Operation and Experiments on LECR3

LECR3 (Lanzhou Electron Cyclotron Resonance ion source No.3) which aims to produce intense highly charged ion beams for atomic physics research, was designed and constructed based on LECR2 (Lanzhou Electron Cyclotron Resonance ion source No.2) with high B mode. In year 2003, according to the arrangements of atomic physics research experiments and the ECR ion source research activities, ion beams of 14 elements were produced on LECR3. The elements include ^16O, ^40At, ^129Xe, ^63Cu, ^65Zn, ^56Fe, ^58Ni, ^26Mg, ^208Pb, ^35C1, ^37C1, ^28Si, ^84Kr and ^181Ta. Many of them were tested for the first time on LECR3 ion source.     

Emittance Measurements for Beams Extracted from LECR3 Ion Source

High quality ion beams are required by IMP cyclotron and atomic physics research, so it is important to research and measure beam emitt ance of ECR ion source. Intense beams extracted from ECR ion source usually have low energy, so it is suitable to use Electric-Sweep Scanner to measure the emittance. This kind of measurement is popularly used at ECR ion source, and it has some prominent merits such as high accuracy, very short time of data processing and easy expressing of the emittance pattern. So we designed and built this emittance scanner to measure emittance of the ion beams produced by LECR3 ion source. The structure of the ESS is shown in Fig.l, and the photo of the ESS is shown in Fig.2.     

NSCL溅射金属离子产生研究进展(摘要)

Production of metallic ion beams in support of the experimental program at the Coupled Cyclotron Facility at the NSCL required the development of ion sputtering feed of metallic molybdenum,nickel,uranium, and zirconium for use with the ARTEMIS ion source.The production of high intensity lower to medium charge state ions required high material consumption,posing some significant difficulties in reliable long term beam stability.Resultant and ongoing hardware and technique developments to resolve these difficulties will be presented in this poster along with interesting effects of the ion source solenoid field polarity on the sputtering process.     

VENUS离子源的最新结果(28GHz)

The nest generation, superconducting ECR ion source VENUS (Versatile ECR ion source for Nuclear Science) has operated with 28GHz since 2004,and has produced world record ion beam intesities. The VENUS project is focused on two main objectives. First, for the 88-Inch Cyclotron,VENUS will serve as the third injector soures boosting both the energy and itensity of beams available form the facility.Seconly,VENUS also serves as the prototype injector source for a high intensity heavy ion beam driver linac for a next generation radioactive ion beam facility, where the goal is to produce intense beams of medium to low charge states ions such as 240eμA of Xe 20 or 250eμA of U28 to 34 . These high intensity ion beam requerements present a challenge for the beam transport system since the total currents extracte from the ECR ion source reach several mA. Therefore in parallel to io beam develoments,we are also enhancing our ion beam diagnostics devices and are conducting an extensive ion beam simulation effort to improve the understanding of the ion beam ransprot form the VENUS ECR ion source. The paper will give an overview of recent experiments with the VENUS ECR ion source. Since the last ECR ion source workshop in Berkeley in 2004.we have installed a new plasma chamber,which includes X-ray shielding.This enables us to operate the source reliably at high power 28GHz operation.With this new chamber several high intensity beams(such as 2.4mA ofO6 ,600eμA of Ar9 ,etc.) have been produced. In addition, we have started the developent of high intensity uranium beams. For example, 200eμA of U33 and U34 have been produced so far. In respect to high charge state ions,leμA of Ar18 ,133eμA of Ar16 ,and 4.9eμA of U47 have been measured. In addition,ion beam profile meaurements are presented with ,and without the sextupole magnetic field energized. These expeerimental results are being compared with simulations using the WARP code.     

SECRAL在18GHz频率下产生强流高电荷态离子束的初步结果

A Superconducting ECR ion source with Advanced design in Lanzhou (SECRAL) was successfully built to produce intense beams of highly charged ions for Heavy Ion Research Facility in Lanzhou (HIRFL).The ion source has been optimized to be operated at 28GHz for its maximum performance.The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping.For 28GHz operation,the magnet assembly can produce peak mirror fields on axis 3.6T at injection,2.2T at extraction and a radial sextupole field of 2.0T at plasma chamber wall.A unique feature of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. During the ongoing commissioning phase at 18GHz with a stainless steel chamber,tests with various gases and some metals have been conducted with microwave power less than 3.2kW and it turned out the performance is very promising.Some record ion beam intensities have been produced,for instance,810eμA of O~(7 ),505eμA of Xe~(20 ),306eμA of Xe~(27 ),21eμA of Xe~(34 ),2.4eμA of Xe~(38 ) and so on.To reach better results for highly charged ion beams,further modifications such as an aluminium chamber with better cooling,higher microwave power and a movable extraction system will be done,and also emittance measurements are being prepared.     

Multiple charge ion beam generation with a 2.45 GHz electron cyclotron resonance ion source

<正>Multiple charge ions (MCIs) are necessary for increasing the output energy of particles in accelerators. In general, MCI beams are largely produced by electron beam ion source (EBIS) [1], laser ion source (LIS) [2], or high-frequency (mostly 5 GHz) electron cyclotron resonance (ECR) ion source [3]. Among these, only ECR ion source can operate in the continuous wave (CW) mode, while EBIS and LIS only support pulses. In addition, ECR ion source with lower frequency (mostly 2.45 GHz) are required primarily for generating single charge state ions, because the corresponding ECR field (875 Gs) is not sufficiently strong for MCI generation [4].     

LAPECR2离子源在320kV高压平台上的试运行

The high charge state all permanent Electron Cyclotron Resonance Ion Source(ECRIS)LAPECR2 (Lanzhou All Permanent magnet ECR ion source No.2)has been successfully put on the 320kV HV platform at IMP and also has been connected with the successive LEBT system.This source is the largest and heaviest all permanent magnet ECRIS in the world.The maximum mirror field is 1.28T(without iron plug)and the effective plasma chamber volume is as large as (?)67mm×255mm.It was designed to be operated at 14.5GHz and aimed to produce medium charge state and high charge state gaseous and also metallic ion beams.The source has already successfully delivered some intense gaseous ion beams to successive experimental terminals.This paper will give a brief overview of the basic features of this permanent magnet ECRIS.Then commissioning results of this source on the platform,the design of the extraction system together with the successive LEBT system will be presented.     

Operation of LECR2 for HIRFL Facility

LECI:L2 (Lanzhou Electron Cyclotron l:tesonance No.2) is a 14.5 GHz ECR ion source (ECRIS) used at the axial injection beam line as an external ion source of the injector SFC. In 2003, to be adapted with the SFC reconstruction and modification, the source was moved from the north side of the beam line to the east side, and the other source LECR1 worked at 10 GHz was removed from the beam line. At the moment LECR2 is the only ion source in service for HIRFL accelerators.     

HIRFL Operation and Upgrade

After almost one year shutdown for upgrading the vacuum chamber of the iniector SFC,SFC has been in operation separately since May 2003. The SFC operation statistics and accelerated heams from May to December 2003 are shown in Table 1 and 2. The main cyclotron SSC has beenfor still shut down in 2003 for upgrading the SSC power supply system, control and diagnostic system, and themain experimental area, LECR3, an ECR ion source dedicated for atomic physics and surface physics research, has provided 2488 hours beams for experiments of atomic physics research.     

CEA/Saclay的ECR轻离子离子源

In the beginning of the 90s,T.Taylor and his collaborators demonstrated ECR sources operating at low frequency(i.e.2.45GHz)are able to produce very intense single charge light ion beams. At CEA/Saclay,the SILHI source developments started in 1995.Since 1997 more than 100mA proton or deuteron beams are routinely produced in pulsed or continuous mode.To comply with ADS reliability constraint,important improvements have been performed to increase the installation reliability.Moreover,to optimize the beam transport in the low energy beam line,the extraction system was carefully designed and space charge compensation studies were undertaken.An important step has been reached in 2005 with the development of a permanent magnet source able to produce a total beam of 109mA at 85kV. A new test bench named BETSI,especially dedicated to permanent magnet source developments,is presently under construction.It will allow analysing positive or negative extracted beams up to 50keV and 100mA. In addition,for several years work has been done to optimize the production of negative hydrogen ion beam with such an ECR source.Recent analysis pushed towards the construction of a new set up based on a multicusp magnetic configuration. After a brief overview of the CEA/Saclay source developments,this article will point out on the recent results and present status.     

高电荷态ECR离子源——LECR3

研制成功了一台新的高电荷态ECR离子源,该离子源主要为原子物理实验提供各种高电荷态离子束流,是基于中国科学院近代物理研究所14.5GHz高电荷态ECR离子源设计建成的,同时在该离子源中应用多种有利于提高束流强度的技术,设计时考虑到采用双频加热,试图通过试验双频加热模式来提高高电荷态离子的产额,并设计建造了一套束流聚焦分析系统,以提高电荷态分辨率和束流传输效率.     

LECR2离子源的改造及初步运行结果

The Latest developed LECR2M (Lanzhou ECR No.2 Modified)source is the updated one of LECR2(Lanzhou ECR No.2)source at IMP.It has been assembled on the low energy ion beam experimental platform to produce MCI beams for atomic physics and material pllysics experimental research.In our updating program,the structure of injection and extraction components has been modified to make the source structure more simple and effective.The hexapole magnet has also been replaced by a new hexapole magnet with higher radial field and larger inner diameter.With this updating,stronger magnetic field confinement of the ECR plasma is possible and better base vacuum condition is also achieved.LECR2M was designed to be operated at 14.5GHz.During the preliminary test.1.3emA O6 beam was extracted with the injected rf power of 1.1kW.The source has been used to deliver intense MCI beams for different experiments.After some discussion of the main features of this newly updated source,some of the typical commissioning test results of LECR2M will be presented.     

兰州全永磁ECR离子源——LAPECR1

The Lanzhou All Permanent magnet ECR ion source NO.1(LAPECR1)is the first all permanent magnet multiple ECRIS made in IMP.This ECRIS is running at 14.5GHz and can provide intense low charge state ion beams(varying from several to hundreds of eμA)or medium charge state ion beams(varying from several to tens of eμA).The size of source body is (?)102mm×296mm,the compactness and economical features enable the source suitable to be put on a HV platform or equipped by a small laboratory.This article gives the main parameters of the ion source.     

高电荷态金属离子的产生实验研究

 为满足兰州重离子加速器的实验要求，在14.5GHz高电荷态ECR离子源上做了一系列产生金属离子的实验，尝试了多种方法，包括炉子加热及MIVOC（Metallic Ion form Volatile Compounds）两种方法，其中，用炉子做的结果较理想。实验主要研究了铜、锌、镍多种电荷态离子的产生，具有代表性的是39euA的¹³⁺，30euA的Zn¹³⁺和29euA的Ni¹⁰⁺。分别给出了这三种金属离子产生的多电荷态束流峰谱图，以及实验的一些其它现象及结果，并对其进行了讨论与总结。     

Afterglow工作模式下ECR离子源脉冲束的产生

为满足国家大科学工程兰州重离子冷却储存环的要求,在14.5GHz ECR 离子源上进行afterglow工作模式的实验,首次产生了高电荷态脉冲束流Ar¹¹⁺和Ar¹²⁺,给出了初步实验结果,并对结果进行了分析和解释.     

GANIL有机金属离子束流的现状报告

Previous experiments with organo-metallic compounds like ferrocene,nickelocene and magnesocene showed that a pure spectrum must be obtained on the residual gas mass analyser before running successfully on the ion source.In collaboration with the chemistry department of the University of Caen,LCMT-ENSI Caen,the synthesis of these metallocene compounds has been studied to provide enriched isotopic compounds to GANIL’s users.The chemical transformation yields were 90%,80% and 43%,respectively.Vanadocene, chromocene,colbatocene and ruthenocene compounds have first been studied with a gas mass analyser and then successfully tested on the ECR 4M ion source at GANIL.Some 15eμA of ~(51)V~(11 ),20eμA of ~(52)Cr~(11 ), 22eμA of 59Co~(11 ),and 17eμA of ~(102)Ru~(11 ) were achieved.The comparison between the results obtained on the gas mass analyser and the ion beams provided by the source has allowed us to validate this method of determining whether or not an organo-metallic compound could be a candidate for running on our ECR ion source.As the ECR ion sources are tuned and used alternately on the GANIL injectors,the available time for the tests is rare,so this method could be an alternative for the validation of new compounds.     

ECR离子源束流发射度的实验研究

利用最新自行研制的电扫描发射度探测系统, 在ECR离子源上进行了一系列关于ECR离子源引出束流发射度的研究. 这套电扫描发射度探测系统安装在中国科学院近代物理研究所(兰州)的LECR3试验平台的束运线上. 试验中, 通过测量相关参数, 研究了磁场、微波、掺气效应及负偏压效应等对引出束流发射度的影响. 利用实验所得的结果与关于ECR等离子体和离子源束流发射度的半经验理论, 分析推导了离子源各可调参数与ECR等离子体的直接关系, 这为分析探索ECR离子源的工作机制提供了一定的参考依据.