Advanced Acceleration Concepts Advanced Acceleration Concepts Levi - PowerPoint PPT Presentation

Advanced Acceleration Concepts Advanced Acceleration Concepts Levi Schä ächter chter Levi Sch Technion – Israel Institute of Technology

Acknowledgement Acknowledgement • R.H. Siemann (SLAC) • W. D. Kimura (STI) • I. Ben-Zvi (BNL) • D. Sutter (DoE) Levi Schächter, CERN , October 2002

Outline Outline • Some brief guidelines • Novel Acceleration Schemes: Concepts & Results • Concluding Remarks Levi Schächter, CERN , October 2002

Guidelines Guidelines What will be presented next as Advanced Acceleration Concepts: ≥ 1. Focuses on gradients 1 [GV/m] ∼ 2. As reference: SLC 20 [MV/m] ∼ NLC 50 [MV/m] 3. Discuss e - & e + 4. Optical regime Levi Schächter, CERN , October 2002

Inverse Radiation Processes • Inverse Cerenkov (slow wave) • Inverse Cerenkov (slow wave) • Inverse FEL… (fast-wave) • Inverse FEL… (fast-wave) • Inverse Transition Radiation (LEAP) • Inverse Transition Radiation (LEAP) • Inverse Laser (Amplified Wake) • Inverse Laser (Amplified Wake) Space-Charge Wakes • Laser Wake-Field • Laser Wake-Field • Plasma Wake-Field • Plasma Wake-Field • Plasma Beat-Wave • Plasma Beat-Wave • Resonant Absorption • Resonant Absorption Levi Schächter, CERN , October 2002

Inverse Radiation Processes Inverse Cerenkov: An Optical Acceleration Structure ?! y No metals !! At optical wavelengths (1 µ m) • dielectrics have higher E th . Dielectric Reflecting Structure ≤ E ∼ 2GV/m @ 0.5psec max Frequency dependence of ε leads to r 0 • ε φ R 0 reduced wake effect since the x ⇒ Vacuum 5 # of modes drops : 10 10 Electron Bunch • Technion & SLAC - Field Confinement Field Confinement - - Highest Symmetry Highest Symmetry - - Reduce Max. Field Reduce Max. Field - Levi Schächter, CERN , October 2002 Photonic Band Gap Optical Fibers Photonic Crystal Bragg Structure

Inverse Radiation Processes Figures of Merit -- Emittance & Planar Structures • In an azimuthally symmetric structure, the ratio of the transverse force to the longitudinal force is virtually negligible since ε ω   F 1 a ≈ ⊥ R   b γ 2 F 4  c  z ε • In a non-symmetric structure of a typical transverse dimension a , − 1 ω   F ≈  ⊥ a  F  c  z ε (out) − ε (in) 4.14 � ε (in) 2   N +  1 st Schächter; AAC’2002 Proceedings   15  Levi Schächter, CERN , October 2002

Inverse Radiation Processes • Inverse Cerenkov (slow wave) • Inverse Cerenkov (slow wave) • Inverse FEL… (fast-wave) • Inverse FEL… (fast-wave) • Inverse Transition Radiation (LEAP) • Inverse Transition Radiation (LEAP) • Inverse Laser (Amplified Wake) • Inverse Laser (Amplified Wake) Space-Charge Wakes • Laser Wake-Field • Laser Wake-Field • Plasma Wake-Field • Plasma Wake-Field • Plasma Beat-Wave • Plasma Beat-Wave • Resonant Absorption • Resonant Absorption Levi Schächter, CERN , October 2002

Inverse Radiation Processes (R. Palmer 1972) Inverse Free Electron Laser • Electrons oscillate in a S N S N S N transverse magnetic field. • Ponderomotive force may λ w N S N S N S accelerate electrons. γ − 1 λ • Acceleration: E ∝ E B Laser beam has no E z ACC L W W B γ 2 2 E ∝ • Deceleration: DEC W B λ γ 6 > I I − 2 2 E > E ⇒ ∝ • Threshold: ACC DEC W W th • Example: B w =1T, λ w =2cm @ 1 TeV => I th =10 25 W/cm 2 !! B w =1T, λ w =2cm @ 1 GeV => I th =10 7 W/cm 2 . Levi Schächter, CERN , October 2002

Inverse Radiation Processes Inverse Free Electron Laser Driving Electron CO 2 Laser Beam Kimura, PRL, 86, 4041 (2001) Pulse 24MW 300 MW • STELLA Experiment: BNL-ATF, STI & UCLA 2m !! Pre-buncher IFEL • Goal: Staging optical modules Energy Shift (%) Energy Shift (%) -5 -4 -3 -2 -1 0 1 2 3 4 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 600 600 DATA DATA MODEL 500 500 (051800_171) (051800_156) Electron Distribution Electron Distribution MODEL 400 400 300 300 200 200 Two wigglers Two wigglers One wiggler One wiggler 100 100 0 0 -2 -1 0 1 2 -2 -1 0 1 2 Energy Shift (MeV) Energy Shift (MeV) alignment & phase- -control control alignment & phase µ m @ 10.6 µ m @ 10.6 Levi Schächter, CERN , October 2002

Inverse Radiation Processes • Inverse Cerenkov (slow wave) • Inverse Cerenkov (slow wave) • Inverse FEL… (fast-wave) • Inverse FEL… (fast-wave) • Inverse Transition Radiation (LEAP) • Inverse Transition Radiation (LEAP) • Inverse Laser (Amplified Wake) • Inverse Laser (Amplified Wake) Space-Charge Wakes • Laser Wake-Field • Laser Wake-Field • Plasma Wake-Field • Plasma Wake-Field • Plasma Beat-Wave • Plasma Beat-Wave • Resonant Absorption • Resonant Absorption Levi Schächter, CERN , October 2002

Inverse Radiation Processes Inverse Transition Radiation LEAP : L aser driven E lectron A ccelerator P rogram (Stanford U.) Huang & Byer APL 68, 753 (1996) • Electron traversing a discontinuity generates radiation. • Illuminating a geometric discontinuity may cause acceleration of an electron by proper choice of phase. Single Cavity Single Cavity θ Lawson- -Woodward: Woodward: Lawson Interaction in Interaction in finite- -length length region region finite Levi Schächter, CERN , October 2002

Direct Laser Acceleration Direct Laser Acceleration Lasers promise extraordinary accelerating fields, provided effic Lasers promise extraordinary accelerating fields, provided efficient coupling structures can be developed ient coupling structures can be developed crossed laser beams The E163 Experiment (Stanford/SLAC/Tsing Hua) Objective: To demonstrate laser driven electron acceleration in a dielectric structure in vacuum. The acceleration cell: Two Gaussian beams of 800 nm laser light cross at 1.4 o to form the acceleration field. Electrons are injected between the prisms into the crossed laser field. electron Electron beam Beam Lithographic Accelerator Photonic Band Gap Fiber Structures Accelerator (SLAC/Stanford): (SLAC/Technion): Higher-order Lithographic, planar structures mode-free accelerator structure with designed to use one laser pulse to good coupling impedance that can be accelerate many parallel electron fabricated by standard fiber bundle bunches assembly methods. Ring Resonated Laser Cerenkov Amplification Single mode Er-doped fiber Accelerator LASER MEDIA: Nd:YAG PZT Accelerator (Technion/SLAC): Phase (SLAC/Stanford): Laser Shifter Laser Cerenkov wake of triggering bunch is pulse Trigger bunch Accelerated bunch s accelerator embedded in ring LASER MEDIA: Nd:YAG amplified in laser media, accelerating E- bea resonator to use one laser pulse m trailing bunch. PZT to accelerate many successive Phase Shifter Levi Schächter, CERN , October 2002 electron bunches Single mode Er-doped fiber

Inverse Radiation Processes • Inverse Cerenkov (slow wave) • Inverse Cerenkov (slow wave) • Inverse FEL… (fast-wave) • Inverse FEL… (fast-wave) • Inverse Transition Radiation (LEAP) • Inverse Transition Radiation (LEAP) • Inverse Laser (Amplified Wake) • Inverse Laser (Amplified Wake) Space-Charge Wakes • Laser Wake-Field • Laser Wake-Field • Plasma Wake-Field • Plasma Wake-Field • Plasma Beat-Wave • Plasma Beat-Wave • Resonant Absorption • Resonant Absorption Levi Schächter, CERN , October 2002

Inverse Radiation Processes Inverse Laser: Wake Amplification Accelerator Wake generation : Pulse amplification : EM wake Input pulse Amplified pulse Active Medium Passive Medium Electron bunch Wake amplification: Saturation Energy stored Energy stored Trigger bunch in in Active Medium Active Medium Schächter & Siemann, PRL, 87, 134802 (2001) Active Medium Levi Schächter, CERN , October 2002 Amplified Wake Accelerated bunch

Inverse Radiation Processes Inverse Laser: Wake Amplification Accelerator Conceptual experiment proposed to ORION @ SLAC System Nd:YAG System Flash-Lamp Nd:YAG Nd:YAG: UNIFORM Beam: 10 9 electrons - 6mm diameter - 10 cm length 30 GeV - Nd – 10 20 cm -3 5 Joules - 200 Joules Schächter & Siemann, PRL, 87, 134802 (2001) Levi Schächter, CERN , October 2002

Inverse Radiation Processes Inverse Laser: Wake Amplification Accelerator Conceptual experiment proposed to ATF@BNL: Driving 0.1 µ F; 20-25kV, Electron Laser CO 2 Beam Pulse 20 Joule, 100nsec 24MW 300 MW 0.3-0.5GW 2m !! Pre-buncher IFEL Levi Schächter, CERN , October 2002

Inverse Radiation Processes • Inverse Cerenkov (slow wave) • Inverse Cerenkov (slow wave) • Inverse FEL… (fast-wave) • Inverse FEL… (fast-wave) • Inverse Transition Radiation (LEAP) • Inverse Transition Radiation (LEAP) • Inverse Laser (Amplified Wake) • Inverse Laser (Amplified Wake) Space-Charge Wakes • Laser Wake-Field • Laser Wake-Field • Plasma Wake-Field • Plasma Wake-Field • Plasma Beat-Wave • Plasma Beat-Wave • Resonant Absorption • Resonant Absorption Levi Schächter, CERN , October 2002