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.     

BRIF and CARIF progress

China Institute of Atomic Energy (CIAE) is currently constructing Beijing rare ion beam facility (BRIF) and is proposing China advanced rare ion beam facility (CARIF). This paper is aiming at introducing the progress of BRIF project and the con ceptual design CARIF. The ISOL type facility BRIF under construction is composed of a 100 MeV 300 ?A proton cyclotron, an ISOL with mass resolution of 20000, and a super-conducting LINAC of 2 MeV/q, and will be commissioned in 2013. CARIF facility proposed is planned...     

Influence of radial magnetic field on emittance in the median plane at CYCIAE-100

A 75—100 MeV H- compact cyclotron CYCIAE-100 is being constructed at China Institute of Atomic Energy (CIAE). About 200 μA proton beam will be provided by CYCIAE-100. The imperfection of magnetic fields will remarkably affect the acceleration orbit and beam envelope in CYCIAE-100. The effects to the accelerating beam by the imperfection fields, especially the field components Br on the mid-plane will be analyzed in detail with tracking code COMA. Poles misalignment that causes magnetic imperfection will be described in the paper. According to the simulation results, the tolerance of the poles machining and assembly will be illustrated in this paper.     

BRIF and CARIF progress

China Institute of Atomic Energy (CIAE) is currently constructing Beijing rare ion beam facility (BRIF) and is proposing China advanced rare ion beam facility (CARIF). This paper is aiming at introducing the progress of BRIF project and the conceptual design CARIF. The ISOL type facility BRIF under construction is composed of a 100 MeV 300 μA proton cyclotron, an ISOL with mass resolution of 20000, and a super-conducting LINAC of 2 MeV/q, and will be commissioned in 2013. CARIF facility proposed is planned to use both ISOL and PF techniques. It is based on a China advanced research reactor CARR that was critical, with ISOL separation of fission fragment, post acceleration to 150 MeV/u, and fragmentation of neutron-rich fission fragment beam like ¹³²Sn. Such unique combination will allow CARIF to deliver beam intensity better than the best world facilities by more than one order of magnitude.     

利用强流ISOL束研究20Na的奇异衰变模式(英文)

北京放射性离子束装置（Beijing Radioactive Ion-beam Facility,BRIF）是基于在线同位素分离器技术的国家大科学平台。在BRIF装置上利用100 MeV的质子束轰击较厚的反应靶产生放射性核素;反应产物经离子源电离和在线分离,在线同位素分离段可引出100~300 keV的放射性核束,质量分辨率达20 000。在基金委科学仪器基础研究专项的支持下,建成了多用途的衰变实验终端,包括束流传输管道、通用靶室、带电粒子和γ探测器、集成电子学和数据获取系统等。利用100 MeV的质子束轰击MgO厚靶产生了流强高达1×105 pps的20Na放射性核束。通过高效率地同时测量β,γ和α,第一次直接观测到20Na非常稀有的β-γ-α衰变模式。Beijing Radioactive Ion-beam Facility(BRIF) has been commissioned as the national Radioactive Ion Beam(RIB) facility based on the Isotope Separator On Line(ISOL) technique since 2016. At BRIF, the radioactive nuclides are produced by the proton beam of 100 MeV bombarding a thick-target, the reaction products diffusing out of the target are ionized by an ion source and delivered to the online mass separator. In addition to the post-accelerated radioactive ion beams, BRIF can provide low-energy ISOL beams of 100 to 300 keV with a mass resolution of 20 000. A general-purpose decay station has been built including the ISOL beam transport line, a conventional reaction chamber, charge-particle and γ detectors with integrated electronics and data acquisition system. An intense 20Na ISOL beam up to 1×105 pps was produced by using the 100 MeV proton beam bombarding a MgO thick target. With high-efficiency measurements of β, γ and α simultaneously, very rare β-γ-α decay mode in 20Na has been directly observed for the first time in the present work.     

原子能院的核天体物理研究和串列升级工程进展(英文)

在北京串列实验室建立了次级束流实验装置 ,用于放射性核束物理和核天体物理研究 .先后开展了7Be(d ,n) 8B ,11C(d ,n) 12 N ,8Li(d ,p) 9Li和6 He(p ,n) 6 Li核天体物理重要反应的研究 .介绍了串列加速器升级工程的进展情况 .该工程在现有串列加速器的基础上 ,将建立 10 0MeV/ 2 0 0 μA的质子回旋加速器、在线同位素分离器和超导加速段 .在此装置上 ,将可以产生质量数最高为 12 0 ,强度最高为 10 9particles/s的放射性束流 . A secondary beam line (GIRAFFE) at the Beijing Tandem accelerator lab was constructed for yielding low energy secondary beams. The current progress on the study of nuclear astrophysics and nuclear structure is presented. Up to now, We have carried out measurement of~(7)Be(d, n)~( 8)B,~(11)C(d, n)~(12)N,~(8)Li(d, p)~(9)Li, and~(6)He(p, n)~(6)Li reactions. The proposed Beijing radioactive nuclear beam facility (BRIF ) and its current R&D progress are briefly introduced. This facility is based on...     

Study of energy deposition and stripper temperature for CYCIAE-100

Nowadays high intensity proton accelerators are extensively applied, and this paper gives particular emphasis on CYCIAE-100, a 100 MeV high intensity compact cyclotron being constructed at CIAE. For accelerators of this type, the study is focused on how to improve the beam intensity. As for CYCIAE-100, the charge-exchange extraction is used to get protons. So it is crucial to enhance the lifetime of the stripping foil, which is largely determined by the energy deposition on it. For this cyclotron, due to the influence of the magnetic field, the electrons will spin near the foil and lose energy each time when they cross the foil. The energy deposition refers to all the energy deposition of protons and electrons. This paper stresses the stripper study of CYCIAE-100, in which the particle distribution on the foil is simulated and the energy deposition of the protons and electrons stripped from the H- ions are calculated. The temperature distributions are then calculated as a main reference for the foil design.     

Stripping extraction calculation and simulation for CYCIAE-100

A 100 MeV H- compact cyclotron is under construction at China Institute of Atomic Energy (CYCIAE-100). The proton beams of 75 MeV-100 MeV at an intensity of 200 μA will be extracted in dual opposite directions by charge exchange stripping devices. The crossing point at the switching magnet center is fixed inside the magnet yoke and the stripping points for various extraction energies are calculated by the code CYCTRS. With the code GOBLIN, we can calculate the transfer matrix including the dispersion effects from the stripping point to the switch magnet. The beam distribution just after stripping foil can be obtained from the multi-particle tracking code COMA and the extracted beam parameters after the switch magnet such as emittance, envelope, dispersion, energy spread, bunch length, etc. are given by the extraction orbit simulations.     

Study of energy deposition and stripper temperature for CYCIAE-100

Nowadays high intensity proton accelerators are extensively applied, and this paper gives particular emphasis on CYCIAE-100, a 100~MeV high intensity compact cyclotron being constructed at CIAE. For accelerators of this type, the study is focused on how to improve the beam intensity. As for CYCIAE-100, the charge-exchange extraction is used to get protons. So it is crucial to enhance the lifetime of the stripping foil, which is largely determined by the energy deposition on it. For this cyclotron, due to the influence of the magnetic field, the electrons will spin near the foil and lose energy each time when they cross the foil. The energy deposition refers to all the energy deposition of protons and electrons. This paper stresses the stripper study of CYCIAE-100, in which the particle distribution on the foil is simulated and the energy deposition of the protons and electrons stripped from the H^－ ions are calculated. The temperature distributions are then calculated as a main reference for the foil design.     

The radioactive ion beam project at VECC, Kolkata-A status report

A project to build an ISOL-post accelerator type of radioactive ion beam (RIB) facility has been undertaken at VECC, Kolkata. The funding for the first phase of the project was approved in August 1997. This phase will be the R&D phase and will be completed by December 2003. The present status of development of the various sub-systems of the RIB facility will be discussed.     

BRISOL铝同位素放射性核束的产生

北京放射性核束装置在线同位素分离器(BRISOL)采用100 MeV回旋加速器提供的最大200μA的质子束打靶在线产生放射性核束。在BRISOL上已经使用氧化钙靶、氧化镁靶产生了Na⁺、K⁺等放射性核束。为了产生铝同位素放射性核束,研发了碳化硅靶材,开展了碳化硅靶产生铝放射性核束的实验研究。在BRISOL装置上首次产生了铝同位素放射性核束,其中^26gAl⁺的束流强度为8.7×10⁷ pps,²³Al⁺的束流强度为2.2×10² pps,同时将BRISOL靶能承受的质子束流强提升至15。     

100 MeV强流质子回旋加速器束流调试靶系统

中国原子能科学研究院正在建造一台100 MeV,200 A的强流质子回旋加速器,需要使用束流调试靶来调试加速器,为此设计了一套束流功率为20 kW的质子束调试系统。对该系统的束流输运线、靶材料的选取、靶结构、水冷计算、屏蔽结构等作了介绍。给出了整条束流输运线的匹配计算结果;通过对质子打靶后的中子产额、角通量、靶的活化等方面的比较,最终选用铝作为靶材料;根据加速器引出束流能量和功率,设计了分层式靶结构,同时对靶进行了水冷计算;打靶产生的出射粒子平均能量较高,导致产生的辐射剂量很大,考虑到对环境与工作人员的影响及费用,需要对其进行局部屏蔽,给出了屏蔽计算结果及屏蔽结构的设计。     

ISAC-I and ISAC-II: Present status and future perspectives

The ISAC facility at TRIUMF utilizes up to 100 μA from the 500 MeV H^- cyclotron to produce the RIB using the Isotopic Separation On Line (ISOL) method. The ISAC-I facility comprised the RNB production target stations, the mass separator and the beam delivery to low energy area and to a room temperature linear accelerator composed of a 4-rod RFQ and an inter-digital H type structure Drift Tube LINAC. ISAC-I linear accelerator can provide beam from A = 3 to 30 amu with an energy range from 0.15 to 1.5 A MeV. Since the beginning of operations target development program has been to increase proton beam currents on targets. Now we routinely operate our target at 50 to 85 μA and recently we have operated our target at 100 μA. Other developments are in place to add other ion sources, laser, FEBIAD and ECRIS to the actual surface ion source. The last two five year plans were mainly devoted to the construction of a heavy ion superconducting LINAC (ISAC-II), that will upgrade the mass and the energy range from 30 to 150 and 1.5 to 6.5 A MeV, respectively. We are now commissioning the medium β section and first experiment is scheduled for the fall 2006.     

100MeV强流质子回旋加速器高频腔公差研究

针对中国原子能科学研究院正在设计的100MeV强流质子回旋加速器, 研究并提出高频腔公差. 高频腔的误差包括加工安装的误差和重力引起的D板变形. 加工安装误差的存在干扰束团的径向和轴向运动, 用理论分析和数值模拟相结合的方法给出加工安装的公差; D板的重力变形引起加速间隙的轴向错位从而使束团产生轴向的相干振荡, 计算结果表明目前结构的D板变形在允许范围内.     

用于放射性核束设施驱动加速器的100MeV强流质子回旋加速器

中国原子能科学研究院得到批准建设HI-13串列加速器升级工程, 目前完成了该工程的初步设计.文章报告主工艺设备——100MeV强流质子回旋加速器的设计方案、设计特点, 总体设计结果及主要技术指标、关键设备(离子源、轴向注入线、中心区、主磁铁、高频系统、引出系统、诊断系统等)的简要设计结果等.     

Radioactive ion beam post-acceleration at ISAC

ISAC at TRIUMF is a world-class facility for the production and post-acceleration of radioactive ion beams (RIB). Commissioned in 2002 the ISAC I linear accelerator serves three different beam lines delivering both stable and radioactive species. Two of them are permanent experiments (DRAGON and TUDA); the third one is a general purpose station (GPS). The maximum energy we can reach in ISAC I is 1.8 MeV/u. ISAC II is a phased upgrade of the ISAC facility. The beam coming from ISAC I is injected at 1.5 MeV/u into a new superconducting LINAC. In `Phase I' the LINAC adds 20 MV to the beam energy and 20 MV more will be added in `Phase II'. The paper will give an overview of both the ISAC I and ISAC II accelerators. Operational experience with accelerating RIBs in ISAC I is summarized. First ISAC II commissioning results are presented.     

The design and construction of a pulsed beam generation system based on high intensity cyclotron

In order to perform the studies on a pulsed beam generation system based on a high intensity cyclotron, a test beam line with a pulsed beam generation for a 10 MeV compact cyclotron (CYCIAE-10) has been designed and constructed at China Institute of Atomic Energy (CIAE). A 70 MHz continuous H-beam can be pulsed to the pulse length of less than 10 ns with a repetition rate of 4.4 MHz. The sine waveform with a frequency of 2.2 MHz is adopted for the chopper and a mesh structure with single drift and dual gaps is used for the 70 MHz buncher. A helical resonator is designed and constructed based on simulations and experiments on the RF matching for the chopper. A helical inductance loop that is exceptionally large of its kind and equipped with water cooling for the resonator has been successfully wound and a 500 W solid RF amplifier has been manufactured. A special measuring device has been designed, which can be used to measure both the DC beam and the pulsed beam. The required pulsed beam was obtained after pulsed beam tuning.     

DC-SC光阴极注入器的束载实验的调试进展

 北京大学射频超导实验室设计了新型超导光电子枪——DC-SC光阴极注入器，目标是为自由电子激光平台提供能量在2~3MeV，脉宽小于10ps，脉冲重复频率为81.25MHz，平均流强约为1mA的低发射度电子束。现在已经建成了DC-SC光阴极注入器实验平台，包括激光驱动光阴极系统，Pierce直流高压加速结构，1.3GHz 1＋1/2纯铌超导腔，恒温器低温系统，4.5kW连续波微波系统，1/16分频与同步控制系统，束流诊断系统和能量分析系统等。并且完成了超导腔的静态实验，直流加速结构也经过了100μA低电流测试。实验结果符合设计要求，整体调试后即可以进行束载实验。     

Study on CYCIAE-100 radiation field and residual radioactivity

The accelerators should be properly designed to make the radiation field produced by beam loss satisfy the dose limits. The radiation field for high intensity H- cyclotron includes prompt radiation and residual radiation field. The induced radioactivity in accelerator components is the dominant source of occupational radiation exposure if the accelerator is well shielded. The source of radiation is the beam loss when cyclotron is operating. In this paper, the radiation field for CYCIAE-100 is calculated using Monte Carlo method and the radioactive contamination near stripping foil is studied. A method to reduce the dose equivalent rate of maintenance staff is also given.     

The design and construction of a pulsed beam generation system based on high intensity cyclotron

In order to perform the studies on a pulsed beam generation system based on a high intensity cyclotron, a test beam line with a pulsed beam generation for a 10 MeV compact cyclotron (CYCIAE-10) has been designed and constructed at China Institute of Atomic Energy (CIAE). A 70 MHz continuous H-beam can be pulsed to the pulse length of less than 10 ns with a repetition rate of 4.4 MHz. The sine waveform with a frequency of 2.2 MHz is adopted for the chopper and a mesh structure with single drift and dual gaps is used for the 70 MHz buncher. A helical resonator is designed and constructed based on simulations and experiments on the RF matching for the chopper. A helical inductance loop that is exceptionally large of its kind and equipped with water cooling for the resonator has been successfully wound and a 500 W solid RF amplifier has been manufactured. A special measuring device has been designed, which can be used to measure both the DC beam and the pulsed beam. The required pulsed beam was obtained after pulsed beam tuning.