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This overview from the LINAC12 conference discusses the evolution of light sources, from first-generation synchrotron radiation to cutting-edge fourth-generation systems. It highlights developments in Free Electron Lasers (FELs), Energy Recovery Linacs (ERLs), and novel applications such as medical and military uses. The status of significant facilities like the European XFEL and LCLS, alongside future research directions for high-field undulators and plasma wakefield acceleration, are examined. Key challenges and innovations in neutron acceleration and emerging RF technologies are also addressed.
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Overview of the LINAC12 conference Alexander Gerbershagen and Jürgen Pfingstner 19th of September 2012
Overview of Light sources • Rings: • 1st generation light sources: SR just byproduct • 2nd generation light sources: dedicated rings to create SR • 3rd generation light sources: strong use of undulators • 4th gen. light sources: Everything that exceeds performance of 3rd gen. • LINAC: • FEL (undulator): Emission • SASE-FEL (microbunching): • Emission • Recent and future activities: • Laser-seeded FEL (FERMI@electra) • XFEL oscillators • Energy recovery linacs (ERL) • Use of RF-cavities as undulators
Applications of synchrotron light • Medical applications: to cut tissue • Military applications: anti aircraft and missile system • Surface processing and machining • Diffraction imaging: • already several Nobel prices • using FELs
Status of LCLS and the European Light Source (TU2A03, MO1A02) • European XFEL: • DESY • Will surpass the performance of LCLS: 0.05-6nm light • Successor of FLASH • SASE-FEL • Also X-FELO in discussion • Currently under construction • Three undulator systems • Start of commissioning summer 2015 • LCLS: • SLAC • Most powerful FEL currently • Hard X-rays: 0.15-15nm • Upgrade of LCLS to LCLS-II • 2 new beams to increase the number of users served • also improved performance (1fs pulse length, wider X-ray range) • Planed start of operation 2019
X-ray FEL Oscillator (XFELO, TU2A02) • Average Brightness very high • Not realised yet • R&D issues are components as mirrors that can work in the X-ray regime • XFELO can be build shorter than SASE-FELs • The temporal coherence is much better • e-beam charge can be lower and bunch length longer, CW
Linac-based laser Compton scattering X-ray and gamma-ray sources (WE1A05) • Use the scattering of laser photons with and electron beam from an linac to create X-ray photons • Not as short wavelengths as modern FELs, but much more compact and portable. • With the changing of the properties of the electron beam and the laser, the properties of the scattered photons can be changed, e.g. polarization.
ERL-based light source challenges (WE1A01) • Discussion about future challenges • Some designs shown • Can also be combined with X-FELO • Principle can also be used for Lepton-Hadron colliders (eRHIC and LHeC)
High-field short-period microwave undulators (WE2A03) • The wavelength of an FEL with undulator is given by: • With permanent magnet cannot be reduced very much anymore. • Use instead of alternating magnetic field an RF cavity • RF undulator requires very high EM fields which causes many problems for the design of the cavity • A cavity design was shown
Overview of Activities (MO1A01, TU1A02, FR1A03, …) • High intensity proton and ion beams: intensity frontier research • Project X (Fermilab) • MW proton beam that will be used for different exper. • Neutrino physics, physics of rare processes , nuclear studies • SAREF (Soreq, Israel) • Adjoined to Soreq Nuclear Research Center (SNRC) • Fast neutron source • Enrich uranium and transmutation of long- lived radioactive waste • Radioactive ion beams: nuclear research, comparable to ISOLDE • Californium Rare Ion Breeder Upgrade (CARIBU) at ANL ATLAS facility
Injection schemes for plasma wakefield acceleration (MO2A01) • Scheme a: Self injection • Works in Bubble regime • Black: electron evacuation • Yellow: electron accumulation • Some of the electrons get trapped and accelerated • Scheme b: Colliding laser pulses • Less non-linear wake than Bubble regime • An injection laser pulse collides with the drive pulse and creates beatwave. • Electrons are pre-accelerated and some are trapped and accelerated • Properties of electron beam can be varied by laser beams
Advances in Photonic and Metamaterial RF-structures (TU3A02) • Photonic band gap structures support only very narrow frequency band • HOM are strongly reduced • Acceleration gradients up to 100 MV/m, Q > 109 • In research • Metamaterial RF-structure • Periodic structure with conductors worked in • Creates ε < 0 and μ < 0 • Different EM properties than in nature • Planed to be used for wakefield reduction in structures and for couplers
Acceleration/Deceleration of slow neutrons (MO3A04) • Measurement of neutron electric dipole moment (nEDM) could reveal physics beyond the standard model • High intensity neutron beams needed • Problem: Energy spread of ultra cold neutrons (UCN) expands beam • Re-bunching was demonstrated, where fast neutrons were decelerated and slow ones accelerated • Energy of neutrons is changed by flipping magnetic dipole spin with RF wave in static magnetic field.
Electron beam current-profile shaping via transverse-to-longitudinal phase-space exchange (TU3A04) • Using double dog leg to exchange transversal and long. phase space • By shaping transverse profile with filter, many different long profiles can be created. • Applications: bunching for FELs and triangular shape for wakefield acceleration.