A   B   C   D   E   F   G   H   I   K   L   M   O   P   Q   R   S   T   U   V    

radiation

    
Paper Title Other Keywords Page
MO101 Advanced Analysis in Nanospace: Research with the XFEL electron, laser, free-electron-laser 1
 
  • H. Dosch
    MPI, Stuttgart
  Little happens in industrialised countries without the use of high-tech materials which are the building blocks of all modern technologies ranging from information, communication, health, energy and environment to transport. In the last decades the development of novel materials has progressed at a breathtaking rate. This has become possible through our microscopic insight into the atomistic structure of condensed matter which finally enabled us to assemble new material systems atom-by-atom. These days, we are facing a revolution in the investigation of nanospace: Through new concepts in accelerator physics, electrons can be forced to emit short-pulsed x-ray laser radiation. Such a futuristic European x-ray free electron laser (XFEL) laboratory is currently being constructed and will allow mankind to finally get holographic snapshots of the motion of atoms and electrons in materials. Ultimate insights into matter, as the realtime-observation of the formation and the breaking of molecular bonds, sound like science fiction, but could become reality in less than a decade, if Europe embarks today into this bold adventure which will lead us into unexplored dimensions of nanospace.  
 
MOP30 Linear Accelerator LINAC-800 of the DELSY Project electron, acceleration, linac, gun 105
 
  • V.V. Kobets, N. Balalykin, I.N. Meshkov, I.A. Seleznev, G. Shirkov
    JINR, Dubna, Moscow Region
  In the report the modernization of electron linear accelerator MEA (Medium Energy Accelerator) is discussed. The goal of the work is to create on the base of MEA a complex of free electron lasers overlaying a range of radiation waves from infrared to ultraviolet. Status of the work is reported.  
 
MOP81 Analysis of the Qualification-Tests Performance of the Superconducting Cavities for the SNS Linac linac, simulation, electron, ion 210
 
  • J. R. Delayen, J. Mammosser, O. Ozelis
    Jefferson Lab, Newport News, Virginia
  Thomas Jefferson National Accelerating Facility (Jefferson Lab) is producing superconducting radio frequency (SRF) cryomodules for the Spallation Neutron Source (SNS) cold linac. This consists of 11 medium-beta (β=0.61) cyomodules of 3 cavities each, and 12 high-beta (β=0.81) cryomodules of 4 cavities each. Before assembly into cavity strings the cavities undergo individual qualification tests in a vertical cryostat (VTA). In this paper we analyze the performance of the cavities during these qualification tests, and attempt to correlate this performance with cleaning, assembly, and testing procedures. We also compare VTA performance with performance in completed cryomodules.  
 
TU203 High Pressure, High Gradient RF Cavities for Muon Beam Cooling emittance, simulation, collider, vacuum 266
 
  • R. P. Johnson, M. Popovic
    FNAL, Batavia, Illinois
  • M.M. Alsharo'a, R.E. Hartline, M. Kuchnir, T.J. Roberts
    Muons, Inc., Batavia
  • C. M. Ankenbrandt, A. Moretti
    Fermilab, Batavia, Illinois
  • K. Beard, A. Bogacz, Y.S. Derbenev
    Jefferson Lab, Newport News, Virginia
  • D. M. Kaplan, K. Yonehara
    IIT, Chicago, Illinois
  High intensity, low emittance muon beams are needed for new applications such as muon colliders and neutrino factories based on muon storage rings. Ionization cooling, where muon energy is lost in a low-Z absorber and only the longitudinal component is regenerated using RF cavities, is presently the only known cooling technique that is fast enough to be effective in the short muon lifetime. RF cavities filled with high-pressure hydrogen gas bring two advantages to the ionization technique:
  1. the energy absorption and energy regeneration happen simultaneously rather than sequentially, and
  2. higher RF gradients and better cavity breakdown behavior are possible than in vacuum due to the Paschen effect.
These advantages and some disadvantages and risks will be discussed along with a description of the present and desired RF R&D efforts needed to make accelerators and colliders based on muon beams less futuristic.
 
Transparencies
 
TUP45 Extended Parametric Evaluation for 1 Å FEL - Emittance and Current Requirements emittance, undulator, electron, gun 369
 
  • M. Pedrozzi, G. Ingold
    PSI, Villigen
  In the synchrotron radiation community there is a strong request for high brightness, coherent X-ray light pulses, especially in the 1 to 0.1 nm wave length range. A Free Electron Laser (FEL), driven by a linear single pass accelerator, is today the most promising mechanism able to produce such radiation. Since the electron beam brightness plays a major role in the laser saturation process and in the final energy of the driving linac, many laboratories are presently working on a new generation of low emittances sources. The present analysis will give an indication about the FEL behaviour and the undulator parameters versus the slice beam quality (emittance, current, energy spread).  
 
TUP74 The Beam Diagnostics System in the J-PARC LINAC linac, beam-losses, quadrupole, diagnostics 441
 
  • S. Lee, Z. Igarashi, T. Toyama
    KEK, Ibaraki
  • H. Akikawa
    JAERI/LINAC, Ibaraki-ken
  • F. Hiroki, J. Kishiro, S. Sato, M. Tanaka, T. Tomisawa
    JAERI, Ibaraki-ken
  • H. Yoshikawa
    JAERI/FEL, Ibaraki-ken
  Large amount of beam monitors will be installed in J-PARC linac. Electrostatic computations are used to adjust the BPM cross-section parameters to obtain 50 Ω transmission lines. BPMs are designed to control the offset between quadrupole magnet and BPM electrical centers less than 0.1mm. We present a procedure of beam based calibration/alignment (BBC/BBA) method to confirm the displacement of linac BPMs. The fast current transformer (FCT) has response of relative bunch phase <1%. To measure the beam energy at every accelerator tank and injection point of 3 GeV RCS, phase difference of FCT pairs are used, and 10-4 order energy resolutions can be expected. The loss monitor system (BLM) is composed of scintillator and Ar-CH4/CO2 gas filled proportional counter. To prevent the activation and heat load by intense beam loss, fast time response of loss signals is required. Profile measurements can also be used to determine the beam emittance of a matched beam in a periodic focusing lattice. The thin sensing wire scanner (WS) has been designed to obtain a current density distribution of the beam. This paper describes the instruments and R&D result of beam monitors in J-PARC linac.  
 
TUP75 The High Accuracy RF Phase Detector Research for 200 MeV LINAC linac, synchrotron, electron, synchrotron-radiation 444
 
  • S. Dong, G. Huang, D. Jia, G. Li, Y.G. Zhou
    USTC/NSRL, Hefei, Anhui
  The basic configuration of one experimental RF Phase detector and its research significance is introduced by characteristic of Hefei 200 MeV RF Linear accelerator and developments of RF Phase detector technology. The beam energy could be stabilized by implementing RF Phase detector into phase locked system for 5 cascaded accelerator tubes, which composed 200 MeV linac as the injector of Hefei Light Source (HLS). The tabletop experiments are given and the RF Phase detector is tuned in the off-line status. The microwave in 2856 MHz under CW mode is differentiated accurately by the developed RF phase detector. The measured results are better than prediction. The accuracy of the basic configuration of the RF Phase detector is verified, which establishes foundations for further in-line experiments.  
 
TUP78 Diagnostics for the Low Level RF Control for the European XFEL diagnostics, monitoring, feedback, laser 453
 
  • T. Jezynski, P. Pucyk
    WUT, Warsaw
  • S. Simrock
    DESY, Hamburg
  One of the most important aims of the diagnostic system is to provide high reliability. This article describes the concept and the proposal for diagnostic system for Low Level Radio Frequency system for EU-XFEL. It enables immediate location of faults and understanding of their causes, tests the functionality of LLRF system, tests each the electronic board and connections. Diagnostic system tests different system components and compares results from these tests with e.g. from power supplies monitors. Hardware, software and database aspect of diagnostic system is presented. The main part of this paper is devoted to hardware and software specification.  
 
WE104 State of the Art Electron Bunch Compression electron, synchrotron, emittance, bunching 528
 
  • P. Piot
    FNAL, Batavia, Illinois
  Many accelerator applications such as advanced accelerator R&D, free-electron laser drivers and linear colliders, require high peak current electron bunches. The bunch is generally shortened via magnetic compression. In the present paper we review various bunch compression schemes and discuss their limitations. We present experimental results, achieved at various facilities, along with on-going theoretical work on promising novel compression techniques.  
Transparencies
 
WE203 Challenges of Linac Driven Light Sources linac, brilliance, synchrotron, synchrotron-radiation 543
 
  • C. Bocchetta
    ELETTRA, Basovizza, Trieste
  The use of linacs allows novel light sources to be conceived by not being limited by equilibrium dynamics or IBS effects. These new sources can be single pass or recirculated (with or without energy recovery) or linac augmented storage rings. They allow tuneable polarised radiation of unprecedented brilliance, short pulse lengths that may reach the atto-second scale and full coherence. Both SC and NC machines are being proposed, designed and constructed. Photon output characteristics range from incoherent synchrotron radiation to SASE to seeded HGHG. The proposed beams can be low to high average current and pulse time structures range from CW to highly variable with mutual exclusion amongst different forms of operation. The multiple challenges of these machines reside not only in the requirement of beams of extremely high quality (energy, emittance, energy-spread and temporal stability) for the brightest, shortest wavelength sources but also in the demanding technologies and control of beam-machine interactions for the high current energy recovery ones. The paper gives an overview of these broad challenges and of the directions taken to reach the objectives of a user facility.  
Transparencies
 
WE204 PAL Linac Upgrade for a 1-3 Å XFEL linac, undulator, emittance, electron 544
 
  • J-O. Oh, W. Namkung
    POSTECH, Pohang
  • Y. Kim
    DESY, Hamburg
  With the successful SASE FEL saturation at 80 nm wavelength at TTF1, TTF2 will begin re-commissioning in the fall of 2004 as an FEL user facility to 6 nm with 1 GeV beams. The high gain harmonic generation is also confirmed by the DUV-FEL experiments at 266 nm with seeding wavelength at 800 nm. In order to realize a hard X-ray SASE FEL (SASE XFEL) with a lower energy beams, we need a long in-vacuum mini-gap undulator and a GeV-scale FEL driving linac that can supply an extremely low slice emittance, a high peak current, and an extremely low slice energy spread. PAL is operating a 2.5 GeV electron linac as a full-energy injector to the PLS storage ring. By adding an RF photo-cathode gun, two bunch compressors, and a 0.5 GeV S-band injector linac to the existing PLS linac, and by installing a 60 m long in-vacuum undulator, the PLS linac can be converted to a SASE XFEL facility (PAL XFEL) which supplies coherent X-ray down to 0.3 nm wavelength. The third harmonic enhancement technique can supply coherent hard X-ray beams to 0.1 nm. The technical parameters related to these goals are examined, and preliminary design details are reviewed for the PAL linac upgrade idea for a 1-3 Å PAL XFEL.  
Transparencies
 
THP32 New Accelerating Modules RF Test at TTF linac, klystron, pick-up, superconductivity 672
 
  • D. Kostin
    DESY, Hamburg
  Five new accelerating modules were installed into the TTF tunnel as a part of the VUV FEL Linac. They are tested prior to the linac operation. The RF test includes processing of the superconducting cavities, as well as maximum module performance tests. The test procedure and the achieved performance together with the test statistical analysis are presented.  
 
THP53 Quasi-Optical Components for Future Linear Colliders linac, impedance, alignment, linear-collider 730
 
  • S. Kuzikov, G. G. Denisov, M. Yu. Shmelyov
    IAP, Nizhniy Novgorod
  • J.L. Hirshfield
    Omega-P, Inc., New Haven, Connecticut
  This paper presents a concept of the quasi-optical RF system for future Ka-band electron-positron linear collider. According to this concept two RF feeding systems are considered: a Delay Line Distribution System (DLDS) and a pulse compressor based on the multi-mirror traveling-wave resonator. The DLDS is based on oversized waveguides. In such waveguides the so-called image multiplication phenomena are used for power launching, extracting, combining, and splitting of waves. Recent low power tests of mode launchers and other DLDS components are discussed. The 34 GHz pulse compressors, based on three and four-mirror resonators, are considered. The tests of the prototypes at a low power level under different modulation methods are discussed. The simulations and tests of mode converters, miter bends, RF loads, and other components, to be necessary for both compression systems, also are resulted.