| Paper | Title | Page |
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| MOPFI037 | Design and Experiment of a Compact C-band Photocathode RF Gun for UED | 369 |
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| A compact C-band photocathode RF gun for the MeV UED facility is developed in Tsinghua University, which is designed to work at the frequency of 5.712GHz. This paper presents the physics and RF structure design, and beam dynamics optimization of this C-band RF gun. Some new structure design will be adopted in this gun, including the optimized cavity length and elliptical iris, which is helpful to achieve lower emittance and larger mode separation. This paper likewise presents experiment parameters and the cold test results of this C-band RF gun. | ||
| TUPEA021 | Calculation of Wakefields in Plasma Filled Dielectric Capillaries Generated by a Relativistic Electron Beam | 1205 |
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| In this paper we give an analytical solution of TM0n mode for wakefields generated by a relativistic electron beam passing through plasma-filled capillary waveguides. The numerical solution shows that the fields of TM0n modes could not be ignored when the plasma wave length is comparable with the effective radius of the capillary tube, which means that the boundaries are not shielded completely by plasma. Numerical examples are given in several typical cases. | ||
| TUPME025 | Calculation of the Equilibrium Parameters for the Compact Ring of TTX | 1625 |
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| Intra-Beam Scattering (IBS) can cause emittance growth in high intensity low energy beams. We study its effect on the compact low energy electron storage ring, proposed for Tsinghua Thomson Scattering X-ray source (TTX). For a single bunch with peak current at about 17A and re-entrant type normal conducting RF cavity with peak voltage at 15kV, the equilibrium horizontal and vertical emittances are 2.9 and 0.3 μm, and the rms momentum spread and bunch length are about 0.2%, and 23ps. In this paper, we report the methods and results of the IBS calculation. | ||
| WEPWA020 | Laser Electron Storage Ring for TTX | 2171 |
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| Tsinghua Thomson scattering X-ray (TTX) source, proposed by Tsinghua University, is a hard x-ray source with multi-application in condensed matter physics, etc. The TTX is composed of an S-band photocathode RF gun and a SLAC type 3m travelling wave Linac, and a femto-second tera-watt laser system drives the photocathode. The TTX source is in operation. To extend the capability of TTX, we plan to design a ring based system to increase the photon flux. In this paper, we report the design of the compact electron storage ring and optical cavity, expected performance, and future prospects. | ||
| WEPWA021 | X-ray Spectra Reconstruction with HOPG Crystal on TTX | 2174 |
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| Thomson Scattering sources, as the new generation of bright X-ray sources, have great application potential in many respects. Traditional spectra measurement methods, applied to measured the spectra of Thomson Scattering source, are troublesome as the X-ray beam is too intense to cause pile up problems. In this article, we use the HOPG crystal to reconstruct the X-ray spectra of Tsinghua Thomson X-ray source (TTX) through Braggs law. This method can get reasonable results with single or several shots, with high energy resolution. We also compare the experiment results of this method with the reconstructed spectra by analyzing the attenuation data of the X-ray beam in silicon , and these two results agree well with each other. | ||
| WEPME024 | Gaussian Spectrum Fiber Laser Pulses Generated in an All-normal-dispersion Cavity | 2983 |
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| In this paper, we reported generating a broad bandwidth Gaussian shape spectrum fiber laser pulse directly in an all-normal dispersive cavity. Pulse-shaping is based on spectral filtering. The spectrum has a ~20 nm 20-dB spectrum bandwidth and it is different from the typical spectrum, of steep edge and two spikes. The Gaussian spectrum is preferred since it can be dechirped to transform-limited pulsed duration. The pulse duration corresponds to this kind of spectrum is ~315fs, and pulse energy is up to~9nJ, with a repetition rate of 18.9MHz. | ||
| THPWO049 | Preliminary Beam Dynamics and Structure Design of One 50mA/CW RFQ with Ramped Inter-vane Voltage | 3881 |
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Funding: Work supported by National Natural Scienccontracte Foundation of China (Major Research Plan Grant No. 91126003 and Project 11175096). The beam dynamics and structure design of a ramped-voltage CW RFQ (Radio Frequency Quadrupole) accelerator for a NSFC (National Natural Science Foundation of China) Project at Tsinghua University is presented in this paper. The ramped-voltage RFQ, in which the inter-vane voltage increases from the low-energy end to the high-energy end, is compact and efficient. The RFQ, with the operating frequency of 325 MHz, will capture a 50 mA/CW, 50 keV proton beam from the RF source and accelerate it to 3 MeV, an energy suitable for chopping and injecting the beam in a conventional Drift Tube Linac. After optimization, the total length is as short as 2.9 m and the transmission rate is above 97%. The design of RFQ structure including the undercuts will also be shown. |
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| THPWO050 | High Power Test and Beam Commissioning of he CPHS RFQ Accelerator | 3884 |
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Funding: Work supported by the “985 Project” of the Ministry of Education of China, National Natural Science Foundation of China (Major Research Plan Grant No. 91126003 and 11175096). We present, in this paper, the high power test result and the beam commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The 3-meter-long RFQ is designed to deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. The RFQ has been designed, manufactured, and installed at Tsinghua University. High-vacuum test of the RFQ has been carried out carefully and the cooling system has been mounted. At the beginning of 2013, the high power RF test has been performed and the first 3 MeV proton beam is obtained. |
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| THPWO051 | Status of CPHS Project | 3887 |
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| CPHS (Compact Pulsed Hadron Source) project was initiated in Tsinghua University at 2009. It consists of a 13 MeV proton Linac (RFQ+DTL), a neutron target station and some neutron stations. The construction of 3 MeV Linac (RFQ only) and target station will be finished at the end of 2012. And initial commissioning will be started at the early of year 2013. The progress and results of early commissioning will be presented at this paper. Then we will report the next plan also. | ||