| Paper |
Title |
Page |
| TU201 |
The KEK C-Band RF System for a Linear Collider
|
256 |
| |
- H. Matsumoto, S. Takeda, S.S. Win, M. Yoshida
KEK, Ibaraki
- H. Baba, T. Shintake
RIKEN Spring-8 Harima, Hyogo
- J-O. Oh
PAL, Pohang
|
|
| |
The C-band (5712 MHz) main linac has been developed just motivated by the urgent and essential physics program at the e+e- linear collider. In total ~8000 accelerating structures and ~4000 klystrons with modulators are needed for 500 GeV C.M. energy. Therefore these units have to meet strict requirements for: high reliability, simplicity, easy operation, reasonable power efficiency and low cost. This list provides a guiding principle and the boundary conditions for our design work. We have already developed the conventional and PPM type 50 MW class C-band klystrons, modulators, and HOM-free accelerator structures. The first high power an rf compressor cavity made of a low thermal expansion material was designed to provide stable operation even with a very high Q of 200 k, it was successfully operated an output rf power of 135 MW at KEK. The C-band linac rf-system will be used for the SASE-FEL project at SPring-8, but it will also serve to verify the design and components, which can eventually be deployed for the main linac rf system in a future linear collider.
|
|
|
Transparencies
|
| TU202 |
Low Emittance 500 kV Thermionic Electron Gun
|
261 |
| |
- K. Togawa, H. Baba, T. Inagaki, K. Onoe, T. Shintake, T. Tanaka
RIKEN Spring-8 Harima, Hyogo
- H. Matsumoto
KEK, Ibaraki
|
|
| |
A 500 kV pulsed electron gun has been constructed for the injector system of the SASE-FEL project at SPring-8 (SCSS project). A CeB6 single crystal was chosen as a thermionic cathode, because of its excellent emission properties. We have succeeded in generating a 500 keV beam with 1 A peak current and 3 μs FWHM. The beam was very stable with low jitter. The beam emittance has been measured by means of double-slits method, and the normalized rms emittance of 1.1 π·mm·mrad has been obtained. We report on the experimental result on the emittance measurement of the CeB6 electron gun.
|
|
|
|
Transparencies
|
| TU203 |
High Pressure, High Gradient RF Cavities for Muon Beam Cooling
|
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: - the energy absorption and energy regeneration happen simultaneously rather than sequentially, and
- 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
|
| TU204 |
Effect of High Solenoidal Magnetic Fields on Breakdown Voltages of High Vacuum 805 MHz Cavities
|
271 |
| |
- A. Moretti, A.D. Bross, S. Geer, Z. Qian
Fermilab, Batavia, Illinois
- D.M. Errede
University of Illinois at Urbana-Champaign, Urbana, Illinois
- D. Li
LBNL/AFR, Berkeley, California
- J. Norem
ANL, Argonne, Illinois
- R.A. Rimmer
Jefferson Lab, Newport News, Virginia
- Y. Torun
IIT, Chicago, Illinois
- M.S. Zisman
LBNL, Berkeley, California
|
|
| |
The demonstration of muon ionization cooling by a large factor is necessary to demonstrate the feasilibility of a collider or neutrino factory. An important cooling experiment, MICE [1], has been proposed to demonstrate 10 % cooling which will validate the technology. Ionization cooling is accomplished by passing a high-emittance beam in a multi-Tesla solenoidal channel alternately through regions of low Z material and very high accelerating RF Cavities. To determine the effect of very large solenoidal magnetic fields on the generations of Dark current, X-Rays and breakdown Voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station, and a large bore 5 T solenoidal superconducting magnet containing a pill box type Cavity with thin removable window apertures allowing dark current studies and breakdown studies of different materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by almost a factor two in a 4 T field.
[1] http://mice.iit.edu/.
|
|
|
|
Transparencies
|