NuFact'06 WG3, Aug. 2006A. Fabich, CERNBeta-beam Ion Losses, 1 The EURISOL Beta-beam Acceleration Scenario: Ion Losses A. Fabich, CERN NuFact’06, UCIrvine

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 2 Outline EURISOLDS Beta-beam layout Accumulation & accelerator cycle Ion intensities Accelerator chain Decay distribution Dynamic vacuum Decay ring Stored energy Particle turnover

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 3 Beta-beam EURISOL design Neutrino Source Decay Ring Ion production ISOL target & Ion source Proton Driver SPS Acceleration to medium energy RCS PS Acceleration to final energy PS & SPS Beam to experiment Ion acceleration Linac Beam preparation ECR pulsed Ion productionAcceleration Neutrino source Low-energy part High-energy part Decay ring B  max = 1000 Tm B = ~6 T C = ~7000 m L ss = ~2500 m 6 He:  = Ne:  = 100

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 4 magnet cycle (abstract) cycle of 6 He Machine cycle Baseline version: Production 6 He, 18 Ne ECR, Linac and RCS Cycling at 10 Hertz Accumulation in the PS Accumulation of 20 RCS bunches (~2 seconds) Acceleration through PS and SPS as fast as possible  top = 100 for both isotopes Injection into decay ring Merging with circulating bunches Every 6 s for 6 He and every 3.6 s for 18 Ne

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 5 For the design goal of 2.9*10 18 antineutrinos/year 1.1*10 18 neutrinos/year Required isotope intensities: For cycling of version EURISOL DS Typical intensities of ions for LHC injector operation (PS and SPS) Ion intensities (1) 6 He 18 Ne Decay ring [ions stored]9.7* *10 13 SPS ej [ions/cycle]9. 0* *10 12 PS ej [ions/cycle]9.5* *10 12 Source rate to ECR [ions/s]2*10 13

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 6 Ion intensities (2) Cycle optimized for neutrino rate. 30% of first 6 He bunch injected are reaching decay ring Overall only 50% ( 6 He) and 80% ( 18 Ne) reach decay ring Normalization Single bunch intensity to maximum/bunch Total intensity to total number accumulated in RCS Bunch 20 th 15 th 10 th 5th 1st total

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 7 Decay losses Relative decay distribution similar for both isotopes ~90% of all decays before entering decay ring occur in the PS Can be translated into power losses and compared with “existing” high intensity operation …

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 8 1E-9 Loss distribution and dyn. vacuum PS SPS New “PS” Pressure evolution due to desorption P. Spiller et al., GSI Average pressure [mbar] 1E-10 1E-11 1E-12 1E-8 Average pressure [mbar] 1E-9 PS SPS New “PS”

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 9 Beam intensities in the decay ring Stored energy LHC refers to proton operation. Transverse density:  =E stored /(2*Pi*  x *  y ) Beta-beam operates at reasonable stored energy and energy density. “Stored energy” is most relevant for irregular operation. LHC project report 773 bb

NuFact'06 WG3, Aug A. Fabich, CERN Beta-beam Ion Losses, 10 Particle turnover 810 kJ respect kJ beam energy/cycle injected  ejected All ions have to be removed again Either as parent or daughter ion 1)Decay deposition in arcs: protect SC dipoles from quench caused by deposition accumulated after drift (quench limit 10W/m) 2)Decays accumulated along straight section: 300 or 400 kJ dumped per cycle (50 or 120 kW average) via extraction system at end of straight section 3)Momentum collimation at/after merging process: Cycle average: 62 or 230 kW (6 resp 3.6 s) LHC: 10 kW average, peak 100 kW over seconds or 500 kW peak Process average: 1.2 or 2.8 MW (0.3 s, continuous collimation during bunch compression) p-collimation merging decay losses injection 1)+2) 3)