M. Steck, RUPAC 2006, Novosibirsk Cooling of Rare Isotope Beams in the ESR Cooling by: Stochastic cooling (pre-cooling) Electron cooling (final cooling) M. Steck, for the FSR team: K. Beckert, P. Beller †, C. Dimopoulou, A. Dolinskii, V. Gostishchev, I. Nesmiyan, F. Nolden, C. Peschke Injection of: Highly charged heavy ions from SIS18 Rare isotope beams via fragment separator FRS

M. Steck, RUPAC 2006, Novosibirsk The Existing GSI Accelerator Facility

M. Steck, RUPAC 2006, Novosibirsk Stochastic Cooling at the ESR energy 400 (-550) MeV/u bandwidth 0.8 GHz (range GHz)  p/p =  p/p =     m    m electrodes installed inside magnets combination of signals from electrodes power amplifiers for generation of correction kicks Fast pre-cooling of hot fragment beams

M. Steck, RUPAC 2006, Novosibirsk The ESR Electron Cooler electron beam parameters energy 1.6 – 250 keV current – 1 A diameter 50.8 mm gun perveance 1.95  P collection efficiency > temperature transverse 0.1 eV longitudinal ~ 0.1 meV magnetic field strength – 0.2 T straightness 1×10 -4 vacuum  2× mbar

M. Steck, RUPAC 2006, Novosibirsk Stochastic Cooling Longitudinal cooling Transverse cooling Cooling time dependent on beam intensity (Schottky noise) (beam profile) Ar 18+ cooling time for U 92+ (N=10 6 ): longit., vert.: 0.5 s, horiz.: 2.5 s 5 s Ar 18+

M. Steck, RUPAC 2006, Novosibirsk Stochastic Cooling of U 92+ Beam Minimum longitudinal cooling time (for N = 8  10 6 ): 0.3 s previously (not optimized): vertical 0.5, horizontal 2.5 s  reduction by factor 3 compared to Ar 18+ optimization of system gain U MeV/u momentum spread  p/p time t [s]

M. Steck, RUPAC 2006, Novosibirsk Equilibrium Beam Parameters of Cooled Beams in the ESR [mmmrad] 10 6 limited by intrabeam scattering Electron cooling results in smaller momentum spread and smaller emittance compared to stochastic cooling. The equilibrium is a balance between the cooling rate and the heating rate by intrabeam scattering. calculated IBS-heating/cooling rate [s -1 ] longit. transv. stoch. cool el. cool. [25 mA] el. cool. [250 mA]  Electron cooling is more powerful for cold beams.

M. Steck, RUPAC 2006, Novosibirsk Fast stochastic pre-cooling One trace every 120 ms 5.52 s in total Subsequent electron cooling Inj. 3 s 5 s Primary Uranium beam heated in thick target stochastic pre-cooling + final electron cooling immediately after injection Combination of Stochastic and Electron Cooling Stochastic pre-cooling reduces the total cooling time to a few seconds, electron cooling only takes s Accumulation of secondary beams 1) s.c. on injection orbit 2) rf stacking 3) electron cooling of stack Ion current [mA] time [s] Intensity increase for secondary beams

M. Steck, RUPAC 2006, Novosibirsk Electron Cooled Beams in Equilibrium with Intrabeam Scattering Phase space volume increases with: ion beam intensity and ion charge by non-destructive methods (particle detectors, profile monitor) by destructive scraping  p/p  N 0.3  x,y  N  x [mm mrad] vertical radius [mm]  y [mm mrad] horizontal radius [mm] E = 400 MeV/u

M. Steck, RUPAC 2006, Novosibirsk Observation of Ultra-cold Beam temporal evolution of Schottky noise allows independent determination of particle number decay time due to REC sudden reduction of the momentum spread for less than about one thousand stored ions  linear ordering in ion string storage time [min]  p/p Schottky noise power [a.u.] Reduction of momentum spread

M. Steck, RUPAC 2006, Novosibirsk Transverse Beam Size of Ultra-cold Beam lowest temperature for C 6+ at 4800 MeV kT  = 0.26 meV kT X = 0.14 meV [mm ] minimum ion temperature of the order of the longitudinal electron temperature  magnetized cooling [a.u. ] high precision measurement employing a scraper in a dispersive section ( D  1 m ) scraper position [mm]

M. Steck, RUPAC 2006, Novosibirsk Detection of Single Ions decay of an unstable nucleus measurement of excited states in unstable nuclei resolution m/  m up to 1×10 6

M. Steck, RUPAC 2006, Novosibirsk p-bar target p-linac Super- FRS SIS100 SIS300 HESR CR RESR Unilac SIS 100 PANDA Atomic Phys. Plasma Phys. NESR HESR Low Energy Exp. High Energy Exp. NESR Exp. Antiproton Prod. Target SIS18 Upgrade CR FAIR Baseline Layout SuperFRS FLAIR RESR p-linacSIS 300 Atomic Physics HADES & CBM Accelerator Experiment

M. Steck, RUPAC 2006, Novosibirsk Cooling of Secondary Beams at the FAIR Storage Rings HESR CR complex (CR, RESR) NESR NESR Electron Cooling CR Stochastic Cooling RI beams pbars HESR Electron Cooling in collaboration with BINP Novosibirsk 5 (8) MeV 2 A 450 keV 2 A B = 0.5 T B = 0.2 T RESR pbar accumulation

M. Steck, RUPAC 2006, Novosibirsk Cooling Systems at FAIR CR:stochastic pre-cooling of 1) RIBs at 740 MeV/u (cooling time  1.5 s ) 2) antiprotons at 3 GeV (cooling time 10 (5) s ) RESR:accumulation of antiprotons at 3 GeV (electron cooling of antiprotons at 400 MeV) NESR:electron cooling of 1) ions at MeV/u (accumulation at MeV/u) 2) antiprotons at 30 / 800 MeV (during deceleration) HESR:electron cooling of antiprotons at (15) GeV FLAIR:electron cooling of ions and antiprotons below 30 MeV/u

M. Steck, RUPAC 2006, Novosibirsk The Collector Ring CR circumference 212 m magnetic bending power 13 Tm RIB pbar energy 740 MeV/u 3.0 GeV tunes Q x /Q y 3.17/ /4.24 mom. accept.  1.5 %  3.0 % transv. accept. 200  m 240  m transition energy isochronous (RIB)  790 MeV/u 2.55/3.17  0.7 % 70/50  m  1.84 fast stochastic cooling of antiprotons and rare isotope beams fast bunch rotation with rf voltage 200(400)kV adiabatic debunching stochastic pre-cooling system 1-2 (1-4) GHz optimized ring lattice for proper mixing large acceptance superconducting dipoles isochronous mass measurements of rare isotope beams operation at transition energy

M. Steck, RUPAC 2006, Novosibirsk Techniques for Fast Cooling in CR Fast bunch rotation of SIS100 bunch rf voltage 200 (400) kV at h=1 after passage of production target to reduce momentum spread (2.5  0.5 %) SIS100 bunch after bunch rotation and debunching in CR providing optimum initial parameters for stochastic cooling Fast stochastic pre-cooling system band width 1-2 (1-4) GHz matched to velocities  = rf power ~ kW per system electrode prototype front and back side CERN AC, band 1 58 mm horizontal GSI 6 mm air gap 92 mm horizontal Increase of impedance (factor of 4) Frequency [GHz] analysis by L. Thorndahl

M. Steck, RUPAC 2006, Novosibirsk RESR The Antiproton Accumulator Ring RESR accumulation of antiprotons by stochastic cooling max. accumulation rate 7  /h (first stage 2.6  /h) circumference m magnetic bending power 13 Tm tunes Q x /Q y 3.8/3.3 momentum acceptance  1.0 % transverse accept. h/v 80/35  m transition energy 3.62 Additional mode: fast deceleration of RIBs

M. Steck, RUPAC 2006, Novosibirsk NESR Versatile Storage Ring for Physics Experiments Ions storage and cooling of ion beams in the energy range 740  4 MeV/u maximum deceleration rate 1 T/s experiments with internal target luminosity up to cm -2 s -1 RIB accumulation by electron cooling collider mode 1) with electrons luminosity up to cm -2 s -1 2) with antiprotons luminosity up to cm -2 s -1 electron target Antiprotons deceleration 3000  800  30 MeV electron cooling at 800 MeV circumference m magnetic bending power 13 Tm tunes Q x /Q y 3.4 / 3.2 momentum acceptance  1.75 % transverse accep. h/v 160/100  m length of straight section 18 m

M. Steck, RUPAC 2006, Novosibirsk NESR Electron Cooler design by BINP, Novosibirsk Cooler Parameters energy keV max. current 2 A beam radius mm magnetic field gun up to 0.4 T cool. sect. up to 0.2 T straightness 2×10 -5 vacuum  mbar high voltage up to 500 kV fast ramping, up to 250 kV/s magnetic field quality Issues:

M. Steck, RUPAC 2006, Novosibirsk BETACOOL Simulations of Electron Cooling in NESR Antiprotons E = 800 MeV I e = 2 A, r e = 1 cm, B = 0.2 T Cooling time dependence on beam quality RIB 132 Sn 50+, E = 740 MeV/u I e = 1 A, r e = 0.5 cm, B = 0.2 T

M. Steck, RUPAC 2006, Novosibirsk Final Remarks Aspects of Antiproton Cooling in the HESR were given in a separate presentation on Monday by D. Prasuhn We appreciate the long standing collaboration with many cool Russians, particularly from BINP Novosibirsk: I.A. Koop, P.V. Logatchov, V.V. Parkhomchuk, P.Yu. Shatunov, Yu.M. Shatunov, A.N. Skrinsky, P. Vobly JINR Dubna: I.N. Meshkov, R.V. Pivin, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov ………….. and many others hope to see you at: COOL07, Bad Kreuznach, Germany September 10-14, 2007