Rong Xiang

Peking university superconducting accelerator facility for free electron laser

Peking University Superconducting Accelerator Facility (PKU-SCAF) is to generate high-quality electron beams with high average current. It is mainly composed of a DC-SC photocathode injector and a superconducting accelerator. It will operate in CW mode. The energy of the electrons is 20–35 MeV and the emittance is o15p mm mrad. PKUSCAF will be used for Free Electron Lasers. r 2002 Elsevier Science B.V. All rights reserved. PACS: 41.85.Ar; 41.60.Cr

Research and experiments on niobium-sputtered superconducting QWR in Peking University

R&D on SC quarter wave resonators (QWRs) for heavy ion linacs were initiated in China several years ago. A DC bias-voltage sputtering technology was developed in Peking University for niobium-coated copper QWR. A niobium-sputtered copper QWR with good niobium films was successfully made in October 1999. Low temperature experiments were carried out from November 1999 to September 2000. The accelerating gradient of 5/spl sim/6 MV/m can be obtained with no beam load at 4.2 K. The QWR is installed after the 2/spl times/6 MV tandem and is used to accelerate proton beams. The accelerating gradient of 3 MV/m was obtained with a proton beam load.

DC-SC Photoinjector with Low Emittance at Peking Univeristy

High average power Free Electron Lasers require the high average current electron beams with the low emittance. The DC-SC photoinjector developed at Peking University, directly combining a DC Pierce gun with an SRF cavity, can produce the high brightness beam with moderate bunch charge and high duty factor. In order to optimize the transverse emittance which sharply increases at the beginning of the DC gun, a carefully design for the DC gap and the cavity shape is needed. In this paper, the simulation of an upgraded design has been performed. This photoinjector, consisting of a DC gap and a 2+1/2 cell SRF cavity, can produce 4.2 MeV electron beams with 100 pC per bunch and 1.1 μm normalized emittance.

Research on Peking University Superconducting Accelerator Facility (PKU-SCAF)

Peking University Superconducting Accelerator Facility (PKU-SCAF) is under development now. This facility is mainly composed of a DC-SC photocathode injector and a main accelerator with 9-cell cavity. It will provide high quality electron beams with 1 mA average current and 20 MeV energy.