Research on RF Cavity Tolerance of CYCIAE-100

The tolerances of the manufacture and installation errors and Dees deformation caused by gravity in RF cavity of CYCIAE-100 are investigated.Both the analytic treatment and numerical simulation are carried out to give the tolerance of the manufacture and installation errors which disturb the radial and vertical motion of the beam.The Dees deformation caused by gravity leads to axial misalignment of the Dees and then induces the build-up of coherent axial oscillations.However,the calculated results show that the deformation of our Dees is acceptable.

Development of a seven-cell S-band standing-wave RF-deflecting cavity for Tsinghua Thomson scattering X-ray source

A 2856-MHz,π-mode,seven-cell standingwave deflecting cavity was designed and fabricated for bunch length measurement in Tsinghua Thomson scattering X-ray source(TTX)facility.This cavity was installed in the TTX and provided a deflecting voltage of 4.2 MV with an input power of 2.5 MW.Bunch length diagnoses of electron beams with energies up to 39 MeV have been performed.In this article,the RF design of the cavity using HFSS,fabrication,and RF test processes are reviewed.High-power operation with accelerated beams and calibration of the deflecting voltage are also presented.

Theoretical and Practical Study on RF Model Cavity of 100MeV H^- Cyclotron

In a cyclotron,the RF cavity is the key device to accelerate ions.The RF cavity design for the 100MeV H^- cyclotron is very complex since the space is narrow and the Dee voltage is 60kV at the center and 120kV at the extraction region.CST MICROWAVE STUDIO is used in the design,and a real model has been made.The test result on the model is in good agreement with the simulation result.

RF deflecting cavity design for bunch length measurement of photoinjector at Tsinghua University

RF deflecting cavity can be used for bunch length measurement and is designed to diagnose the beam produced by the photocathode electron gun which was built at Tsinghua University for the Thomson scattering experiment. Detailed discussion and calculation for measuring the 3.5 MeV bunch and another with further acceleration to 50 MeV, which is under development, are presented. A standing-wave deflecting cavity working at 2856 MHz is designed and the power feeding system has been planned.

RF deffecting cavity for bunch length measurement in Tsinghua Thomson scattering X-ray source

An RF deffecting cavity used for bunch length measurement has been designed and fabricated at Tsinghua University for the Thomson Scattering X-Ray Source. The cavity is a 2856 MHz, π-mode, 3-cell standing-wave cavity, to diagnose the 3.5 MeV beam produced by photocathode electron gun. With a larger power source, the same cavity will again be used to measure the accelerated beam with energy of 50 MeV before colliding with the laser pulse. The RF design using MAFIA for both the cavity shape and the power coupler is reviewed, followed by presenting the fabrication procedure and bench measurement results of two cavities.

Experimental study on SC RF cavities by using China large grain niobium for ILC

Large grain niobium has the potential of simplifying the production sequence and consequently reducing the cost of the superconducting RF cavities for ILC. To investigate the feasibility of fabrication and the possibility to achieve high gradient by large grain cavities, two 1.3 GHz cavities were made of China large grain niobium and a series of vertical tests were carried out following several different surfaces treatment procedures. Two cavities have both reached the high gradient of more than 43 MV/m repeatedly and the maximum accelerating field of 47.9 MV/m has been achieved by China large grain niobium. This paper introduces the features of the fabrication and surface treatments on the large grain cavities and presents the preliminary results of the research.

Recent Activities of Cryogenic System in Overseas and Domestic Accelerators

The superconducting RF cavity and superconducting magnet are the key devices in modern accelerators. With the development of accelerator technology and requirement of higher beam energy and luminosity,the cryogenic and superconducting technologies are applied widely in the accelerator construction.Based on the study of several typical accelerators which adopted cryogenic and superconducting technology,this paper introduces the recent activities of cryogenic system in overseas and domestic accelerators.

Physics design of CYCAIE-100

The design and construction of Beijing Radioactive Ion-beam Facility (BRIF) was started at China Institute of Atomic Energy -CIAE) in 2004. In this project, a 100 MeV high intensity cyclotron, CYCIAE100, is selected as a driving accelerator for radioactive ion beam production. It will provide a proton beam of 75—100 MeV with an intensity of 200—500 μA. The scheme adopted in this design, i.e., stripping the accelerated H-, makes the structure more compact and construction cost much lower. At present, the design for each system has been accomplished. This paper depicts the basic physics design of the machine, including its major structure and parameters, beam dynamics and each relevant system, e.g. basic structure of the main magnet, numerical simulation of the RF resonant cavity, axial injection system, central region, and study on crucial physics problems concerning the extraction and beam lines. The major problems encountered during the design of CYCIAE-100 are also summarized in this paper.

Design and construction progress of BRIF

A new RIB project, the Beijing Radioactive Ion-beam Facility （BRIF）, has been running at CIAE since 2004. In this project, a 100 MeV H-cyclotron, CYCIAE-100, is selected as the driving accelerator providing a 75-100 MeV, 200-500 μA proton beam. An ISOL system employs two stage separators to reach the mass resolution of 20000. Its RIB beam will be injected into the existing Tandem and a superconducting booster installed down stream of the Tandem will increase the energy by 2 MeV/q. The progress of BRIF, giving special emphasis to CYCIAE-100, will be introduced in this paper.

Development of X-band accelerating structures for high gradients

Short copper standing wave （SW） structures operating at an X-band frequency have been recently designed and manufactured at the Laboratori Nazionali di Frascati of the Istituto Nazionale di Fisica Nucleare （INFN） using the vacuum brazing technique. High power tests of the structures have been performed at the SLAC National Accelerator Laboratory. In this manuscript we report the results of these tests and the activity in progress to enhance the high gradient performance of the next generation of structures, particularly the technological characterization of high performance coatings obtained via molybdenum sputtering.