Conceptual design of Hefei advanced light source

The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm·rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.     

Low emittance lattice for the storage ring of the Turkish Light Source Facility TURKAY

The TAC(Turkish Accelerator Center) project aims to build an accelerator center in Turkey. The first stage of the project is to construct an Infra-Red Free Electron Laser(IR-FEL) facility. The second stage is to build a synchrotron radiation facility named TURKAY, which is a third generation synchrotron radiation light source that aims to achieve a high brilliance photon beam from a low emittance electron beam at 3 Ge V. The electron beam parameters are highly dependent on the magnetic lattice of the storage ring. In this paper a low emittance storage ring for TURKAY is proposed and the beam dynamic properties of the magnetic lattice are investigated.     

高能同步辐射光源

基于多弯铁消色散结构的超低发射度储存环光源是新一代同步辐射光源发展的一个重要方向。作为国内第一台第四代同步辐射光源,高能同步辐射光源已经完成物理及工程设计,并于2019年启动建设。高能同步辐射光源电子能量6 GeV,流强200 mA,水平自然发射度低于60 pm?rad,可提供能量达300 keV的X射线,在典型硬X射线波段的同步辐射亮度达1×1022 phs·s?1·mm?2·mrad?2·（0.1%bw）?1,可为材料科学、化学工程、能源环境、生物医学、航空航天、能源环境等众多基础和工程科学研究领域提供先进的实验平台。本文将介绍高能同步辐射光源项目的整体方案及物理设计。     

Measurement of optics for the SSRF storage ring in commissioning

The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report presents the common methods for measuring some optics parameters of the storage ring, including the betatron tune, beta function, chromaticity, natural chromaticity and dispersion. The results and analysis of measurement for the optics parameters are given here, which are indispensable for the orbit correction of the accelerator and the nonlinear optimization.     

Minimizing radial emittance of a beam from a synchrotron radiation source

The feasibility of minimizing the radial emittance of a beam from a synchrotron radiation source (storage ring) is studied. It is shown that the emittance can be diminished by producing nonuniform fields in the magnetic storage ring.     

Measurement of optics for the SSRF storage ring in commissioning

The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report presents the common methods for measuring some optics parameters of the storage ring, including the betatron tune, beta function, chromaticity, natural chromaticity and dispersion. The results and analysis of measurement for the optics parameters are given here, which are indispensable for the orbit correction of the accelerator and the nonlinear optimization.     

低能区衍射限储存环同步辐射的应用浅析

在科学技术新需求的推动下,同步辐射光源持续往前发展。目前,同步辐射装置发展已历经三代,正处于第四代同步辐射光源蓬勃发展阶段。基于衍射极限储存环的同步辐射装置是第四代同步辐射光源的典型代表之一。第四代同步辐射光源主要发展趋势是进一步减小电子束流发射度,使光源具有极好的横向相干性,以及产生圆截面辐射的能力。如果束流发射度降至光学衍射极限“辐射波长/4π”,其亮度比第三代同步辐射光源高2个数量级。这种同步辐射光源在性能上发生的质的飞跃,将给同步辐射实验技术带来实质性的突破,从而给前沿科学技术研究和现代产业发展带来全新的机遇。从国际同步辐射发展趋势入手,首先介绍低能区衍射限储存环光源的特色和性能,然后介绍其带来的同步辐射实验技术的进步,并浅析低能区衍射限储存环光源在材料科学、能源科学、生命科学和环境科学上的应用,以及其带来的产业机遇。最后,总结和展望了低能区衍射限储存环光源带来的技术突破和潜在的应用前景。     

Conceptual design of Hefei Advanced Light Source (HALS) injection system

The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article.     

Conceptual design of Hefei Advanced Light Source(HALS)injection system

The Hefei Advanced Light Source(HALS)is a super low emittance storage ring and has a very short beam life time.In order to run the ring stablely,top-up injection will be necessary.The injection system will greatly affect the quality of beam.This article first gives a physics design of the injecting system.Then the injecting system is tracked under different errors.The responses of storage beam and injecting beam are given in the article.     

Commissioning experience with insertion devices at PETRA III

PETRA III is a new hard X-ray synchrotron radiation source, operating at 6 GeV with a beam current of up to 100 mA and extremely low horizontal emittance of 1 nm rad. Such low emittance is achieved by using two 100 m long damping wiggler sections which reduce the emittance by a factor of 4. Altogether the damping sections contain 20 wigglers of 4m length each. The emitted synchrotron radiation power produced by wigglers amounts to 420 kW at 100 mA beam current in total. In the new octant of PETRA III, there are 14 undulator beamlines, with a brilliance up to 10²¹ (s mrad² mm² 0.1% BW)⁻¹ which cover an energy range from 0.3 keV to more than 100 keV. The low emittance raises very high requirements to the field quality of the insertion devices. At first, it should not affect the positron beam trajectory. Secondly, the spectral properties of the radiation created, like the intensity of higher harmonics, should not be limited by the undulator field quality, but by the beam emittance effects in order to have some reserve for future machine upgrades or possible radiation demagnetization. This paper presents the current status of PETRA III insertion devices and describes intermediate commissioning results like impact of IDs on the positron beam orbit or photon beam and radiation problems.     

Effect of undulators on the stored electron beam of Indus-2

Indus-2 is an Indian synchrotron light source, operating at 2.5 Ge V and generating synchrotron radiation from its bending magnets. In order to provide more intense synchrotron radiation to the synchrotron users, there is a plan to install five insertion devices in the Indus-2 storage ring. In the first phase of installation of insertion devices, there is a proposal to install two out- vacuum pure permanent magnet linearly polarized undulators in long straight sections of the Indus-2 storage ring. The presence of the insertion devices in the ring has inevitable effects on beam parameters like betatron tune, betatron amplitude function, closed orbit, emittance, energy spread and dynamic aperture etc. In this paper, the effect of two undulators on the above mentioned parameters of the Indus-2stored electron beam at 2.5 Ge V is presented. Moreover a correction scheme for the restoration of the betatron tune and amplitude function is also presented.     

PETRA IV Workshop on Research with High-Energy X-rays at Ultra-Low Emittance Sources

Recent advances in storage ring technology pioneered by MAX IV (Sweden) allow synchrotron radiation sources to achieve significantly smaller emittances than those currently in operation. This new, multi-bend achromat technology can thus boost spectral brightness, enabling unprecedented experimental possibilities. The high-energy synchrotron radiation facilities ESRF (France), SPring-8 (Japan), and APS (USA) have settled upgrade plans to improve their storage ring emittance by up to two orders of magnitude at 6 GeV electron energy. PETRA III at DESY has the largest circumference with 2.3 km. As the emittance scales favorably with the storage ring size, an upgrade of PETRA III offers the unique potential to reach a diffraction limit up to X-ray energies of 10 keV. Operating at 6 GeV with an emittance of 10 pmrad, this PETRA IV facility would pave the way for new experimental opportunities, especially for those using high photon energies.     

Toward therapeutics for clostridium botulinum neurotoxins

Construction work on the new MAX IV synchrotron light facility in northeastern Lund, Sweden, began on May 18, 2011. The MAX IV accelerator system will consist of three parts: one 3 GeV injector linac (also used for the production of short X-ray pulses) and two storage rings operated at 1.5 GeV and 3 GeV, respectively. The two-ring concept will allow the production of synchrotron radiation from optimized undulators within a broad spectral region. The 3 GeV ring has an emittance between 0.2 and 0.4 nm rad, depending on the ID configuration, and the emittance of the 1.5 GeV ring is 5 nm rad.     

The Brazilian synchrotron light source

The Brazilian synchrotron light source, designed and constructed at LNLS, is composed of a 1.37 GeV electron storage ring and a 120 MeV LINAC for low‐energy injection. It has been commissioned and, in July 1997, reached the design electron beam energy, current and emittance. Seven beamlines (TGM, SGM, SXS, XAFS, XRD, SAXS, PCr) have been constructed in parallel with the electron accelerators. The LNLS synchrotron source was opened to users 1st July, 1997, and is now in operation. This revised version was published online in August 2006 with corrections to the Cover Date.     

用于太赫兹光源的准等时性储存环的设计

介绍了一种获得准等时性储存环的方案,即调节Lattice参数,在色散段引入负色散函数从而降低线性滑相因子,获得短束团。根据此方案设计了用于相干太赫兹光源的准等时性储存环,结果给出了线形光学函数曲线以及粒子的动力学孔径,表明了通过调节四极铁参数可以达到降低束团长度获得准等时性储存环的目的。还设计了用于准等时性储存环弯铁处的真空室的3维模型,并对其类腔体部分的本征模进行了计算,得到特性阻抗与品质因数的比值在10-3量级以下,表明类腔体部分对束流的影响很小。     

Low emittance lattice optimization using a multi-objective evolutionary algorithm

A low emittance lattice design and optimization procedure are systematically studied with a non-dominated sorting-based multi-objective evolutionary algorithm which not only globally searches the low emittance lattice, but also optimizes some beam quantities such as betatron tunes, momentum compaction factor and dispersion function simultaneously. In this paper the detailed algorithm and lattice design procedure are presented. The Hefei light source upgrade project storage ring lattice, with fixed magnet layout, is designed to illustrate this optimization procedure.     

New high-power source of directional electromagnetic radiation

A new source of electromagnetic radiation in a wide spectral range can be based on multiple contactless deflection of the beams of charged particles in a circular channel. The radiation with wavelengths ranging from submillimeter to radio ranges can be generated using nonrelativistic electrons. Directional radiation is obtained at relativistic energies. The IR, optical, and UV radiation can be generated. The X-ray and gamma-radiation can be obtained at relatively high energies. The new source is compared with the source of synchrotron radiation. The radiation intensity at energies of 1–2 GeV is relatively high, since strong currents are possible in the ring channel. The channeling and synchrotron emission are simultaneously obtained at relatively small (several tens of nanometers) internal diameters of the ring.     

KTP(001)晶体分光性能研究

根据同步辐射光源对软X射线分光晶体的性能要求,分析了软X射线能区常用分光晶体的性能优劣,指出对于晶格常数值大的分光晶体,KTP(KTiOPO₄)(011)是该能区比较理想的分光晶体. 同时提出了一种利用同步辐射光源测量晶体衍射效率的实验方法,指出光源的发散度与晶体的衍射效率密切相关. 测量了KTP(011)晶体的晶格常数,给出了KTP(011)晶体的实测衍射效率. 关键词： 同步辐射 KTP(011)晶体 衍射效率 光源发散度     

北京大学ERL装置交汇段的研究与设计

 在交汇段设计理论的基础上，针对北京大学ERL的具体情况，对交汇段的束流传输结构进行了优化设计，通过模拟得到了满足要求的一组设计参数；研究了空间电荷效应以及相干同步辐射对束流发射度、能散及包络的影响。结果表明：空间电荷效应对发射度影响不大，但对束流包络影响较明显；相干同步辐射引起的发射度增长及能散较小，且不影响束流包络。