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Li, D.

Paper Title Page
MOPAS029 Progress on the Design and Fabrication of the MICE Spectrometer Solenoids 497
 
  • S. P. Virostek, M. A. Green, D. Li, M. S. Zisman
    LBNL, Berkeley, California
 
  Funding: This work was supported by the U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling in a short section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory (RAL) in the UK. A five-coil, superconducting spectrometer solenoid magnet at each end of the cooling channel will provide a 4 T uniform field region for the scintillating fiber tracker within the magnet bore tubes. The tracker modules are used to measure the muon beam emittance as it enters and exits the cooling channel. The cold mass for the 400 mm warm bore magnet consists of two sections: a three-coil spectrometer magnet and a two-coil matching section that matches the uniform field of the solenoid into the MICE cooling channel. The detailed design and analysis of the two spectrometer solenoids has been completed, and the fabrication of the magnets is in its final stages. The primary features of the spectrometer solenoid magnetic and mechanical designs are presented along with a summary of key fabrication issues and photos of the fabrication process.

 
TUPMN109 A High Repetition Rate VUV-Soft X-Ray FEL Concept 1167
 
  • J. N. Corlett, J. M. Byrd, W. M. Fawley, M. Gullans, D. Li, S. M. Lidia, H. A. Padmore, G. Penn, I. V. Pogorelov, J. Qiang, D. Robin, F. Sannibale, J. W. Staples, C. Steier, M. Venturini, S. P. Virostek, W. Wan, R. P. Wells, R. B. Wilcox, J. S. Wurtele, A. Zholents
    LBNL, Berkeley, California
 
  Funding: This work was supported by the Director, Office of Science, High Energy Physics, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The FEL process increases radiation flux by several orders of magnitude above existing incoherent sources, and offers the additional enhancements attainable by optical manipulations of the electron beam: control of the temporal duration and bandwidth of the coherent output, and wavelength; utilization of harmonics to attain shorter wavelengths; and precise synchronization of the x-ray pulse with laser systems. We describe an FEL facility concept based on a high repetition rate RF photocathode gun, that would allow simultaneous operation of multiple independent FELs, each producing high average brightness, tunable over the soft x-ray-VUV range, and each with individual performance characteristics determined by the configuration of the FEL SASE, enhanced-SASE (ESASE), seeded, self-seeded, harmonic generation, and other configurations making use of optical manipulations of the electron beam may be employed, providing a wide range of photon beam properties to meet varied user demands. FELs would be tailored to specific experimental needs, including production of ultrafast pulses even into the attosecond domain, and high temporal coherence (i.e. high resolving power) beams.

 
WEPMN090 Recent RF Results from the MuCool Test Area 2239
 
  • J. Norem
    ANL, Argonne, Illinois
  • A. Bross, A. Moretti, Z. Qian
    Fermilab, Batavia, Illinois
  • D. Huang, Y. Torun
    IIT, Chicago, Illinois
  • D. Li, M. S. Zisman
    LBNL, Berkeley, California
  • R. A. Rimmer
    Jefferson Lab, Newport News, Virginia
 
  Funding: Supported by the USDOE Office of High Energy Physics

The MuCool Experiment has been continuing to take data with 805 and 201 MHz cavities in the MuCool Test Area. The system uses rf power sources from the Fermilab Linac. Although the experimental program is primarily aimed at the Muon Ionization Cooling Experiment (MICE), we have been studying the dependence of rf limits on frequency, cavity material, high magnetic fields, gas pressure, coatings, etc. with the general aim of understanding the basic mechanisms involved. The 201 MHz cavity, essentially a prototype for the MICE experiment, was made using cleaning techniques similar to those employed for superconducting cavities and operates at its design field with very little conditioning.

 
WEPMN118 Mechanical Design and Analysis of a 200 MHz, Bolt-together RFQ for the Accelerator Driven Neutron Source 2313
 
  • S. P. Virostek, M. D. Hoff, D. Li, J. W. Staples, R. P. Wells
    LBNL, Berkeley, California
 
  Funding: This work was supported by the U. S. Dept. of Energy under Contract No. DE-AC02-05CH11231 and by the Dept. of Homeland Security's Domestic Nuclear Detection Office under Award No. HSHQPB-05-X-00033.

A high-yield neutron source to screen sea-land cargo containers for shielded Special Nuclear Materials (SNM) has been designed at LBNL. The Accelerator-Driven Neutron Source (ADNS) utilizes the D(d,n)3He reaction to produce a forward directed neutron beam. Key components are a high-current radio-frequency quadrupole (RFQ) accelerator and a high-power neutron production target capable of delivering a neutron flux of >107 n/(cm2 s) at a distance of 2.5 m. The mechanical design and analysis of the four-module, bolt-together RFQ will be presented here. Operating at 200 MHz, the 5.1 m long RFQ will accelerate a 40 mA deuteron beam to 6 MeV. At a 5% duty factor, the time-average d+ beam current on target is 1.5 mA. Each of the 1.27 m long RFQ modules will consist of four solid OFHC copper vanes. A specially designed 3-D O-ring will be used to provide vacuum sealing between both the vanes and the modules. RF connections are made by means of canted coil spring contacts. Quadrupole mode stabilization is obtained with a series of 60 water-cooled pi-mode rods. A set of 80 evenly spaced fixed slug tuners is used for final frequency adjustment and local field perturbation correction.

 
THPAN054 Experiment on a Cold Test Model of a 2-Cell SC Deflecting Cavity for ALS at LBNL 3348
 
  • J. Shi, H. Chen, C.-X. Tang, S. Zheng
    TUB, Beijing
  • D. Li
    LBNL, Berkeley, California
 
  Deflecting Cavities can be used to generate sub-pico-second X-ray pulse and are proposed at ALS at LBNL. A 2-cell structure has been simulated earlier to achieve the required deflecting voltage with damping waveguide to get low impedance. An aluminum cold test model has been made to demonstrate the simulation and the idea for damping LOM with waveguide. Field distribution as well as (R/Q)s are measured using 'bead-pull' method. Qs with/without waveguide loaded are measured and compared with simulation. Detailed configuration and experiment progress is presented.