 1st stage 2nd stage Bunch charge, nC 1  1.5 Bunch duration, cm 2.0 0.6 Peak current, A 16 50 Norm. emittance, ∙mm∙mrad 30 p/p 1∙10E-3 Injection/recuperation energy 1.5 MeV Average current, mA 30 10 ERL FEL Injector I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 *) *) Nikolai Vinokurov (Budker INP), private communication, March 2009

  40. 6. “Coherent electron cooling” *) See T.Roser talk as well First idea: Yaroslav Derbenev, Proc. 7th All-Soviet Acc. Conf., v. 1, p. 269 Recent development: Ya. Derbenev (JNL), Vl.Litvinenko (BNL), PRL 102, 114801 (2009) 1 2 3 4 5 6 7 Scheme of “The coherent electron cooler” (courtesy of Vl.Litvinenko, March 2009) : 1) Junction of ions and electrons, 2)Excitation of of electron beam bunching by ions (“plasma oscillation”) when traveling together, 3) Separation of ions and electrons, 4) Amplification of e-beam bunching when passing the undulator and separation of fast and slow ions in dispersion section, 5) Junction of ions and electrons, 6) Damping of ion momentum spread (kicker), 7) Separation of ions and electrons. I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 *) Vladimir Litvinenko (BNL) courtesy, March 2009

  41. Thank you for your attention! I.Meshkov, HE e-coolers MAMI and BeyondSchloss Waldthausen30.03 –3.04, 2009 Conclusion • Electron cooling method was successfully developed and applied to high energy antiprotons up to 8 GeV (4.34 MeV electron energy); 2.There are a few projects of HE electron coolers for ion energy range 2  8 MeV/u based on electrostatic acceleration that is adequate to this energy range; 3. An advance into higher energy range should be accomplished by development of novel ideas.

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