Paper | Title | Page |
---|---|---|
MOZAKI01 | Compensation of the Crossing Angle with Crab Cavities at KEKB | 27 |
|
||
The crab cavities are presently being installed in the KEKB rings to compensate the crossing angle at collision and thus increase luminosity. This will be the first experience with such cavities in colliders. Results on the beam operation of the new cavities, both for single and colliding beams, will be presented including the luminosity performance and limitations.
Work presented on behalf of the KEKB Accelerator Group. |
||
|
Slides | |
TUPMN044 | Status of R&D Efforts Toward the ERL-based Future Light Source in Japan | 1016 |
|
||
Energy Recovery Linacs (ERL), based on superconducting accelerators, are one of the most promising synchrotron light sources in future. The KEK and the JAEA, in collaboration with the ISSP, the UVSOR, and the SPring-8, are considering to realize together the ERL-based next-generation light source in Japan. To establish key technologies for that, active R&D efforts started. The R&D program includes the developments of ultra-low-emittance photocathode guns and of superconducting cavities, as well as experimental proofs of accelerator-physics issues at the ERL test facility, which will be built at the KEK campus. We are currently working on constructing a prototype photocathode gun, on designing superconducing cavities, and on designing a prototype ERL. The current plan of the prototype ERL comprises a full injector linac, one or two cryomodules for the main linac, and the beam return loop, which can be operated at beam energies from 60 to 160 MeV. The up-to-date R&D status will be reported. | ||
WEPMN028 | Development of Digital Low-level RF Control System using Multi-intermediate Frequencies | 2110 |
|
||
Digital low level rf (LLRF) control system has been developed in Superconducting RF Test Facility (STF) at KEK to carry out the accelerating electric field stability of 0.3% (rms) in amplitude and 0.3 degree (rms) in phase, respectively. In the digital LLRF system, rf probe signal from cavity is down-converted to intermediate frequency (IF) for acquisition at analog-to-digital converter (ADC) and the number of ADCs required is equal to the number of cavities. In order to decrease the number of ADCs, a new digital LLRF control system is under development. In this LLRF system, rf signals are down-converted to different IF and combined. The combined signal is detected with one ADC and I/Q components of each rf signal are calculated with digital signal processing. This paper describes a result of simulation and estimation using cavity simulator based on FPGA board about this new technique. | ||
WEPMN029 | Status of the Low-Level RF System at KEK-STF | 2113 |
|
||
RF field stabilities of less than 0.3%, 0.3deg. are required at STF llrf system. In order to satisfy these requirements, digital FB system using a FPGA is adopted. The FB system consists of a FPGA (VirtexIIPro30) with ten 16-bit ADCs and two 14-bit DACs. The rf (1.3 GHz) probe signals are downconverted to the IF (10 MHz) and directly acquired at ADCs. Total 8 cavities will be installed at STF-Phase 1 in 2007 and vector sum control of 8 cavity signals will be carried out. The performance of the FB system is examined with electric cavity simulators prior to the rf operation. | ||
THIBKI04 | Developments of Long-pulse Klystron Modulator for KEK Super-conducting RF Test Facility | 2691 |
|
||
NICHICON (KUSATSU) CORPORATION and KEK have developed a novel long-pulse klystron modulator for both of single-beam tube(136kVp*100A) and multi-beam tube(120kVp*140A). The main features are; - crowberless system with optimized IGBT snubber circuit, - compact and highly reliable Self-Healing capacitors, - HV & LV twin pulse transformers of laminated steel core for reduced tank volume. Detailed configuration and test results to be presented. | ||
|
Slides | |
THPMN031 | Experiment of X-Ray Source by 9.4 GHz X-Band Linac for Nondestractive Testing System | 2781 |
|
||
We are developing a compact X-ray source for Nondestractive Testing (NDT) system. We aim to develop a portable X-ray NDT system by 950 keV X-band linac to realize in-site inspection. Our system has 20 kV electron gun, and accelerate electron beam to 950 keV with 9.4 GHz X-band linac. RF source of this system is 250kW magnetron. Our target spot size and spatial resolution are 1mm. We adopted APS (Alternative Periodic Structure) tube of pi/2 mode for easy manufacturing. It is difficult to realize a high-shunt-impedance for low-energy-cells, which attributes to manufacturing problems. Instead, we use three pi-mode cavities there. Further, we choose the low power magnetron for small cooling system and the low voltage electron gun for small power supply. For the stability of the X-ray yield the system include the Auto Frequency Control (AFC), which detect and tune the frequency shift at the magnetron. We have also performed X-ray generation calculation by the Monte Carlo code of GEANT and EGS to confirm the X-ray source size. We are going to construct the whole system and verify it experimentally. Updated results are presented at the spot. | ||
TUPAN045 | Beam Operation with Crab Cavities at KEKB | 1487 |
|
||
Beam operation with crab cavities is planned in early 2007 at KEKB. The crab crossing scheme is expected to increase the vertical beam-beam tune-shift parameter significantly. One crab cavity will be installed in each ring where conditions for beam optics are matched to compensate the beam crossing angle of 22 mrad. Operation results on collision tuning with the crab cavities will be presented.
For the KEKB Accelerator Group. |