The high power EUV source is one of key issues in the development of EUV lithography which is con... more The high power EUV source is one of key issues in the development of EUV lithography which is considered to be the most promising technology among the next generation lithography. However neither DPP nor LPP seems to meet the requirements of the commercial high-volume product. Insuciency of DPP and LPP motivate the investigation of other means to produce the EUV radiation required in lithography. ECR plasma seems to be one of the alternatives. In order to investigate the feasibility of ECR plasma as a EUV light source, the EUV power emitted by SECRAL was measured. A EUV power of 1.03W in 4 sr solid angle was obtained when 2000W 18GHz rf power was launched, and the corresponding CE was 0.5%. Considering that SECRAL is designed to produce very high charge state ions, this very preliminary result is inspiring. Room-temperature ECR plasma and Sn plasma are both in the planned schedule.
SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in ro... more SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in routine operation for Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex since May 2007. To further enhance the SECRAL performance in order to satisfy the increasing demand for intensive highly charged ion beams, 3-5 kW high power 24 GHz single frequency and 24 GHz +18 GHz double frequency with an aluminum plasma chamber were tested, and some exciting results were produced with quite a few new record highly charged ion beam intensities, such as (129)Xe(35+) of 64 eμA, (129)Xe(42+) of 3 eμA, (209)Bi(41+) of 50 eμA, (209)Bi(50+) of 4.3 eμA and (209)Bi(54+) of 0.2 eμA. In most cases SECRAL is operated at 18 GHz to deliver highly charged heavy ion beams for the HIRFL accelerator, only for those very high charge states and very heavy ion beams such as (209)Bi(36+) and (209)Bi(41+), SECRAL has been operated at 24 GHz. The total operation beam time provided by SECRAL up to July 2011 has exceeded 7720 hours. In this paper, the latest performance, development, and operation status of SECRAL ion source are presented. The latest results and reliable long-term operation for the HIRFL accelerator have demonstrated that SECRAL performance for production of highly charged heavy ion beams remains improving at higher RF power with optimized tuning.
Highly charged ECR ion source development plays an important role in the heavy ion accelerators a... more Highly charged ECR ion source development plays an important role in the heavy ion accelerators advancement at IMP, such as HIRFL upgrade, heavy ion treatment complex HIMM, future heavy ion facility HIAF, and so on. As requested by those projects, many high performance highly charged ECR ion sources with different technologies have been built, or under development. The representative ion sources are superconducting ECR ion sources SECRAL and recently built SECRAL-II, room temperature LECR4 ion source with an innovative evaporative cooling method, permanent magnet ECR ion sources of LAPECR series, and a 45 GHz 4th generation ECR ion source FECR. In this talk, a general review of highly charged ECR ion sources will be presented. The typical performances, operation status, as well as the future developments will be dis-cussed.
Experimental evidence of the property of transverse coupling of beam from Electron Cyclotron Reso... more Experimental evidence of the property of transverse coupling of beam from Electron Cyclotron Resonance (ECR) ion source is presented. It is especially of interest for an ECR ion source, where the cross section of extracted beam is not round along transport path due to the magnetic confinement configuration. When the ions are extracted and accelerated through the descending axial magnetic field at the extraction region, the horizontal and vertical phase space strongly coupled. In this study, the coupling configuration between the transverse phase spaces of the beam from ECR ion source is achieved by beam back-tracking simulation based on the measurements. The reasonability of this coupling configuration has been proven by a series of subsequent simulations.
Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world b... more Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world because they are capable of producing high current beams of highly charged ions. However, the design of the Q/A selector system for these devices is challenging, because it must have a sufficient ion resolution while controlling the beam emittance growth. Moreover, this system has to be matched for a wide range of ion beam species with different intensities. In this paper, research on the Q/A selector system at the SECRAL (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou) platform both in experiment and simulation is presented. Based on this study, a new Q/A selector system has been designed for SECRAL II. The features of the new design including beam simulations are also presented.
Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below ... more Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow band EUV power around 13.5 nm emitted by two highly charged ECR ion sources -- LECR2M and SECRAL -- was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2005
ABSTRACT Electron Cyclotron Resonance (ECR) ion sources have been under development in Institute ... more ABSTRACT Electron Cyclotron Resonance (ECR) ion sources have been under development in Institute of Modern physics (IMP) for more than 25 years. With these years’ study, we have done a lot in this field and developed many outstanding high performance ECR ion sources including the 10 GHz LECR1 (Lanzhou ECR ion source No.1), 14.5 GHz LECR2, the double-frequency heating ECR ion source-LECR3 and the latest being developed fully superconducting source-SECRAL (Superconducting ECR ion source with Advanced design at Lanzhou), which is supposed to be a higher performance source with an innovative magnet design. Apart from the solenoidal coils type ECR ion sources we have also constructed some all permanent ECR ion sources, such as the LAPECR1 (Lanzhou All Permanent ECR ion source No.1) and LAPECR2. These sources mentioned above work together to deliver intense multiple charge state ion beams for HIRFL (Heavy Ion Research Facility at Lanzhou) accelerators’ injection and atomic physics research. In this paper, we will have a brief review on the IMP ECR ion sources and the typical results of the gaseous element ion beams and also the metallic ion beams. The application of the ion beams on accelerators and atomic physics research will be briefly introduced.
Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain ke... more Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain key understanding in nuclear science and in particular regarding the properties of nuclei far from the valley of stability or the nuclear processes in the universe. In addition it will also allow experimenters to test fundamental symmetries. The production of rare isotopes with FRIB will be achieved, using a heavy ion driver linac that will accelerate a stable isotope beam to 200 Mev/u and deliver it on a fragmentation target. FRIB aims to reach a primary beam power of 400 kW for light to heavy elements up to uranium. To meet the intensity requirement, two high performance ECR ion sources operating at 28 GHz will be used to produce high intensity of medium to high charge states ion beams. Plans regarding initial beam production with the ECR ion sources and beam transport through the front end will be discussed.
To meet the increasing needs of modern heavy ion accelerators, ECR ion source must be developed t... more To meet the increasing needs of modern heavy ion accelerators, ECR ion source must be developed to deliver high intensity high brightness high charge state ion beams, in terms of accelerator output power and beam transmission efficiency. With the success in several laboratories on fully superconducting ECR ion source development, the performance of highly charged heavy ion beams have been greatly enhanced. For instance, U33+ intensity had been doubled in 2011 by VENUS source at LBNL. This paper will present the development work at IMP towards high performance ECR ion source. Recent high intensity bismuth results will be given, such as 710 eμA Bi30+ with SECRAL source. The first room temperature ECR ion source using evaporative cooling technique will also be reviewed. And the discussion of ECRIS beam extraction and the transmission beam line elements on ion beam quality will also be presented in this paper.
Institute of Modern Physics is developing a Nb3Sn superconducting magnet system for a 45-GHz elec... more Institute of Modern Physics is developing a Nb3Sn superconducting magnet system for a 45-GHz electron cyclotron resonance ion source. To achieve this complicated and challenging Nb3Sn magnet, a prototype with identical cross section but half the length of the magnet is proposed. A single sextupole coil prototype with 457 mm length has been fabricated and tested. This sextupole coil is 38 mm thick with an aperture of 200 mm. It was wound by using a 1.3-mm diameter Nb3Sn wire insulated with 0.11-mm-thick braided S-2 glass fiber. In order to test the coil in similar conditions than the magnet operation, a sextupole magnetic mirror structure is utilized. The bladder and key technology is employed to exert the required preload on the coil. This article describes the magnetic field design of the sextupole mirror structure, presents the fabrication of the sextupole coil, and reports the cryogenic test results.
The high power EUV source is one of key issues in the development of EUV lithography which is con... more The high power EUV source is one of key issues in the development of EUV lithography which is considered to be the most promising technology among the next generation lithography. However neither DPP nor LPP seems to meet the requirements of the commercial high-volume product. Insuciency of DPP and LPP motivate the investigation of other means to produce the EUV radiation required in lithography. ECR plasma seems to be one of the alternatives. In order to investigate the feasibility of ECR plasma as a EUV light source, the EUV power emitted by SECRAL was measured. A EUV power of 1.03W in 4 sr solid angle was obtained when 2000W 18GHz rf power was launched, and the corresponding CE was 0.5%. Considering that SECRAL is designed to produce very high charge state ions, this very preliminary result is inspiring. Room-temperature ECR plasma and Sn plasma are both in the planned schedule.
SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in ro... more SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in routine operation for Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex since May 2007. To further enhance the SECRAL performance in order to satisfy the increasing demand for intensive highly charged ion beams, 3-5 kW high power 24 GHz single frequency and 24 GHz +18 GHz double frequency with an aluminum plasma chamber were tested, and some exciting results were produced with quite a few new record highly charged ion beam intensities, such as (129)Xe(35+) of 64 eμA, (129)Xe(42+) of 3 eμA, (209)Bi(41+) of 50 eμA, (209)Bi(50+) of 4.3 eμA and (209)Bi(54+) of 0.2 eμA. In most cases SECRAL is operated at 18 GHz to deliver highly charged heavy ion beams for the HIRFL accelerator, only for those very high charge states and very heavy ion beams such as (209)Bi(36+) and (209)Bi(41+), SECRAL has been operated at 24 GHz. The total operation beam time provided by SECRAL up to July 2011 has exceeded 7720 hours. In this paper, the latest performance, development, and operation status of SECRAL ion source are presented. The latest results and reliable long-term operation for the HIRFL accelerator have demonstrated that SECRAL performance for production of highly charged heavy ion beams remains improving at higher RF power with optimized tuning.
Highly charged ECR ion source development plays an important role in the heavy ion accelerators a... more Highly charged ECR ion source development plays an important role in the heavy ion accelerators advancement at IMP, such as HIRFL upgrade, heavy ion treatment complex HIMM, future heavy ion facility HIAF, and so on. As requested by those projects, many high performance highly charged ECR ion sources with different technologies have been built, or under development. The representative ion sources are superconducting ECR ion sources SECRAL and recently built SECRAL-II, room temperature LECR4 ion source with an innovative evaporative cooling method, permanent magnet ECR ion sources of LAPECR series, and a 45 GHz 4th generation ECR ion source FECR. In this talk, a general review of highly charged ECR ion sources will be presented. The typical performances, operation status, as well as the future developments will be dis-cussed.
Experimental evidence of the property of transverse coupling of beam from Electron Cyclotron Reso... more Experimental evidence of the property of transverse coupling of beam from Electron Cyclotron Resonance (ECR) ion source is presented. It is especially of interest for an ECR ion source, where the cross section of extracted beam is not round along transport path due to the magnetic confinement configuration. When the ions are extracted and accelerated through the descending axial magnetic field at the extraction region, the horizontal and vertical phase space strongly coupled. In this study, the coupling configuration between the transverse phase spaces of the beam from ECR ion source is achieved by beam back-tracking simulation based on the measurements. The reasonability of this coupling configuration has been proven by a series of subsequent simulations.
Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world b... more Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world because they are capable of producing high current beams of highly charged ions. However, the design of the Q/A selector system for these devices is challenging, because it must have a sufficient ion resolution while controlling the beam emittance growth. Moreover, this system has to be matched for a wide range of ion beam species with different intensities. In this paper, research on the Q/A selector system at the SECRAL (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou) platform both in experiment and simulation is presented. Based on this study, a new Q/A selector system has been designed for SECRAL II. The features of the new design including beam simulations are also presented.
Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below ... more Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow band EUV power around 13.5 nm emitted by two highly charged ECR ion sources -- LECR2M and SECRAL -- was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2005
ABSTRACT Electron Cyclotron Resonance (ECR) ion sources have been under development in Institute ... more ABSTRACT Electron Cyclotron Resonance (ECR) ion sources have been under development in Institute of Modern physics (IMP) for more than 25 years. With these years’ study, we have done a lot in this field and developed many outstanding high performance ECR ion sources including the 10 GHz LECR1 (Lanzhou ECR ion source No.1), 14.5 GHz LECR2, the double-frequency heating ECR ion source-LECR3 and the latest being developed fully superconducting source-SECRAL (Superconducting ECR ion source with Advanced design at Lanzhou), which is supposed to be a higher performance source with an innovative magnet design. Apart from the solenoidal coils type ECR ion sources we have also constructed some all permanent ECR ion sources, such as the LAPECR1 (Lanzhou All Permanent ECR ion source No.1) and LAPECR2. These sources mentioned above work together to deliver intense multiple charge state ion beams for HIRFL (Heavy Ion Research Facility at Lanzhou) accelerators’ injection and atomic physics research. In this paper, we will have a brief review on the IMP ECR ion sources and the typical results of the gaseous element ion beams and also the metallic ion beams. The application of the ion beams on accelerators and atomic physics research will be briefly introduced.
Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain ke... more Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain key understanding in nuclear science and in particular regarding the properties of nuclei far from the valley of stability or the nuclear processes in the universe. In addition it will also allow experimenters to test fundamental symmetries. The production of rare isotopes with FRIB will be achieved, using a heavy ion driver linac that will accelerate a stable isotope beam to 200 Mev/u and deliver it on a fragmentation target. FRIB aims to reach a primary beam power of 400 kW for light to heavy elements up to uranium. To meet the intensity requirement, two high performance ECR ion sources operating at 28 GHz will be used to produce high intensity of medium to high charge states ion beams. Plans regarding initial beam production with the ECR ion sources and beam transport through the front end will be discussed.
To meet the increasing needs of modern heavy ion accelerators, ECR ion source must be developed t... more To meet the increasing needs of modern heavy ion accelerators, ECR ion source must be developed to deliver high intensity high brightness high charge state ion beams, in terms of accelerator output power and beam transmission efficiency. With the success in several laboratories on fully superconducting ECR ion source development, the performance of highly charged heavy ion beams have been greatly enhanced. For instance, U33+ intensity had been doubled in 2011 by VENUS source at LBNL. This paper will present the development work at IMP towards high performance ECR ion source. Recent high intensity bismuth results will be given, such as 710 eμA Bi30+ with SECRAL source. The first room temperature ECR ion source using evaporative cooling technique will also be reviewed. And the discussion of ECRIS beam extraction and the transmission beam line elements on ion beam quality will also be presented in this paper.
Institute of Modern Physics is developing a Nb3Sn superconducting magnet system for a 45-GHz elec... more Institute of Modern Physics is developing a Nb3Sn superconducting magnet system for a 45-GHz electron cyclotron resonance ion source. To achieve this complicated and challenging Nb3Sn magnet, a prototype with identical cross section but half the length of the magnet is proposed. A single sextupole coil prototype with 457 mm length has been fabricated and tested. This sextupole coil is 38 mm thick with an aperture of 200 mm. It was wound by using a 1.3-mm diameter Nb3Sn wire insulated with 0.11-mm-thick braided S-2 glass fiber. In order to test the coil in similar conditions than the magnet operation, a sextupole magnetic mirror structure is utilized. The bladder and key technology is employed to exert the required preload on the coil. This article describes the magnetic field design of the sextupole mirror structure, presents the fabrication of the sextupole coil, and reports the cryogenic test results.
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