Paper | Title | Other Keywords | Page |
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THOA3 | Demonstration of Transverse-to-longitudinal Emittance Exchange at A0 Photoinjector | emittance, cavity, space-charge, radiation | 443 |
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The 3-D phase-space manipulation of electron beams enhances the performance of next generation accelerators including high energy colliders and accelerator based light sources. In this paper we will report an observation of near ideal transverse to longitudinal emittance exchange at the Fermilab A0 Photoinjector. The emittance exchange (EEX) beamline consists a 3.9 GHz normal conducting deflecting mode cavity positioned between two magnetic doglegs. We will also compare the experiment results to simulations. | |||
THPA06 | Emittance for Different Bunch Charges at the Upgraded PITZ Facility | emittance, gun, laser, cavity | 473 |
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Optimizations of electron sources for short-wavelength Free Electron Laser (FELs) at the Photo Injector Test facility at DESY, location Zeuthen (PITZ) have been continued with a new radio frequency (RF) gun cavity, a new post-accelerating Cut Disk Structure (CDS) booster cavity and several upgraded diagnostic components. The new booster cavity allows stable operation with higher acceleration and longer pulse trains than the operation with the previous TESLA type cavity. Electron beams with a maximum mean momentum of about 25 MeV/c can be produced with the setup described in this paper. Together with the upgraded RF system for the gun and the new CDS booster cavity, the electron beam stability was significantly improved. A large fraction of the measurement program in 2010-2011was devoted to study the dependence of the transverse projected emittance on the bunch charge. Measurement results using this upgraded facility are reported and discussed. | |||
THPA21 | Commissioning of a Streak Camera for Laser Characterization at NML | laser, space-charge, linac, cryomodule | 515 |
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A streak camera will be used for longitudinal profile measurement of a drive laser for the superconducting radio frequency photoinjector test facility at Fermilab. We are evaluating both a Photek intensified CCD camera and a Hamamatsu cooled CCD camera as the readout camera option for the Hamamatsu C5680 streak camera unit with a synchroscan sweep unit. Trade on low signal sensitivity and spatial resolution for the two lens-coupled options are being evaluated. In addition, an ultrashort laser pulse from a Ti:sapphire laser is used to measure the temporal resolution for both configurations. | |||
THPA30 | First Results with Tomographic Reconstruction of the Transverse Phase Space at PITZ | emittance, laser, cathode, gun | 543 |
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The development of high brightness electron sources capable to drive FELs like FLASH and European XFEL is a major objective of the Photo-Injector Test Facility at DESY in Zeuthen, PITZ. A key parameter used to define the beam quality at PITZ is the transverse phase-space density distribution and its evolution along the beamline. Complementary to the standard phase-space measurement setup constituting slit-scan stations, a module for tomographic diagnostics has been commissioned in 2010/2011. It consists of four observation screens separated by FODO cells and an upstream matching section. The expected advantages of the tomography method are the possibility to measure both transverse planes simultaneously and an improved resolution for low charges and short pulse trains. The fundamental challenges are related to strong space-charge forces at low beam momentum of only 25~MeV/c at PITZ at the moment. Such a constraint presents an obstacle to obtain beam envelope parameters well-matched to the optics of the FODO lattice. This contribution presents the first practical experience with the phase-space tomography module. | |||
THPB02 | Implementation of 2D-emittance Compensation Scheme in the BERLinPro Injector | emittance, space-charge, linac, solenoid | 564 |
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Helmholtz-Zentrum Berlin officially started Jan. 2011 the design and construction of the Berlin Energy Recovery Linac Project BERLinPro. The initial goal of this compact ERL is to develop the ERL accelerator physics and technology required to accelerate a high-current (100 mA) low emittance beam (1 mm•mrad normalized), as required for future ERL-based synchrotron light sources. High power ERL based FELs demand low emittance, high peak and average current beams. The injection energy in an ERL is usually rather low to decrease power consumption and avoid activation of the beam dump. Therefore, the space charge is the main reason of the emittance degradation in the injector. The implementation of an emittance compensation scheme in the injector is necessary to achieve a low emittance. Since injector’s optics is axially non-symmetric, the 2D-emittance compensation scheme [1] should be used. The implementation of the 2D-emittance compensation scheme at BERLinPro injector is presented in this contribution. Other sources of emittance growth in ERL injectors are also discussed.
[1] S.V. Miginsky, "Emittance compensation of elliptical beam", NIM A 603 (2009), pp 32-34. |
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THPB24 | Generation and Acceleration of Uniformly-filled Ellipsoidal Bunches Obtained via Space-charge Expansion from a Semiconductor Photocathode | laser, electron, cavity, simulation | 605 |
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We report on the experimental generation, acceleration and characterization of a uniformly-filled electron bunch obtained via space-charge-driven expansion (so called "blow-out regime") at the A0 photoinjector at Fermilab. The beam is photoemitted from a CsTe photocathode using a short (<~200 fs) ultraviolet pulse obtained via frequency-tripling of an amplified Ti:Sp infrared pulse. The produced electron bunches are characterized with conventional diagnostics and the measurements are bench-marked against numerical simulations performed with ASTRA and GPT. | |||
THPB27 | Application and Design of the Streak and TV Readout Systems at PITZ | electron, laser, radiation, dipole | 613 |
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Funding: Deutsches Elektronen-Synchrotron DESY, Germany The Photo Injector Test facility at DESY in Zeuthen (PITZ) was built to develop and optimize photoelectron injectors for FELs like FLASH and the European XFEL. In PITZ electrons can be accelerated to momenta up to 20 MeV/c. Optimization of all injector parameters such as the longitudinal properties of the electron bunch is needed. A streak system is used to measure the complete longitudinal phase space distribution of the bunch with an accuracy of few ps. In this system the electron beam penetrates Aerogel radiators or Optical Transition Radiation screens OTR and produces Cherenkov light, which is transported by an optical line to a streak camera. The emitted light presents the charge distribution in the electron bunch. Some modifications of the streak beamline, such as using a Hybrid of lenses and mirrors to improve resolution and using quartz lenses to overcome the radiation damage are foreseen. A TV system is used to observe the electron beam directly, where screens of Yttrium Aluminum Garnet YAG and OTR are used to produce a direct image of the beam. An overview of the existing systems, the measurements, the difficulties and future modifications will be presented. |
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