DUHOCAMIS: a dual hollow cathode ion source for metal ion beams.

PubMed

Zhao, W J; Müller, M W O; Janik, J; Liu, K X; Ren, X T

2008-02-01

In this paper we describe a novel ion source named DUHOCAMIS for multiply charged metal ion beams. This ion source is derived from the hot cathode Penning ion gauge ion source (JINR, Dubna, 1957). A notable characteristic is the modified Penning geometry in the form of a hollow sputter electrode, coaxially positioned in a compact bottle-magnetic field along the central magnetic line of force. The interaction of the discharge geometry with the inhomogeneous but symmetrical magnetic field enables this device to be operated as hollow cathode discharge and Penning discharge as well. The main features of the ion source are the very high metal ion efficiency (up to 25%), good operational reproducibility, flexible and efficient operations for low charged as well as highly charged ions, compact setup, and easy maintenance. For light ions, e.g., up to titanium, well-collimated beams in the range of several tens of milliamperes of pulsed ion current (1 ms, 10/s) have been reliably performed in long time runs.

Simulation of charge breeding of rubidium using Monte Carlo charge breeding code and generalized ECRIS model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, L.; Cluggish, B.; Kim, J. S.

2010-02-15

A Monte Carlo charge breeding code (MCBC) is being developed by FAR-TECH, Inc. to model the capture and charge breeding of 1+ ion beam in an electron cyclotron resonance ion source (ECRIS) device. The ECRIS plasma is simulated using the generalized ECRIS model which has two choices of boundary settings, free boundary condition and Bohm condition. The charge state distribution of the extracted beam ions is calculated by solving the steady state ion continuity equations where the profiles of the captured ions are used as source terms. MCBC simulations of the charge breeding of Rb+ showed good agreement with recentmore » charge breeding experiments at Argonne National Laboratory (ANL). MCBC correctly predicted the peak of highly charged ion state outputs under free boundary condition and similar charge state distribution width but a lower peak charge state under the Bohm condition. The comparisons between the simulation results and ANL experimental measurements are presented and discussed.« less

Characterization of an atomic hydrogen source for charge exchange experiments

DOE PAGES

Leutenegger, M. A.; Beiersdorfer, P.; Betancourt-Martinez, G. L.; ...

2016-07-02

Here, we characterized the dissociation fraction of a thermal dissociation atomic hydrogen source by injecting the mixed atomic and molecular output of the source into an electron beam ion trap containing highly charged ions and recording the x-ray spectrum generated by charge exchange using a high-resolution x-ray calorimeter spectrometer. We exploit the fact that the charge exchange state-selective capture cross sections are very different for atomic and molecular hydrogen incident on the same ions, enabling a clear spectroscopic diagnostic of the neutral species.

Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

PubMed

Zhao, H W; Sun, L T; Zhang, X Z; Guo, X H; Cao, Y; Lu, W; Zhang, Z M; Yuan, P; Song, M T; Zhao, H Y; Jin, T; Shang, Y; Zhan, W L; Wei, B W; Xie, D Z

2008-02-01

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz 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. An innovative design 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. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL (invited)a)

NASA Astrophysics Data System (ADS)

Zhao, H. W.; Sun, L. T.; Zhang, X. Z.; Guo, X. H.; Cao, Y.; Lu, W.; Zhang, Z. M.; Yuan, P.; Song, M. T.; Zhao, H. Y.; Jin, T.; Shang, Y.; Zhan, W. L.; Wei, B. W.; Xie, D. Z.

2008-02-01

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion 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. An innovative design 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. For 28GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6T at injection, 2.2T at extraction, and a radial sextupole field of 2.0T at plasma chamber wall. During the commissioning phase at 18GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5kW by two 18GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810eμA of O7+, 505eμA of Xe20+, 306eμA of Xe27+, and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

Development of electron beam ion source for nanoprocess using highly charged ions

NASA Astrophysics Data System (ADS)

Sakurai, Makoto; Nakajima, Fumiharu; Fukumoto, Takunori; Nakamura, Nobuyuki; Ohtani, Shunsuke; Mashiko, Shinro; Sakaue, Hiroyuki

2005-07-01

Highly charged ion is useful to produce nanostructure on various materials, and is key tool to realize single ion implantation technique. On such demands for the application to nanotechnology, we have designed an electron bean ion source. The design stresses on the volume of drift tubes where highly charged ions are confined and the efficiency of ion extraction from the drift tube through collector electrode in order to obtain intense ion beam as much as possible. The ion source uses a discrete superconducting magnet cooled by a closed-cycle refrigerator in order to reduce the running costs and to simplify the operating procedures. The electrodes of electron gun, drift tubes, and collector are enclosed in ultrahigh vacuum tube that is inserted into the bore of the magnet system.

Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

NASA Astrophysics Data System (ADS)

Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.

2017-09-01

The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

Steady-State Ion Beam Modeling with MICHELLE

NASA Astrophysics Data System (ADS)

Petillo, John

2003-10-01

There is a need to efficiently model ion beam physics for ion implantation, chemical vapor deposition, and ion thrusters. Common to all is the need for three-dimensional (3D) simulation of volumetric ion sources, ion acceleration, and optics, with the ability to model charge exchange of the ion beam with a background neutral gas. The two pieces of physics stand out as significant are the modeling of the volumetric source and charge exchange. In the MICHELLE code, the method for modeling the plasma sheath in ion sources assumes that the electron distribution function is a Maxwellian function of electrostatic potential over electron temperature. Charge exchange is the process by which a neutral background gas with a "fast" charged particle streaming through exchanges its electron with the charged particle. An efficient method for capturing this is essential, and the model presented is based on semi-empirical collision cross section functions. This appears to be the first steady-state 3D algorithm of its type to contain multiple generations of charge exchange, work with multiple species and multiple charge state beam/source particles simultaneously, take into account the self-consistent space charge effects, and track the subsequent fast neutral particles. The solution used by MICHELLE is to combine finite element analysis with particle-in-cell (PIC) methods. The basic physics model is based on the equilibrium steady-state application of the electrostatic particle-in-cell (PIC) approximation employing a conformal computational mesh. The foundation stems from the same basic model introduced in codes such as EGUN. Here, Poisson's equation is used to self-consistently include the effects of space charge on the fields, and the relativistic Lorentz equation is used to integrate the particle trajectories through those fields. The presentation will consider the complexity of modeling ion thrusters.

An electron beam ion trap and source for re-acceleration of rare-isotope ion beams at TRIUMF

NASA Astrophysics Data System (ADS)

Blessenohl, M. A.; Dobrodey, S.; Warnecke, C.; Rosner, M. K.; Graham, L.; Paul, S.; Baumann, T. M.; Hockenbery, Z.; Hubele, R.; Pfeifer, T.; Ames, F.; Dilling, J.; Crespo López-Urrutia, J. R.

2018-05-01

Electron beam driven ionization can produce highly charged ions (HCIs) in a few well-defined charge states. Ideal conditions for this are maximally focused electron beams and an extremely clean vacuum environment. A cryogenic electron beam ion trap fulfills these prerequisites and delivers very pure HCI beams. The Canadian rare isotope facility with electron beam ion source-electron beam ion sources developed at the Max-Planck-Institut für Kernphysik (MPIK) reaches already for a 5 keV electron beam and a current of 1 A with a density in excess of 5000 A/cm2 by means of a 6 T axial magnetic field. Within the trap, the beam quickly generates a dense HCI population, tightly confined by a space-charge potential of the order of 1 keV times the ionic charge state. Emitting HCI bunches of ≈107 ions at up to 100 Hz repetition rate, the device will charge-breed rare-isotope beams with the mass-over-charge ratio required for re-acceleration at the Advanced Rare IsotopE Laboratory (ARIEL) facility at TRIUMF. We present here its design and results from commissioning runs at MPIK, including X-ray diagnostics of the electron beam and charge-breeding process, as well as ion injection and HCI-extraction measurements.

Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

PubMed

Kondo, K; Kanesue, T; Tamura, J; Okamura, M

2010-02-01

Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

Computer Modeling of High-Intensity Cs-Sputter Ion Sources

NASA Astrophysics Data System (ADS)

Brown, T. A.; Roberts, M. L.; Southon, J. R.

The grid-point mesh program NEDLab has been used to computer model the interior of the high-intensity Cs-sputter source used in routine operations at the Center for Accelerator Mass Spectrometry (CAMS), with the goal of improving negative ion output. NEDLab has several features that are important to realistic modeling of such sources. First, space-charge effects are incorporated in the calculations through an automated ion-trajectories/Poissonelectric-fields successive-iteration process. Second, space charge distributions can be averaged over successive iterations to suppress model instabilities. Third, space charge constraints on ion emission from surfaces can be incorporate under Child's Law based algorithms. Fourth, the energy of ions emitted from a surface can be randomly chosen from within a thermal energy distribution. And finally, ions can be emitted from a surface at randomized angles The results of our modeling effort indicate that significant modification of the interior geometry of the source will double Cs+ ion production from our spherical ionizer and produce a significant increase in negative ion output from the source.

Recent Development of IMP LECR3 Ion Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Z.M.; Zhao, H.W.; Li, J.Y.

2005-03-15

18GHz microwave has been fed to the LECR3 ion source to produce intense highly charged ion beams although this ion source was designed for 14.5GHz. Then 1.1 emA Ar8+ and 325 e{mu}A Ar11+ were obtained at 18GHz. During the source running for atomic physics experiment, some higher charge state ion beams such as Ar17+ and Ar18+ were detected and have been validated by atomic physics method. Furthermore, a few special gases, e.g. SiH4 and SF6, were tested on LECR3 ion source to produce required ion beams to satisfy the requirements of atomic physics experiments.

First charge breeding results at CARIBU EBIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondrashev, S., E-mail: kondrashev@anl.gov; Barcikowski, A., E-mail: kondrashev@anl.gov; Dickerson, C., E-mail: kondrashev@anl.gov

The Electron Beam Ion Source (EBIS) developed to breed CARIBU radioactive beams at ATLAS is currently in the off-line commissioning stage. The beam commissioning is being performed using a low emittance surface ionization source producing singly-charged cesium ions. The primary goal of the off-line commissioning is the demonstration of high-efficiency charge breeding in the pulsed injection mode. An overview of the final design of the CARIBU EBIS charge breeder, the off-line commissioning installation and the first results on charge breeding of stable cesium ions are presented and discussed.

Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Levand, A.; Pardo, R.

2012-02-15

The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi {sup 252}Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci {sup 252}Cf source to produce radioactive beamsmore » with intensities up to 10{sup 6} ions/s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for {sup 23}Na{sup 8+}, 15.6% for {sup 84}Kr{sup 17+}, and 13.7% for {sup 85}Rb{sup 19+} with typical breeding times of 10 ms/charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for {sup 143}Cs{sup 27+} and 14.7% for {sup 143}Ba{sup 27+}. The project has been commissioned with a radioactive beam of {sup 143}Ba{sup 27+} accelerated to 6.1 MeV/u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.« less

Electron cyclotron resonance sources: Historical review and future prospects (invited)

NASA Astrophysics Data System (ADS)

Geller, R.

1998-03-01

Low charge state electron cyclotron resonance ion source (ECRIS) work since 1965 and high charge state ECRIS since 1974. These ECR sources are categorized into three main sections: (1) Low charged ion (ECRIS) inside simple magnetic mirror or Bucket configurations. (2) High charged ion ECRIS inside min-B mirror configurations. (3) Short pulsed ECRIS with highly charged ions where the ion confinement is disturbed for a short while, which allows the extraction of intense ion pulses. Future prospects are based on rational scaling of the magnetic confinement including high B modes, by increasing the radio frequency (rf) frequency and ECR magnetic field. In this case, charge exchange has to be minimized and plasma instabilities have to be avoided. However, clever empirical tricks lead also to outstanding not always predicted improvements. Let us cite: optimized rf plasma coupling, electron guns, gas mixing, wall coating, biased electrodes, and more recently multiple ECR frequency heating. ECRIS have not yet achieved their optimal possibilities. Let us wait for the next generation of superconducting ECRIS and the possible use of subcentimeter waves.

Electron cyclotron resonance sources: Historical review and future prospects (invited)

NASA Astrophysics Data System (ADS)

Geller, R.

1998-02-01

Low charge state electron cyclotron resonance ion source (ECRIS) work since 1965 and high charge state ECRIS since 1974. These ECR sources are categorized into three main sections: (1) Low charged ion (ECRIS) inside simple magnetic mirror or Bucket configurations. (2) High charged ion ECRIS inside min-B mirror configurations. (3) Short pulsed ECRIS with highly charged ions where the ion confinement is disturbed for a short while, which allows the extraction of intense ion pulses. Future prospects are based on rational scaling of the magnetic confinement including high B modes, by increasing the radio frequency (rf) frequency and ECR magnetic field. In this case, charge exchange has to be minimized and plasma instabilities have to be avoided. However, clever empirical tricks lead also to outstanding not always predicted improvements. Let us cite: optimized rf plasma coupling, electron guns, gas mixing, wall coating, biased electrodes, and more recently multiple ECR frequency heating. ECRIS have not yet achieved their optimal possibilities. Let us wait for the next generation of superconducting ECRIS and the possible use of subcentimeter waves.

Kinetic energy offsets for multicharged ions from an electron beam ion source.

PubMed

Kulkarni, D D; Ahl, C D; Shore, A M; Miller, A J; Harriss, J E; Sosolik, C E; Marler, J P

2017-08-01

Using a retarding field analyzer, we have measured offsets between the nominal and measured kinetic energy of multicharged ions extracted from an electron beam ion source (EBIS). By varying source parameters, a shift in ion kinetic energy was attributed to the trapping potential produced by the space charge of the electron beam within the EBIS. The space charge of the electron beam depends on its charge density, which in turn depends on the amount of negative charge (electron beam current) and its velocity (electron beam energy). The electron beam current and electron beam energy were both varied to obtain electron beams of varying space charge and these were related to the observed kinetic energy offsets for Ar 4+ and Ar 8+ ion beams. Knowledge of these offsets is important for studies that seek to utilize slow, i.e., low kinetic energy, multicharged ions to exploit their high potential energies for processes such as surface modification. In addition, we show that these offsets can be utilized to estimate the effective radius of the electron beam inside the trap.

Evolution of Instrumentation for the Study of Gas-Phase Ion/Ion Chemistry via Mass Spectrometry

PubMed Central

Xia, Yu; McLuckey, Scott A.

2008-01-01

The scope of gas phase ion/ion chemistry accessible to mass spectrometry is largely defined by the available tools. Due to the development of novel instrumentation, a wide range of reaction phenomenologies have been noted, many of which have been studied extensively and exploited for analytical applications. This perspective presents the development of mass spectrometry-based instrumentation for the study of the gas phase ion/ion chemistry in which at least one of the reactants is multiply-charged. The instrument evolution is presented within the context of three essential elements required for any ion/ion reaction study: the ionization source(s), the reaction vessel or environment, and the mass analyzer. Ionization source arrangements have included source combinations that allow for reactions between multiply charged ions of one polarity and singly charged ions of opposite polarity, arrangements that enable the study of reactions of multiply charged ions of opposite polarity, and most recently, arrangements that allow for ion formation from more than two ion sources. Gas phase ion/ion reaction studies have been performed at near atmospheric pressure in flow reactor designs and within electrodynamic ion traps operated in the mTorr range. With ion trap as a reaction vessel, ionization and reaction processes can be independently optimized and ion/ion reactions can be implemented within the context of MSn experiments. Spatial separation of the reaction vessel from the mass analyzer allows for the use of any form of mass analysis in conjunction with ion/ion reactions. Time-of-flight mass analysis, for example, has provided significant improvements in mass analysis figures of merit relative to mass filters and ion traps. PMID:18083527

Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions.

PubMed

Lu, W; Li, J Y; Kang, L; Liu, H P; Li, H; Li, J D; Sun, L T; Ma, X W

2014-02-01

The 320 kV platform for multi-discipline research with highly charged ions is a heavy ion beam acceleration instrument developed by Institute of Modern Physics, which is dedicated to basic scientific researches such as plasma, atom, material physics, and astrophysics, etc. The platform has delivered ion beams of 400 species for 36,000 h. The average operation time is around 5000 h/year. With the beams provided by the platform, lots of outstanding progresses were made in various research fields. The ion source of the platform is an all-permanent magnet electron cyclotron resonance ion source, LAPECR2 (Lanzhou All Permanent ECR ion source No. 2). The maximum axial magnetic fields are 1.28 T at injection and 1.07 T at extraction, and the radial magnetic field is up to 1.21 T at the inner wall of the plasma chamber. The ion source is capable to produce low, medium, and high charge state gaseous and metallic ion beams, such as H(+), (40)Ar(8+), (129)Xe(30+), (209)Bi(33+), etc. This paper will present the latest result of LAPECR2 and the routine operation status for the high voltage platform.

Generation of multicomponent ion beams by a vacuum arc ion source with compound cathode.

PubMed

Savkin, K P; Yushkov, Yu G; Nikolaev, A G; Oks, E M; Yushkov, G Yu

2010-02-01

This paper presents the results of time-of-flight mass spectrometry studies of the elemental and mass-to-charge state compositions of metal ion beams produced by a vacuum arc ion source with compound cathode (WC-Co(0.5), Cu-Cr(0.25), Ti-Cu(0.1)). We found that the ion beam composition agrees well with the stoichiometric composition of the cathode material from which the beam is derived, and the maximum ion charge state of the different plasma components is determined by the ionization capability of electrons within the cathode spot plasma, which is common to all components. The beam mass-to-charge state spectrum from a compound cathode features a greater fraction of multiply charged ions for those materials with lower electron temperature in the vacuum arc cathode spot, and a smaller fraction for those with higher electron temperature within the spot. We propose a potential diagram method for determination of attainable ion charge states for all components of the compound cathodes.

Charge breeding of radioactive isotopes at the CARIBU facility with an electron beam ion source

NASA Astrophysics Data System (ADS)

Vondrasek, R. C.; Dickerson, C. A.; Hendricks, M.; Ostroumov, P.; Pardo, R.; Savard, G.; Scott, R.; Zinkann, G.

2018-05-01

An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed at Argonne National Laboratory as part of the californium rare ion breeder upgrade. For the past year, the EBIS-CB has been undergoing commissioning as part of the ATLAS accelerator complex. It has delivered both stable and radioactive beams with A/Q < 6, breeding times <30 ms, low background contamination, and charge breeding efficiencies >18% into a single charge state. The operation of this device, challenges during the commissioning phase, and future improvements will be discussed.

Progress of superconducting electron cyclotron resonance ion sources at Institute of Modern Physics (IMP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, L., E-mail: sunlt@impcas.ac.cn; Feng, Y. C.; Zhang, W. H.

2014-02-15

Superconducting ECR ion sources can produce intense highly charged ion beams for the application in heavy ion accelerators. Superconducting Electron Resonance ion source with Advanced Design (SECRAL) is one of the few fully superconducting ECR ion sources that has been successfully built and put into routine operation for years. With enormous efforts and R and D work, promising results have been achieved with the ion source. Heated by the microwave power from a 7 kW/24 GHz gyrotron microwave generator, very intense highly charged gaseous ion beams have been produced, such as 455 eμA Xe{sup 27+}, 236 eμA Xe{sup 30+}, andmore » 64 eμA Xe{sup 35+}. Since heavy metallic ion beams are being more and more attractive and important for many accelerator projects globally, intensive studies have been made to produce highly charged heavy metal ion beams, such as those from bismuth and uranium. Recently, 420 eμA Bi{sup 30+} and 202 eμA U{sup 33+} have been produced with SECRAL source. This paper will present the latest results with SECRAL, and the operation status will be discussed as well. An introduction of recently started SECRAL II project will also be given in the presentation.« less

Progress of superconducting electron cyclotron resonance ion sources at Institute of Modern Physics (IMP).

PubMed

Sun, L; Lu, W; Feng, Y C; Zhang, W H; Zhang, X Z; Cao, Y; Zhao, Y Y; Wu, W; Yang, T J; Zhao, B; Zhao, H W; Ma, L Z; Xia, J W; Xie, D

2014-02-01

Superconducting ECR ion sources can produce intense highly charged ion beams for the application in heavy ion accelerators. Superconducting Electron Resonance ion source with Advanced Design (SECRAL) is one of the few fully superconducting ECR ion sources that has been successfully built and put into routine operation for years. With enormous efforts and R&D work, promising results have been achieved with the ion source. Heated by the microwave power from a 7 kW/24 GHz gyrotron microwave generator, very intense highly charged gaseous ion beams have been produced, such as 455 eμA Xe(27+), 236 eμA Xe(30+), and 64 eμA Xe(35+). Since heavy metallic ion beams are being more and more attractive and important for many accelerator projects globally, intensive studies have been made to produce highly charged heavy metal ion beams, such as those from bismuth and uranium. Recently, 420 eμA Bi(30+) and 202 eμA U(33+) have been produced with SECRAL source. This paper will present the latest results with SECRAL, and the operation status will be discussed as well. An introduction of recently started SECRAL II project will also be given in the presentation.

Ionization source utilizing a jet disturber in combination with an ion funnel and method of operation

DOEpatents

Smith, Richard D.; Kim, Taeman; Tang, Keqi; Udseth, Harold R.

2003-06-24

A jet disturber used in combination with an ion funnel to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of the ions and other charged particles. The jet disturber is positioned within an ion funnel and may be interfaced with a multi-capillary inlet juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure. The invention finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer.

Determination of gas phase protein ion densities via ion mobility analysis with charge reduction.

PubMed

Maisser, Anne; Premnath, Vinay; Ghosh, Abhimanyu; Nguyen, Tuan Anh; Attoui, Michel; Hogan, Christopher J

2011-12-28

We use a charge reduction electrospray (ESI) source and subsequent ion mobility analysis with a differential mobility analyzer (DMA, with detection via both a Faraday cage electrometer and a condensation particle counter) to infer the densities of single and multiprotein ions of cytochrome C, lysozyme, myoglobin, ovalbumin, and bovine serum albumin produced from non-denaturing (20 mM aqueous ammonium acetate) and denaturing (1 : 49.5 : 49.5, formic acid : methanol : water) ESI. Charge reduction is achieved through use of a Po-210 radioactive source, which generates roughly equal concentrations of positive and negative ions. Ions produced by the source collide with and reduce the charge on ESI generated drops, preventing Coulombic fissions, and unlike typical protein ESI, leading to gas-phase protein ions with +1 to +3 excess charges. Therefore, charge reduction serves to effectively mitigate any role that Coulombic stretching may play on the structure of the gas phase ions. Density inference is made via determination of the mobility diameter, and correspondingly the spherical equivalent protein volume. Through this approach it is found that for both non-denaturing and denaturing ESI-generated ions, gas-phase protein ions are relatively compact, with average densities of 0.97 g cm(-3) and 0.86 g cm(-3), respectively. Ions from non-denaturing ESI are found to be slightly more compact than predicted from the protein crystal structures, suggesting that low charge state protein ions in the gas phase are slightly denser than their solution conformations. While a slight difference is detected between the ions produced with non-denaturing and denaturing ESI, the denatured ions are found to be much more dense than those examined previously by drift tube mobility analysis, in which charge reduction was not employed. This indicates that Coulombic stretching is typically what leads to non-compact ions in the gas-phase, and suggests that for gas phase measurements to be correlated to biomolecular structures in solution, low charge state ions should be analyzed. Further, to determine if different solution conditions give rise to ions of different structure, ions of similar charge state should be compared. Non-denatured protein ion densities are found to be in excellent agreement with non-denatured protein ion densities inferred from prior DMA and drift tube measurements made without charge reduction (all ions with densities in the 0.85-1.10 g cm(-3) range), showing that these ions are not strongly influenced by Coulombic stretching nor by analysis method.

Numerical Simulation of Ion Transport in a Nano-Electrospray Ion Source at Atmospheric Pressure

NASA Astrophysics Data System (ADS)

Wang, Wei; Bajic, Steve; John, Benzi; Emerson, David R.

2018-03-01

Understanding ion transport properties from the ion source to the mass spectrometer (MS) is essential for optimizing device performance. Numerical simulation helps in understanding of ion transport properties and, furthermore, facilitates instrument design. In contrast to previously reported numerical studies, ion transport simulations in a continuous injection mode whilst considering realistic space-charge effects have been carried out. The flow field was solved using Reynolds-averaged Navier-Stokes (RANS) equations, and a particle-in-cell (PIC) method was applied to solve a time-dependent electric field with local charge density. A series of ion transport simulations were carried out at different cone gas flow rates, ion source currents, and capillary voltages. A force evaluation analysis reveals that the electric force, the drag force, and the Brownian force are the three dominant forces acting on the ions. Both the experimental and simulation results indicate that cone gas flow rates of ≤250 slph (standard liter per hour) are important for high ion transmission efficiency, as higher cone gas flow rates reduce the ion signal significantly. The simulation results also show that the ion transmission efficiency reduces exponentially with an increased ion source current. Additionally, the ion loss due to space-charge effects has been found to be predominant at a higher ion source current, a lower capillary voltage, and a stronger cone gas counterflow. The interaction of the ion driving force, ion opposing force, and ion dispersion is discussed to illustrate ion transport mechanism in the ion source at atmospheric pressure. [Figure not available: see fulltext.

Numerical Simulation of Ion Transport in a Nano-Electrospray Ion Source at Atmospheric Pressure.

PubMed

Wang, Wei; Bajic, Steve; John, Benzi; Emerson, David R

2018-03-01

Understanding ion transport properties from the ion source to the mass spectrometer (MS) is essential for optimizing device performance. Numerical simulation helps in understanding of ion transport properties and, furthermore, facilitates instrument design. In contrast to previously reported numerical studies, ion transport simulations in a continuous injection mode whilst considering realistic space-charge effects have been carried out. The flow field was solved using Reynolds-averaged Navier-Stokes (RANS) equations, and a particle-in-cell (PIC) method was applied to solve a time-dependent electric field with local charge density. A series of ion transport simulations were carried out at different cone gas flow rates, ion source currents, and capillary voltages. A force evaluation analysis reveals that the electric force, the drag force, and the Brownian force are the three dominant forces acting on the ions. Both the experimental and simulation results indicate that cone gas flow rates of ≤250 slph (standard liter per hour) are important for high ion transmission efficiency, as higher cone gas flow rates reduce the ion signal significantly. The simulation results also show that the ion transmission efficiency reduces exponentially with an increased ion source current. Additionally, the ion loss due to space-charge effects has been found to be predominant at a higher ion source current, a lower capillary voltage, and a stronger cone gas counterflow. The interaction of the ion driving force, ion opposing force, and ion dispersion is discussed to illustrate ion transport mechanism in the ion source at atmospheric pressure. Graphical Abstract.

Numerical simulation of ion charge breeding in electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, L., E-mail: zhao@far-tech.com; Kim, Jin-Soo

2014-02-15

The Electron Beam Ion Source particle-in-cell code (EBIS-PIC) tracks ions in an EBIS electron beam while updating electric potential self-consistently and atomic processes by the Monte Carlo method. Recent improvements to the code are reported in this paper. The ionization module has been improved by using experimental ionization energies and shell effects. The acceptance of injected ions and the emittance of extracted ion beam are calculated by extending EBIS-PIC to the beam line transport region. An EBIS-PIC simulation is performed for a Cs charge-breeding experiment at BNL. The charge state distribution agrees well with experiments, and additional simulation results ofmore » radial profiles and velocity space distributions of the trapped ions are presented.« less

Performance and operation of advanced superconducting electron cyclotron resonance ion source SECRAL at 24 GHza)

NASA Astrophysics Data System (ADS)

Zhao, H. W.; Lu, W.; Zhang, X. Z.; Feng, Y. C.; Guo, J. W.; Cao, Y.; Li, J. Y.; Guo, X. H.; Sha, S.; Sun, L. T.; Xie, D. Z.

2012-02-01

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 129Xe35+ of 64 eμA, 129Xe42+ of 3 eμA, 209Bi41+ of 50 eμA, 209Bi50+ of 4.3 eμA and 209Bi54+ 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 209Bi36+ and 209Bi41+, 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.

Recent Development of IMP ECR Ion Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, H.W.; Zhang, Z.M.; Sun, L.T.

2005-03-15

Great efforts have been made to develop highly charged ECR ion sources for application of heavy ion accelerator and atomic physics research at IMP in the past few years. The latest development of ECR ion sources at IMP is briefly reviewed. Intense beams with high and intermediate charge states have been produced from IMP LECR3 by optimization of the ion source conditions including rf frequency extended up to 18GHz. 1.1 emA of Ar8+ and 325 e{mu} A of Ar11+ were produced. Dependence of beam emittance on those key parameters of ECR ion source, beam extraction and space charge compensation weremore » experimentally studied at LECR3. Furthermore, an advanced superconducting ECR ion source named SECRAL is being constructed. SECRAL is designed to operate at rf frequency 18-28GHz with axial mirror magnetic fields 3.6-4.0 Tesla at injection, 2.2 Tesla at extraction and sextupole field 2.0 Tesla at the wall. The superconducting magnet with sextupole and three solenoids was tested in a test-cryostat and 95% of designed fields were reached. Construction status and planed schedule of SECRAL are presented.« less

Electron-beam-ion-source (EBIS) modeling progress at FAR-TECH, Inc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, J. S., E-mail: kim@far-tech.com; Zhao, L., E-mail: kim@far-tech.com; Spencer, J. A., E-mail: kim@far-tech.com

FAR-TECH, Inc. has been developing a numerical modeling tool for Electron-Beam-Ion-Sources (EBISs). The tool consists of two codes. One is the Particle-Beam-Gun-Simulation (PBGUNS) code to simulate a steady state electron beam and the other is the EBIS-Particle-In-Cell (EBIS-PIC) code to simulate ion charge breeding with the electron beam. PBGUNS, a 2D (r,z) electron gun and ion source simulation code, has been extended for efficient modeling of EBISs and the work was presented previously. EBIS-PIC is a space charge self-consistent PIC code and is written to simulate charge breeding in an axisymmetric 2D (r,z) device allowing for full three-dimensional ion dynamics.more » This 2D code has been successfully benchmarked with Test-EBIS measurements at Brookhaven National Laboratory. For long timescale (< tens of ms) ion charge breeding, the 2D EBIS-PIC simulations take a long computational time making the simulation less practical. Most of the EBIS charge breeding, however, may be modeled in 1D (r) as the axial dependence of the ion dynamics may be ignored in the trap. Where 1D approximations are valid, simulations of charge breeding in an EBIS over long time scales become possible, using EBIS-PIC together with PBGUNS. Initial 1D results are presented. The significance of the magnetic field to ion dynamics, ion cooling effects due to collisions with neutral gas, and the role of Coulomb collisions are presented.« less

Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, W., E-mail: luwang@impcas.ac.cn; University of Chinese Academy of Sciences, Beijing 100049; Li, J. Y.

2014-02-15

The 320 kV platform for multi-discipline research with highly charged ions is a heavy ion beam acceleration instrument developed by Institute of Modern Physics, which is dedicated to basic scientific researches such as plasma, atom, material physics, and astrophysics, etc. The platform has delivered ion beams of 400 species for 36 000 h. The average operation time is around 5000 h/year. With the beams provided by the platform, lots of outstanding progresses were made in various research fields. The ion source of the platform is an all-permanent magnet electron cyclotron resonance ion source, LAPECR2 (Lanzhou All Permanent ECR ion source No.more » 2). The maximum axial magnetic fields are 1.28 T at injection and 1.07 T at extraction, and the radial magnetic field is up to 1.21 T at the inner wall of the plasma chamber. The ion source is capable to produce low, medium, and high charge state gaseous and metallic ion beams, such as H{sup +}, {sup 40}Ar{sup 8+}, {sup 129}Xe{sup 30+}, {sup 209}Bi{sup 33+}, etc. This paper will present the latest result of LAPECR2 and the routine operation status for the high voltage platform.« less

Extraction of space-charge-dominated ion beams from an ECR ion source: Theory and simulation

NASA Astrophysics Data System (ADS)

Alton, G. D.; Bilheux, H.

2004-05-01

Extraction of high quality space-charge-dominated ion beams from plasma ion sources constitutes an optimization problem centered about finding an optimal concave plasma emission boundary that minimizes half-angular divergence for a given charge state, independent of the presence or lack thereof of a magnetic field in the extraction region. The curvature of the emission boundary acts to converge/diverge the low velocity beam during extraction. Beams of highest quality are extracted whenever the half-angular divergence, ω, is minimized. Under minimum half-angular divergence conditions, the plasma emission boundary has an optimum curvature and the perveance, P, current density, j+ext, and extraction gap, d, have optimum values for a given charge state, q. Optimum values for each of the independent variables (P, j+ext and d) are found to be in close agreement with those derived from elementary analytical theory for extraction with a simple two-electrode extraction system, independent of the presence of a magnetic field. The magnetic field only increases the emittances of beams through additional aberrational effects caused by increased angular divergences through coupling of the longitudinal to the transverse velocity components of particles as they pass though the mirror region of the electron cyclotron resonance (ECR) ion source. This article reviews the underlying theory of elementary extraction optics and presents results derived from simulation studies of extraction of space-charge dominated heavy-ion beams of varying mass, charge state, and intensity from an ECR ion source with emphasis on magnetic field induced effects.

High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, W., E-mail: luwang@impcas.ac.cn; Qian, C.; Sun, L. T.

2016-02-15

LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage tomore » the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O{sup 7+}, 620 eμA of Ar{sup 11+}, 430 eμA of Ar{sup 12+}, 430 eμA of Xe{sup 20+}, and so on. The comparison will be discussed in the paper.« less

Highly charged ion secondary ion mass spectroscopy

DOEpatents

Hamza, Alex V.; Schenkel, Thomas; Barnes, Alan V.; Schneider, Dieter H.

2001-01-01

A secondary ion mass spectrometer using slow, highly charged ions produced in an electron beam ion trap permits ultra-sensitive surface analysis and high spatial resolution simultaneously. The spectrometer comprises an ion source producing a primary ion beam of highly charged ions that are directed at a target surface, a mass analyzer, and a microchannel plate detector of secondary ions that are sputtered from the target surface after interaction with the primary beam. The unusually high secondary ion yield permits the use of coincidence counting, in which the secondary ion stops are detected in coincidence with a particular secondary ion. The association of specific molecular species can be correlated. The unique multiple secondary nature of the highly charged ion interaction enables this new analytical technique.

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.

The Electron Beam Ion Source (EBIS), developed to breed CARIBU radioactive beams at ATLAS, is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The offline charge breeding tests are being performed using a surface ionization source that produces singly-charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition ratemore » and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20±0.7)% breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Composition of inner-source heavy pickup ions at 1 AU: SOHO/CELIAS/CTOF observations. Implications for the production mechanisms

NASA Astrophysics Data System (ADS)

Taut, A.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

2015-04-01

Context. Pickup ions in the inner heliosphere mainly originate in two sources, one interstellar and one in the inner solar system. In contrast to the interstellar source that is comparatively well understood, the nature of the inner source has not been clearly identified. Former results obtained with the Solar Wind Ion Composition Spectrometer on-board the Ulysses spacecraft revealed that the composition of inner-source pickup ions is similar, but not equal, to the elemental solar-wind composition. These observations suffered from very low counting statistics of roughly one C+ count per day. Aims: Because the composition of inner-source pickup ions could lead to identifying their origin, we used data from the Charge-Time-Of-Flight sensor on-board the Solar and Heliospheric Observatory. It offers a large geometry factor that results in about 100 C+ counts per day combined with an excellent mass-per-charge resolution. These features enable a precise determination of the inner-source heavy pickup ion composition at 1 AU. To address the production mechanisms of inner-source pickup ions, we set up a toy model based on the production scenario involving the passage of solar-wind ions through thin dust grains to explain the observed deviations of the inner-source PUI and the elemental solar-wind composition. Methods: An in-flight calibration of the sensor allows identification of heavy pickup ions from pulse height analysis data by their mass-per-charge. A statistical analysis was performed to derive the inner-source heavy pickup ion relative abundances of N+, O+, Ne+, Mg+, Mg2+, and Si+ compared to C+. Results: Our results for the inner-source pickup ion composition are in good agreement with previous studies and confirm the deviations from the solar-wind composition. The large geometry factor of the Charge-Time-of-Flight sensor even allowed the abundance ratios of the two most prominent pickup ions, C+ and O+, to be investigated at varying solar-wind speeds. We found that the O+/C+ ratio increases systematically with higher solar-wind speeds. This observation is an unprecedented feature characterising the production of inner-source pickup ions. Comparing our observations to the toy model results, we find that both the deviation from the solar-wind composition and the solar-wind-speed dependent O+/C+ ratio can be explained.

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources

DOEpatents

Alton, Gerald D.

1998-01-01

Microwave injection methods for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant "volume" ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources.

Ionization source utilizing a multi-capillary inlet and method of operation

DOEpatents

Smith, Richard D.; Kim, Taeman; Udseth, Harold R.

2004-10-12

A multi-capillary inlet to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of ions and other charged particles. The multi-capillary inlet is juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure, it finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer, and finds its greatest advantages when deployed in conjunction with an electrodynamic (RF) ion funnel deployed within the interior of the mass spectrometer, particularly an ion funnel equipped with a jet disturber.

Status of the laser ion source at IMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sha, S.; Graduate University of Chinese Academy of Sciences, Beijing 100049; School of Nuclear science and technology, Lanzhou University, Lanzhou 73000

2012-02-15

A laser (Nd:YAG laser, 3 J, 1064 nm, 8-10 ns) ion source has been built and under development at IMP to provide pulsed high-charge-state heavy ion beams to a radio frequency quadrupole (RFQ) for upgrading the IMP accelerators with a new low-energy beam injector. The laser ion source currently operates in a direct plasma injection scheme to inject the high charge state ions produced from a solid target into the RFQ. The maximum power density on the target was about 8.4 x 10{sup 12} W/cm{sup 2}. The preliminary experimental results will be presented and discussed in this paper.

ECR Plasma Source for Heavy Ion Beam Charge Neutralization

NASA Astrophysics Data System (ADS)

Efthimion, P. C.; Gilson, E.; Grishman, L.; Kolchin, P.; Davidson, R. C.

2002-01-01

Highly ionized plasmas are being considered as a medium for charge neutralizing heavy ion beams in order to focus beyond the space-charge limit. Calculations suggest that plasma at a density of 1 - 100 times the ion beam density and at a length of approximately 0.1-2 m would be suitable for achieving a high level of charge neutralization. An ECR source has been built at the Princeton Plasma Physics Laboratory (PPPL) to support a joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 1-10 gauss. The goal is to operate the source at pressures of approximately 10-6 torr at full ionization. The initial operation of the source has been at pressures of 10-4 - 10-1. Electron densities in the range of 108 - 1011 per cubic centimeter have been achieved. Low-pressure operation is important to reduce ion beam ionization. A cusp magnetic field has been installed to improve radial confinement and reduce the field strength on the beam axis. In addition, axial confinement is believed to be important to achieve lower-pressure operation. To further improve breakdown at low pressure, a weak electron source will be placed near the end of the ECR source.

ION PRODUCING MECHANISM (CHARGE CUPS)

DOEpatents

Brobeck, W.W.

1959-04-21

The problems of confining a charge material in a calutron and uniformly distributing heat to the charge is described. The charge is held in a cup of thermally conductive material removably disposed within the charge chamber of the ion source block. A central thermally conducting stem is incorporated within the cup for conducting heat to the central portion of the charge contained within the cup.

Quightness: A proposed figure of merit for sources of low-energy, high-charge-state ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmieder, R.W.

A variety of ion sources, including the EBIS and ECRIS, are distinguished by their ability to produce low-energy ions of very high charge state. It would be useful to have some figure of merit that is particularly sensitive to this performance. I propose here such a quantity, called Quightness,'' which is related to brightness but which enhances the contrast between sources supplying multicharged ions of low energy. The rationale for introducing this quantity, its etymology and relationship to other figures of merit, and some representative values are presented.

Energy & mass-charge distribution peculiarities of ion emitted from penning source

NASA Astrophysics Data System (ADS)

Mamedov, N. V.; Kolodko, D. V.; Sorokin, I. A.; Kanshin, I. A.; Sinelnikov, D. N.

2017-05-01

The optimization of hydrogen Penning sources used, in particular, in plasma chemical processing of materials and DLC deposition, is still very important. Investigations of mass-charge composition of these ion source emitted beams are particular relevant for miniature linear accelerators (neutron flux generators) nowadays. The Penning ion source energy and mass-charge ion distributions are presented. The relation between the discharge current abrupt jumps with increasing plasma density in the discharge center and increasing potential whipping (up to 50% of the anode voltage) is shown. Also the energy spectra in the discharge different modes as the pressure and anode potential functions are presented. It has been revealed that the atomic hydrogen ion concentration is about 5-10%, and it weakly depends on the pressure and the discharge current (in the investigated range from 1 to 10 mTorr and from 50 to 1000 μA) and increases with the anode voltage (up 1 to 3,5 kV).

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, W.; Zhao, H.W.; Liu, Zh.W.

To study the injection of additional electrons from an external electron gun into the plasma of a Penning ionization gauge (PIG) ion source, a test bench for the external electron-beam enhancement of the PIG (E-PIG) ion source was set up. A source magnet assembly was built to satisfy the request for magnetic field configuration of the E-PIG ion source. Numerical calculations have been done to optimize the magnetic field configuration so as to fit the primary electrons to be fed into the PIG discharge chamber along the spreading magnetic field lines. Many possible methods for improving the performance and stabilitymore » of the PIG ion source have been used in the E-PIG ion source, including the use of multicrystal LaB{sub 6} cathode and optimized axial magnetic field. This article presents a detailed design of the E-PIG ion source. Substantial enhancement of ion charge state is expected to be observed which demonstrates that the E-PIG is a viable alternative to other much more costly and difficult to operate devices for the production of intense ion beams of higher charge state.« less

Electron cyclotron resonance ion source for high currents of mono- and multicharged ion and general purpose unlimited lifetime application on implantation devices

NASA Astrophysics Data System (ADS)

Bieth, C.; Bouly, J. L.; Curdy, J. C.; Kantas, S.; Sortais, P.; Sole, P.; Vieux-Rochaz, J. L.

2000-02-01

The electron cyclotron resonance (ECR) ion sources were originally developed for high energy physic applications. They are used as injectors on linear accelerators and cyclotrons to further increase the particle energy via high charge state ions. This ECR technology is well suited for sources placed on a high voltage platform where ac power available is limited by insulated transformers. The PANTECHNIK family of ion source with its wide range of ion beam (various charge states with various beam currents) offers new possibilities and perspectives in the field of ion implantation. In addition to all these possibilities, the PANTECHNIK ion sources have many other advantages like: a very long lifetime without maintenance expense, good stability, efficiency of ionization close to 100% (this improves the lifetime of the pumping system and other equipment), the possibility of producing ion beams with different energies, and a very good reproducibility. The main characteristics of sources like Nanogan or SuperNanogan will be recalled. We will especially present the results obtained with the new Microgan 10 GHz source that can be optimized for the production of high currents of monocharged ion, including reactive gas like BF3 (2 mA e of B+) or medium currents of low charge state like 0.5 mA e of Ar4+. The latest results obtained with Microgan 10 GHz show that it is possible to drive the source up to 30 mA e of total current, with an emittance of 150 π mm mrad at 40 kV and also to maintain the production of multicharged ions like Ar8+.

Wall-loss distribution of charge breeding ions in an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, S. C.; Oyaizu, M.; Imai, N.

2012-02-15

We investigated the ion-loss distribution on the sidewall of an electron cyclotron resonance (ECR) plasma chamber using the 18-GHz ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex (TRIAC). Similarities and differences between the ion-loss distributions (longitudinal and azimuthal) of different ion species (i.e., radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions that are typical volatile and nonvolatile elements) was qualitatively discussed to understand the element dependence of the charge breeding efficiency. Especially, the similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.

Charge breeding simulations for radioactive ion beam production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Variale, V.; Raino, A. C.; Clauser, T.

2012-02-15

The charge breeding technique is used for radioactive ion beam (RIB) production in order of optimizing the re-acceleration of the radioactive element ions produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In order to get high intensity RIB, experiments with charge breeding of very high efficiency could be required. To reach this goal, the charge breeding simulation could help to optimize the high charge state production efficiency by finding more proper parameters for the radioactive 1+more » ions. In this paper a device based on an electron beam ion source (EBIS) is considered. In order to study that problem, a code already developed for studying the ion selective containment in an EBIS with RF quadrupoles, BRICTEST, has been modified to simulate the ion charge state breeding rate for different 1+ ion injection conditions. Particularly, the charge breeding simulations for an EBIS with a hollow electron beam have been studied.« less

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources

DOEpatents

Alton, G.D.

1998-11-24

Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

Heavy ion beams from an Alphatross source for use in calibration and testing of diagnostics

NASA Astrophysics Data System (ADS)

Ward, R. J.; Brown, G. M.; Ho, D.; Stockler, B. F. O. F.; Freeman, C. G.; Padalino, S. J.; Regan, S. P.

2016-10-01

Ion beams from the 1.7 MV Pelletron Accelerator at SUNY Geneseo have been used to test and calibrate many inertial confinement fusion (ICF) diagnostics and high energy density physics (HEDP) diagnostics used at the Laboratory for Laser Energetics (LLE). The ion source on this accelerator, a radio-frequency (RF) alkali-metal charge exchange source called an Alphatross, is designed to produce beams of hydrogen and helium isotopes. There is interest in accelerating beams of carbon, oxygen, argon, and other heavy ions for use in testing several diagnostics, including the Time Resolved Tandem Faraday Cup (TRTF). The feasibility of generating these heavy ion beams using the Alphatross source will be reported. Small amounts of various gases are mixed into the helium plasma in the ion source bottle. A velocity selector is used to allow the desired ions to pass into the accelerator. As the heavy ions pass through the stripper canal of the accelerator, they emerge in a variety of charge states. The energy of the ion beam at the high-energy end of the accelerator will vary as a function of the charge state, however the maximum energy deliverable to target is limited by the maximum achievable magnetic field produced by the accelerator's steering magnet. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Numerical simulations of gas mixing effect in electron cyclotron resonance ion sources

NASA Astrophysics Data System (ADS)

Mironov, V.; Bogomolov, S.; Bondarchenko, A.; Efremov, A.; Loginov, V.

2017-01-01

The particle-in-cell Monte Carlo collisions code nam-ecris is used to simulate the electron cyclotron resonance ion source (ECRIS) plasma sustained in a mixture of Kr with O2 , N2 , Ar, Ne, and He. The model assumes that ions are electrostatically confined in the ECR zone by a dip in the plasma potential. A gain in the extracted krypton ion currents is seen for the highest charge states; the gain is maximized when oxygen is used as a mixing gas. The special feature of oxygen is that most of the singly charged oxygen ions are produced after the dissociative ionization of oxygen molecules with a large kinetic energy release of around 5 eV per ion. The increased loss rate of energetic lowly charged ions of the mixing element requires a building up of the retarding potential barrier close to the ECR surface to equilibrate electron and ion losses out of the plasma. In the mixed plasmas, the barrier value is large (˜1 V ) compared to pure Kr plasma (˜0.01 V ), with longer confinement times of krypton ions and with much higher ion temperatures. The temperature of the krypton ions is increased because of extra heating by the energetic oxygen ions and a longer time of ion confinement. In calculations, a drop of the highly charged ion currents of lighter elements is observed when adding small fluxes of krypton into the source. This drop is caused by the accumulation of the krypton ions inside plasma, which decreases the electron and ion confinement times.

Formation of stable inverse sheath in ion–ion plasma by strong negative ion emission

NASA Astrophysics Data System (ADS)

Zhang, Zhe; Wu, Bang; Yang, Shali; Zhang, Ya; Chen, Dezhi; Fan, Mingwu; Jiang, Wei

2018-06-01

The effect of strong charged particle emission on plasma–wall interactions is a classical, yet unresolved question in plasma physics. Previous studies on secondary electron emission have shown that with different emission coefficients, there are classical, space-charge-limited, and inverse sheaths. In this letter, we demonstrate that a stable ion–ion inverse sheath and ion–ion plasma are formed with strong surface emission of negative ions. The continuous space-charge-limited to inverse ion–ion sheath transition is observed, and the plasma near the surface consequently transforms into pure ion–ion plasma. The results may explain the long-puzzled experimental observation that the density of negative ions depends on only charge not mass in negative ion sources.

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE PAGES

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; ...

2015-08-28

The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this study, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.

The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this study, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostroumov, P. N., E-mail: ostroumov@anl.gov; Barcikowski, A.; Dickerson, C. A.

The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Controlling Gas-Phase Reactions for Efficient Charge Reduction Electrospray Mass Spectrometry of Intact Proteins

PubMed Central

Frey, Brian L.; Lin, Yuan; Westphall, Michael S.; Smith, Lloyd M.

2006-01-01

Charge reduction electrospray mass spectrometry (CREMS) reduces the charge states of electrospray-generated ions, which concentrates the ions from a protein into fewer peaks spread over a larger m/z range, thereby increasing peak separation and decreasing spectral congestion. An optimized design for a CREMS source is described that provides an order-of-magnitude increase in sensitivity compared to previous designs and provides control over the extent of charge reduction. Either a corona discharge or an α-particle source was employed to generate anions that abstract protons from electrosprayed protein cations. These desired ion/ion proton transfer reactions predominated, but some oxidation and ion-attachment reactions also occurred leading to new peaks or mass-shifted broader peaks while decreasing signal intensity. The species producing these deleterious side-reactions were identified, and conditions were found that prevented their formation. Spectrometer m/z biases were examined because of their effect upon the signal intensity of higher m/z charge-reduced protein ions. The utility of this atmospheric pressure CREMS was demonstrated using a cell lysate fraction from E. coli. The spectral simplification afforded by CREMS reveals more proteins than are observed without charge reduction. PMID:16198118

Electrospray ion source with reduced analyte electrochemistry

DOEpatents

Kertesz, Vilmos [Knoxville, TN; Van Berkel, Gary [Clinton, TN

2011-08-23

An electrospray ion (ESI) source and method capable of ionizing an analyte molecule without oxidizing or reducing the analyte of interest. The ESI source can include an emitter having a liquid conduit, a working electrode having a liquid contacting surface, a spray tip, a secondary working electrode, and a charge storage coating covering partially or fully the liquid contacting surface of the working electrode. The liquid conduit, the working electrode and the secondary working electrode can be in liquid communication. The electrospray ion source can also include a counter electrode proximate to, but separated from, said spray tip. The electrospray ion source can also include a power system for applying a voltage difference between the working electrodes and a counter-electrode. The power system can deliver pulsed voltage changes to the working electrodes during operation of said electrospray ion source to minimize the surface potential of the charge storage coating.

Electrospray ion source with reduced analyte electrochemistry

DOEpatents

Kertesz, Vilmos; Van Berkel, Gary J

2013-07-30

An electrospray ion (ESI) source and method capable of ionizing an analyte molecule without oxidizing or reducing the analyte of interest. The ESI source can include an emitter having a liquid conduit, a working electrode having a liquid contacting surface, a spray tip, a secondary working electrode, and a charge storage coating covering partially or fully the liquid contacting surface of the working electrode. The liquid conduit, the working electrode and the secondary working electrode can be in liquid communication. The electrospray ion source can also include a counter electrode proximate to, but separated from, said spray tip. The electrospray ion source can also include a power system for applying a voltage difference between the working electrodes and a counter-electrode. The power system can deliver pulsed voltage changes to the working electrodes during operation of said electrospray ion source to minimize the surface potential of the charge storage coating.

CALUTRON CONTROL DEVICE

DOEpatents

Baldwin, L.W.

1959-08-25

Several interlock and control circuits for a calutron are described. In one of the arrangements, the ton source cooling water flow is interlocked with the current supply to the heaters assoctated with the charge chamber, arc chamber, and electrode structure. When the ion source coolant flow rate exceeds a predetermined level, the heater associated with the charge chamber is energized. After the charge chamber has reached a predetermined temperature, the arc chamber heater is energized. Thereafter, the electrode structure heater is energized and the ion source is ready to have the operating voltages applied.

The preliminary tests of the superconducting electron cyclotron resonance ion source DECRIS-SC2.

PubMed

Efremov, A; Bekhterev, V; Bogomolov, S; Drobin, V; Loginov, V; Lebedev, A; Yazvitsky, N; Yakovlev, B

2012-02-01

A new compact version of the "liquid He-free" superconducting ECR ion source, to be used as an injector of highly charged heavy ions for the MC-400 cyclotron, is designed and built at the Flerov Laboratory of Nuclear Reactions in collaboration with the Laboratory of High Energy Physics of JINR. The axial magnetic field of the source is created by the superconducting magnet and the NdFeB hexapole is used for the radial plasma confinement. The microwave frequency of 14 GHz is used for ECR plasma heating. During the first tests, the source shows a good enough performance for the production of medium charge state ions. In this paper, we will present the design parameters and the preliminary results with gaseous ions.

Electron cyclotron resonance ion sources with arc-shaped coils.

PubMed

Suominen, P; Wenander, F

2008-02-01

The minimum-B magnetic field structure of electron cyclotron resonance ion sources (ECRIS) has conventionally been formed with a combination of solenoids and a hexapole magnet. However, minimum-B structure can also be formed with arc-shaped coils. Recently it was shown that multiply charged heavy-ions can be produced with an ECRIS based on such a structure. In the future, the ARC-ECRIS magnetic field structure can be an interesting option for radioactive ion-beam sources and charge-breeders as well as for high performance ECRIS allowing for 100 GHz plasma heating. This paper presents some design aspects of the ARC-ECRIS.

Inner Source Pickup Ions Observed by Ulysses

NASA Astrophysics Data System (ADS)

Gloeckler, G.

2016-12-01

The existence of an inner source of pickup ions close to the Sun was proposed in order to explain the unexpected discovery of C+ in the high-speed polar solar wind. Here I report on detailed analyses of the composition and the radial and latitudinal variations of inner source pickup ions measured with the Solar Wind Ion Composition Spectrometer on Ulysses from 1991 to 1998, approaching and during solar minimum. We find that the C+ intensity drops off with radial distance R as R-1.53, peaks at mid latitudes and drops to its lowest value in the ecliptic. Not only was C+ observed, but also N+, O+, Ne+, Na+, Mg+, Ar+, S+, K+, CH+, NH+, OH+, H2O+, H3O+, MgH+, HCN+, C2H4+, SO+ and many other singly-charged heavy ions and molecular ions. The measured velocity distributions of inner source pickup C+ and O+ indicate that these inner source pickup ions are most likely produced by charge exchange, photoionization and electron impact ionization of neutrals close to the Sun (within 10 to 30 solar radii). Possible causes for the unexpected latitudinal variations and the neutral source(s) producing the inner source pickup ions as well as plausible production mechanisms for inner source pickup ions will be discussed.

Investigation of ion beam space charge compensation with a 4-grid analyzer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ullmann, C., E-mail: c.ullmann@gsi.de; Adonin, A.; Berezov, R.

2016-02-15

Experiments to investigate the space charge compensation of pulsed high-current heavy ion beams are performed at the GSI ion source text benches with a 4-grid analyzer provided by CEA/Saclay. The technical design of the 4-grid analyzer is revised to verify its functionality for measurements at pulsed high-current heavy ion beams. The experimental investigation of space charge compensation processes is needed to increase the performance and quality of current and future accelerator facilities. Measurements are performed directly downstream a triode extraction system mounted to a multi-cusp ion source at a high-current test bench as well as downstream the post-acceleration system ofmore » the high-current test injector (HOSTI) with ion energies up to 120 keV/u for helium and argon. At HOSTI, a cold or hot reflex discharge ion source is used to change the conditions for the measurements. The measurements were performed with helium, argon, and xenon and are presented. Results from measurements with single aperture extraction systems are shown.« less

The Development Of New Space Charge Compensation Methods For Multi-Components Ion Beam Extracted From ECR Ion Source at IMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, L.; Zhao, H.W.; Cao, Y.

2005-03-15

Two new space charge compensation methods developed in IMP are discussed in this paper. There are negative high voltage electrode method (NHVEM) and electronegative charge gas method (EGM). Some valuable experimental data have been achieved, especially using electronegative gas method in O6+ and O7+ dramatic and stable increasing of ion current was observed.

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Kutsaev, Sergey; Delahaye, P.

2012-11-15

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficienciesmore » of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.« less

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Delahaye, P.; Kutsaev, Sergey

2012-11-01

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a 252Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies ofmore » both gaseous and solid species including 14.7% for the radioactive species 143Ba27+. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for 23Na7+ and 17.9% for 39K10+ were obtained injecting stable Na+ and K+ beams from a surface ionization source.« less

Production of highly charged ion beams with SECRALa)

NASA Astrophysics Data System (ADS)

Sun, L. T.; Zhao, H. W.; Lu, W.; Zhang, X. Z.; Feng, Y. C.; Li, J. Y.; Cao, Y.; Guo, X. H.; Ma, H. Y.; Zhao, H. Y.; Shang, Y.; Ma, B. H.; Wang, H.; Li, X. X.; Jin, T.; Xie, D. Z.

2010-02-01

Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e μA of Xe37+, 1 e μA of Xe43+, and 0.16 e μA of Ne-like Xe44+. To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi31+ beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e μA of Bi31+, 22 e μA of Bi41+, and 1.5 e μA of Bi50+ have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

Effect of axial magnetic field on a 2.45 GHz permanent magnet ECR ion source.

PubMed

Nakamura, T; Wada, H; Asaji, T; Furuse, M

2016-02-01

Herein, we conduct a fundamental study to improve the generation efficiency of a multi-charged ion source using argon. A magnetic field of our electron cyclotron resonance ion source is composed of a permanent magnet and a solenoid coil. Thereby, the axial magnetic field in the chamber can be tuned. Using the solenoid coil, we varied the magnetic field strength in the plasma chamber and measured the ion beam current extracted at the electrode. We observed an approximately three times increase in the Ar(4+) ion beam current when the magnetic field on the extractor-electrode side of the chamber was weakened. From our results, we can confirm that the multi-charged ion beam current changes depending on magnetic field intensity in the plasma chamber.

Design of a compact all-permanent magnet ECR ion source injector for ReA at the MSU NSCL

NASA Astrophysics Data System (ADS)

Pham, Alfonse N.; Leitner, Daniela; Glennon, Patrick; Ottarson, Jack; Lawton, Don; Portillo, Mauricio; Machicoane, Guillaume; Wenstrom, John; Lajoie, Andrew

2016-06-01

The design of a compact all-permanent magnet electron cyclotron resonance (ECR) ion source injector for the ReAccelerator Facility (ReA) at the Michigan State University (MSU) National Superconducting Cyclotron Laboratory (NSCL) is currently being carried out. The ECR ion source injector will complement the electron beam ion trap (EBIT) charge breeder as an off-line stable ion beam injector for the ReA linac. The objective of the ECR ion source injector is to provide continuous-wave beams of heavy ions from hydrogen to masses up to 136Xe within the ReA charge-to-mass ratio (Q / A) operational range from 0.2 to 0.5. The ECR ion source will be mounted on a high-voltage platform that can be adjusted to obtain the required 12 keV/u injection energy into a room temperature radio-frequency quadrupole (RFQ) for further acceleration. The beam line consists of a 30 kV tetrode extraction system, mass analyzing section, and optical matching section for injection into the existing ReA low energy beam transport (LEBT) line. The design of the ECR ion source and the associated beam line are discussed.

The charge spectrum of positive ions in a hydrogen aurora

NASA Technical Reports Server (NTRS)

Lynch, J.; Pulliam, D.; Leach, R.; Scherb, F.

1976-01-01

An auroral ion charge spectrometer was flown into a hydrogen aurora on a Javelin sounding rocket launched from Churchill, Manitoba. The instrument contained an electrostatic analyzer which selected particles with incident energy per unit charge up to 20 keV/charge and an 80-kV power supply which accelerated these ions onto an array of solid state detectors. Ions tentatively identified as H(+), He(+2), and O(+) were detected from 225 to 820 km in altitude. The experiment did not discriminate between H(+) and He(+), or between O(+), N(+), and C(+). Upper limits of highly charged heavy ion abundances have been set at 20% of the He(+2) and 0.15% of the H(+). It is concluded that both terrestrial and solar wind sources play significant roles in auroral ion precipitation.

Future carbon beams at SPIRAL1 facility: Which method is the most efficient?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maunoury, L., E-mail: maunoury@ganil.fr; Delahaye, P.; Dubois, M.

2014-02-15

Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P.more » Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO{sub 2}), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.« less

Future carbon beams at SPIRAL1 facility: Which method is the most efficient?

NASA Astrophysics Data System (ADS)

Maunoury, L.; Delahaye, P.; Angot, J.; Dubois, M.; Dupuis, M.; Frigot, R.; Grinyer, J.; Jardin, P.; Leboucher, C.; Lamy, T.

2014-02-01

Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P. Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO2), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.

Future carbon beams at SPIRAL1 facility: which method is the most efficient?

PubMed

Maunoury, L; Delahaye, P; Angot, J; Dubois, M; Dupuis, M; Frigot, R; Grinyer, J; Jardin, P; Leboucher, C; Lamy, T

2014-02-01

Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P. Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO2), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.

An electron cyclotron resonance ion source based low energy ion beam platform.

PubMed

Sun, L T; Shang, Y; Ma, B H; Zhang, X Z; Feng, Y C; Li, X X; Wang, H; Guo, X H; Song, M T; Zhao, H Y; Zhang, Z M; Zhao, H W; Xie, D Z

2008-02-01

To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ion beam platform is under design at IMP. A simple test bench has been set up to test the ion beam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ion beams. LAPECR1 source has already been ignited. Some intense low charge state ion beams have been produced on it, but the first test also reveals that many problems are existing on the ion beam transmission line. The ion beam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ion beam, after being analyzed by a double-focusing analyzer magnet, the selected ion beam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ion beam focusing. In this paper, the conceptual design of deceleration system will be discussed.

Ion sources for electric propulsion

NASA Technical Reports Server (NTRS)

Stuhlinger, E.

1971-01-01

Ion systems, which accelerate ions of Cs, Hg, or colloid particles by electrostatic fields, are furthest advanced and ready for application. Four kinds of ion sources have been developed: The contact ionization source for Cs as propellants, the electron bombardment source for Cs or Hg, the RF ionization source for Hg, and the hollow needle spray nozzle for colloidal glycerol particles. In each case, the ion beam must be neutralized by injection of electrons shortly behind the exit orifice to avoid adverse space charge effects.

Solid state electrochromic light modulator

DOEpatents

Cogan, Stuart F.; Rauh, R. David

1993-01-01

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Solid state electrochromic light modulator

DOEpatents

Cogan, Stuart F.; Rauh, R. David

1993-12-07

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Solid state electrochromic light modulator

DOEpatents

Cogan, Stuart F.; Rauh, R. David

1990-01-01

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Solid state electrochromic light modulator

DOEpatents

Cogan, S.F.; Rauh, R.D.

1990-07-03

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counter electrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films. 4 figs.

Single-atom detection of isotopes

DOEpatents

Meyer, Fred W.

2002-01-01

A method for performing accelerator mass spectrometry, includes producing a beam of positive ions having different multiple charges from a multicharged ion source; selecting positive ions having a charge state of from +2 to +4 to define a portion of the beam of positive ions; and scattering at least a portion of the portion of the beam of positive ions off a surface of a target to directly convert a portion of the positive ions in the portion of the beam of positive ions to negative ions.

ECR Plasma Source for Heavy Ion Beam Charge Neutralization

NASA Astrophysics Data System (ADS)

Efthimion, P. C.; Gilson, E.; Grisham, L.; Davidson, R. C.; Yu, S.; Logan, B. G.

2002-11-01

Highly ionized plasmas are being considered as a medium for charge neutralizing heavy ion beams in order to focus beyond the space-charge limit. Calculations suggest that plasma at a density of 1 - 100 times the ion beam density and at a length ˜ 0.1-0.5 m would be suitable for achieving a high level of charge neutralization. An ECR source has been built at the Princeton Plasma Physics Laboratory (PPPL) to support a joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 1-10 gauss. The goal is to operate the source at pressures ˜ 10-5 Torr at full ionization. The initial operation of the source has been at pressures of 10-4 - 10-1 Torr. Electron densities in the range of 10^8 - 10^11 cm-3 have been achieved. Low-pressure operation is important to reduce ion beam ionization. A cusp magnetic field has been installed to improve radial confinement and reduce the field strength on the beam axis. In addition, axial confinement is believed to be important to achieve lower-pressure operation. At moderate pressures (> 1 mTorr) the wave damping is collisional, and at low pressures (< 1 mTorr) there is a distinct electron cyclotron resonance. The source has recently been configured to operate with 2.45 GHz microwaves with similar results. At the present operating range the source can simulate the plasma produced by photo-ionization in the target chamber.

ECR plasma source for heavy ion beam charge neutralization

NASA Astrophysics Data System (ADS)

Efthimion, Philip C.; Gilson, Erik; Grisham, Larry; Kolchin, Pavel; Davidson, Ronald C.; Yu, Simon; Logan, B. Grant

2003-01-01

Highly ionized plasmas are being considered as a medium for charge neutralizing heavy ion beams in order to focus beyond the space-charge limit. Calculations suggest that plasma at a density of 1 100 times the ion beam density and at a length [similar]0.1 2 m would be suitable for achieving a high level of charge neutralization. An Electron Cyclotron Resonance (ECR) source has been built at the Princeton Plasma Physics Laboratory (PPPL) to support a joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 1 10 gauss. The goal is to operate the source at pressures [similar]10[minus sign]6 Torr at full ionization. The initial operation of the source has been at pressures of 10[minus sign]4 10[minus sign]1 Torr. Electron densities in the range of 108 to 1011 cm[minus sign]3 have been achieved. Low-pressure operation is important to reduce ion beam ionization. A cusp magnetic field has been installed to improve radial confinement and reduce the field strength on the beam axis. In addition, axial confinement is believed to be important to achieve lower-pressure operation. To further improve breakdown at low pressure, a weak electron source will be placed near the end of the ECR source. This article also describes the wave damping mechanisms. At moderate pressures (> 1 mTorr), the wave damping is collisional, and at low pressures (< 1 mTorr) there is a distinct electron cyclotron resonance.

Production of highly charged ion beams Kr32+, Xe44+, Au54+ with Electron String Ion Source (ESIS) Krion-2 and corresponding basic and applied studies

NASA Astrophysics Data System (ADS)

Donets, D. E.; Donets, E. D.; Donets, E. E.; Salnikov, V. V.; Shutov, V. B.

2010-09-01

Electron String Ion Source (ESIS) Krion-2 (JINR, Dubna) was used for basic and applied research in various aspects of multiply charged heavy ions production. Energy recuperation mode in ESIS has been proofed first and used for production of highly charged ions 84Kr28+÷84Kr32+, 124Xe40÷124Xe44 and Au51+÷ Au54+. Krion-2 ESIS was mounted on high voltage (HV) platform of LU-20 Linac and used as an injector of highly charged ions during Nuclotron run N° 41. Krion-2 ESIS has produced 3.0.107 124Xe42+ ions per pulse of 7 μs duration. This ion beam was injected into LU-20 and Nuclotron, accelerated up to energy of 186 GeV and the extracted Xe beam was used for physics experiments. Electron String Ion Source Krion-2 demonstrated the high reliability and stability running during 30 days on HV platform. We believe that it is due to an extremely low electron beam power, provided by using the electron string mode of operation: 50 W pulse power and about 10 W average power. Other possible application of ESIS could be its use in injection complexes of synchrotrons and cyclotrons for cancer therapy. Slow and fast extraction of C4+ and C6+ beams from Krion-2 ESIS were preliminary studied towards ESIS optimization for medical accelerators requirements.

Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, L., E-mail: sunlt@impcas.ac.cn; Lu, W.; Zhang, W. H.

2016-02-15

At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showedmore » its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω{sup 2} scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE{sub 01} and HE{sub 11} modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar{sup 12+}, 0.92 emA Xe{sup 27+}, and so on, will be presented.« less

Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion source.

PubMed

Kondo, K; Yamamoto, T; Sekine, M; Okamura, M

2012-02-01

The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (∼100 μA) with high charge (∼10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

Electrochemical Ionization and Analyte Charging in the Array of Micromachined UltraSonic Electrospray (AMUSE) Ion Source

PubMed Central

Forbes, Thomas P.; Degertekin, F. Levent; Fedorov, Andrei G.

2010-01-01

Electrochemistry and ion transport in a planar array of mechanically-driven, droplet-based ion sources are investigated using an approximate time scale analysis and in-depth computational simulations. The ion source is modeled as a controlled-current electrolytic cell, in which the piezoelectric transducer electrode, which mechanically drives the charged droplet generation using ultrasonic atomization, also acts as the oxidizing/corroding anode (positive mode). The interplay between advective and diffusive ion transport of electrochemically generated ions is analyzed as a function of the transducer duty cycle and electrode location. A time scale analysis of the relative importance of advective vs. diffusive ion transport provides valuable insight into optimality, from the ionization prospective, of alternative design and operation modes of the ion source operation. A computational model based on the solution of time-averaged, quasi-steady advection-diffusion equations for electroactive species transport is used to substantiate the conclusions of the time scale analysis. The results show that electrochemical ion generation at the piezoelectric transducer electrodes located at the back-side of the ion source reservoir results in poor ionization efficiency due to insufficient time for the charged analyte to diffuse away from the electrode surface to the ejection location, especially at near 100% duty cycle operation. Reducing the duty cycle of droplet/analyte ejection increases the analyte residence time and, in turn, improves ionization efficiency, but at an expense of the reduced device throughput. For applications where this is undesirable, i.e., multiplexed and disposable device configurations, an alternative electrode location is incorporated. By moving the charging electrode to the nozzle surface, the diffusion length scale is greatly reduced, drastically improving ionization efficiency. The ionization efficiency of all operating conditions considered is expressed as a function of the dimensionless Peclet number, which defines the relative effect of advection as compared to diffusion. This analysis is general enough to elucidate an important role of electrochemistry in ionization efficiency of any arrayed ion sources, be they mechanically-driven or electrosprays, and is vital for determining optimal design and operation conditions. PMID:20607111

A compact source for bunches of singly charged atomic ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murböck, T.; Birkl, G.; Schmidt, S.

2016-04-15

We have built, operated, and characterized a compact ion source for low-energy bunches of singly charged atomic ions in a vacuum beam line. It is based on atomic evaporation from an electrically heated oven and ionization by electron impact from a heated filament inside a grid-based ionization volume. An adjacent electrode arrangement is used for ion extraction and focusing by applying positive high-voltage pulses to the grid. The method is particularly suited for experimental environments which require low electromagnetic noise. It has proven simple yet reliable and has been used to produce μs-bunches of up to 10{sup 6} Mg{sup +}more » ions at a repetition rate of 1 Hz. We present the concept, setup and characterizing measurements. The instrument has been operated in the framework of the SpecTrap experiment at the HITRAP facility at GSI/FAIR to provide Mg{sup +} ions for sympathetic cooling of highly charged ions by laser-cooled {sup 24}Mg{sup +}.« less

Measurements of charge state breeding efficiency at BNL test EBIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondrashev, S.; Alessi, J.; Beebe, E.N.

Charge breeding of singly charged ions is required to efficiently accelerate rare isotope ion beams for nuclear and astrophysics experiments, and to enhance the accuracy of low-energy Penning trap-assisted spectroscopy. An efficient charge breeder for the Californium Rare Isotope Breeder Upgrade (CARIBU) to the ANL Tandem Linear Accelerator System (ATLAS) facility is being developed using the BNL Test Electron Beam Ion Source (Test EBIS) as a prototype. Parameters of the CARIBU EBIS charge breeder are similar to those of the BNL Test EBIS except the electron beam current will be adjustable in the range from 1 to 2 {angstrom}. Themore » electron beam current density in the CARIBU EBIS trap will be significantly higher than in existing operational charge state breeders based on the EBIS concept. The charge state breeding efficiency is expected to be about 25% for the isotope ions extracted from the CARIBU. For the success of our EBIS project, it is essential to demonstrate high breeding efficiency at the BNL Test EBIS tuned to the regime close to the parameters of the CARIBU EBIS at ANL. The breeding efficiency optimization and measurements have been successfully carried out using a Cs{sup +} surface ionization ion source for externally pulsed injection into the BNL Test EBIS. A Cs{sup +} ion beam with a total number of ions of 5 x 10{sup 8} and optimized pulse length of 70 {mu}s has been injected into the Test EBIS and charge-bred for 5.3 ms for two different electron beam currents 1 and 1.5 {angstrom}. In these experiments we have achieved 70% injection/extraction efficiency and breeding efficiency into the most abundant charge state 17%.« less

Metrology and Transport of Multiply Charged Ions

NASA Astrophysics Data System (ADS)

Kulkarni, Dhruva

The transport and interaction of singly- and multiply-charged ions with matter has been studied. The experiments were performed in an ultra-high vacuum environment. The low- and hyperthermal-energy ion beamline was used as a source of singly charged ions, while the CUEBIT facility was used as a source of multiply charged ions. The kinetic energy of the ion beam obtained from the CUEBIT is offset from the nominal value expected from the applied electrostatic potentials. These offsets were studied by measuring the kinetic energy of the beam using a retarding field analyzer (RFA). The offset was attributed to the space charge of the electron beam that is used to create the multiply charged ions. The charge density of the electron beam was varied by changing operational parameters of the electron beam, namely the electron beam current and the energy of the electron beam. Ion beams of Ar4+ and Ar8+ were extracted from the source and the offsets observed in the kinetic energy were related to the variation in the space charge potential of the electron beam. Measurements of these offsets, ranging from 100 eV/Q to 300 eV/Q, are significant and important for experiments that aim to utilize the potential energy of slow multiply charged ions. The transport of ions using capillaries has been studied to investigate the viability of ion-guiding as a means for a novel ion delivery mechanism. Results on transport through large bore capillaries (macrocapillaries) that probe both the geometric and ionguided mechanisms are presented. The angle- and position-dependent transport properties were found to depend on the material of the capillary (specifically, whether metal or insulator) and the geometry of the capillary. Rb+ ions at a kinetic energy of 1 keV were transmitted through metal and glass capillaries that were a few centimeters in length and a few millimeters in diameter. Oscillations were observed in the capillaries made of glass which were absent in the metal capillaries. Calculations based on the geometry of the experimental setup and kinematics of the ions showed that these oscillations could be attributed to the charge patches formed on the capillary walls. Electronic excitations in solids due to energetic ions at low kinetic energy were measured by using Schottky diodes. Hot electron currents measured at the backside of an Ag/n-Si Schottky diode due to ion bombardment on the frontside were found to depend on the kinetic energy (500 eV to 1500 eV) and angle of incidence (+/-30°) of the ion (Rb+) beam. A sharp upturn in the energy dependent yield is consistent with a kinetic emission model for electronic excitations utilizing the device Schottky barrier as determined from current-voltage characteristics. Backside currents measured for ion incident angle are strongly peaked about normal incidence. Accounting for the increased transport distance for excited charges at non-normal incidence, the mean free path for electrons in silver was found to be 5.2 +/- 1.4 nm, which is consistent with values reported in the literature.

Development of a compact ECR ion source for various ion production.

PubMed

Muramatsu, M; Hojo, S; Iwata, Y; Katagiri, K; Sakamoto, Y; Takahashi, N; Sasaki, N; Fukushima, K; Takahashi, K; Suzuki, T; Sasano, T; Uchida, T; Yoshida, Y; Hagino, S; Nishiokada, T; Kato, Y; Kitagawa, A

2016-02-01

There is a desire that a carbon-ion radiotherapy facility will produce various ion species for fundamental research. Although the present Kei2-type ion sources are dedicated for the carbon-ion production, a future ion source is expected that could provide: (1) carbon-ion production for medical use, (2) various ions with a charge-to-mass ratio of 1/3 for the existing Linac injector, and (3) low cost for modification. A prototype compact electron cyclotron resonance (ECR) ion source, named Kei3, based on the Kei series has been developed to correspond to the Kei2 type and to produce these various ions at the National Institute of Radiological Sciences (NIRS). The Kei3 has an outer diameter of 280 mm and a length of 1120 mm. The magnetic field is formed by the same permanent magnet as Kei2. The movable extraction electrode has been installed in order to optimize the beam extraction with various current densities. The gas-injection side of the vacuum chamber has enough space for an oven system. We measured dependence of microwave frequency, extraction voltage, and puller position. Charge state distributions of helium, carbon, nitrogen, oxygen, and neon were also measured.

Development of a compact ECR ion source for various ion production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muramatsu, M., E-mail: m-mura@nirs.go.jp; Hojo, S.; Iwata, Y.

2016-02-15

There is a desire that a carbon-ion radiotherapy facility will produce various ion species for fundamental research. Although the present Kei2-type ion sources are dedicated for the carbon-ion production, a future ion source is expected that could provide: (1) carbon-ion production for medical use, (2) various ions with a charge-to-mass ratio of 1/3 for the existing Linac injector, and (3) low cost for modification. A prototype compact electron cyclotron resonance (ECR) ion source, named Kei3, based on the Kei series has been developed to correspond to the Kei2 type and to produce these various ions at the National Institute ofmore » Radiological Sciences (NIRS). The Kei3 has an outer diameter of 280 mm and a length of 1120 mm. The magnetic field is formed by the same permanent magnet as Kei2. The movable extraction electrode has been installed in order to optimize the beam extraction with various current densities. The gas-injection side of the vacuum chamber has enough space for an oven system. We measured dependence of microwave frequency, extraction voltage, and puller position. Charge state distributions of helium, carbon, nitrogen, oxygen, and neon were also measured.« less

ION SOURCE

DOEpatents

Brobeck, W.M.

1959-04-14

This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from thc source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a varuum lock arrangement in conjunction with an arm for manipulating the bottle.

Ion source

DOEpatents

Brobeck, W. M.

1959-04-14

This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from the source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a vacuum lock arrangement in conjunction with an arm for manipulating the bottle.

Development of a pepper pot emittance probe and its application for ECR ion beam studies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondrashev, S.; Barcikowski, A.; Mustapha, B.

2009-07-21

A pepper pot-scintillator screen system has been developed and used to measure the emittance of DC ion beams extracted from a high-intensity permanent magnet ECR ion source. The system includes a fast beam shutter with a minimum dwell time of 18 ms to reduce the degradation of the CsI(Tl) scintillator by DC ion beam irradiation and a CCD camera with a variable shutter speed in the range of 1 {micro}s-65 s. On-line emittance measurements are performed by an application code developed on a LabVIEW platform. The sensitivity of the device is sufficient to measure the emittance of DC ion beamsmore » with current densities down to about 100 nA/cm{sup 2}. The emittance of all ion species extracted from the ECR ion source and post-accelerated to an energy of 75-90 keV/charge have been measured downstream of the LEBT. As the mass-to-charge ratio of ion species increases, the normalized RMS emittances in both transverse phase planes decrease from 0.5-1.0 {pi} mm mrad for light ions to 0.05-0.09 {pi} mm mrad for highly charged {sup 209}Bi ions. The dependence of the emittance on ion's mass-to-charge ratio follows very well the dependence expected from beam rotation induced by decreasing ECR axial magnetic field. The measured emittance values cannot be explained by only ion beam rotation for all ion species and the contribution to emittance of ion temperature in plasma, non-linear electric fields and non-linear space charge is comparable or even higher than the contribution of ion beam rotation.« less

Laser ion source activities at Brookhaven National Laboratory

DOE PAGES

Kanesue, Takeshi; Okamura, Masahiro

2015-07-31

In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 10more » 10 of C 6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.« less

Charge state distribution and emission characteristics in a table top reflex discharge - Effect of ion confinement and electrons accelerated across the sheath

DOE PAGES

Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; ...

2015-11-05

Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ~10 18mmore » –3 with a significant fraction >0.01 of fast primary electrons. As a result, the implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.« less

Argonne National Laboratory |

Science.gov Websites

for next-gen lithium batteries. Spotlight New ion source dramatically improves radioactive beams for Argonne's CARIBU facility A new Electron Beam Ion Source Charge Breeder operated with Argonne's CARIBU and

Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion sourcea)

NASA Astrophysics Data System (ADS)

Kondo, K.; Yamamoto, T.; Sekine, M.; Okamura, M.

2012-02-01

The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (˜100 μA) with high charge (˜10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

Neutralization of space charge forces using ionized background gas

NASA Astrophysics Data System (ADS)

Steski, D. B.; Zarcone, M. J.; Smith, K. S.; Thieberger, P.

1996-03-01

The Tandem Van de Graaff at Brookhaven National Laboratory has delivered pulsed gold beam to the Alternating Gradient Synchrotron (AGS) and AGS Booster since 1992 for relativistic heavy ion physics. There is an ongoing effort to improve the quality and intensity of the negative ion beam delivered to the Tandem from the present Cs sputter sources. Because the beam energy is low (approximately 30 keV) and the current high, there are significant losses due to space charge forces. One of the ways being explored to overcome these losses is to neutralize the space charge forces with ionized background gas. On an ion source test bench, using three different gases (Ar, N2, and Xe), the percentage of current transported from the source to a downstream Faraday cup was increased from 10% to 40% by bleeding in gas. Bleeding in Xe resulted in the best transmission. The time dependence of the neutralization as a function of gas pressure was also observed. This system is presently being transferred to the Negative Ion Injector of the Tandem for use in upcoming heavy ion experiments.

High brilliance negative ion and neutral beam source

DOEpatents

Compton, Robert N.

1991-01-01

A high brilliance mass selected (Z-selected) negative ion and neutral beam source having good energy resolution. The source is based upon laser resonance ionization of atoms or molecules in a small gaseous medium followed by charge exchange through an alkali oven. The source is capable of producing microampere beams of an extremely wide variety of negative ions, and milliampere beams when operated in the pulsed mode.

Laboratory Studies in UV and EUV Solar Physics

NASA Technical Reports Server (NTRS)

Parkinson, William

2003-01-01

The Ion Beam Experiment at the Center for Astrophysics is dedicated to the study of ion-electron collision processes of importance in solar physics. A paper describing our most recent measurement 'Absolute cross section for Si(2+)(3s3p(sup 3)Rho (sup 0) yields 3s3p(sup 1)Rho(sup 0)) electron-impact excitation' was published during the past year. Dr. Paul Janzen received his PhD. from the Harvard Physics Department on the basis of this and other work, such as the new electron cyclotron resonance (ECR) ion source. The ion source is producing stable beams with large currents for our present work on C(2+), and it also produces stable beams with large currents of more highly charged systems, for future work on systems such as O(4+). The past year has been focussed on our current program to measure absolute cross sections for Electron Impact Excitation (EIE) in C(2+), one of the primary ions used for probing the solar transition region. C(2+) beams produced by the ion source have been transported to the interaction region of the experiment, where the collisions are studied, and Visiting Scientist Dr. Adrian Daw is currently collecting data to measure the C(2+)(2s2p(sup 3)Rho(sup 0) yields 2p(sup 2)(sup 3)Rho) EIE cross section as a function of collision energy, under the guidance of Drs. John Kohl, Larry Gardner and Bill Parkinson. Also this year, modifications were made to the ECR ion source in order to produce greater currents of highly charged ions. Testing of the ion source was completed. Modifications were designed to extend the photon detection capabilities of the apparatus to shorter UV wavelengths, or EUV. Following the work on C(2+)(2s2p(sup 3)Pho(sup 0) yields 2p(sup 2)(sup 3)Rho), the extended UV detection capabilities will be used to measure the C(2+)(2s(sup 2)(sup 1)S yields 2s2p(sup 1)Rho(sup 0)) EIE cross section. The EUV modifications complement those of the new ion source, by enabling detection of EUV light generated by high charge state ions and putting us in a position to measure the excitation cross sections for more highly charged ions as well.

First results from the new RIKEN superconducting electron cyclotron resonance ion source (invited).

PubMed

Nakagawa, T; Higurashi, Y; Ohnishi, J; Aihara, T; Tamura, M; Uchiyama, A; Okuno, H; Kusaka, K; Kidera, M; Ikezawa, E; Fujimaki, M; Sato, Y; Watanabe, Y; Komiyama, M; Kase, M; Goto, A; Kamigaito, O; Yano, Y

2010-02-01

The next generation heavy ion accelerator facility, such as the RIKEN radio isotope (RI) beam factory, requires an intense beam of high charged heavy ions. In the past decade, performance of the electron cyclotron resonance (ECR) ion sources has been dramatically improved with increasing the magnetic field and rf frequency to enhance the density and confinement time of plasma. Furthermore, the effects of the key parameters (magnetic field configuration, gas pressure, etc.) on the ECR plasma have been revealed. Such basic studies give us how to optimize the ion source structure. Based on these studies and modern superconducting (SC) technology, we successfully constructed the new 28 GHz SC-ECRIS, which has a flexible magnetic field configuration to enlarge the ECR zone and to optimize the field gradient at ECR point. Using it, we investigated the effect of ECR zone size, magnetic field configuration, and biased disk on the beam intensity of the highly charged heavy ions with 18 GHz microwaves. In this article, we present the structure of the ion source and first experimental results with 18 GHz microwave in detail.

Observations of Heavy Ions in the Magnetosphere

NASA Astrophysics Data System (ADS)

Kistler, L. M.

2017-12-01

There are two sources for the hot ions in the magnetosphere: the solar wind and the ionosphere. The solar wind is predominantly protons, with about 4% He++ and less than 1% other high charge state heavy ions. The ionospheric outflow is also predominantly H+, but can contain a significant fraction of heavy ions including O+, N+, He+, O++, and molecular ions (NO+, N2+, O2+). The ionospheric outflow composition varies significantly both with geomagnetic activity and with solar EUV. The variability in the contribution of the two sources, the variability in the ionospheric source itself, and the transport paths of the different species are all important in determining the ion composition at a given location in the magnetosphere. In addition to the source variations, loss processes within the magnetosphere can be mass dependent, changing the composition. In particular, charge exchange is strongly species dependent, and can lead to heavy ion dominance at some energies in the inner magnetosphere. In this talk we will review the current state of our understanding of the composition of the magnetosphere and the processes that determine it.

Liquid metal ion source assembly for external ion injection into an electron string ion source (ESIS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segal, M. J., E-mail: mattiti@gmail.com; University of Cape Town, Rondebosch, Cape Town 7700; Bark, R. A.

An assembly for a commercial Ga{sup +} liquid metal ion source in combination with an ion transportation and focusing system, a pulse high-voltage quadrupole deflector, and a beam diagnostics system has been constructed in the framework of the iThemba LABS (Cape Town, South Africa)—JINR (Dubna, Russia) collaboration. First, results on Ga{sup +} ion beam commissioning will be presented. Outlook of further experiments for measurements of charge breeding efficiency in the electron string ion source with the use of external injection of Ga{sup +} and Au{sup +} ion beams will be reported as well.

RF Plasma Source for Heavy Ion Beam Charge Neutralization

NASA Astrophysics Data System (ADS)

Efthimion, P. C.; Gilson, E.; Grisham, L.; Davidson, R. C.

2003-10-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1 - 100 times the ion beam density and at a length 0.1-0.5 m would be suitable for achieving a high level of charge neutralization. An ECR source has been built at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 0-10 gauss. The goal is to operate the source at pressures 10-5 Torr at full ionization. The initial operation of the source has been at pressures of 10-4 - 10-1 Torr. Electron densities in the range of 10^8 - 10^11 cm-3 have been achieved. Recently, pulsed operation of the source has enabled operation at pressures in the 10-6 Torr range with densities of 10^11 cm-3. Near 100% ionization has been achieved. The source has been integrated with NTX and is being used in the experiments. The plasma is approximately 10 cm in length in the direction of the beam propagation. Modifications to the source will be presented that increase its length in the direction of beam propagation.

The charge-energy-mass spectrometer for 0.3-300 keV/e ions on the AMPTE CCE

NASA Technical Reports Server (NTRS)

Gloeckler, G.; Ipavich, F. M.; Hamilton, D. C.; Lundgren, R. A.; Studemann, W.; Wilken, B.; Kremser, G.; Hovestadt, D.; Gliem, F.; Rieck, W.

1985-01-01

The charge-energy-mass (CHEM) spectrometer on the Charge Composition Explorer (CCE) has the function to measure the energy spectra, pitch-angle distributions, and ionization states of ions in the earth's magnetosphere and magnetosheath in the energy range from 0.3 to 300 keV/charge with a time resolution of less than 1 min. The obtained data will provide essential information on outstanding problems related to ion sources and dynamical processes of space plasmas and of suprathermal ions. A description of the CHEM experiment is given, taking into account the principle of operation, the sensor, the electronics, instrument characteristics, specifications, and requirements. Questions of postlaunch performance are also discussed.

Electron beam ion source and electron beam ion trap (invited).

PubMed

Becker, Reinard; Kester, Oliver

2010-02-01

The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not "sorcery" but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

Charge-Control Unit for Testing Lithium-Ion Cells

NASA Technical Reports Server (NTRS)

Reid, Concha M.; Mazo, Michelle A.; Button, Robert M.

2008-01-01

A charge-control unit was developed as part of a program to validate Li-ion cells packaged together in batteries for aerospace use. The lithium-ion cell charge-control unit will be useful to anyone who performs testing of battery cells for aerospace and non-aerospace uses and to anyone who manufacturers battery test equipment. This technology reduces the quantity of costly power supplies and independent channels that are needed for test programs in which multiple cells are tested. Battery test equipment manufacturers can integrate the technology into their battery test equipment as a method to manage charging of multiple cells in series. The unit manages a complex scheme that is required for charging Li-ion cells electrically connected in series. The unit makes it possible to evaluate cells together as a pack using a single primary test channel, while also making it possible to charge each cell individually. Hence, inherent cell-to-cell variations in a series string of cells can be addressed, and yet the cost of testing is reduced substantially below the cost of testing each cell as a separate entity. The unit consists of electronic circuits and thermal-management devices housed in a common package. It also includes isolated annunciators to signal when the cells are being actively bypassed. These annunciators can be used by external charge managers or can be connected in series to signal that all cells have reached maximum charge. The charge-control circuitry for each cell amounts to regulator circuitry and is powered by that cell, eliminating the need for an external power source or controller. A 110-VAC source of electricity is required to power the thermal-management portion of the unit. A small direct-current source can be used to supply power for an annunciator signal, if desired.

Discovery of Suprathermal Ionospheric Origin Fe+ in and Near Earth's Magnetosphere

NASA Astrophysics Data System (ADS)

Christon, S. P.; Hamilton, D. C.; Plane, J. M. C.; Mitchell, D. G.; Grebowsky, J. M.; Spjeldvik, W. N.; Nylund, S. R.

2017-11-01

Suprathermal (87-212 keV/e) singly charged iron, Fe+, has been discovered in and near Earth's 9-30 RE equatorial magnetosphere using 21 years of Geotail STICS (suprathermal ion composition spectrometer) data. Its detection is enhanced during higher geomagnetic and solar activity levels. Fe+, rare compared to dominant suprathermal solar wind and ionospheric origin heavy ions, might derive from one or all three candidate lower-energy sources: (a) ionospheric outflow of Fe+ escaped from ion layers near 100 km altitude, (b) charge exchange of nominal solar wind iron, Fe+≥7, in Earth's exosphere, or (c) inner source pickup Fe+ carried by the solar wind, likely formed by solar wind Fe interaction with near-Sun interplanetary dust particles. Earth's semipermanent ionospheric Fe+ layers derive from tons of interplanetary dust particles entering Earth's atmosphere daily, and Fe+ scattered from these layers is observed up to 1000 km altitude, likely escaping in strong ionospheric outflows. Using 26% of STICS's magnetosphere-dominated data when possible Fe+2 ions are not masked by other ions, we demonstrate that solar wind Fe charge exchange secondaries are not an obvious Fe+ source. Contemporaneous Earth flyby and cruise data from charge-energy-mass spectrometer on the Cassini spacecraft, a functionally identical instrument, show that inner source pickup Fe+ is likely not important at suprathermal energies. Consequently, we suggest that ionospheric Fe+ constitutes at least a significant portion of Earth's suprathermal Fe+, comparable to the situation at Saturn where suprathermal Fe+ is also likely of ionospheric origin.

ION SOURCE FOR A CALUTRON

DOEpatents

Backus, J.G.

1957-12-24

This patent relates to ion sources and more particularly describes an ion source for a calutron which has the advantage of efficient production of an ion beam and long operation time without recharging. The source comprises an arc block provided with an arc chamber connected to a plurality of series-connected charge chambers and means for heating the charge within the chambers. A cathode is disposed at one end of the arc chamber and enclosed hy a vapor tight housing to protect the cathode. The arc discharge is set up between the cathode and the block due to a difference in potentials placed on these parts, and a magnetic field is aligned with the arc discharge. Cooling of the arc block is accomplished by passing coolant through a hollow stem secured at one end to the block and rotatably mounted at the other end through the wall of the calutron. The ions are removed through a slit in the arc chamber by accelerating electrodes.

Ions beams and ferroelectric plasma sources

NASA Astrophysics Data System (ADS)

Stepanov, Anton

Near-perfect space-charge neutralization is required for the transverse compression of high perveance ion beams for ion-beam-driven warm dense matter experiments, such as the Neutralized Drift Compression eXperiment (NDCX). Neutralization can be accomplished by introducing a plasma in the beam path, which provides free electrons that compensate the positive space charge of the ion beam. In this thesis, charge neutralization of a 40 keV, perveance-dominated Ar+ beam by a Ferroelectric Plasma Source (FEPS) is investigated. First, the parameters of the ion beam, such as divergence due to the extraction optics, charge neutralization fraction, and emittance were measured. The ion beam was propagated through the FEPS plasma, and the effects of charge neutralization were inferred from time-resolved measurements of the transverse beam profile. In addition, the dependence of FEPS plasma parameters on the configuration of the driving pulser circuit was studied to optimize pulser design. An ion accelerator was constructed that produced a 30-50 keV Ar + beam with pulse duration <300 mus and dimensionless perveance Q up to 8 x 10-4. Transverse profile measurements 33 cm downstream of the ion source showed that the dependence of beam radius on Q was consistent with space charge expansion. It was concluded that the beam was perveance-dominated with a charge neutralization fraction of approximately zero in the absence of neutralizing plasma. Since beam expansion occurred primarily due to space charge, the decrease in effective perveance due to neutralization by FEPS plasma can be inferred from the reduction in beam radius. Results on propagation of the ion beam through FEPS plasma demonstrate that after the FEPS is triggered, the beam radius decreases to its neutralized value in about 5 mus. The duration of neutralization was about 10 mus at a charging voltage VFEPS = 5.5 kV and 35 mus at VFEPS = 6.5 kV. With VFEPS = 6.5 kV, the transverse current density profile 33 cm downstream of the source had a Gaussian shape with xrms =5 mm, which corresponds to a half-angle divergence of 0.87°. The measurements show that near-perfect charge neutralization with FEPS can be attained. No loss of ion beam current was detected, indicating the absence of a neutral cloud in the region of beam propagation, which would cause beam loss to charge exchange collisions. This provides evidence in favor of using FEPS in a future Heavy Ion Fusion accelerator. The FEPS discharge was investigated based on current-voltage measurements in the pulser circuit. Different values of series resistance and storage capacitance in the pulser circuit were used. The charged particle current emitted by the FEPS into vacuum was measured from the difference in forward and return currents in the driving circuit. It was found that FEPS is an emitter of negative charge, and that electron current emission begins approximately 0.5 mus after the fast-rising high voltage pulse is applied and lasts for tens of mus. The value of the series resistance in the pulser circuit was varied to change the rise time of the voltage pulse; plasma density was expected to decrease with increasing values of resistance. However, the data showed that changing the resistance had no significant effect. The average charge emitted per shot depends strongly on the value of the storage capacitance. Lowering the capacitance from 141 nF to 47 nF resulted in a near-complete shut-off of charge emission, although the amplitude of the applied voltage pulse was as high, and rise time as short, as when high-density plasma was produced. Increasing the capacitance from 141 nF to 235 nF increased the average charge emitted per shot by a factor of 2.

Superconducting ECR ion source: From 24-28 GHz SECRAL to 45 GHz fourth generation ECR

NASA Astrophysics Data System (ADS)

Zhao, H. W.; Sun, L. T.; Guo, J. W.; Zhang, W. H.; Lu, W.; Wu, W.; Wu, B. M.; Sabbi, G.; Juchno, M.; Hafalia, A.; Ravaioli, E.; Xie, D. Z.

2018-05-01

The development of superconducting ECR source with higher magnetic fields and higher microwave frequency is the most straight forward path to achieve higher beam intensity and higher charge state performance. SECRAL, a superconducting third generation ECR ion source, is designed for 24-28 GHz microwave frequency operation with an innovative magnet configuration of sextupole coils located outside the three solenoids. SECRAL at 24 GHz has already produced a number of record beam intensities, such as 40Ar12+ 1.4 emA, 129Xe26+ 1.1 emA, 129Xe30+ 0.36 emA, and 209Bi31+ 0.68 emA. SECRAL-II, an upgraded version of SECRAL, was built successfully in less than 3 years and has recently been commissioned at full power of a 28 GHz gyrotron and three-frequency heating (28 + 45 + 18 GHz). New record beam intensities for highly charged ion production have been achieved, such as 620 eμA 40Ar16+, 15 eμA 40Ar18+, 146 eμA 86Kr28+, 0.5 eμA 86Kr33+, 53 eμA 129Xe38+, and 17 eμA 129Xe42+. Recent beam test results at SECRAL and SECRAL II have demonstrated that the production of more intense highly charged heavy ion beams needs higher microwave power and higher frequency, as the scaling law predicted. A 45 GHz superconducting ECR ion source FECR (a first fourth generation ECR ion source) is being built at IMP. FECR will be the world's first Nb3Sn superconducting-magnet-based ECR ion source with 6.5 T axial mirror field, 3.5 T sextupole field on the plasma chamber inner wall, and 20 kW at a 45 GHz microwave coupling system. This paper will focus on SECRAL performance studies at 24-28 GHz and technical design of 45 GHz FECR, which demonstrates a technical path for highly charged ion beam production from 24 to 28 GHz SECRAL to 45 GHz FECR.

Optimizing charge breeding techniques for ISOL facilities in Europe: Conclusions from the EMILIE project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delahaye, P., E-mail: delahaye@ganil.fr; Jardin, P.; Maunoury, L.

The present paper summarizes the results obtained from the past few years in the framework of the Enhanced Multi-Ionization of short-Lived Isotopes for Eurisol (EMILIE) project. The EMILIE project aims at improving the charge breeding techniques with both Electron Cyclotron Resonance Ion Sources (ECRIS) and Electron Beam Ion Sources (EBISs) for European Radioactive Ion Beam (RIB) facilities. Within EMILIE, an original technique for debunching the beam from EBIS charge breeders is being developed, for making an optimal use of the capabilities of CW post-accelerators of the future facilities. Such a debunching technique should eventually resolve duty cycle and time structuremore » issues which presently complicate the data-acquisition of experiments. The results of the first tests of this technique are reported here. In comparison with charge breeding with an EBIS, the ECRIS technique had lower performance in efficiency and attainable charge state for metallic ion beams and also suffered from issues related to beam contamination. In recent years, improvements have been made which significantly reduce the differences between the two techniques, making ECRIS charge breeding more attractive especially for CW machines producing intense beams. Upgraded versions of the Phoenix charge breeder, originally developed by LPSC, will be used at SPES and GANIL/SPIRAL. These two charge breeders have benefited from studies undertaken within EMILIE, which are also briefly summarized here.« less

Maximization of DRAM yield by control of surface charge and particle addition during high dose implantation

NASA Astrophysics Data System (ADS)

Horvath, J.; Moffatt, S.

1991-04-01

Ion implantation processing exposes semiconductor devices to an energetic ion beam in order to deposit dopant ions in shallow layers. In addition to this primary process, foreign materials are deposited as particles and surface films. The deposition of particles is a major cause of IC yield loss and becomes even more significant as device dimensions are decreased. Control of particle addition in a high-volume production environment requires procedures to limit beamline and endstation sources, control of particle transport, cleaning procedures and a well grounded preventative maintenance philosophy. Control of surface charge by optimization of the ion beam and electron shower conditions and measurement with a real-time charge sensor has been effective in improving the yield of NMOS and CMOS DRAMs. Control of surface voltages to a range between 0 and -20 V was correlated with good implant yield with PI9200 implanters for p + and n + source-drain implants.

Behavior of moving plasma in solenoidal magnetic field in a laser ion source

NASA Astrophysics Data System (ADS)

Ikeda, S.; Takahashi, K.; Okamura, M.; Horioka, K.

2016-02-01

In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

Behavior of moving plasma in solenoidal magnetic field in a laser ion source.

PubMed

Ikeda, S; Takahashi, K; Okamura, M; Horioka, K

2016-02-01

In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

Characterization of charge separation in the Array of Micromachined UltraSonic Electrospray (AMUSE) ion source for mass spectrometry.

PubMed

Forbes, Thomas P; Dixon, R Brent; Muddiman, David C; Degertekin, F Levent; Fedorov, Andrei G

2009-09-01

An initial investigation into the effects of charge separation in the Array of Micromachined UltraSonic Electrospray (AMUSE) ion source is reported to gain understanding of ionization mechanisms and to improve analyte ionization efficiency and operation stability. In RF-only mode, AMUSE ejects, on average, an equal number of slightly positive and slightly negative charged droplets due to random charge fluctuations, providing inefficient analyte ionization. Charge separation at the nozzle orifice is achieved by the application of an external electric field. By bringing the counter electrode close to the nozzle array, strong electric fields can be applied at relatively low DC potentials. It has been demonstrated, through a number of electrode/electrical potential configurations, that increasing charge separation leads to improvement in signal abundance, signal-to-noise ratio, and signal stability.

Results of RIKEN superconducting electron cyclotron resonance ion source with 28 GHz.

PubMed

Higurashi, Y; Ohnishi, J; Nakagawa, T; Haba, H; Tamura, M; Aihara, T; Fujimaki, M; Komiyama, M; Uchiyama, A; Kamigaito, O

2012-02-01

We measured the beam intensity of highly charged heavy ions and x-ray heat load for RIKEN superconducting electron cyclotron resonance ion source with 28 GHz microwaves under the various conditions. The beam intensity of Xe(20+) became maximum at B(min) ∼ 0.65 T, which was ∼65% of the magnetic field strength of electron cyclotron resonance (B(ECR)) for 28 GHz microwaves. We observed that the heat load of x-ray increased with decreasing gas pressure and field gradient at resonance zone. It seems that the beam intensity of highly charged heavy ions with 28 GHz is higher than that with 18 GHz at same RF power.

First test of BNL electron beam ion source with high current density electron beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pikin, Alexander, E-mail: pikin@bnl.gov; Alessi, James G., E-mail: pikin@bnl.gov; Beebe, Edward N., E-mail: pikin@bnl.gov

A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm{sup 2} and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, themore » EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given.« less

Charge state breeding experiences and plans at TRIUMF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ames, F., E-mail: ames@triumf.ca; Marchetto, M.; Mjøs, A.

At the Isotope Separation and ACceleration (ISAC) facility at TRIUMF, an electron cyclotron resonance ion source (ECRIS) has been set up for the charge state breeding of radioactive ions. In order to reduce background from stable ions generated in the ECRIS, several measures, including changing materials for the plasma chamber and the surrounding components, have been implemented. Further reduction has been achieved by using the post-accelerator chain as a mass filter. Since the implementation of those measures in 2013, physics experiments with accelerated radioactive isotopes of Rb, Sr, K, and Mg have been performed. In most cases, a charge breedingmore » efficiency of several percent has been achieved. With the planned expansion of the isotope production capabilities at TRIUMF within the Advanced Rare IsotopE Laboratory project, two new target stations, one using photo-fission induced by a high-power electron beam at 50 MeV and the other one using 480 MeV protons as at ISAC, will be put into operation within the next 5 yr. Additionally, a new electron beam ion source (EBIS) based charge state breeding system will be installed. Background from such a source is expected to be much lower. The drawback is that for the efficient operation of such a system, pulsed beam operation is required, which makes the installation of an additional ion buncher in front of the EBIS necessary.« less

Laser ion source with solenoid field

NASA Astrophysics Data System (ADS)

Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

2014-11-01

Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

Production of High Energy Ions Near an Ion Thruster Discharge Hollow Cathode

NASA Technical Reports Server (NTRS)

Katz, Ira; Mikellides, I. G.; Goebel, D. M.; Jameson, K. K.; Wirz, R.; Polk, James E.

2006-01-01

Several researchers have measured ions leaving ion thruster discharge chambers with energies far greater than measured discharge chamber potentials. Presented in this paper is a new mechanism for the generation of high energy ions and a comparison with measured ion spectra. The source of high energy ions has been a puzzle because they not only have energies in excess of measured steady state potentials, but as reported by Goebel et. al. [1], their flux is independent of the amplitude of time dependent plasma fluctuations. The mechanism relies on the charge exchange neutralization of xenon ions accelerated radially into the potential trough in front of the discharge cathode. Previous researchers [2] have identified the importance of charge exchange in this region as a mechanism for protecting discharge cathode surfaces from ion bombardment. This paper is the first to identify how charge exchange in this region can lead to ion energy enhancement.

Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap.

PubMed

Nikolaev, A G; Savkin, K P; Oks, E M; Vizir, A V; Yushkov, G Yu; Vodopyanov, A V; Izotov, I V; Mansfeld, D A

2012-02-01

A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent "minimum-B" structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap--axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 μs) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

The Role of Dopant Ions on Charge Injection and Transport in Electrochemically Doped Quantum Dot Films.

PubMed

Gudjonsdottir, Solrun; van der Stam, Ward; Kirkwood, Nicholas; Evers, Wiel H; Houtepen, Arjan J

2018-05-16

Control over the charge density is very important for implementation of colloidal semiconductor nanocrystals into various optoelectronic applications. A promising approach to dope nanocrystal assemblies is charge injection by electrochemistry, in which the charge compensating electrolyte ions can be regarded as external dopant ions. To gain insight into the doping mechanism and the role of the external dopant ions, we investigate charge injection in ZnO nanocrystal assemblies for a large series of charge compensating electrolyte ions with spectroelectrochemical and electrochemical transistor measurements. We show that charge injection is limited by the diffusion of cations in the nanocrystal films as their diffusion coefficient are found to be ∼7 orders of magnitude lower than those of electrons. We further show that the rate of charge injection depends strongly on the cation size and cation concentration. Strikingly, the onset of electron injection varies up to 0.4 V, depending on the size of the electrolyte cation. For the small ions Li + and Na + the onset is at significantly less negative potentials. For larger ions (K + , quaternary ammonium ions) the onset is always at the same, more negative potential, suggesting that intercalation may take place for Li + and Na + . Finally, we show that the nature of the charge compensating cation does not affect the source-drain electronic conductivity and mobility, indicating that shallow donor levels from intercalating ions fully hybridize with the quantum confined energy levels and that the reorganization energy due to intercalating ions does not strongly affect electron transport in these nanocrystal assemblies.

The Role of Dopant Ions on Charge Injection and Transport in Electrochemically Doped Quantum Dot Films

PubMed Central

2018-01-01

Control over the charge density is very important for implementation of colloidal semiconductor nanocrystals into various optoelectronic applications. A promising approach to dope nanocrystal assemblies is charge injection by electrochemistry, in which the charge compensating electrolyte ions can be regarded as external dopant ions. To gain insight into the doping mechanism and the role of the external dopant ions, we investigate charge injection in ZnO nanocrystal assemblies for a large series of charge compensating electrolyte ions with spectroelectrochemical and electrochemical transistor measurements. We show that charge injection is limited by the diffusion of cations in the nanocrystal films as their diffusion coefficient are found to be ∼7 orders of magnitude lower than those of electrons. We further show that the rate of charge injection depends strongly on the cation size and cation concentration. Strikingly, the onset of electron injection varies up to 0.4 V, depending on the size of the electrolyte cation. For the small ions Li+ and Na+ the onset is at significantly less negative potentials. For larger ions (K+, quaternary ammonium ions) the onset is always at the same, more negative potential, suggesting that intercalation may take place for Li+ and Na+. Finally, we show that the nature of the charge compensating cation does not affect the source-drain electronic conductivity and mobility, indicating that shallow donor levels from intercalating ions fully hybridize with the quantum confined energy levels and that the reorganization energy due to intercalating ions does not strongly affect electron transport in these nanocrystal assemblies. PMID:29718666

Ionization based multi-directional flow sensor

DOEpatents

Chorpening, Benjamin T [Morgantown, WV; Casleton, Kent H [Morgantown, WV

2009-04-28

A method, system, and apparatus for conducting real-time monitoring of flow (airflow for example) in a system (a hybrid power generation system for example) is disclosed. The method, system and apparatus measure at least flow direction and velocity with minimal pressure drop and fast response. The apparatus comprises an ion source and a multi-directional collection device proximate the ion source. The ion source is configured to generate charged species (electrons and ions for example). The multi-directional collection source is configured to determine the direction and velocity of the flow in real-time.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maimone, F., E-mail: f.maimone@gsi.de; Tinschert, K.; Endermann, M.

In order to increase the intensity of the highly charged ions produced by the Electron Cyclotron Resonance Ion Sources (ECRISs), techniques like the frequency tuning and the afterglow mode have been developed and in this paper the effect on the ion production is shown for the first time when combining both techniques. Recent experimental results proved that the tuning of the operating frequency of the ECRIS is a promising technique to achieve higher ion currents of higher charge states. On the other hand, it is well known that the afterglow mode of the ECRIS operation can provide more intense pulsedmore » ion beams in comparison with the continuous wave (cw) operation. These two techniques can be combined by pulsing the variable frequency signal driving the traveling wave tube amplifier which provides the high microwave power to the ECRIS. In order to analyze the effect of these two combined techniques on the ion source performance, several experiments were carried out on the pulsed frequency tuned CAPRICE (Compacte source A Plusiers Résonances Ionisantes Cyclotron Electroniques)-type ECRIS. Different waveforms and pulse lengths have been investigated under different settings of the ion source. The results of the pulsed mode have been compared with those of cw operation.« less

Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

NASA Astrophysics Data System (ADS)

Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Hojo, S.; Sakamoto, Y.; Sato, S.; Ogawa, Hirotsugu; Yamada, S.; Ogawa, Hiroyuki; Yoshida, Y.; Ueda, T.; Miyazaki, H.; Drentje, A. G.

2008-11-01

Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C4+ based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C4+ was obtained to be 618 eμA under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

Current-voltage characteristics influenced by the nanochannel diameter and surface charge density in a fluidic field-effect-transistor.

PubMed

Singh, Kunwar Pal; Guo, Chunlei

2017-06-21

The nanochannel diameter and surface charge density have a significant impact on current-voltage characteristics in a nanofluidic transistor. We have simulated the effect of the channel diameter and surface charge density on current-voltage characteristics of a fluidic nanochannel with positive surface charge on its walls and a gate electrode on its surface. Anion depletion/enrichment leads to a decrease/increase in ion current with gate potential. The ion current tends to increase linearly with gate potential for narrow channels at high surface charge densities and narrow channels are more effective to control the ion current at high surface charge densities. The current-voltage characteristics are highly nonlinear for wide channels at low surface charge densities and they show different regions of current change with gate potential. The ion current decreases with gate potential after attaining a peak value for wide channels at low values of surface charge densities. At low surface charge densities, the ion current can be controlled by a narrow range of gate potentials for wide channels. The current change with source drain voltage shows ohmic, limiting and overlimiting regions.

Emittance study of a 28 GHz electron cyclotron resonance ion source for the Rare Isotope Science Project superconducting linear accelerator.

PubMed

Park, Bum-Sik; Hong, In-Seok; Jang, Ji-Ho; Jin, Hyunchang; Choi, Sukjin; Kim, Yonghwan

2016-02-01

A 28 GHz electron cyclotron resonance (ECR) ion source is being developed for use as an injector for the superconducting linear accelerator of the Rare Isotope Science Project. Beam extraction from the ECR ion source has been simulated using the KOBRA3-INP software. The simulation software can calculate charged particle trajectories in three dimensional complex magnetic field structures, which in this case are formed by the arrangement of five superconducting magnets. In this study, the beam emittance is simulated to understand the effects of plasma potential, mass-to-charge ratio, and spatial distribution. The results of these simulations and their comparison to experimental results are presented in this paper.

Nonlinear ion dynamics in Hall thruster plasma source by ion transit-time instability

NASA Astrophysics Data System (ADS)

Lim, Youbong; Choe, Wonho; Mazouffre, Stéphane; Park, Jae Sun; Kim, Holak; Seon, Jongho; Garrigues, L.

2017-03-01

High-energy tail formation in an ion energy distribution function (IEDF) is explained in a Hall thruster plasma with the stationary crossed electric and magnetic fields whose discharge current is oscillated at the ion transit-time scale with a frequency of 360 kHz. Among ions in different charge states, singly charged Xe ions (Xe+) have an IEDF that is significantly broadened and shifted toward the high-energy side, which contributes to tail formation in the entire IEDF. Analytical and numerical investigations confirm that the IEDF tail is due to nonlinear ion dynamics in the ion transit-time oscillation.

High current multicharged metal ion source using high power gyrotron heating of vacuum arc plasma.

PubMed

Vodopyanov, A V; Golubev, S V; Khizhnyak, V I; Mansfeld, D A; Nikolaev, A G; Oks, E M; Savkin, K P; Vizir, A V; Yushkov, G Yu

2008-02-01

A high current, multi charged, metal ion source using electron heating of vacuum arc plasma by high power gyrotron radiation has been developed. The plasma is confined in a simple mirror trap with peak magnetic field in the plug up to 2.5 T, mirror ratio of 3-5, and length variable from 15 to 20 cm. Plasma formed by a cathodic vacuum arc is injected into the trap either (i) axially using a compact vacuum arc plasma gun located on axis outside the mirror trap region or (ii) radially using four plasma guns surrounding the trap at midplane. Microwave heating of the mirror-confined, vacuum arc plasma is accomplished by gyrotron microwave radiation of frequency 75 GHz, power up to 200 kW, and pulse duration up to 150 micros, leading to additional stripping of metal ions by electron impact. Pulsed beams of platinum ions with charge state up to 10+, a mean charge state over 6+, and total (all charge states) beam current of a few hundred milliamperes have been formed.

Wall charging of a helicon antenna wrapped plasma filled dielectric tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barada, Kshitish K., E-mail: kbarada@physics.ucla.edu; Chattopadhyay, P. K., E-mail: pkchatto@ipr.res.in; Ghosh, J.

2015-01-15

Dielectric wall charging of a cylindrical glass wall surrounded by a helicon antenna of 18 cm length is measured in a linear helicon plasma device with a diverging magnetic field. The ions because of their lesser mobility do not respond to the high frequency electric field and the electrons charge the wall to a negative DC potential also known as the DC self-bias. The wall potential in this device is characterized for different neutral pressure, magnetic field, and radio frequency (RF) power. Axial variation of wall potential shows higher self-bias potentials near the antenna rings. Ion magnetization in the source chambermore » increases both wall charging and plasma potential of the source due to confinement.« less

Techniques for correcting velocity and density fluctuations of ion beams in ion inducti on accelerators

NASA Astrophysics Data System (ADS)

Woo, K. M.; Yu, S. S.; Barnard, J. J.

2013-06-01

It is well known that the imperfection of pulse power sources that drive the linear induction accelerators can lead to time-varying fluctuation in the accelerating voltages, which in turn leads to longitudinal emittance growth. We show that this source of emittance growth is correctable, even in space-charge dominated beams with significant transients induced by space-charge waves. Two correction methods are proposed, and their efficacy in reducing longitudinal emittance is demonstrated with three-dimensional particle-in-cell simulations.

Characterization of Charge Separation in the Array of Micromachined UltraSonic Electrospray (AMUSE) Ion Source for Mass Spectrometry

PubMed Central

Forbes, Thomas P.; Dixon, R. Brent; Muddiman, David C.; Degertekin, F. Levent; Fedorov, Andrei G.

2009-01-01

An initial investigation into the effects of charge separation in the Array of Micromachined UltraSonic Electrospray (AMUSE) ion source is reported in order to gain understanding of ionization mechanisms and to improve analyte ionization efficiency and operation stability. In RF-only mode, AMUSE ejects on average, an equal number of slightly positive and slightly negative charged droplets due to random charge fluctuations, providing inefficient analyte ionization. Charge separation at the nozzle orifice is achieved by the application of an external electric field. By bringing the counter electrode close to the nozzle array, strong electric fields can be applied at relatively low DC potentials. It has been demonstrated, through a number of electrode/electrical potential configurations that increasing charge separation leads to improvement in signal abundance, signal-to-noise ratio, and signal stability. PMID:19525123

Ion Sources

NASA Astrophysics Data System (ADS)

Haseroth, Helmut; Hora, Heinrich

1993-03-01

Ion sources for accelerators are based on plasma configurations with an extraction system in order to gain a very high number of ions within an appropriately short pulse and of sufficiently high charge number Z for advanced research. Beginning with the duoplasmatron, all established ion sources are based on low-density plasmas, of which the electron beam ionization source (EBIS) and the electron cyclotron resonance (ECR) source are the most advanced; for example they result in pulses of nearly 6 × 108 fully stripped sulfur ions per pulse in the Super Proton Synchrotron (SPS) at CERN with energies of 200 GeV/u. As an example of a forthcoming development, we are reporting about the lead ion source for the same purpose. Contrary to these cases of low-density plasmas, where a rather long time is always necessary to generate sufficiently high charge states, the laser ion source uses very high density plasmas and therefore produced, for example in 1983, single shots of Au51+ ions of high directivity with energies above 300 MeV within 2 ns irradiation time of a gold target with a medium-to-large CO2 laser. Experiments at Dubna and Moscow, using small-size lasers, produced up to one million shots with 1 Hz sequence. After acceleration by a linac or otherwise, ion pulses of up to nearly 5 × 1010 ions of C4+ or Mg12+ with energies in the synchrotrons of up to 2 GeV/u were produced. The physics of the laser generation of the ions is most complex, as we know from laser fusion studies, including non-linear dynamic and dielectric effects, resonances, self-focusing, instabilities, double layers, and an irregular pulsation in the 20 ps range. This explains not only what difficulties are implied with the laser ion source, but also why it opens up a new direction of ion sources.

ION SOURCE FOR A CALUTRON

DOEpatents

Lofgren, E.J.

1959-04-14

This patcnt relates to calutron devices and deals particularly with the mechanism used to produce the beam of ions wherein a charge material which is a vapor at room temperature is used. A charge container located outside the tank is connected through several conduits to various points along the arc chamber of the ion source. In addition, the rate of flow of the vapor to the arc chamber is controlled by a throttle valve in each conduit. By this arrangement the arc can be regulated accurately and without appreciable time lag, inasmuch as the rate of vapor flow is immediately responsive to the manipulation of the throttle valves.

Low energy ion beam dynamics of NANOGAN ECR ion source

NASA Astrophysics Data System (ADS)

Kumar, Sarvesh; Mandal, A.

2016-04-01

A new low energy ion beam facility (LEIBF) has been developed for providing the mass analyzed highly charged intense ion beams of energy ranging from a few tens of keV to a few MeV for atomic, molecular and materials sciences research. The new facility consists of an all permanent magnet 10 GHz electron cyclotron resonance (ECR) ion source (NANOGAN) installed on a high voltage platform (400 kV) which provides large currents of multiply charged ion beams. Higher emittance at low energy of intense ion beam puts a tremendous challenge to the beam optical design of this facility. The beam line consists of mainly the electrostatic quadrupoles, an accelerating section, analyzing cum switching magnet and suitable beam diagnostics including vacuum components. The accelerated ion beam is analyzed for a particular mass to charge (m/q) ratio as well as guided to three different lines along 75°, 90° and 105° using a large acceptance analyzing cum switching magnet. The details of transverse beam optics to all the beam lines with TRANSPORT and GICOSY beam optics codes are being described. Field computation code, OPERA 3D has been utilized to design the magnets and electrostatic quadrupoles. A theoretical estimation of emittance for optimized geometry of ion source is given so as to form the basis of beam optics calculations. The method of quadrupole scan of the beam is used to characterize the emittance of the final beam on the target. The measured beam emittance increases with m/q ratios of various ion beams similar to the trend observed theoretically.

Laser ion source with solenoid field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanesue, Takeshi, E-mail: tkanesue@bnl.gov; Okamura, Masahiro; Fuwa, Yasuhiro

2014-11-10

Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 10{sup 11}, which was provided by a single 1 J Nd-YAGmore » laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.« less

Laser ion source with solenoid field

DOE PAGES

Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; ...

2014-11-12

Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. In this study, the laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 10 11,more » which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.« less

Near Earth Inner-Source and Interstellar Pickup Ions Observed with the Hot Plasma Composition Analyzer of the Magnetospheric Multiscale Mission Mms-Hpca

NASA Astrophysics Data System (ADS)

Gomez, R. G.; Fuselier, S. A.; Mukherjee, J.; Gonzalez, C. A.

2017-12-01

Pickup ions found near the earth are generally picked up in the rest frame of the solar wind, and propagate radially outward from their point of origin. While propagating, they simultaneously gyrate about the magnetic field. Pickup ions come in two general populations; interstellar and inner source ions. Interstellar ions originate in the interstellar medium, enter the solar system in a neutral charge state, are gravitationally focused on the side of the sun opposite their arrival direction and, are ionized when they travel near the sun. Inner-source ions originate at a location within the solar system and between the sun and the observation point. Both pickup ion populations share similarities in composition and charge states, so measuring of their dynamics, using their velocity distribution functions, f(v)'s, is absolutely essential to distinguishing them, and to determining their spatial and temporal origins. Presented here will be the results of studies conducted with the four Hot Plasma Composition Analyzers of the Magnetospheric Multiscale Mission (MMS-HPCA). These instruments measure the full sky (4π steradians) distribution functions of near earth plasmas at a 10 second cadence in an energy-to-charge range 0.001-40 keV/e. The instruments are also capable of parsing this combined energy-solid angle phase space with 22.5° resolution polar angle, and 11.25° in azimuthal angle, allowing for clear measurement of the pitch angle scattering of the ions.

Implementation of a Battery Health Monitor and Vertical Lift Aircraft Testbed for the Application of an Electrochemisty-Based State of Charge Estimator

NASA Technical Reports Server (NTRS)

Potteiger, Timothy R.; Eure, Kenneth W.; Levenstein, David

2017-01-01

Prediction methods concerning remaining charge in lithium-ion batteries that power unmanned aerial vehicles are of critical concern for the safe fulfillment of mission objectives. In recent years, lithium-ion batteries have been the power source for both fixed wing and vertical lift electric vehicles. The purpose of this document is to describe in detail the implementation of a battery health monitor for estimating the state of charge of a lithium-ion battery and a lithium-ion polymer battery that is used to power a vertical lift aircraft test-bed. It will be demonstrated that an electro-chemistry based state of charge estimator effectively tracks battery discharge characteristics and may be employed as a useful tool in monitoring battery health.

Solar Wind Charge Exchange Studies Of Highly Charged Ions On Atomic Hydrogen

NASA Astrophysics Data System (ADS)

Draganić, I. N.; Seely, D. G.; McCammon, D.; Havener, C. C.

2011-06-01

Accurate studies of low-energy charge exchange (CX) are critical to understanding underlying soft X-ray radiation processes in the interaction of highly charged ions from the solar wind with the neutral atoms and molecules in the heliosphere, cometary comas, planetary atmospheres, interstellar winds, etc.. Particularly important are the CX cross sections for bare, H-like, and He-like ions of C, N, O and Ne, which are the dominant charge states for these heavier elements in the solar wind. Absolute total cross sections for single electron capture by H-like ions of C, N, O and fully-stripped O ions from atomic hydrogen have been measured in an expanded range of relative collision energies (5 eV/u-20 keV/u) and compared to previous H-oven measurements. The present measurements are performed using a merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source installed on a high voltage platform at the Oak Ridge National Laboratory. For the collision energy range of 0.3 keV/u-3.3 keV/u, which corresponds to typical ion velocities in the solar wind, the new measurements are in good agreement with previous H-oven measurements. The experimental results are discussed in detail and compared with theoretical calculations where available.

Low temperature ion source for calutrons

DOEpatents

Veach, Allen M.; Bell, Jr., William A.; Howell, Jr., George D.

1981-01-01

A new ion source assembly for calutrons has been provided for the efficient separation of elements having high vapor pressures. The strategic location of cooling pads and improved insulation permits operation of the source at lower temperatures. A vapor valve constructed of graphite and located in a constantly increasing temperature gradient provides reliable control of the vapor flow from the charge bottle to the arc chamber. A pronounced saving in calutron operating time and equipment maintenance has been achieved with the use of the present ion source.

Low temperature ion source for calutrons

DOEpatents

Veach, A.M.; Bell, W.A. Jr.; Howell, G.D. Jr.

1979-10-10

A new ion source assembly for calutrons has been provided for the efficient separation of elements having high vapor pressures. The strategic location of cooling pads and improved insulation permits operation of the source at lower temperatures. A vapor valve constructed of graphite and located in a constantly increasing temperature gradient provides reliable control of the vapor flow from the charge bottle to the arc chamber. A pronounced saving in calutron operating time and equipment maintenance has been achieved with the use of the present ion source.

Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

PubMed Central

Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; Moore, Ronald J.; Ibrahim, Yehia M.; Smith, Richard D.

2016-01-01

The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher-pressure regions (e.g., ion source interfaces) of mass spectrometers, thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to-charge ratios. In this study, a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadrupole mass spectrometer was developed and characterized. An orthogonal ion injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at a pressure of 9–10 Torr. Key factors for the HPIF performance characterized included the effects of RF amplitude, the DC gradient, and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. The sensitivity enhancement in liquid chromatography selected reaction monitoring (LC-SRM) analyses of low-abundance peptides spiked into a highly complex mixture was also compared with that obtained using both a commercial S-lens interface and an in-line dual-ion funnel interface. PMID:26107611

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanesue, Takeshi; Ikeda, Shunsuke

A laser ion source is a promising candidate as an ion source for heavy ion inertial fusion (HIF), where a pulsed ultra-intense and low-charged heavy ion beam is required. It is a key development for a laser ion source to transport laser-produced plasma with a magnetic field to achieve a high current beam. The effect of a tapered magnetic field on laser produced plasma is demonstrated by comparing the results with a straight solenoid magnet. The magnetic field of interest is a wider aperture on a target side and narrower aperture on an extraction side. Furthermore, based on the experimentallymore » obtained results, the performance of a scaled laser ion source for HIF was estimated.« less

Design for simultaneous acceleration of stable and unstable beams in a superconducting heavy-ion linear accelerator for RISP

NASA Astrophysics Data System (ADS)

Kim, Jongwon; Son, Hyock-Jun; Park, Young-Ho

2017-11-01

The post-accelerator of isotope separation on-line (ISOL) system for rare isotope science project (RISP) is a superconducting linear accelerator (SC-linac) with a DC equivalent voltage of around 160 MV. An isotope beam extracted from the ISOL is in a charge state of 1+ and its charge state is increased to n+ by charge breeding with an electron beam ion source (EBIS). The charge breeding takes tens of ms and the pulse width of extracted beam from the EBIS is tens of μs, which operates at up to 30 Hz. Consequently a large portion of radio frequency (rf) time of the post SC-linac is unused. The post-linac is equipped also with an electron cyclotron resonance (ECR) ion source for stable ion acceleration. Thanks to the large phase acceptance of SC-linac, it is possible to accelerate simultaneously both stable and radioisotope ions with a similar charge to mass ratio by sharing rf time. This operation scheme is implemented for RISP with the addition of an electric chopper and magnetic kickers. The facility will be capable of providing the users of the ISOL and in-flight fragmentation (IF) systems with different beams simultaneously, which would help nuclear science users in obtaining a beam time as high-precision measurements often need long hours.

A Charge-Exchange Neutral Particle Analyzer for an Inertial Electrostatic Confinement Fusion Device

NASA Astrophysics Data System (ADS)

Becerra, Gabriel; Kulcinski, Gerald; Santarius, John; Emmert, Gilbert

2013-10-01

An electrostatic energy analyzer for outgoing charge-exchange neutral particles has been designed and constructed for application on HELIOS, an inertial electrostatic confinement (IEC) fusion device designed for advanced fuel studies. Ions are extracted from an external helicon plasma source and subsequently accelerated radially into an electrostatic potential well set up by a semi-transparent cathode grid inside the HELIOS spherical chamber. Analysis of fast neutrals produced by charge exchange between energetic ions and background gas yields information on primary ion energy spectra, as well as a quantitative measure of charge exchange as an energy loss mechanism in IEC devices. Preliminary data with helium is used to benchmark the two-charge-state helium formalism of VICTER, a numerical code on spherically convergent ion flow, as it relates to IEC operation with helium-3 fuel. Research supported by the Greatbatch Foundation.

Challenges/issues of NIS used in particle accelerator facilities

NASA Astrophysics Data System (ADS)

Faircloth, Dan

2013-09-01

High current, high duty cycle negative ion sources are an essential component of many high power particle accelerators. This talk gives an overview of the state-of-the-art sources used around the world. Volume, surface and charge exchange negative ion production processes are detailed. Cesiated magnetron and Penning surface plasma sources are discussed along with surface converter sources. Multicusp volume sources with filament and LaB6 cathodes are described before moving onto RF inductively coupled volume sources with internal and external antennas. The major challenges facing accelerator facilities are detailed. Beam current, source lifetime and reliability are the most pressing. The pros and cons of each source technology is discussed along with their development programs. The uncertainties and unknowns common to these sources are discussed. The dynamics of cesium surface coverage and the causes of source variability are still unknown. Minimizing beam emittance is essential to maximizing the transport of high current beams; space charge effects are very important. The basic physics of negative ion production is still not well understood, theoretical and experimental programs continue to improve this, but there are still many mysteries to be solved.

Microwave ion source

DOEpatents

Leung, Ka-Ngo; Reijonen, Jani; Thomae, Rainer W.

2005-07-26

A compact microwave ion source has a permanent magnet dipole field, a microwave launcher, and an extractor parallel to the source axis. The dipole field is in the form of a ring. The microwaves are launched from the middle of the dipole ring using a coaxial waveguide. Electrons are heated using ECR in the magnetic field. The ions are extracted from the side of the source from the middle of the dipole perpendicular to the source axis. The plasma density can be increased by boosting the microwave ion source by the addition of an RF antenna. Higher charge states can be achieved by increasing the microwave frequency. A xenon source with a magnetic pinch can be used to produce intense EUV radiation.

Operation of the CAPRICE electron cyclotron resonance ion source applying frequency tuning and double frequency heating.

PubMed

Maimone, F; Tinschert, K; Celona, L; Lang, R; Mäder, J; Rossbach, J; Spädtke, P

2012-02-01

The properties of the electromagnetic waves heating the electrons of the ECR ion sources (ECRIS) plasma affect the features of the extracted ion beams such as the emittance, the shape, and the current, in particular for higher charge states. The electron heating methods such as the frequency tuning effect and the double frequency heating are widely used for enhancing the performances of ECRIS or even for the routine operation during the beam production. In order to better investigate these effects the CAPRICE ECRIS has been operated using these techniques. The ion beam properties for highly charged ions have been measured with beam diagnostic tools. The reason of the observed variations of this performance can be related to the different electromagnetic field patterns, which are changing inside the plasma chamber when the frequency is varying.

Soft Landing of Mass-Selected Gold Clusters: Influence of Ion and Ligand on Charge Retention and Reactivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Grant E.; Laskin, Julia

Herein, we employ a combination of reduction synthesis in solution, soft landing of mass-selected precursor and product ions, and in situ time-of-flight secondary ion mass spectrometry (TOF-SIMS) to examine the influence of ion and the length of diphosphine ligands on the charge retention and reactivity of ligated gold clusters deposited onto self-assembled monolayer surfaces (SAMs). Product ions (Au10L42+, (10,4)2+, L = 1,3-bis(diphenyl-phosphino)propane, DPPP) were prepared through in-source collision induced dissociation (CID) and precursor ions [(8,4)2+, L = 1,6-bis(diphenylphosphino)hexane, DPPH] were synthesized in solution for comparison to (11,5)3+ precursor ions ligated with DPPP investigated previously (ACS Nano 2012, 6, 573 andmore » J. Phys. Chem. C. 2012, 116, 24977). Similar to (11,5)3+ precursor ions, the (10,4)2+ product ions are shown to retain charge on 1H,1H,2H,2H-perfluorodecanethiol monolayers (FSAMs). Additional abundant peaks at higher m/z indicative of reactivity are observed in the TOF-SIMS spectrum of (10,4)2+ product ions that are not seen for (11,5)3+ precursor ions. The abundance of (10,4)2+ on 16-mercaptohexadecanoic acid (COOH-SAMs) is demonstrated to be lower than on FSAMs, consistent with partial reduction of charge. The (10,4)2+ product ion on 1-dodecanethiol (HSAMs) exhibits peaks similar to those seen on the COOH-SAM. On the HSAM, higher m/z peaks indicative of reactivity are observed similar to those on the FSAM. The (8,4)2+ DPPH precursor ions are shown to retain charge on FSAMs similar to (11,5)3+ precursor ions prepared with DPPP. An additional peak corresponding to attachment of one gold atom to (8,4)2+ is observed at higher m/z for DPPH-ligated clusters. On the COOH-SAM, (8,4)2+ is less abundant than on the FSAM consistent with partial neutralization. The results indicate that although retention of charge by product ions generated by CID is similar to precursor ions their reactivity during analysis with SIMS is different resulting in the formation of peaks corresponding to reaction products. The length of the ligand exerts only a minor influence on the charge retention and reactivity of gold clusters. Based on the observed reactivity of (10,4)2+ it is anticipated that in-source CID will be increasingly applied for the preparation of a distribution of product ions, including undercoordinated and reactive species, for soft landing onto surfaces.« less

Recent charge-breeding developments with EBIS/T devices (invited).

PubMed

Schwarz, S; Lapierre, A

2016-02-01

Short breeding times, narrow charge state distributions, low background, high efficiency, and the flexible time structure of the ejected low-emittance ion pulses are among the most attractive features of electron beam ion source or trap (EBIS/T) based charge breeders. Significant progress has been made to further improve these properties: Several groups are working to increase current densities towards 10(3) or even 10(4) A/cm(2). These current densities will become necessary to deliver high charge states of heavy nuclei in a short time and/or provide sufficient space-charge capacity to handle high-current ion beams in next-generation rare-isotope beam (RIB) facilities. Efficient capture of continuous beams, attractive because of its potential of handling highest-current ion beams, has become possible with the development of high-density electron beams of >1 A. Requests for the time structure of the charge bred ion pulse range from ultra-short pulses to quasi-continuous beams. Progress is being made on both ends of this spectrum, by either dividing the extracted charge in many pulse-lets, adjusting the extraction potential for a near-uniform long pulse, or adding dedicated devices to spread the ion bunches delivered from the EBIS/T in time. Advances in EBIS/T charge state breeding are summarized, including recent results with NSCL's ReA EBIS/T charge breeder.

Recent charge-breeding developments with EBIS/T devices (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwarz, S., E-mail: schwarz@nscl.msu.edu; Lapierre, A.

Short breeding times, narrow charge state distributions, low background, high efficiency, and the flexible time structure of the ejected low-emittance ion pulses are among the most attractive features of electron beam ion source or trap (EBIS/T) based charge breeders. Significant progress has been made to further improve these properties: Several groups are working to increase current densities towards 10{sup 3} or even 10{sup 4} A/cm{sup 2}. These current densities will become necessary to deliver high charge states of heavy nuclei in a short time and/or provide sufficient space-charge capacity to handle high-current ion beams in next-generation rare-isotope beam (RIB) facilities.more » Efficient capture of continuous beams, attractive because of its potential of handling highest-current ion beams, has become possible with the development of high-density electron beams of >1 A. Requests for the time structure of the charge bred ion pulse range from ultra-short pulses to quasi-continuous beams. Progress is being made on both ends of this spectrum, by either dividing the extracted charge in many pulse-lets, adjusting the extraction potential for a near-uniform long pulse, or adding dedicated devices to spread the ion bunches delivered from the EBIS/T in time. Advances in EBIS/T charge state breeding are summarized, including recent results with NSCL’s ReA EBIS/T charge breeder.« less

Accelerating Radioactive Ion Beams With REX-ISOLDE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ames, F.; Emhofer, S.; Habs, D.

2003-08-26

The post accelerator REX-ISOLDE is installed at the ISOLDE facility at CERN, where a broad variety of radioactive ions can be addressed. Since the end of 2001 beams at the final energy of 2.2 MeV/u are available. REX-ISOLDE uses a unique system of beam bunching and charge breeding. First a Penning trap accumulates and bunches the ions, which are delivered as a quasi-continuous beam from the ISOLDE target-ion-source, and then an electron beam ion source (EBIS) charge-breeds them to a mass-to-charge ratio below 4.5. This enables a very compact design for the following LINAC, consisting of a 4 rod RFQ,more » an IH structure and three 7-gap-resonators. The later ones allow a variation of the final energy between 0.8 and 2.2 MeV/u. Although the machine is still in the commissioning phase, first physics experiments have been done with neutron rich Na and Mg isotopes and 9Li. A total efficiency of several percent has already been obtained.« less

Effect of a metal-dielectric structure introduced in the plasma chamber of the Frankfurt 14 GHz electron cyclotron resonance ion source

NASA Astrophysics Data System (ADS)

Schächter, L.; Stiebing, K. E.; Dobrescu, S.; Badescu-Singureanu, Al. I.; Schmidt, L.; Hohn, O.; Runkel, S.

1999-02-01

A new approach of the possibility to significantly increase the high charge state ion beams delivered by electron cyclotron resonance (ECR) ion sources by using metal-dielectric (MD) structures characterized by high secondary electron emission properties is presented. The intensities of argon ion beams extracted from the 14 GHz electron cyclotron resonance ion source of the Institut für Kernphysik (IKF) der Johann Wolfgang Goethe-Universität in Frankfurt/Main were measured when a 26 mm diam disk of a specially treated MD structure (Al-Al2O3) was introduced axially close to the ECR plasma. The Ar beam intensities and charge-state distributions obtained with this disk are compared to measurements with disks of iron and pure aluminum at the same position relative to the plasma. All measurements were performed with the disk at the plasma chamber potential. The results with the MD structure show a net shift of the beam intensity towards higher charge states as compared with the other disk materials. Enhancement factors of the beam current of up to 10 (for Ar12+) when using a MD disk compared to the output when using an aluminum disk and up to 40 (for Ar11+) when using an iron disk were measured.

Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

DOE PAGES

Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; ...

2015-06-24

The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ionmore » injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.« less

Laboratory Studies of Thermal Energy Charge Transfer of Multiply Charged Ions in Astrophysical Plasmas

NASA Technical Reports Server (NTRS)

Kwong, Victor H. S.

2003-01-01

The laser ablation/ion storage facility at the UNLV Physics Department has been dedicated to the study of atomic and molecular processes in low temperature plasmas. Our program focuses on the charge transfer (electron capture) of multiply charged ions and neutrals important in astrophysics. The electron transfer reactions with atoms and molecules is crucial to the ionization condition of neutral rich photoionized plasmas. With the successful deployment of the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Chandra X-ray Observatory by NASA high resolution VUV and X-ray emission spectra fiom various astrophysical objects have been collected. These spectra will be analyzed to determine the source of the emission and the chemical and physical environment of the source. The proper interpretation of these spectra will require complete knowledge of all the atomic processes in these plasmas. In a neutral rich environment, charge transfer can be the dominant process. The rate coefficients need to be known accurately. We have also extended our charge transfer measurements to KeV region with a pulsed ion beam. The inclusion of this facility into our current program provides flexibility in extending the measurement to higher energies (KeV) if needed. This flexibility enables us to address issues of immediate interest to the astrophysical community as new observations are made by high resolution space based observatories.

Method and source for producing a high concentration of positively charged molecular hydrogen or deuterium ions

DOEpatents

Ehlers, Kenneth W.; Leung, Ka-Ngo

1988-01-01

A high concentration of positive molecular ions of hydrogen or deuterium gas is extracted from a positive ion source having a short path length of extracted ions, relative to the mean free path of the gas molecules, to minimize the production of other ion species by collision between the positive ions and gas molecules. The ion source has arrays of permanent magnets to produce a multi-cusp magnetic field in regions remote from the plasma grid and the electron emitters, for largely confining the plasma to the space therebetween. The ion source has a chamber which is short in length, relative to its transverse dimensions, and the electron emitters are at an even shorter distance from the plasma grid, which contains one or more extraction apertures.

Studies of Ion Beam Charge Neutralization by Ferroelectric Plasma Sources

NASA Astrophysics Data System (ADS)

Stepanov, A.; Gilson, E. P.; Grisham, L.; Davidson, R. C.

2013-10-01

Space-charge forces limit the possible transverse compression of high perveance ion beams that are used in ion-beam-driven high energy density physics applications; the minimum radius to which a beam can be focused is an increasing function of perveance. The limit can be overcome if a plasma is introduced in the beam path between the focusing element and the target in order to neutralize the space charge of the beam. This concept has been implemented on the Neutralized Drift Compression eXperiment (NDCX) at LBNL using Ferroelectric Plasma Sources (FEPS). In our experiment at PPPL, we propagate a perveance-dominated ion beam through a FEPS to study the effect of the neutralizing plasma on the beam envelope and its evolution in time. A 30-60 keV space-charge-dominated Argon beam is focused with an Einzel lens into a FEPS located at the beam waist. The beam is intercepted downstream from the FEPS by a movable Faraday cup that provides time-resolved 2D current density profiles of the beam spot on target. We report results on: (a) dependence of charge neutralization on FEPS plasma density; (b) effects on beam emittance, and (c) time evolution of the beam envelope after the FEPS pulse. Research supported by the U.S. Department of Energy.

Preliminary result of rapid solenoid for controlling heavy-ion beam parameters of laser ion source

DOE PAGES

Okamura, M.; Sekine, M.; Ikeda, S.; ...

2015-03-13

To realize a heavy ion inertial fusion driver, we have studied a possibility of laser ion source (LIS). A LIS can provide high current high brightness heavy ion beams, however it was difficult to manipulate the beam parameters. To overcome the issue, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The rapid ramping magnetic field could enhance limited time slice of the current and simultaneously the beam emittance changed accordingly. This approach may also useful to realize an ion source for HIF power plant.

Preliminary Ionization Efficiencies of {sup 11}C and {sup 14}O with the LBNL ECR Ion Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Z.Q.; Cerny, J.; Guo, F.Q.

1998-10-05

High charge states, up to fully stripped {sup 11}C and {sup 14}O ion, beams have been produced with the electron cyclotron resonance ion sources (LBNL, ECR and AECR-U) at Lawrence Berkeley National Laboratory. The radioactive atoms of {sup 11}C and {sup 14}O were collected in batch mode with an LN{sub 2} trap and then bled into the ECR ion sources. Ionization efficiency as high as 11% for {sup 11}C{sup 4+} was achieved.

Studies on low energy beam transport for high intensity high charged ions at IMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Y., E-mail: yangyao@impcas.ac.cn; Lu, W.; Fang, X.

2014-02-15

Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou (SECRAL) is an advanced fully superconducting ECR ion source at IMP designed to be operational at the microwave frequency of 18–24 GHz. The existing SECRAL beam transmission line is composed of a solenoid lens and a 110° analyzing magnet. Simulations of particle tracking with 3D space charge effect and realistic 3D magnetic fields through the line were performed using particle-in-cell code. The results of the beam dynamics show that such a low energy beam is very sensitive to the space charge effect and significantly suffers from the second-order aberrationmore » of the analyzing magnet resulting in large emittance. However, the second-order aberration could be reduced by adding compensating sextupole components in the beam line. On this basis, a new 110° analyzing magnet with relatively larger acceptance and smaller aberration is designed and will be used in the design of low energy beam transport line for a new superconducting ECR ion source SECRAL-II. The features of the analyzer and the corresponding beam trajectory calculation will be detailed and discussed in this paper.« less

Means for obtaining a metal ion beam from a heavy-ion cyclotron source

DOEpatents

Hudson, E.D.; Mallory, M.L.

1975-08-01

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

Progress on MEVVA source VARIS at GSI

NASA Astrophysics Data System (ADS)

Adonin, A.; Hollinger, R.

2018-05-01

For the last few years, the development of the VARIS (vacuum arc ion source) was concentrated on several aspects. One of them was the production of high current ion beams of heavy metals such as Au, Pb, and Bi. The requested ion charge state for these ion species is 4+. This is quite challenging to produce in vacuum arc driven sources for reasonable beam pulse length (>120 µs) due to the physical properties of these elements. However, the situation can be dramatically improved by using the composite materials or alloys with enhanced physical properties of the cathodes. Another aspect is an increase of the beam brilliance for intense U4+ beams by the optimization of the geometry of the extraction system. A new 7-hole triode extraction system allows an increase of the extraction voltage from 30 kV to 40 kV and also reduces the outer aperture of the extracted ion beam. Thus, a record beam brilliance for the U4+ beam in front of the RFQ (Radio-Frequency Quadrupole) has been achieved, exceeding the RFQ space charge limit for an ion current of 15 mA. Several new projectiles in the middle-heavy region have been successfully developed from VARIS to fulfill the requirements of the future FAIR (Facility for Antiproton and Ion Research) programs. An influence of an auxiliary gas on the production performance of certain ion charge states as well as on operation stability has been investigated. The optimization of the ion source parameters for a maximum production efficiency and highest particle current in front of the RFQ has been performed. The next important aspect of the development will be the increase of the operation repetition rate of VARIS for all elements especially for uranium to 2.7 Hz in order to provide the maximum availability of high current ion beams for future FAIR experiments.

Emittance studies of the 2.45 GHz permanent magnet ECR ion source

NASA Astrophysics Data System (ADS)

Zelenak, A.; Bogomolov, S. L.; Yazvitsky, N. Yu.

2004-05-01

During the past several years different types of permanent magnet 2.45 GHz (electron cyclotron resonance) ion sources were developed for production of singly charged ions. Ion sources of this type are used in the first stage of DRIBs project, and are planned to be used in the MASHA mass separator. The emittance of the beam provided by the source is one of the important parameters for these applications. An emittance scanner composed from a set of parallel slits and rotary wire beam profile monitor was used for the studying of the beam emittance characteristics. The emittance of helium and argon ion beams was measured with different shapes of the plasma electrode for several ion source parameters: microwave power, source potential, plasma aperture-puller aperture gap distance, gas pressure. The results of measurements are compared with previous simulations of ion optics.

Off-line commissioning of EBIS and plans for its integration into ATLAS and CARIBU.

PubMed

Ostroumov, P N; Barcikowski, A; Dickerson, C A; Mustapha, B; Perry, A; Sharamentov, S I; Vondrasek, R C; Zinkann, G

2016-02-01

An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed at Argonne to breed radioactive beams from the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne Tandem Linac Accelerator System (ATLAS). The EBIS-CB will replace the existing ECR charge breeder to increase the intensity and significantly improve the purity of reaccelerated radioactive ion beams. The CARIBU EBIS-CB has been successfully commissioned offline with an external singly charged cesium ion source. The performance of the EBIS fully meets the specifications to breed rare isotope beams delivered from CARIBU. The EBIS is being relocated and integrated into ATLAS and CARIBU. A long electrostatic beam transport system including two 180° bends in the vertical plane has been designed. The commissioning of the EBIS and the beam transport system in their permanent location will start at the end of this year.

Off-line commissioning of EBIS and plans for its integration into ATLAS and CARIBU

NASA Astrophysics Data System (ADS)

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Mustapha, B.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G.

2016-02-01

An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed at Argonne to breed radioactive beams from the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne Tandem Linac Accelerator System (ATLAS). The EBIS-CB will replace the existing ECR charge breeder to increase the intensity and significantly improve the purity of reaccelerated radioactive ion beams. The CARIBU EBIS-CB has been successfully commissioned offline with an external singly charged cesium ion source. The performance of the EBIS fully meets the specifications to breed rare isotope beams delivered from CARIBU. The EBIS is being relocated and integrated into ATLAS and CARIBU. A long electrostatic beam transport system including two 180° bends in the vertical plane has been designed. The commissioning of the EBIS and the beam transport system in their permanent location will start at the end of this year.

Isotope separation by selective charge conversion and field deflection

DOEpatents

Hickman, Robert G.

1978-01-01

A deuterium-tritium separation system wherein a source beam comprised of positively ionized deuterium (D.sup.+) and tritium (T.sup.+) is converted at different charge-exchange cell sections of the system to negatively ionized deuterium (D.sup.-) and tritium (T.sup.-). First, energy is added to the beam to accelerate the D.sup.+ ions to the velocity that is optimum for conversion of the D.sup.+ ions to D.sup.- ions in a charge-exchange cell. The T.sup.+ ions are accelerated at the same time, but not to the optimum velocity since they are heavier than the D.sup.+ ions. The T.sup.+ ions are, therefore, not converted to T.sup.- ions when the D.sup.+ ions are converted to D.sup.- ions. This enables effective separation of the beam by deflection of the isotopes with an electrostatic field, the D.sup.- ions being deflected in one direction and the T.sup.+ ions being deflected in the opposite direction. Next, more energy is added to the deflected beam of T.sup.+ ions to bring the T.sup.+ ions to the optimum velocity for their conversion to T.sup.- ions. In a particular use of the invention, the beams of D.sup.- and T.sup.- ions are separately further accelerated and then converted to energetic neutral particles for injection as fuel into a thermonuclear reactor. The reactor exhaust of D.sup.+ and T.sup.+ and the D.sup.+ and T.sup.+ that was not converted in the respective sections is combined with the source beam and recycled through the system to increase the efficiency of the system.

Monoenergetic source of kilodalton ions from Taylor cones of ionic liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larriba, C.; Castro, S.; Fernandez de la Mora, J.

2007-04-15

The ionic liquid ion sources (ILISs) recently introduced by Lozano and Martinez Sanchez [J. Colloid Interface Sci. 282, 415 (2005)], based on electrochemically etched tungsten tips as emitters for Taylor cones of ionic liquids (ILs), have been tested with ionic liquids [A{sup +}B{sup -}] of increasing molecular weight and viscosity. These ILs have electrical conductivities well below 1 S/m and were previously thought to be unsuitable to operate in the purely ionic regime because their Taylor cones produce mostly charged drops from conventional capillary tube sources. Strikingly, all the ILs tried on ILIS form charged beams composed exclusively of smallmore » ions and cluster ions A{sup +}(AB){sub n} or B{sup -}(AB){sub n}, with abundances generally peaking at n=1. Particularly interesting are the positive and negative ion beams produced from the room temperature molten salts 1-methyl-3-pentylimidazolium tris(pentafluoroethyl) trifluorophosphate (C{sub 5}MI-(C{sub 2}F{sub 5}){sub 3}PF{sub 3}) and 1-ethyl-3-methylimidazolium bis(pentafluoroethyl) sulfonylimide (EMI-(C{sub 2}F{sub 5}SO{sub 3}){sub 2}N). We extend to these heavier species the previous conclusions from Lozano and Martinez Sanchez on the narrow energy distributions of the ion beams. In combination with suitable ILs, this source yields nanoamphere currents of positive and negative monoenergetic molecular ions with masses exceeding 2000 amu. Potential applications are in biological secondary ion mass spectrometry, chemically assisted high-resolution ion beam etching, and electrical propulsion. Advantages of the ILISs versus similar liquid metal ion sources include the possibility to form negative as well as positive ion beams and a much wider range of ion compositions and molecular masses.« less

Application and development of ion-source technology for radiation-effects testing of electronics

NASA Astrophysics Data System (ADS)

Kalvas, T.; Javanainen, A.; Kettunen, H.; Koivisto, H.; Tarvainen, O.; Virtanen, A.

2017-09-01

Studies of heavy-ion induced single event effect (SEE) on space electronics are necessary to verify the operation of the components in the harsh radiation environment. These studies are conducted by using high-energy heavy-ion beams to simulate the radiation effects in space. The ion beams are accelerated as so-called ion cocktails, containing several ion beam species with similar mass-to-charge ratio, covering a wide range of linear energy transfer (LET) values also present in space. The use of cocktails enables fast switching between beam species during testing. Production of these high-energy ion cocktails poses challenging requirements to the ion sources because in most laboratories reaching the necessary beam energies requires very high charge state ions. There are two main technologies producing these beams: The electron beam ion source EBIS and the electron cyclotron resonance ion source ECRIS. The EBIS is most suitable for pulsed accelerators, while ECRIS is most suitable for use with cyclotrons, which are the most common accelerators used in these applications. At the Accelerator Laboratory of the University of Jyväskylä (JYFL), radiation effects testing is currently performed using a K130 cyclotron and a 14 GHz ECRIS at a beam energy of 9.3 MeV/u. A new 18 GHz ECRIS, pushing the limits of the normal conducting ECR technology is under development at JYFL. The performances of existing 18 GHz ion sources have been compared, and based on this analysis, a 16.2 MeV/u beam cocktail with 1999 MeV 126Xe44+ being the most challenging component to has been chosen for development at JYFL. The properties of the suggested beam cocktail are introduced and discussed.

Universal main magnetic focus ion source for production of highly charged ions

NASA Astrophysics Data System (ADS)

Ovsyannikov, V. P.; Nefiodov, A. V.; Levin, A. A.

2017-10-01

A novel room-temperature compact ion source has been developed for the efficient production of atomic ions by means of an electron beam with energy Ee and current density je controllable within wide ranges (100 eV ≲Ee ≲ 60 keV, 10 A/cm2 ≲je ≲ 20 kA/cm2). In the first experiments, the X-ray emission of Ir64+ ions has been measured. Based on a combination of two different techniques, the device can operate both as conventional Electron Beam Ion Source/Trap and novel Main Magnetic Focus Ion Source. The tunable electron-optical system allows for realizing laminar and turbulent electron flows in a single experimental setup. The device is intended primarily for fundamental and applied research at standard university laboratories.

Effect of tapered magnetic field on expanding laser-produced plasma for heavy-ion inertial fusion

DOE PAGES

Kanesue, Takeshi; Ikeda, Shunsuke

2016-12-20

A laser ion source is a promising candidate as an ion source for heavy ion inertial fusion (HIF), where a pulsed ultra-intense and low-charged heavy ion beam is required. It is a key development for a laser ion source to transport laser-produced plasma with a magnetic field to achieve a high current beam. The effect of a tapered magnetic field on laser produced plasma is demonstrated by comparing the results with a straight solenoid magnet. The magnetic field of interest is a wider aperture on a target side and narrower aperture on an extraction side. Furthermore, based on the experimentallymore » obtained results, the performance of a scaled laser ion source for HIF was estimated.« less

Thermal-electric numerical simulation of a surface ion source for the production of radioactive ion beams

NASA Astrophysics Data System (ADS)

Manzolaro, Mattia; Meneghetti, Giovanni; Andrighetto, Alberto

2010-11-01

In a facility for the production of radioactive ion beams (RIBs), the target system and the ion source are the most critical objects. In the context of the Selective Production of Exotic Species (SPES) project, a proton beam directly impinges a Uranium Carbide production target, generating approximately 10 13 fissions per second. The radioactive isotopes produced by the 238U fissions are then directed to the ion source to acquire a charge state. After that, the radioactive ions obtained are transported electrostatically to the subsequent areas of the facility. In this work the surface ion source at present adopted for the SPES project is studied by means of both analytical and numerical thermal-electric models. The theoretical results are compared with temperature and electric potential difference measurements.

Source Determination for Substorm-Related Ion Injections

NASA Technical Reports Server (NTRS)

Strangeway, Robert J.; Evans, David (Technical Monitor)

2001-01-01

The grant supported an effort to restore and analyze data from the Spacecraft Charging at High Altitude (SCATHA) spacecraft. This spacecraft, which was originally an Air Force mission, was launched into a near geo-synchronous orbit in early 1979 to, investigate the inner magnetosphere at altitudes where it was known that spacecraft can undergo significant charging events. SCATHA included an ion composition experiment (designated SC8) and in many ways was a precursor to other missions, such as the AMPTE Charge Composition Explorer.

Formation of multiply charged ions from large molecules using massive-cluster impact.

PubMed

Mahoney, J F; Cornett, D S; Lee, T D

1994-05-01

Massive-cluster impact is demonstrated to be an effective ionization technique for the mass analysis of proteins as large as 17 kDa. The design of the cluster source permits coupling to both magnetic-sector and quadrupole mass spectrometers. Mass spectra are characterized by the almost total absence of chemical background and a predominance of multiply charged ions formed from 100% glycerol matrix. The number of charge states produced by the technique is observed to range from +3 to +9 for chicken egg lysozyme (14,310 Da). The lower m/z values provided by higher charge states increase the effective mass range of analyses performed with conventional ionization by fast-atom bombardment or liquid secondary ion mass spectrometry.

Development of a 1-m plasma source for heavy ion beam charge neutralization

NASA Astrophysics Data System (ADS)

Efthimion, Philip C.; Gilson, Erik P.; Grisham, Larry; Davidson, Ronald C.; Yu, Simon; Waldron, William; Grant Logan, B.

2005-05-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ˜0.1-1 m would be suitable for achieving a high level of charge neutralization. A radio frequency (RF) source was constructed at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization. Pulsing the source enabled operation at pressures ˜10 -6 Torr with plasma densities of 10 11 cm -3. Near 100% ionization was achieved. The plasma was 10 cm in length, but future experiments require a source 1 m long. The RF source does not easily scale to the length. Consequently, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO 3 to form metal plasma. A 1 m long section of the drift tube inner surface of NTX will be covered with ceramic. A high voltage (˜1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. Plasma densities of 10 12 cm -3 and neutral pressures ˜10 -6 Torr are expected. A test stand to produce 20 cm long plasma is being constructed and will be tested before a 1 m long source is developed.

An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy.

PubMed

Cao, Yun; Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia

2014-02-01

A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 eμA of C(5+) ion beam should be extracted from the ion source, and the beam emittance better than 75 π*mm*mrad. In recent commissioning, about 120 eμA of C(5+) ion beam was got when work gas was CH4 while about 262 eμA of C(5+) ion beam was obtained when work gas was C2H2 gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.

Distinguishing aspartic and isoaspartic acids in peptides by several mass spectrometric fragmentation methods

PubMed Central

DeGraan-Weber, Nick; Zhang, Jun; Reilly, James P.

2016-01-01

Six ion fragmentation techniques that can distinguish aspartic acid from its isomer, isoaspartic acid, were compared. MALDI post source decay (PSD), MALDI 157 nm photodissociation, TMPP charge tagging in PSD and photodissociation, ESI collision-induced dissociation (CID), electron transfer dissociation (ETD), and free-radical initiated peptide sequencing (FRIPS) with CID were applied to peptides containing either aspartic or isoaspartic acid. Diagnostic ions, such as the y-46 and b+H2O, are present in PSD, photodissociation, and charge tagging. c•+57 and z-57 ions are observed in ETD and FRIPS experiments. For some molecules, aspartic and isoaspartic acid yield ion fragments with significantly different intensities. ETD and charge tagging appear to be most effective at distinguishing these residues. PMID:27613306

The neon gas field ion source—a first characterization of neon nanomachining properties

NASA Astrophysics Data System (ADS)

Livengood, Richard H.; Tan, Shida; Hallstein, Roy; Notte, John; McVey, Shawn; Faridur Rahman, F. H. M.

2011-07-01

At the Charged Particle Optics Conference (CPO7) in 2006, a novel trimer based helium gas field ion source (GFIS) was introduced for use in a new helium ion microscope (HIM), demonstrating the novel source performance attributes and unique imaging applications of the HIM (Hill et al., 2008 [1]; Livengood et al., 2008 [2]). Since that time there have been numerous enhancements to the HIM source and platform demonstrating resolution scaling into the sub 0.5 nm regime (Scipioni et al., 2009 [3]; Pickard et al., 2010 [4]). At this Charged Particle Optics Conference (CPO8) we will be introducing a neon version of the trimer-GFIS co-developed by Carl Zeiss SMT and Intel Corporation. The neon source was developed as a possible supplement to the gallium liquid metal ion source (LMIS) used today in most focused ion beam (FIB) systems (Abramo et al., 1994 [5]; Young et al.,1998 [6]). The neon GFIS source has low energy spread (∼1 eV) and a small virtual source size (sub-nanometer), similar to that of the helium GFIS. However neon does differ from the helium GFIS in two significant ways: neon ions have high sputtering yields (e.g. 1 Si atom per incident ion at 20 keV); and have relatively shallow implant depth (e.g. 46 nm in silicon at 20 keV). Both of these are limiting factors for helium in many nanomachining applications. In this paper we will present both simulation and experimental results of the neon GFIS used for imaging and nanomachining applications.

Noise reduction in negative-ion quadrupole mass spectrometry

DOEpatents

Chastagner, P.

1993-04-20

A quadrupole mass spectrometer (QMS) system is described having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

Noise reduction in negative-ion quadrupole mass spectrometry

DOEpatents

Chastagner, Philippe

1993-01-01

A quadrupole mass spectrometer (QMS) system having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

Infrared laser dissociation of single megadalton polymer ions in a gated electrostatic ion trap: the added value of statistical analysis of individual events.

PubMed

Halim, Mohammad A; Clavier, Christian; Dagany, Xavier; Kerleroux, Michel; Dugourd, Philippe; Dunbar, Robert C; Antoine, Rodolphe

2018-05-07

In this study, we report the unimolecular dissociation mechanism of megadalton SO 3 -containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) polymer cations and anions with the aid of infrared multiphoton dissociation coupled to charge detection ion trap mass spectrometry. A gated electrostatic ion trap ("Benner trap") is used to store and detect single gaseous polymer ions generated by positive and negative polarity in an electrospray ionization source. The trapped ions are then fragmented due to the sequential absorption of multiple infrared photons produced from a continuous-wave CO 2 laser. Several fragmentation pathways having distinct signatures are observed. Highly charged parent ions characteristically adopt a distinctive "stair-case" pattern (assigned to the "fission" process) whereas low charge species take on a "funnel like" shape (assigned to the "evaporation" process). Also, the log-log plot of the dissociation rate constants as a function of laser intensity between PAMPS positive and negative ions is significantly different.

Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions

NASA Astrophysics Data System (ADS)

Doria, D.; Kar, S.; Ahmed, H.; Alejo, A.; Fernandez, J.; Cerchez, M.; Gray, R. J.; Hanton, F.; MacLellan, D. A.; McKenna, P.; Najmudin, Z.; Neely, D.; Romagnani, L.; Ruiz, J. A.; Sarri, G.; Scullion, C.; Streeter, M.; Swantusch, M.; Willi, O.; Zepf, M.; Borghesi, M.

2015-12-01

The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions.

PubMed

Doria, D; Kar, S; Ahmed, H; Alejo, A; Fernandez, J; Cerchez, M; Gray, R J; Hanton, F; MacLellan, D A; McKenna, P; Najmudin, Z; Neely, D; Romagnani, L; Ruiz, J A; Sarri, G; Scullion, C; Streeter, M; Swantusch, M; Willi, O; Zepf, M; Borghesi, M

2015-12-01

The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

Charge neutralization apparatus for ion implantation system

DOEpatents

Leung, Ka-Ngo; Kunkel, Wulf B.; Williams, Malcom D.; McKenna, Charles M.

1992-01-01

Methods and apparatus for neutralization of a workpiece such as a semiconductor wafer in a system wherein a beam of positive ions is applied to the workpiece. The apparatus includes an electron source for generating an electron beam and a magnetic assembly for generating a magnetic field for guiding the electron beam to the workpiece. The electron beam path preferably includes a first section between the electron source and the ion beam and a second section which is coincident with the ion beam. The magnetic assembly generates an axial component of magnetic field along the electron beam path. The magnetic assembly also generates a transverse component of the magnetic field in an elbow region between the first and second sections of the electron beam path. The electron source preferably includes a large area lanthanum hexaboride cathode and an extraction grid positioned in close proximity to the cathode. The apparatus provides a high current, low energy electron beam for neutralizing charge buildup on the workpiece.

Strong Turbulence in Alkali Halide Negative Ion Plasmas

NASA Astrophysics Data System (ADS)

Sheehan, Daniel

1999-11-01

Negative ion plasmas (NIPs) are charge-neutral plasmas in which the negative charge is dominated by negative ions rather than electrons. They are found in laser discharges, combustion products, semiconductor manufacturing processes, stellar atmospheres, pulsar magnetospheres, and the Earth's ionosphere, both naturally and man-made. They often display signatures of strong turbulence^1. Development of a novel, compact, unmagnetized alkali halide (MX) NIP source will be discussed, it incorporating a ohmically-heated incandescent (2500K) tantulum solenoid (3cm dia, 15 cm long) with heat shields. The solenoid ionizes the MX vapor and confines contaminant electrons, allowing a very dry (electron-free) source. Plasma densities of 10^10 cm-3 and positive to negative ion mass ratios of 1 <= fracm_+m- <= 20 are achievable. The source will allow tests of strong turbulence theory^2. 1 Sheehan, D.P., et al., Phys. Fluids B5, 1593 (1993). 2 Tsytovich, V. and Wharton, C.W., Comm. Plasma Phys. Cont. Fusion 4, 91 (1978).

Boundary conditions on the plasma emitter surface in the presence of a particle counter flow: I. Ion emitter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Astrelin, V. T., E-mail: V.T.Astrelin@inp.nsk.su; Kotelnikov, I. A.

Emission of positively charged ions from a plasma emitter irradiated by a counterpropagating electron beam is studied theoretically. A bipolar diode with a plasma emitter in which the ion temperature is lower than the electron temperature and the counter electron flow is extracted from the ion collector is calculated in the one-dimensional model. An analog of Bohm’s criterion for ion emission in the presence of a counterpropagating electron beam is derived. The limiting density of the counterpropagating beam in a bipolar diode operating in the space-charge-limited-emission regime is calculated. The full set of boundary conditions on the plasma emitter surfacemore » that are required for operation of the high-current optics module in numerical codes used to simulate charged particle sources is formulated.« less

Laboratory Studies in UV and EUV Solar Physics

NASA Technical Reports Server (NTRS)

Parkinson, W. H.; Wagner, William J. (Technical Monitor)

2002-01-01

The Ion Beam Experiment at the Center for Astrophysics is dedicated to the study of ion-electron collision processes of importance in solar physics. The analysis of measurements of Electron Impact Excitation (EIE) from the 3s3p(exp 3)P(exp o) metastable state to the 3s3p(exp 1)P state of Si(2+) was completed during the past year and a paper describing the results is available as a preprint. Our current program is directed at measuring absolute cross sections for dielectronic recombination (DR) and EIE in Si(3+), one of the primary ions used for probing the solar transition region. Our study of DR is particularly concerned with the effects of electric and magnetic fields on the recombination rates. Measurements of silicon ions with charge greater than n=2 have necessitated upgrading the experiment with a new ion source. The new source is also suitable for producing C(2+) beams to be used for measurements of EIE and DR for that system. The source is expected to be capable of producing beams of more highly charged systems as well.

The rare isotope beams production at the Texas A and M university Cyclotron Institute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tabacaru, G.; May, D. P.; Chubarian, G.

2013-04-19

The Cyclotron Institute at Texas A and M initiated an upgrade project for the production of radioactive-ion beams that incorporates a light-ion guide (LIG) and a heavy-ion guide coupled (HIG) with an Electron Cyclotron Resonance Ion Source (ECRIS) constructed for charge-boosting (CB-ECRIS). This scheme is intended to produce radioactive beams suitable for injection into the K500 superconducting cyclotron. The current status of the project and details on the ion sources and devices used in the project is presented.

Laser ion source for heavy ion inertial fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okamura, Masahiro

The proposed heavy ion inertial fusion (HIF) scenarios require ampere class low charge state ion beams of heavy species. A laser ion source (LIS) is recognized as one of the promising candidates of ion beam providers, since it can deliver high brightness heavy ion beams to accelerators. A design of LIS for the HIF depends on the accelerator structure and accelerator complex following the source. In this article, we discuss the specifications and design of an appropriate LIS assuming two major types of the accelerators: radio frequency (RF) high quality factor cavity type and non-resonant induction core type. We believemore » that a properly designed LIS satisfies the requirements of both types, however some issues need to be verified experimentally.« less

Laser ion source for heavy ion inertial fusion

DOE PAGES

Okamura, Masahiro

2018-01-10

The proposed heavy ion inertial fusion (HIF) scenarios require ampere class low charge state ion beams of heavy species. A laser ion source (LIS) is recognized as one of the promising candidates of ion beam providers, since it can deliver high brightness heavy ion beams to accelerators. A design of LIS for the HIF depends on the accelerator structure and accelerator complex following the source. In this article, we discuss the specifications and design of an appropriate LIS assuming two major types of the accelerators: radio frequency (RF) high quality factor cavity type and non-resonant induction core type. We believemore » that a properly designed LIS satisfies the requirements of both types, however some issues need to be verified experimentally.« less

Mean carrier transport properties and charge collection dynamics of single-crystal, natural type IIa diamonds from ion-induced conductivity measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Sung Su

1993-09-01

Ion-induced conductivity has been used to investigate the detector characteristics of diamond detectors. Both integrated-charge, and time-resolved current measurements were performed to examine the mean carrier transport properties of diamond and the dynamics of charge collection under highly-localized and high-density excitation conditions. The integrated-charge measurements were conducted with a standard pulse-counting system with 241Am radioactivity as the excitation source for the detectors. The time-resolved current measurements were performed using a 70 GHz random sampling oscilloscope with the detectors incorporated into high-speed microstrip transmission lines and the excitation source for these measurements was an ion beam of either 5-MeV He +more » or 10-MeV Si 3+. The detectors used in both experiments can be described as metal-semiconductor-metal (MSM) devices where a volume of the detector material is sandwiched between two metal plates. A charge collection model was developed to interpret the integrated-charge measurements which enabled estimation of the energy required to produce an electron-hole pair (ϵ di) and the mean carrier transport properties in diamond, such as carrier mobility and lifetime, and the behavior of the electrical contacts to diamond.« less

Development of an 18 GHz superconducting electron cyclotron resonance ion source at RCNP.

PubMed

Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

2008-02-01

An 18 GHz superconducting electron cyclotron resonance ion source has recently been developed and installed in order to extend the variety and the intensity of ions at the RCNP coupled cyclotron facility. Production of several ions such as O, N, Ar, Kr, etc., is now under development and some of them have already been used for user experiments. For example, highly charged heavy ion beams like (86)Kr(21+,23+) and intense (16)O(5+,6+) and (15)N(6+) ion beams have been provided for experiments. The metal ion from volatile compounds method for boron ions has been developed as well.

Surface and material analytics based on Dresden-EBIS platform technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, M., E-mail: mike.schmidt@dreebit.com; König, J., E-mail: mike.schmidt@dreebit.com; Bischoff, L.

2015-01-09

Nowadays widely used mass spectrometry systems utilize energetic ions hitting a sample and sputter material from the surface of a specimen. The generated secondary ions are separated and detected with high mass resolution to determine the target materials constitution. Based on this principle, we present an alternative approach implementing a compact Electron Beam Ion Source (EBIS) in combination with a Liquid Metal Ion Source (LMIS). An LMIS can deliver heavy elements which generate high sputter yields on a target surface. More than 90% of this sputtered material consists of mono- and polyatomic neutrals. These particles are able to penetrate themore » magnetic field of an EBIS and they will be ionized within the electron beam. A broad spectrum of singly up to highly charged ions can be extracted depending on the operation conditions. Polyatomic ions will decay during the charge-up process. A standard bending magnet or a Wien filter is used to separate the different ion species due to their mass-to-charge ratio. Using different charge states of ions as it is common with EBIS it is also possible to resolve interfering charge-to-mass ratios of only singly charged ions. Different setups for the realization of feeding the electron beam with sputtered atoms of solids will be presented and discussed. As an example the analysis of a copper surface is used to show high-resolution spectra with low background noise. Individual copper isotopes and clusters with different isotope compositions can be resolved at equal atomic numbers. These results are a first step for the development of a new compact low-cost and high-resolution mass spectrometry system. In a more general context, the described technique demonstrates an efficient method for feeding an EBIS with atoms of nearly all solid elements from various solid target materials. The new straightforward design of the presented setup should be of high interest for a broad range of applications in materials research as well as for applications connected to analyzing the biosphere, hydrosphere, lithosphere, cosmosphere and technosphere.« less

Electron Cyclotron Resonance (ECR) Ion Source Development at the Holified Radioactive Ion Beam Facility

NASA Astrophysics Data System (ADS)

Bilheux, Hassina; Liu, Yuan; Alton, Gerald; Cole, John; Williams, Cecil; Reed, Charles

2004-11-01

Performance of ECR ion sources can be significantly enhanced by increasing the physical size of their ECR zones in relation to the size of their plasma volumes (spatial and frequency domain methods).^3-5 A 6 GHz, all-permanent magnet ECR ion source with a large resonant plasma volume has been tested at ORNL.^6 The magnetic circuit can be configured for creating both flat-β (volume) and conventional minimum-β (surface) resonance conditions. Direct comparisons of the performance of the two source types can be made under similar operating conditions. In this paper, we clearly demonstrate that the flat-β source outperforms its minimum-β counterpart in terms of charge state distribution and intensity within a particular charge state. ^1bilheuxhn@ornl.gov ^2Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. ^3G.D. Alton, D.N. Smithe, Rev. Sci. Instrum. 65 (1994) 775. ^4G.D. Alton et al., Rev. Sci. Instrum. 69 (1998) 2305. ^5Z.Q. Xie, C.M. Lyneis, Rev. Sci. Instrum. 66 (1995) 4218. ^6Y. Liu et al., Rev. Sci. Instrum. 69 (1998) 1311.

A hollow cathode ion source for production of primary ions for the BNL electron beam ion source.

PubMed

Alessi, James; Beebe, Edward; Carlson, Charles; McCafferty, Daniel; Pikin, Alexander; Ritter, John

2014-02-01

A hollow cathode ion source, based on one developed at Saclay, has been modified significantly and used for several years to produce all primary 1+ ions injected into the Relativistic Heavy Ion Collider Electron Beam Ion Source (EBIS) at Brookhaven. Currents of tens to hundreds of microamperes have been produced for 1+ ions of He, C, O, Ne, Si, Ar, Ti, Fe, Cu, Kr, Xe, Ta, Au, and U. The source is very simple, relying on a glow discharge using a noble gas, between anode and a solid cathode containing the desired species. Ions of both the working gas and ionized sputtered cathode material are extracted, and then the desired species is selected using an ExB filter before being transported into the EBIS trap for charge breeding. The source operates pulsed with long life and excellent stability for most species. Reliable ignition of the discharge at low gas pressure is facilitated by the use of capacitive coupling from a simple toy plasma globe. The source design, and operating experience for the various species, is presented.

Ring current dynamics and plasma sheet sources. [magnetic storms

NASA Technical Reports Server (NTRS)

Lyons, L. R.

1984-01-01

The source of the energized plasma that forms in geomagnetic storm ring currents, and ring current decay are discussed. The dominant loss processes for ring current ions are identified as charge exchange and resonant interactions with ion-cyclotron waves. Ring current ions are not dominated by protons. At L4 and energies below a few tens of keV, O+ is the most abundant ion, He+ is second, and protons are third. The plasma sheet contributes directly or indirectly to the ring current particle population. An important source of plasma sheet ions is earthward streaming ions on the outer boundary of the plasma sheet. Ion interactions with the current across the geomagnetic tail can account for the formation of this boundary layer. Electron interactions with the current sheet are possibly an important source of plasma sheet electrons.

CALUTRON

DOEpatents

Lofgren, E.J.

1960-01-19

An ion source suitable for use with isotope separators of the calutron class is described in which ion bombardment of source structural members is minimized to lessen deterioration. A hollow conducting block defines an arc chamber which has an ion exit opening in the form of a slot in one wall of the block. A charged electrode spaced from the opening applies an electrical field for withdrawing ions from within the block. To establish a field configuration whereby the impingement of ions on the walls of the block is reduced, the wall edges which define the slot opening are bevelled to converge in the direction of efflux of the ions.

Proceedings of the 10th international workshop on ECR ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, F W; Kirkpatrick, M I

This report contains papers on the following topics: Recent Developments and Future Projects on ECR Ion Sources; Operation of the New KVI ECR Ion Source at 10 GHz; Operational Experience and Status of the INS SF-ECR Ion Source; Results of the New ECR4'' 14.5 GHz ECRIS; Preliminary Performance of the AECR; Experimental Study of the Parallel and Perpendicular Particle Losses from an ECRIS Plasma; Plasma Instability in Electron Cyclotron Resonance Heated Ion Sources; The Hyperbolic Energy Analyzer; Status of ECR Source Development; The New 10 GHz CAPRICE Source; First Operation of the Texas A M ECR Ion Source; Recent Developmentsmore » of the RIKEN ECR Ion Sources; The 14 GHz CAPRICE Source; Characteristics and Potential Applications of an ORNL Microwave ECR Multicusp Plasma Ion Source; ECRIPAC: The Production and Acceleration of Multiply Charged Ions Using an ECR Plasma; ECR Source for the HHIRF Tandem Accelerator; Feasibility Studies for an ECR-Generated Plasma Stripper; Production of Ion Beams by using the ECR Plasmas Cathode; A Single Stage ECR Source for Efficient Production of Radioactive Ion Beams; The Single Staged ECR Source at the TRIUMF Isotope Separator TISOL; The Continuous Wave, Optically Pumped H{sup {minus}} Source; The H{sup +} ECR Source for the LAMPF Optically Pumped Polarized Ion Source; Present Status of the Warsaw CUSP ECR Ion Source; An ECR Source for Negative Ion Production; GYRAC-D: A Device for a 200 keV ECR Plasma Production and Accumulation; Status Report of the 14.4 GHZ ECR in Legnaro; Status of JYFL-ECRIS; Report on the Uppsala ECRIS Facility and Its Planned Use for Atomic Physics; A 10 GHz ECR Ion Source for Ion-Electron and Ion-Atom Collision Studies; and Status of the ORNL ECR Source Facility for Multicharged Ion Collision Research.« less

A review of ion sources for medical accelerators (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muramatsu, M.; Kitagawa, A.

2012-02-15

There are two major medical applications of ion accelerators. One is a production of short-lived isotopes for radionuclide imaging with positron emission tomography and single photon emission computer tomography. Generally, a combination of a source for negative ions (usually H- and/or D-) and a cyclotron is used; this system is well established and distributed over the world. Other important medical application is charged-particle radiotherapy, where the accelerated ion beam itself is being used for patient treatment. Two distinctly different methods are being applied: either with protons or with heavy-ions (mostly carbon ions). Proton radiotherapy for deep-seated tumors has become widespreadmore » since the 1990s. The energy and intensity are typically over 200 MeV and several 10{sup 10} pps, respectively. Cyclotrons as well as synchrotrons are utilized. The ion source for the cyclotron is generally similar to the type for production of radioisotopes. For a synchrotron, one applies a positive ion source in combination with an injector linac. Carbon ion radiotherapy awakens a worldwide interest. About 6000 cancer patients have already been treated with carbon beams from the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan. These clinical results have clearly verified the advantages of carbon ions. Heidelberg Ion Therapy Center and Gunma University Heavy Ion Medical Center have been successfully launched. Several new facilities are under commissioning or construction. The beam energy is adjusted to the depth of tumors. It is usually between 140 and 430 MeV/u. Although the beam intensity depends on the irradiation method, it is typically several 10{sup 8} or 10{sup 9} pps. Synchrotrons are only utilized for carbon ion radiotherapy. An ECR ion source supplies multi-charged carbon ions for this requirement. Some other medical applications with ion beams attract developer's interests. For example, the several types of accelerators are under development for the boron neutron capture therapy. This treatment is conventionally demonstrated by a nuclear reactor, but it is strongly expected to replace the reactor by the accelerator. We report status of ion source for medical application and such scope for further developments.« less

A comparative study on low-energy ion beam and neutralized beam modifications of naked DNA and biological effect on mutation

NASA Astrophysics Data System (ADS)

Sarapirom, S.; Thongkumkoon, P.; Prakrajang, K.; Anuntalabhochai, S.; Yu, L. D.

2012-02-01

DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ion beam biotechnology and ion beam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ion beam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ion beam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli ( E. coli) for mutation analysis indicated that the charged ion beam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ion beam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

Laser acceleration of electrons to giga-electron-volt energies using highly charged ions.

PubMed

Hu, S X; Starace, Anthony F

2006-06-01

The recent proposal to use highly charged ions as sources of electrons for laser acceleration [S. X. Hu and A. F. Starace, Phys. Rev. Lett. 88, 245003 (2002)] is investigated here in detail by means of three-dimensional, relativistic Monte Carlo simulations for a variety of system parameters, such as laser pulse duration, ionic charge state, and laser focusing spot size. Realistic laser focusing effects--e.g., the existence of longitudinal laser field components-are taken into account. Results of spatial averaging over the laser focus are also presented. These numerical simulations show that the proposed scheme for laser acceleration of electrons from highly charged ions is feasible with current or near-future experimental conditions and that electrons with GeV energies can be obtained in such experiments.

A hemispherical Langmuir probe array detector for angular resolved measurements on droplet-based laser-produced plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gambino, Nadia, E-mail: gambinon@ethz.ch; Brandstätter, Markus; Rollinger, Bob

2014-09-15

In this work, a new diagnostic tool for laser-produced plasmas (LPPs) is presented. The detector is based on a multiple array of six motorized Langmuir probes. It allows to measure the dynamics of a LPP in terms of charged particles detection with particular attention to droplet-based LPP sources for EUV lithography. The system design permits to temporally resolve the angular and radial plasma charge distribution and to obtain a hemispherical mapping of the ions and electrons around the droplet plasma. The understanding of these dynamics is fundamental to improve the debris mitigation techniques for droplet-based LPP sources. The device hasmore » been developed, built, and employed at the Laboratory for Energy Conversion, ETH Zürich. The experimental results have been obtained on the droplet-based LPP source ALPS II. For the first time, 2D mappings of the ion kinetic energy distribution around the droplet plasma have been obtained with an array of multiple Langmuir probes. These measurements show an anisotropic expansion of the ions in terms of kinetic energy and amount of ion charge around the droplet target. First estimations of the plasma density and electron temperature were also obtained from the analysis of the probe current signals.« less

Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Praphairaksit, Narong

2000-09-12

An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at ~70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W withmore » an outer gas flow rate of ~4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression of signal for even the most troublesome combination of light analyte and heavy matrix elements can be attenuated from 90-99% to only 2-10% for 2 mM matrix solutions with an ultrasonic nebulizer. The supplemental electron current can be adjusted to ''titrate'' out the matrix effects as desired.« less

Air ion concentrations in various urban outdoor environments

NASA Astrophysics Data System (ADS)

Ling, Xuan; Jayaratne, Rohan; Morawska, Lidia

2010-06-01

Atmospheric ions are produced by many natural and anthropogenic sources and their concentrations vary widely between different environments. There is very little information on their concentrations in different types of urban environments, how they compare across these environments and their dominant sources. In this study, we measured airborne concentrations of small ions, particles and net particle charge at 32 different outdoor sites in and around a major city in Australia and identified the main ion sources. Sites were classified into seven groups as follows: park, woodland, city centre, residential, freeway, power lines and power substation. Generally, parks were situated away from ion sources and represented the urban background value of about 270 ions cm -3. Median concentrations at all other groups were significantly higher than in the parks. We show that motor vehicles and power transmission systems are two major ion sources in urban areas. Power lines and substations constituted strong unipolar sources, while motor vehicle exhaust constituted strong bipolar sources. The small ion concentration in urban residential areas was about 960 cm -3. At sites where ion sources were co-located with particle sources, ion concentrations were inhibited due to the ion-particle attachment process. These results improved our understanding on air ion distribution and its interaction with particles in the urban outdoor environment.

Distinguishing Aspartic and Isoaspartic Acids in Peptides by Several Mass Spectrometric Fragmentation Methods

NASA Astrophysics Data System (ADS)

DeGraan-Weber, Nick; Zhang, Jun; Reilly, James P.

2016-12-01

Six ion fragmentation techniques that can distinguish aspartic acid from its isomer, isoaspartic acid, were compared. MALDI post-source decay (PSD), MALDI 157 nm photodissociation, tris(2,4,6-trimethoxyphenyl)phosphonium bromide (TMPP) charge tagging in PSD and photodissociation, ESI collision-induced dissociation (CID), electron transfer dissociation (ETD), and free-radical initiated peptide sequencing (FRIPS) with CID were applied to peptides containing either aspartic or isoaspartic acid. Diagnostic ions, such as the y-46 and b+H2O, are present in PSD, photodissociation, and charge tagging. c•+57 and z-57 ions are observed in ETD and FRIPS experiments. For some molecules, aspartic and isoaspartic acid yield ion fragments with significantly different intensities. ETD and charge tagging appear to be most effective at distinguishing these residues.

Improvement of Characteristics of Laser Source of Ions Using Two-Element Targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khaydarov, R. T.

2006-12-04

Two-element plasma ions generated from porous (Ho2O3) and solid (PbMg) targets were studied depending on the target density {rho} and on the fraction of light (Mg) component of the target, using a mass-spectrometer. Oxygen ions with maximal charge is observed for small values of {rho}, while the heavy component of the target Ho has maximal charge for larger values of {rho}. The influence of {rho} to the energy spectra and intensity of plasma ions is also investigated. In the case of solid (PbMg) target the increase of the fraction of Mg leads to the widening of the energy spectra ofmore » Pb ions by more than a factor of two, while the intensity of Pb ions of all charge states does not depend on the Mg fraction. These effects are explained by the friction existing between light and heavy ions during their expansion away from the target.« less

Configuration interaction in charge exchange spectra of tin and xenon

NASA Astrophysics Data System (ADS)

D'Arcy, R.; Morris, O.; Ohashi, H.; Suda, S.; Tanuma, H.; Fujioka, S.; Nishimura, H.; Nishihara, K.; Suzuki, C.; Kato, T.; Koike, F.; O'Sullivan, G.

2011-06-01

Charge-state-specific extreme ultraviolet spectra from both tin ions and xenon ions have been recorded at Tokyo Metropolitan University. The electron cyclotron resonance source spectra were produced from charge exchange collisions between the ions and rare gas target atoms. To identify unknown spectral lines of tin and xenon, atomic structure calculations were performed for Sn14+-Sn17+ and Xe16+-Xe20+ using the Hartree-Fock configuration interaction code of Cowan (1981 The Theory of Atomic Structure and Spectra (Berkeley, CA: University of California Press)). The energies of the capture states involved in the single-electron process that occurs in these slow collisions were estimated using the classical over-barrier model.

Effect of source tuning parameters on the plasma potential of heavy ions in the 18 GHz high temperature superconducting electron cyclotron resonance ion source.

PubMed

Rodrigues, G; Baskaran, R; Kukrety, S; Mathur, Y; Kumar, Sarvesh; Mandal, A; Kanjilal, D; Roy, A

2012-03-01

Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz high temperature superconducting ECR ion source, PKDELIS [C. Bieth, S. Kantas, P. Sortais, D. Kanjilal, G. Rodrigues, S. Milward, S. Harrison, and R. McMahon, Nucl. Instrum. Methods B 235, 498 (2005); D. Kanjilal, G. Rodrigues, P. Kumar, A. Mandal, A. Roy, C. Bieth, S. Kantas, and P. Sortais, Rev. Sci. Instrum. 77, 03A317 (2006)]. The ion beam extracted from the source is decelerated close to the location of a mesh which is polarized to the source potential and beams having different plasma potentials are measured on a Faraday cup located downstream of the mesh. The influence of various source parameters, viz., RF power, gas pressure, magnetic field, negative dc bias, and gas mixing on the plasma potential is studied. The study helped to find an upper limit of the energy spread of the heavy ions, which can influence the design of the longitudinal optics of the high current injector being developed at the Inter University Accelerator Centre. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimizes at an optimum value of the gas pressure of the mixing gas and the mean charge state maximizes at this value. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.

Effect of source tuning parameters on the plasma potential of heavy ions in the 18 GHz high temperature superconducting electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodrigues, G.; Mathur, Y.; Kumar, Sarvesh

2012-03-15

Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz high temperature superconducting ECR ion source, PKDELIS [C. Bieth, S. Kantas, P. Sortais, D. Kanjilal, G. Rodrigues, S. Milward, S. Harrison, and R. McMahon, Nucl. Instrum. Methods B 235, 498 (2005); D. Kanjilal, G. Rodrigues, P. Kumar, A. Mandal, A. Roy, C. Bieth, S. Kantas, and P. Sortais, Rev. Sci. Instrum. 77, 03A317 (2006)]. The ion beam extracted from the source is decelerated close to the location of a mesh which is polarized to the source potential and beams having different plasmamore » potentials are measured on a Faraday cup located downstream of the mesh. The influence of various source parameters, viz., RF power, gas pressure, magnetic field, negative dc bias, and gas mixing on the plasma potential is studied. The study helped to find an upper limit of the energy spread of the heavy ions, which can influence the design of the longitudinal optics of the high current injector being developed at the Inter University Accelerator Centre. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimizes at an optimum value of the gas pressure of the mixing gas and the mean charge state maximizes at this value. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.« less

A Microwave Driven Ion Source for Continuous-Flow AMS (Abstract)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wills, J.; Schneider, R.J.; Reden, K.F. von

2005-03-15

A microwave-driven, gas-fed ion source originally developed as a high-current positive ion injector for a Tandem accelerator at Chalk River has been the subject of a three-year development program at the Woods Hole Oceanographic Institution NOSAMS facility. Off-line tests have demonstrated positive carbon currents of 1 mA and negative carbon currents of 80 {mu}A from CO2 gas feed. This source and a magnesium charge-exchange canal were coupled to the recombinator of the NOSAMS Tandetron for on-line tests, with the source fed with reference gasses and a combustion device.The promising results obtained have prompted the redesign of the microwave source formore » use as an on-line, continuous-flow injector for a new AMS facility under construction at NOSAMS. The new design is optimized for best transmission of the extracted positive-ion beam through the charge-exchange canal and for reliable operation at 40 kV extraction voltage. Other goals of the re-design include improved lifetime of the microwave window and the elimination of dead volumes in the plasma generator that increase sample hold-up time.This talk will include a summary of results obtained to date at NOSAMS with the Chalk River source and a detailed description of the new design.« less

Development of a pepper-pot emittance meter for diagnostics of low-energy multiply charged heavy ion beams extracted from an ECR ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagatomo, T., E-mail: nagatomo@riken.jp; Kase, M.; Kamigaito, O.

2016-02-15

Several fluorescent materials were tested for use in the imaging screen of a pepper-pot emittance meter that is suitable for investigating the beam dynamics of multiply charged heavy ions extracted from an ECR ion source. SiO{sub 2} (quartz), KBr, Eu-doped CaF{sub 2}, and Tl-doped CsI crystals were first irradiated with 6.52-keV protons to determine the effects of radiation damage on their fluorescence emission properties. For such a low-energy proton beam, only the quartz was found to be a suitable fluorescent material, since the other materials suffered a decay in fluorescence intensity with irradiation time. Subsequently, quartz was irradiated with heavymore » {sup 12}C{sup 4+}, {sup 16}O{sup 4+}, and {sup 40}Ar{sup 11+} ions, but it was found that the fluorescence intensity decreased too rapidly to measure the emittance of these heavy-ion beams. These results suggest that a different energy loss mechanism occurs for heavier ions and for protons.« less

Innovative Ionic Liquids: Electrolytes for Ion Power Sources

DTIC Science & Technology

2008-01-01

imide–based ILs can function not only as the electrolyte in a conventional lithium ion battery , but also as a solid nanocomposite separator when...conductivity comparable to the pure ionic liquid. Figure 6 shows the charge-discharge behavior of the micro lithium ion battery created entirely by the

Efficient Storing Energy Harvested by Triboelectric Nanogenerators Using a Safe and Durable All-Solid-State Sodium-Ion Battery.

PubMed

Hou, Huidan; Xu, Qingkai; Pang, Yaokun; Li, Lei; Wang, Jiulin; Zhang, Chi; Sun, Chunwen

2017-08-01

Storing energy harvested by triboelectric nanogenerators (TENGs) from ambient mechanical motion is still a great challenge for achieving low-cost and environmental benign power sources. Here, an all-solid-state Na-ion battery with safe and durable performance used for efficient storing pulsed energy harvested by the TENG is demonstrated. The solid-state sodium-ion batteries are charged by galvanostatic mode and pulse mode with the TENG, respectively. The all-solid-state sodium-ion battery displays excellent cyclic performance up to 1000 cycles with a capacity retention of about 85% even at a high charge and discharge current density of 48 mA g -1 . When charged by the TENG, an energy conversion efficiency of 62.3% is demonstrated. The integration of TENGs with the safe and durable all-solid-state sodium-ion batteries is potential for providing more stable power output for self-powered systems.

EUV spectroscopy of highly charged high Z ions in the Large Helical Device plasmas

NASA Astrophysics Data System (ADS)

Suzuki, C.; Koike, F.; Murakami, I.; Tamura, N.; Sudo, S.; Sakaue, H. A.; Nakamura, N.; Morita, S.; Goto, M.; Kato, D.; Nakano, T.; Higashiguchi, T.; Harte, C. S.; OʼSullivan, G.

2014-11-01

We present recent results on the extreme ultraviolet (EUV) spectroscopy of highly charged high Z ions in plasmas produced in the Large Helical Device (LHD) at the National Institute for Fusion Science. Tungsten, bismuth and lanthanide elements have recently been studied in the LHD in terms of their importance in fusion research and EUV light source development. In relatively low temperature plasmas, quasicontinuum emissions from open 4d or 4f subshell ions are predominant in the EUV region, while the spectra tend to be dominated by discrete lines from open 4s or 4p subshell ions in higher temperature plasmas. Comparative analyses using theoretical calculations and charge-separated spectra observed in an electron beam ion trap have been performed to achieve better agreement with the spectra measured in the LHD. As a result, databases on Z dependence of EUV spectra in plasmas have been widely extended.

Performance test of electron cyclotron resonance ion sources for the Hyogo Ion Beam Medical Center

NASA Astrophysics Data System (ADS)

Sawada, K.; Sawada, J.; Sakata, T.; Uno, K.; Okanishi, K.; Harada, H.; Itano, A.; Higashi, A.; Akagi, T.; Yamada, S.; Noda, K.; Torikoshi, M.; Kitagawa, A.

2000-02-01

Two electron cyclotron resonance (ECR) ion sources were manufactured for the accelerator facility at the Hyogo Ion Beam Medical Center. H2+, He2+, and C4+ were chosen as the accelerating ions because they have the highest charge to mass ratio among ion states which satisfy the required intensity and quality. The sources have the same structure as the 10 GHz ECR source at the Heavy Ion Medical Accelerator in Chiba except for a few improvements in the magnetic structure. Their performance was investigated at the Sumitomo Heavy Industries factory before shipment. The maximum intensity was 1500 μA for H2+, 1320 μA for He2+, and 580 μA for C4+ at the end of the ion source beam transport line. These are several times higher than required. Sufficient performance was also observed in the flatness and long-term stability of the pulsed beams. These test results satisfy the requirements for medical use.

Ions with low charges in the solar wind as measured by SWICS on board Ulysses. [Solar Wind Ion Composition Spectrometer

NASA Technical Reports Server (NTRS)

Geiss, J.; Ogilvie, K. W.; Von Steiger, R.; Mall, U.; Gloeckler, G.; Galvin, A. B.; Ipavich, F.; Wilken, B.; Gliem, F.

1992-01-01

We present new data on rare ions in the solar wind. Using the Ulysses-SWICS instrument with its very low background we have searched for low-charge ions during a 6-d period of low-speed solar wind and established sensitive upper limits for many species. In the solar wind, we found He(1+)/He(2+) of less than 5 x 10 exp -4. This result and the charge state distributions of heavier elements indicate that all components of the investigated ion population went through a regular coronal expansion and experienced the typical electron temperatures of 1 to 2 million Kelvin. We argue that the virtual absence of low-charge ions demonstrates a very low level of nonsolar contamination in the source region of the solar wind sample we studied. Since this sample showed the FlP effect typical for low-speed solar wind, i.e., an enhancement in the abundances of elements with low first ionization potential, we conclude that this enhancement was caused by an ion-atom separation mechanism operating near the solar surface and not by foreign material in the corona.

An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Yun, E-mail: caoyun@impcas.ac.cn; Li, Jia Qing; Sun, Liang Ting

2014-02-15

A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 eμA of C{sup 5+} ion beam should be extracted from the ion source, and the beam emittance better than 75 π*mm*mrad. In recent commissioning, about 120 eμA of C{sup 5+} ion beam was got when work gasmore » was CH{sub 4} while about 262 eμA of C{sup 5+} ion beam was obtained when work gas was C{sub 2}H{sub 2} gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.« less

Combining the Power of Irmpd with Ion-Molecule Reactions: the Structure and Reactivity of Radical Ions of Cysteine and its Derivatives

NASA Astrophysics Data System (ADS)

Lesslie, Michael; Osburn, Sandra; Berden, Giel; Oomens, J.; Ryzhov, Victor

2015-06-01

Most of the work on peptide radical cations has involved protons as the source of charge. Nonetheless, using metal ions as charge sources often offers advantages like stabilization of the structure via multidentate coordination and the elimination of the "mobile proton". Moreover, characterization of metal-bound amino acids is of general interest as the interaction of peptide side chains with metal ions in biological systems is known to occur extensively. In the current study, we generate thiyl radicals of cysteine and homocysteine in the gas phase complexed to alkali metal ions. Subsequently, we utilize infrared multiple-photon dissociation (IRMPD) and ion-molecule reactions (IMR) to characterize the structure and reactivity of these radical ions. Our group has worked extensively with the cysteine-based radical cations and anions, characterizing the gas-phase reactivity and rearrangement of the amino acid and several of its derivatives. In a continuation of this work, we are perusing the effects of metal ions as the charge bearing species on the reactivity of the sulfur radical. Our S-nitroso chemistry can easily be used in conjunction with metal ion coordination to produce initial S-based radicals in peptide radical-metal ion complexes. In all cases we have been able to achieve radical formation with significant yield to study reactivity. Ion-molecule reactions of metallated radicals with allyl iodide, dimethyl disulfide, and allyl bromide have all shown decreasing reactivity going down group 1A. Recently, we determined the experimental IR spectra for the homocysteine radical cation with Li+, Na+, and K+ as the charge bearing species at the FELIX facility. For comparison, the protonated IR spectrum of homocysteine has previously been obtained by our group. A preliminary match of the IR spectra has been confirmed. Finally, calculations are underway to determine the bond distances of all the metal adduct structures.

AMS implications of charge-changing during acceleration

NASA Astrophysics Data System (ADS)

Knies, D. L.; Grabowski, K. S.; Cetina, C.; Demoranville, L. T.; Dougherty, M. R.; Mignerey, A. C.; Taylor, C. L.

2007-08-01

The NRL Accelerator Mass Spectrometer facility was recently reconfigured to incorporate a modified Cameca IMS 6f Secondary Ion Mass Spectrometer as a high-performance ion source. The NRL accelerator facility supplants the mass spectrometer portion of the IMS 6f instrument. As part of the initial testing of the combined instrument, charge-state scans were performed under various conditions. These provided the basis for studying the effects of terminal gas pressure on the process of charge-changing during acceleration. A combined system of transmission-micro-channel plate and energy detector was found to remove ghost beams produced from Pd charge-changing events in the accelerator tube.

[Experimental investigation of laser plasma soft X-ray source with gas target].

PubMed

Ni, Qi-liang; Gong, Yan; Lin, Jing-quan; Chen, Bo; Cao, Jian-lin

2003-02-01

This paper describes a debris-free laser plasma soft X-ray source with a gas target, which has high operating frequency and can produce strong soft X-ray radiation. The valve of this light source is drived by a piezoelectrical ceramic whose operating frequency is up to 400 Hz. In comparison with laser plasma soft X-ray sources using metal target, the light source is debris-free. And it has higher operating frequency than gas target soft X-ray sources whose nozzle is controlled by a solenoid valve. A channel electron multiplier (CEM) operating in analog mode is used to detect the soft X-ray generated by the laser plasma source, and the CEM's output is fed to to a charge-sensitive preamplifier for further amplification purpose. Output charges from the CEM are proportional to the amplitude of the preamplifier's output voltage. Spectra of CO2, Xe and Kr at 8-14 nm wavelength which can be used for soft X-ray projection lithography are measured. The spectrum for CO2 consists of separate spectral lines originate mainly from the transitions in Li-like and Be-like ions. The Xe spectrum originating mainly from 4d-5f, 4d-4f, 4d-6p and 4d-5p transitions in multiply charged xenon ions. The spectrum for Kr consists of separate spectral lines and continuous broad spectra originating mainly from the transitions in Cu-, Ni-, Co- and Fe-like ions.

Energetic Nitrogen Ions within the Inner Magnetosphere of Saturn

NASA Astrophysics Data System (ADS)

Sittler, E. C.; Johnson, R. E.; Richardson, J. D.; Jurac, S.; Moore, M.; Cooper, J. F.; Mauk, B. H.; Smith, H. T.; Michael, M.; Paranicus, C.; Armstrong, T. P.; Tsurutani, B.; Connerney, J. E. P.

2003-05-01

Titan's interaction with Saturn's magnetosphere will result in the energetic ejection of atomic nitrogen atoms into Saturn's magnetosphere due to dissociation of N2 by electrons, ions, and UV photons. The ejection of N atoms into Saturn's magnetosphere will form a nitrogen torus around Saturn with mean density of about 4 atoms/cm3 with source strength of 4.5x1025 atoms/sec. These nitrogen atoms are ionized by photoionization, electron impact ionization and charge exchange reactions producing an N+ torus of 1-4 keV suprathermal ions centered on Titan's orbital position. We will show Voyager plasma observations that demonstrate presence of a suprathermal ion component within Saturn's outer magnetosphere. The Voyager LECP data also reported the presence of inward diffusing energetic ions from the outer magnetosphere of Saturn, which could have an N+ contribution. If so, when one conserves the first and second adiabatic invariant the N+ ions will have energies in excess of 100 keV at Dione's L shell and greater than 400 keV at Enceladus' L shell. Energetic charged particle radial diffusion coefficients are also used to constrain the model results. But, one must also consider the solar wind as another important source of keV ions, in the form of protons and alpha particles, for Saturn's outer magnetosphere. Initial estimates indicate that a solar wind source could dominate in the outer magnetosphere, but various required parameters for this estimate are highly uncertain and will have to await Cassini results for confirmation. We show that satellite sweeping and charged particle precipitation within the middle and outer magnetosphere will tend to enrich N+ ions relative to protons within Saturn's inner magnetosphere as they diffuse radially inward for radial diffusion coefficients that do not violate observations. Charge exchange reactions within the inner magnetosphere can be an important loss mechanism for O+ ions, but to a lesser degree for N+ ions. Initial LECP results using composition data at energies greater than 200 keV/nucl., showed that heavy ions within Saturn's inner magnetosphere dominated over protons, but that contrary to original suggestions that these ions were O+ , we now argue that they are instead N+ ions. With energetic N+ ions bombarding the icy satellite surfaces chemical reactions can occur at the end of the ion tracks and produce nitrogen oxides or other nitrogen containing molecules such that the radiology within the icy surfaces is driven by the impacting energetic nitrogen ions. These can accumulate over the lifetime of the Saturn system.

A multicharge ion source (Supernanogan) for the OLIS facility at ISAC/TRIUMF.

PubMed

Jayamanna, K; Wight, G; Gallop, D; Dube, R; Jovicic, V; Laforge, C; Marchetto, M; Leross, M; Louie, D; Laplante, R; Laxdal, R; McDonald, M; Wiebe, G J; Wang, V; Yan, F

2010-02-01

The Off-Line Ion Source (OLIS) [K. Jayamanna, D. Yuan, T. Kuo, M. MacDonald, P. Schmor, and G. Dutto, Rev. Sci. Instrum. 67, 1061 (1996); K. Jayamanna, Rev. Sci. Instrum. 79, 02711 (2008)] facility consists of a high voltage terminal containing a microwave cusp ion source, either a surface ion source or a hybrid surface-arc discharge ion source [K. Jayamanna and C. Vockenhuber, Rev. Sci. Instrum. 79, 02C712 (2008)], and an electrostatic switch that allows the selection of any one of the sources without mechanical intervention. These sources provide a variety of +1 beams up to mass 30 for Isotope Separator and ACcelerator (ISAC) [R. E. Laxdal, Nucl. Instrum. Methods Phys. Res. B 204, 400 (2003)] experiments, commissioning the accelerators, setting up the radioactive experiments, and for tuning the beam lines. The radio frequency quadrupole (RFQ) [M. Marchetto, Z. T. Ang, K. Jayamanna, R. E. Laxdal, A. Mitra, and V. Zvyagintsev, Eur. Phys. J. Spec. Top. 150, 241 (2005)] injector accelerator is a constant velocity machine designed to accept only 2 keV/u and the source extraction energy is limited to 60 kV. Further stripping is then needed downstream of the RFQ to inject the beam into the drift tube linac [M. Marchetto, Z. T. Ang, K. Jayamanna, R. E. Laxdal, A. Mitra, and V. Zvyagintsev, Eur. Phys. J. Spec. Top. 150, 241 (2005)] accelerator that requires A/q up to 6. Base on this constraints a multicharge ion source capable to deliver beams above mass 30 with A/q up to 6 was needed in order to reach full capability of the ISAC facility. A Supernanogan [C. Bieth et al., Nucleonika 48, S93 (2003)] multicharge ion source was then purchased from Pantechnik and was installed in the OLIS terminal. Commissioning and performance of the Supernanogan with some results such as emittance dependence of the charge states as well as charge state efficiencies are presented.

Plasma source for spacecraft potential control

NASA Technical Reports Server (NTRS)

Olsen, R. C.

1983-01-01

A stable electrical ground which enables the particle spectrometers to measure the low energy particle populations was investigated and the current required to neutralize the spacecraft was measured. In addition, the plasma source for potential control (PSPO C) prevents high charging events which could affect the spacecraft electrical integrity. The plasma source must be able to emit a plasma current large enough to balance the sum of all other currents to the spacecraft. In ion thrusters, hollow cathodes provide several amperes of electron current to the discharge chamber. The PSPO C is capable of balancing the net negative currents found in eclipse charging events producing 10 to 100 microamps of electron current. The largest current required is the ion current necessary to balance the total photoelectric current.

A comprehensive suite of suprathermal ion sensors

NASA Astrophysics Data System (ADS)

Allegrini, F.; Ho, G. C.; Desai, M. I.; Ebert, R. W.; Nelson, K.; Ogasawara, K.

2016-12-01

Ions with energies from a few times the solar wind plasma thermal energy up to hundreds of keV/e are called suprathermal (ST) ions. ST ions are ubiquitous throughout the heliosphere and comprise material from many sources that vary in time and space. ST ions constitute a key source of material for solar energetic particles and other higher-energy interplanetary particle populations. Measuring the energy spectra and composition (ionic charge and elemental) of ST ions in the heliosphere has proved to be rather difficult. This is because their energy region lies between that sampled by solar wind instruments, which require long integration times to acquire adequate statistics at these energies, and that by the energetic particle instruments, which typically do not extend down into the lower part of the ST regime due to the low-energy thresholds ( 25-50 keV) of solid-state detectors. We present two novel concepts that, when combined, measure ST ions with high time, mass, and charge state resolution to address these challenges. Both use electrostatic analyzers that essentially serve as spectrographs. They simultaneously select ions over a broad range of energy-per-charge (E/q), thus requiring fewer voltage steps to cover the entire energy range. Their sensitivity is large compared to current instruments because each E/q is sampled for a longer period of time while the geometric factor is comparable. We describe the results obtained with laboratory prototypes. We also present a list of potential options for the detector section.

PULSED ION SOURCE

DOEpatents

Anderson, C.E.; Ehlers, K.W.

1958-06-17

An ion source is described for producing very short high density pulses of ions without bcam scattering. The ions are created by an oscillating electron discharge within a magnetic field. After the ions are drawn from the ionization chamber by an accelerating electrode the ion beam is under the influence of the magnetic field for separation of the ions according to mass and, at the same time, passes between two neutralizing plntes maintained nt equal negative potentials. As the plates are formed of a material having a high ratio of secondary electrons to impinging ions, the ion bombardment of the plntes emits electrons which neutralize the frirge space-charge of the beam and tend to prevent widening of the beam cross section due to the mutual repulsion of the ions.

Charge Exchange X-Ray Emission due to Highly Charged Ion Collisions with H, He, and H2: Line Ratios for Heliospheric and Interstellar Applications

NASA Astrophysics Data System (ADS)

Cumbee, R. S.; Mullen, P. D.; Lyons, D.; Shelton, R. L.; Fogle, M.; Schultz, D. R.; Stancil, P. C.

2018-01-01

The fundamental collisional process of charge exchange (CX) has been established as a primary source of X-ray emission from the heliosphere, planetary exospheres, and supernova remnants. In this process, X-ray emission results from the capture of an electron by a highly charged ion from a neutral atom or molecule, to form a highly excited, high-charge state ion. As the captured electron cascades down to the lowest energy level, photons are emitted, including X-rays. To provide reliable CX-induced X-ray spectral models to realistically simulate these environments, line ratios and spectra are computed using theoretical CX cross sections obtained with the multi-channel Landau-Zener, atomic-orbital close-coupling, molecular-orbital close-coupling, and classical trajectory Monte Carlo methods for various collisional velocities relevant to astrophysics. X-ray spectra were computed for collisions of bare and H-like C to Al ions with H, He, and H2 with results compared to available experimental data. Using these line ratios, XSPEC models of CX emission in the northeast rim of the Cygnus Loop supernova remnant and the heliosphere are shown as examples with ion velocity dependence.

Focused ion beam source method and apparatus

DOEpatents

Pellin, Michael J.; Lykke, Keith R.; Lill, Thorsten B.

2000-01-01

A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.

Discovery of Suprathermal Fe+ in and near Earth's Magnetosphere

NASA Astrophysics Data System (ADS)

Christon, S. P.; Hamilton, D. C.; Plane, J. M. C.; Mitchell, D. G.; Grebowsky, J. M.; Spjeldvik, W. N.; Nylund, S. R.

2017-12-01

Suprathermal (87-212 keV/e) singly charged iron, Fe+, has been observed in and near Earth's equatorial magnetosphere using long-term ( 21 years) Geotail/STICS ion composition data. Fe+ is rare compared to dominant suprathermal solar wind and ionospheric origin heavy ions. Earth's suprathermal Fe+ appears to be positively associated with both geomagnetic and solar activity. Three candidate lower-energy sources are examined for relevance: ionospheric outflow of Fe+ escaped from ion layers altitude, charge exchange of nominal solar wind Fe+≥7, and/or solar wind transported inner source pickup Fe+ (likely formed by solar wind Fe+≥7 interaction with near sun interplanetary dust particles, IDPs). Semi-permanent ionospheric Fe+ layers form near 100 km altitude from the tons of IDPs entering Earth's atmosphere daily. Fe+ scattered from these layers is observed up to 1000 km altitude, likely escaping in strong ionospheric outflows. Using 26% of STICS's magnetosphere-dominated data at low-to-moderate geomagnetic activity levels, we demonstrate that solar wind Fe charge exchange secondaries are not an obvious Fe+ source then. Earth flyby and cruise data from Cassini/CHEMS, a nearly identical instrument, show that inner source pickup Fe+ is likely not important at suprathermal energies. Therefore, lacking any other candidate sources, it appears that ionospheric Fe+ constitutes at least an important portion of Earth's suprathermal Fe+, comparable to observations at Saturn where ionospheric origin suprathermal Fe+ has also been observed.

Laser acceleration of electrons to giga-electron-volt energies using highly charged ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, S. X.; Starace, Anthony F.

2006-06-15

The recent proposal to use highly charged ions as sources of electrons for laser acceleration [S. X. Hu and A. F. Starace, Phys. Rev. Lett. 88, 245003 (2002)] is investigated here in detail by means of three-dimensional, relativistic Monte Carlo simulations for a variety of system parameters, such as laser pulse duration, ionic charge state, and laser focusing spot size. Realistic laser focusing effects--e.g., the existence of longitudinal laser field components--are taken into account. Results of spatial averaging over the laser focus are also presented. These numerical simulations show that the proposed scheme for laser acceleration of electrons from highlymore » charged ions is feasible with current or near-future experimental conditions and that electrons with GeV energies can be obtained in such experiments.« less

EBIT spectroscopy of highly charged heavy ions relevant to hot plasmas

NASA Astrophysics Data System (ADS)

Nakamura, Nobuyuki

2013-05-01

An electron beam ion trap (EBIT) is a versatile device for studying highly charged ions. We have been using two types of EBITs for the spectroscopic studies of highly charged ions. One is a high-energy device called the Tokyo-EBIT, and another is a compact low-energy device called CoBIT. Complementary use of them enables us to obtain spectroscopic data for ions over a wide charge-state range interacting with electrons over a wide energy range. In this talk, we present EBIT spectra of highly charged ions for tungsten, iron, bismuth, etc., which are relevant to hot plasmas. Tungsten is considered to be the main impurity in the ITER (the next generation nuclear fusion reactor) plasma, and thus its emission lines are important for diagnosing and controlling the ITER plasma. We have observed many previously unreported lines to supply the lack of spectroscopic data of tungsten ions. Iron is one of the main components of the solar corona, and its spectra are used to diagnose temperature, density, etc. The diagnostics is usually done by comparing observed spectra with model calculations. An EBIT can provide spectra under a well-defined condition; they are thus useful to test the model calculations. Laser-produced bismuth plasma is one of the candidates for a soft x-ray source in the water window region. An EBIT has a narrow charge state distribution; it is thus useful to disentangle the spectra of laser-produced plasma containing ions with a wide charge-state range. Performed with the support and under the auspices of the NIFS Collaboration Research program (NIFS09KOAJ003) and JSPS KAKENHI Number 23246165, and partly supported by the JSPS-NRF-NSFC A3 Foresight Program in the field of Plasma Physics.

Distinguishing Aspartic and Isoaspartic Acids in Peptides by Several Mass Spectrometric Fragmentation Methods.

PubMed

DeGraan-Weber, Nick; Zhang, Jun; Reilly, James P

2016-12-01

Six ion fragmentation techniques that can distinguish aspartic acid from its isomer, isoaspartic acid, were compared. MALDI post-source decay (PSD), MALDI 157 nm photodissociation, tris(2,4,6-trimethoxyphenyl)phosphonium bromide (TMPP) charge tagging in PSD and photodissociation, ESI collision-induced dissociation (CID), electron transfer dissociation (ETD), and free-radical initiated peptide sequencing (FRIPS) with CID were applied to peptides containing either aspartic or isoaspartic acid. Diagnostic ions, such as the y-46 and b+H 2 O, are present in PSD, photodissociation, and charge tagging. c • +57 and z-57 ions are observed in ETD and FRIPS experiments. For some molecules, aspartic and isoaspartic acid yield ion fragments with significantly different intensities. ETD and charge tagging appear to be most effective at distinguishing these residues. Graphical Abstract ᅟ.

Li-Ion Battery and Supercapacitor Hybrid Design for Long Extravehicular Activities

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith

2013-01-01

With the need for long periods of extravehicular activities (EVAs) on the Moon or Mars or a near-asteroid, the need for long-performance batteries has increased significantly. The energy requirements for the EVA suit, as well as surface systems such as rovers, have increased significantly due to the number of applications they need to power at the same time. However, even with the best state-of-the-art Li-ion batteries, it is not possible to power the suit or the rovers for the extended period of performance. Carrying a charging system along with the batteries makes it cumbersome and requires a self-contained power source for the charging system that is usually not possible. An innovative method to charge and use the Li-ion batteries for long periods seems to be necessary and hence, with the advent of the Li-ion supercapacitors, a method has been developed to extend the performance period of the Li-ion power system for future exploration applications. The Li-ion supercapacitors have a working voltage range of 3.8 to 2.5 V, and are different from a traditional supercapacitor that typically has a working voltage of 1 V. The innovation is to use this Li-ion supercapacitor to charge Liion battery systems on an as-needed basis. The supercapacitors are charged using solar arrays and have battery systems of low capacity in parallel to be able to charge any one battery system while they provide power to the application. Supercapacitors can safely take up fast charge since the electrochemical process involved is still based on charge separation rather than the intercalation process seen in Li-ion batteries, thus preventing lithium metal deposition on the anodes. The lack of intercalation and eliminating wear of the supercapacitors allows for them to be charged and discharged safely for a few tens of thousands of cycles. The Li-ion supercapacitors can be charged from the solar cells during the day during an extended EVA. The Liion battery used can be half the capacity required for a nominal EVA. The small Li-ion battery can be divided into two parallel modules with independent charging ports that would allow the supercapacitors to charge one battery while the other is providing power to the rover or suit.

A Combined Desorption Ionization by Charge Exchange (DICE) and Desorption Electrospray Ionization (DESI) Source for Mass Spectrometry

NASA Astrophysics Data System (ADS)

Chan, Chang-Ching; Bolgar, Mark S.; Miller, Scott A.; Attygalle, Athula B.

2011-01-01

A source that couples the desorption ionization by charge exchange (DICE) and desorption electrospray ionization (DESI) techniques together was demonstrated to broaden the range of compounds that can be analyzed in a single mass spectrometric experiment under ambient conditions. A tee union was used to mix the spray reagents into a partially immiscible blend before this mixture was passed through a conventional electrospray (ES) probe capillary. Using this technique, compounds that are ionized more efficiently by the DICE method and those that are ionized better with the DESI procedure could be analyzed simultaneously. For example, hydroquinone, which is not detected when subjected to DESI-MS in the positive-ion generation mode, or the sodium adduct of guaifenesin, which is not detected when examined by DICE-MS, could both be detected in one experiment when the two techniques were combined. The combined technique was able to generate the molecular ion, proton and metal adduct from the same compound. When coupled to a tandem mass spectrometer, the combined source enabled the generation of product ion spectra from the molecular ion and the [M + H]+ or [M + metal]+ ions of the same compound without the need to physically change the source from DICE to DESI. The ability to record CID spectra of both the molecular ion and adduct ions in a single mass spectrometric experiment adds a new dimension to the array of mass spectrometric methods available for structural studies.

Neutron yield when fast deuterium ions collide with strongly charged tritium-saturated dust particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akishev, Yu. S., E-mail: akishev@triniti.ru; Karal’nik, V. B.; Petryakov, A. V.

2017-02-15

The ultrahigh charging of dust particles in a plasma under exposure to an electron beam with an energy up to 25 keV and the formation of a flux of fast ions coming from the plasma and accelerating in the strong field of negatively charged particles are considered. Particles containing tritium or deuterium atoms are considered as targets. The calculated rates of thermonuclear fusion reactions in strongly charged particles under exposure to accelerated plasma ions are presented. The neutron generation rate in reactions with accelerated deuterium and tritium ions has been calculated for these targets. The neutron yield has been calculatedmore » when varying the plasma-forming gas pressure, the plasma density, the target diameter, and the beam electron current density. Deuterium and tritium-containing particles are shown to be the most promising plasmaforming gas–target material pair for the creation of a compact gas-discharge neutron source based on the ultrahigh charging of dust particles by beam electrons with an energy up to 25 keV.« less

Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS.

PubMed

Thomae, R; Conradie, J; Fourie, D; Mira, J; Nemulodi, F; Kuechler, D; Toivanen, V

2016-02-01

At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.

Top-down mass spectrometry imaging of intact proteins by laser ablation ESI FT-ICR MS.

PubMed

Kiss, András; Smith, Donald F; Reschke, Brent R; Powell, Matthew J; Heeren, Ron M A

2014-05-01

Laser ablation ESI (LAESI) is a recent development in MS imaging. It has been shown that lipids and small metabolites can be imaged in various samples such as plant material, tissue sections or bacterial colonies without any sample pretreatment. Further, LAESI has been shown to produce multiply charged protein ions from liquids or solid surfaces. This presents a means to address one of the biggest challenges in MS imaging; the identification of proteins directly from biological tissue surfaces. Such identification is hindered by the lack of multiply charged proteins in common MALDI ion sources and the difficulty of performing tandem MS on such large, singly charged ions. We present here top-down identification of intact proteins from tissue with a LAESI ion source combined with a hybrid ion-trap FT-ICR mass spectrometer. The performance of the system was first tested with a standard protein with electron capture dissociation and infrared multiphoton dissociation fragmentation to prove the viability of LAESI FT-ICR for top-down proteomics. Finally, the imaging of a tissue section was performed, where a number of intact proteins were measured and the hemoglobin α chain was identified directly from tissue using CID and infrared multiphoton dissociation fragmentation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dynamics of Ion Beam Charge Neutralization by Ferroelectric Plasma Sources

NASA Astrophysics Data System (ADS)

Stepanov, Anton D.; Gilson, Erik P.; Grisham, Larry R.; Kaganovich, Igor D.; Davidson, Ronald C.; Ji, Qing; Persaud, Arun; Seidl, Peter A.; Schenkel, Thomas

2016-10-01

Ferroelectric Plasma Sources (FEPSs) can generate plasma that provides effective space-charge neutralization of intense high-perveance ion beams. Here we present experimental results on charge neutralization of a high-perveance 38 keV Ar+ beam by a FEPS plasma. By comparing the measured beam radius with the envelope model for space-charge expansion, it is shown that a charge neutralization fraction of 98% is attainable. The transverse electrostatic potential of the ion beam is reduced from 15 V before neutralization to 0.3 V, implying that the energy of the neutralizing electrons is below 0.3 eV. Near-complete charge neutralization is established 5 μs after the driving pulse is applied to the FEPS, and can last for 35 μs. It is argued that the duration of neutralization is much longer than a reasonable lifetime of the plasma produced in the sub- μs surface discharge. Measurements of current flow in the driving circuit of the FEPS suggest that plasma can be generated for tens of μs after the high voltage pulse is applied. This is confirmed by fast photography of the plasma in the 1-meter long FEPS on NDCX-II, where effective charge neutralization of the beam was achieved with the optimized FEPS timing. This work was supported by the Office of Science of the US Department of Energy under contracts DE-AC0209CH11466 (PPPL) and DE-AC0205CH11231 (LBNL).

A Penning sputter ion source with very low energy spread

NASA Astrophysics Data System (ADS)

Nouri, Z.; Li, R.; Holt, R. A.; Rosner, S. D.

2010-03-01

We have developed a version of the Frankfurt Penning ion source that produces ion beams with very low energy spreads of ˜3 eV, while operating in a new discharge mode characterized by very high pressure, low voltage, and high current. The extracted ions also comprise substantial metastable and doubly charged species. Detailed studies of the operating parameters of the source showed that careful adjustment of the magnetic field and gas pressure is critical to achieving optimum performance. We used a laser-fluorescence method of energy analysis to characterize the properties of the extracted ion beam with a resolving power of 1×10 4, and to measure the absolute ion beam energy to an accuracy of 4 eV in order to provide some insight into the distribution of plasma potential within the ion source. This characterization method is widely applicable to accelerator beams, though not universal. The low energy spread, coupled with the ability to produce intense ion beams from almost any gas or conducting solid, make this source very useful for high-resolution spectroscopic measurements on fast-ion beams.

A compact time-of-flight mass spectrometer for ion source characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, L., E-mail: l.chen03@gmail.com; Wan, X.; Jin, D. Z.

2015-03-15

A compact time-of-flight mass spectrometer with overall dimension of about 413 × 250 × 414 mm based on orthogonal injection and angle reflection has been developed for ion source characterization. Configuration and principle of the time-of-flight mass spectrometer are introduced in this paper. The mass resolution is optimized to be about 1690 (FWHM), and the ion energy detection range is tested to be between about 3 and 163 eV with the help of electron impact ion source. High mass resolution and compact configuration make this spectrometer useful to provide a valuable diagnostic for ion spectra fundamental research and study themore » mass to charge composition of plasma with wide range of parameters.« less

Ionization efficiency studies with charge breeder and conventional electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koivisto, H., E-mail: hannu.koivisto@phys.jyu.fi; Tarvainen, O.; Toivanen, V.

2014-02-15

Radioactive Ion Beams play an increasingly important role in several European research facility programs such as SPES, SPIRAL1 Upgrade, and SPIRAL2, but even more for those such as EURISOL. Although remarkable advances of ECRIS charge breeders (CBs) have been achieved, further studies are needed to gain insight on the physics of the charge breeding process. The fundamental plasma processes of charge breeders are studied in the frame of the European collaboration project, EMILIE, for optimizing the charge breeding. Important information on the charge breeding can be obtained by conducting similar experiments using the gas mixing and 2-frequency heating techniques withmore » a conventional JYFL 14 GHz ECRIS and the LPSC-PHOENIX charge breeder. The first experiments were carried out with noble gases and they revealed, for example, that the effects of the gas mixing and 2-frequency heating on the production of high charge states appear to be additive for the conventional ECRIS. The results also indicate that at least in the case of noble gases the differences between the conventional ECRIS and the charge breeder cause only minor impact on the production efficiency of ion beams.« less

Studies on a Q/A selector for the SECRAL electron cyclotron resonance ion source.

PubMed

Yang, Y; Sun, L T; Feng, Y C; Fang, X; Lu, W; Zhang, W H; Cao, Y; Zhang, X Z; Zhao, H W

2014-08-01

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.

Production of negatively charged radioactive ion beams

DOE PAGES

Liu, Y.; Stracener, D. W.; Stora, T.

2017-02-15

Beams of short-lived radioactive nuclei are needed for frontier experimental research in nuclear structure, reactions, and astrophysics. Negatively charged radioactive ion beams have unique advantages and allow for the use of a tandem accelerator for post-acceleration, which can provide the highest beam quality and continuously variable energies. Negative ion beams can be obtained with high intensity and some unique beam purification techniques based on differences in electronegativity and chemical reactivity can be used to provide beams with high purity. This article describes the production of negative radioactive ion beams at the former holifield radioactive ion beam facility at Oak Ridgemore » National Laboratory and at the CERN ISOLDE facility with emphasis on the development of the negative ion sources employed at these two facilities.« less

Analysis of a Li-Ion Nanobattery with Graphite Anode Using Molecular Dynamics Simulations

DOE PAGES

Ponce, Victor; Galvez-Aranda, Diego E.; Seminario, Jorge M.

2017-05-19

In this work, molecular dynamics simulations were performed of the initial charging of a Li-ion nanobattery with a graphite anode and lithium hexaflourphosphate (LiPF 6) salt dissolved in ethylene carbonate (CO 3C 2H 4) solvent as the electrolyte solution. The charging was achieved through the application of external electric fields simulating voltage sources. A variety of force fields were combined to simulate the materials of the nanobattery, including the solid electrolyte interphase, metal collectors, and insulator cover. Some of the force field parameters were estimated using ab initio methods and others were taken from the literature. We studied the behaviormore » of Li-ions traveling from cathode to anode through electrolyte solutions of concentrations 1.15 and 3.36 M. Time-dependent variables such as energy, temperature, volume, polarization, and mean square displacement are reported; a few of these variables, as well as others such as current, resistance, current density, conductivity, and resistivity are reported as a function of the external field and charging voltage. A solid electrolyte interphase (SEI) layer was also added to the model to study the mechanism behind the diffusion of the Li-ions through the SEI. As the battery is charged, the depletion of Li atoms in the cathode and their accumulation in the anode follow a linear increase of the polarizability in the solvent, until reaching a saturation point after which the charging of the battery stops, i.e., the energy provided by the external source decays to very low levels. Lastly, the nanobattery model containing the most common materials of a commercial lithium-ion battery is very useful to determine atomistic information that is difficult or too expensive to obtain experimentally; available data shows consistency with our results.« less

Development of dual-beam system using an electrostatic accelerator for in-situ observation of swift heavy ion irradiation effects on materials

NASA Astrophysics Data System (ADS)

Matsuda, M.; Asozu, T.; Sataka, M.; Iwase, A.

2013-11-01

We have developed the dual beam system which accelerates two kinds of ion beams simultaneously especially for real-time ion beam analysis. We have also developed the alternating beam system which can efficiently change beam species in a short time in order to realize efficient ion beam analysis in a limited beam time. The acceleration of the dual beam is performed by the 20 UR Pelletron™ tandem accelerator in which an ECR ion source is mounted at the high voltage terminal [1,2]. The multi-charged ions of two or more elements can be simultaneously generated from the ECR ion source, so dual-beam irradiation is achieved by accelerating ions with the same charge to mass ratio (for example, 132Xe11+ and 12C+). It enables us to make a real-time beam analysis such as Rutherford Back Scattering (RBS) method, while a target is irradiated with swift heavy ions. For the quick change of the accelerating ion beam, the program of automatic setting of the optical parameter of the accelerator has been developed. The switchover time for changing the ion beam is about 5 min. These developments have been applied to the study on the ion beam mixing caused by high-density electronic excitation induced by swift heavy ions.

ICFA Beam Dynamics Newsletter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pikin, A.

2017-11-21

Electron beam ion sources technology made significant progress since 1968 when this method of producing highly charged ions in a potential trap within electron beam was proposed by E. Donets. Better understanding of physical processes in EBIS, technological advances and better simulation tools determined significant progress in key EBIS parameters: electron beam current and current density, ion trap capacity, attainable charge states. Greatly increased the scope of EBIS and EBIT applications. An attempt is made to compile some of EBIS engineering problems and solutions and to demonstrate a present stage of understanding the processes and approaches to build a bettermore » EBIS.« less

Space charge tune shift, fast resonance traversal, and current limits in circular accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rees, G.H.

1996-06-01

Space charge tune shifts, fast resonance traversals, and current limits are important design issues for low energy, high power circular accelerators. Areas of interest are accumulator rings and fast cycling synchrotrons, and typical applications are for pulsed spallation neutron sources, heavy ion fusion storage ring drivers, and booster injectors for high energy proton and ion facilities. Aspects of the three topics are discussed in the paper. {copyright} {ital 1996 American Institute of Physics.}

Singularity and Bohm criterion in hot positive ion species in the electronegative ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aslaninejad, Morteza; Yasserian, Kiomars

2016-05-15

The structure of the discharge for a magnetized electronegative ion source with two species of positive ions is investigated. The thermal motion of hot positive ions and the singularities involved with it are taken into account. By analytical solution of the neutral region, the location of the singular point and also the values of the plasma parameter such as electric potential and ion density at the singular point are obtained. A generalized Bohm criterion is recovered and discussed. In addition, for the non-neutral solution, the numerical method is used. In contrast with cold ion plasma, qualitative changes are observed. Themore » parameter space region within which oscillations in the density and potential can be observed has been scanned and discussed. The space charge behavior in the vicinity of edge of the ion sources has also been discussed in detail.« less

Design study of low-energy beam transport for multi-charge beams at RAON

NASA Astrophysics Data System (ADS)

Bahng, Jungbae; Qiang, Ji; Kim, Eun-San

2015-12-01

The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

Meteoric Ions in Planetary Ionospheres

NASA Technical Reports Server (NTRS)

Pesnell, W. D.; Grebowsky, Joseph M.; Vondrak, Richard R. (Technical Monitor)

2001-01-01

Solar system debris, in the form of meteoroids, impacts every planet. The flux, relative composition and speed of the debris at each planet depends on the planet's size and location in the solar system. Ablation in the atmosphere evaporates the meteoric material and leaves behind metal atoms. During the ablation process metallic ions are formed by impact ionization. For small inner solar system planets, including Earth, this source of ionization is typically small compared to either photoionization or charge exchange with ambient molecular ions. For Earth, the atmosphere above the main deposition region absorbs the spectral lines capable of ionizing the major metallic atoms (Fe and Mg) so that charge exchange with ambient ions is the dominant source. Within the carbon dioxide atmosphere of Mars (and possibly Venus), photoionization is important in determining the ion density. For a heavy planet like Jupiter, far from the sun, impact ionization of ablated neutral atoms by impacts with molecules becomes a prominent source of ionization due to the gravitational acceleration to high incident speeds. We will describe the processes and location and extent of metal ion layers for Mars, Earth and Jupiter, concentrating on flagging the uncertainties in the models at the present time. This is an important problem, because low altitude ionosphere layers for the planets, particularly at night, probably consist predominantly of metallic ions. Comparisons with Earth will be used to illustrate the differing processes in the three planetary atmospheres.

Experimental study of low-energy charge transfer in nitrogen

NASA Technical Reports Server (NTRS)

Smith, A.

1979-01-01

Total charge transfer cross sections were obtained for the N2(+)-N2 system with relative translational ion energies between 9 and 441 eV. Data were obtained to examine the dependence of total cross section on ion energy. The effect of ion excitation on the cross sections was studied by varying the electron ionization energy in the mass spectrometer ion source over an electron energy range between 14.5 and 32.1 eV. The dependence of total cross section on the neutralization chamber gas pressure was examined by obtaining data at pressure values from 9.9 to 0.000199 torr. Cross section values obtained were compared with experimental and theoretical results of other investigations.

Detecting negative ions on board small satellites

NASA Astrophysics Data System (ADS)

Lepri, S. T.; Raines, J. M.; Gilbert, J. A.; Cutler, J.; Panning, M.; Zurbuchen, T. H.

2017-04-01

Recent measurements near comets, planets, and their satellites have shown that heavy ions, energetic neutral atoms, molecular ions, and charged dust contain a wealth of information about the origin, evolution, and interaction of celestial bodies with their space environment. Using highly sensitive plasma instruments, positively charged heavy ions have been used to trace exospheric and surface composition of comets, planets, and satellites as well as the composition of interplanetary and interstellar dust. While positive ions dominate throughout the heliosphere, negative ions are also produced from surface interactions. In fact, laboratory experiments have shown that oxygen released from rocky surfaces is mostly negatively charged. Negative ions and negatively charged nanograins have been detected with plasma electron analyzers in several different environments (e.g., by Cassini and Rosetta), though more extensive studies have been challenging without instrumentation dedicated to negative ions. We discuss an adaptation of the Fast Imaging Plasma Spectrometer (FIPS) flown on MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) for the measurement of negatively charged particles. MESSENGER/FIPS successfully measured the plasma environment of Mercury from 2011 until 2015, when the mission ended, and has been used to map multiple ion species (H+ through Na+ and beyond) throughout Mercury's space environment. Modifications to the existing instrument design fits within a 3U CubeSat volume and would provide a low mass, low power instrument, ideal for future CubeSat or distributed sensor missions seeking, for the first time, to characterize the contribution of negative particles in the heliospheric plasmas near the planets, moons, comets, and other sources.

Optimization of a charge-state analyzer for electron cyclotron resonance ion source beams.

PubMed

Saminathan, S; Beijers, J P M; Kremers, H R; Mironov, V; Mulder, J; Brandenburg, S

2012-07-01

A detailed experimental and simulation study of the extraction of a 24 keV He(+) beam from an ECR ion source and the subsequent beam transport through an analyzing magnet is presented. We find that such a slow ion beam is very sensitive to space-charge forces, but also that the neutralization of the beam's space charge by secondary electrons is virtually complete for beam currents up to at least 0.5 mA. The beam emittance directly behind the extraction system is 65 π mm mrad and is determined by the fact that the ion beam is extracted in the strong magnetic fringe field of the ion source. The relatively large emittance of the beam and its non-paraxiality lead, in combination with a relatively small magnet gap, to significant beam losses and a five-fold increase of the effective beam emittance during its transport through the analyzing magnet. The calculated beam profile and phase-space distributions in the image plane of the analyzing magnet agree well with measurements. The kinematic and magnet aberrations have been studied using the calculated second-order transfer map of the analyzing magnet, with which we can reproduce the phase-space distributions of the ion beam behind the analyzing magnet. Using the transfer map and trajectory calculations we have worked out an aberration compensation scheme based on the addition of compensating hexapole components to the main dipole field by modifying the shape of the poles. The simulations predict that by compensating the kinematic and geometric aberrations in this way and enlarging the pole gap the overall beam transport efficiency can be increased from 16% to 45%.

Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomae, R., E-mail: rthomae@tlabs.ac.za; Conradie, J.; Fourie, D.

2016-02-15

At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the resultsmore » of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.« less

Multicharged iron ions produced by using induction heating vapor source.

PubMed

Kato, Yushi; Kubo, Takashi; Muramatsu, Masayuki; Tanaka, Kiyokatsu; Kitagawa, Atsushi; Yoshida, Yoshikazu; Asaji, Toyohisa; Sato, Fuminobu; Iida, Toshiyuki

2008-02-01

Multiply charged Fe ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with an induction coil which is made of bare molybdenum wire partially covered by ceramic beads in vacuum and surrounding and heating directly the pure Fe rod. Heated material has no contact with insulators, so that outgas is minimized. The evaporator is installed around the mirror end plate outside of the ECR plasma with its hole grazing the ECR zone. Helium or argon gas is usually chosen for supporting gas. The multicharged Fe ions up to Fe(13+) are extracted from the opposite side of mirror and against the evaporator, and then multicharged Fe ion beam is formed. We compare production of multicharged iron ions by using this new source with our previous methods.

Development of a pepper-pot device to determine the emittance of an ion beam generated by electron cyclotron resonance ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strohmeier, M.; University of Applied Sciences Karlsruhe, Moltkestr. 30, 76133 Karlsruhe; Benitez, J. Y.

2010-02-15

This paper describes the recent development and commissioning of a pepper-pot emittance meter at the Lawrence Berkeley National Laboratory (LBNL). It is based on a potassium bromide (KBr) scintillator screen in combination with a charged coupled device camera. Pepper-pot scanners record the full four-dimensional transverse phase space emittances which are particularly interesting for electron cyclotron resonance ion sources. The strengths and limitations of evaluating emittances using optical pepper-pot scanners are described and systematic errors induced by the optical data acquisition system will be presented. Light yield tests of KBr exposed to different ion species and first emittance measurement data usingmore » ion beams extracted from the 6.4 GHz LBNL electron cyclotron resonance ion source are presented and discussed.« less

An electrostatic deceleration lens for highly charged ions.

PubMed

Rajput, J; Roy, A; Kanjilal, D; Ahuja, R; Safvan, C P

2010-04-01

The design and implementation of a purely electrostatic deceleration lens used to obtain beams of highly charged ions at very low energies is presented. The design of the lens is such that it can be used with parallel as well as diverging incoming beams and delivers a well focused low energy beam at the target. In addition, tuning of the final energy of the beam over a wide range (1 eV/q to several hundred eV/q, where q is the beam charge state) is possible without any change in hardware configuration. The deceleration lens was tested with Ar(8+), extracted from an electron cyclotron resonance ion source, having an initial energy of 30 keV/q and final energies as low as 70 eV/q have been achieved.

Energetic neutral particles from Jupiter and Saturn

NASA Astrophysics Data System (ADS)

Cheng, A. F.

1986-04-01

The Voyager 1 spacecraft has detected energetic neutral particles escaping from the magnetospheres of Jupiter and Saturn. These energetic neutrals are created in charge exchange reactions between radiation belt ions and ambient atoms or molecules in the magnetosphere. If the Io torus is assumed to be the dominant Jovian source region for energetic neutrals, the Voyager observations can be used to infer upper limits to the average ion intensities there below about 200 keV. No readily interpretable in-situ measurements are available in the Io torus at these energies. The middle and outer Jovian magnetospheres may also be a significant source of energetic neutrals. At Saturn, the observed neutral particle count rates are too high to be explained by charge exchange between fast protons and H atoms of the Titan torus. Most of the energetic neutrals may be produced by charge exchanges between heavy ions and a neutral cloud containing H2O in Saturn's inner magnetosphere. If so, the Voyager measurements of energetic neutral fluxes would be the first detected emissions from this region of Saturn's magnetosphere.

Spectroscopy of Highly Charged Tin Ions for AN Extreme Ultraviolet Light Source for Lithography

NASA Astrophysics Data System (ADS)

Torretti, Francesco; Windberger, Alexander; Ubachs, Wim; Hoekstra, Ronnie; Versolato, Oscar; Ryabtsev, Alexander; Borschevsky, Anastasia; Berengut, Julian; Crespo Lopez-Urrutia, Jose

2017-06-01

Laser-produced tin plasmas are the prime candidates for the generation of extreme ultraviolet (EUV) light around 13.5 nm in nanolithographic applications. This light is generated primarily by atomic transitions in highly charged tin ions: Sn^{8+}-Sn^{14+}. Due to the electronic configurations of these charge states, thousands of atomic lines emit around 13.5 nm, clustered in a so-called unresolved transition array. As a result, accurate line identification becomes difficult in this regime. Nevertheless, this issue can be circumvented if one turns to the optical: with far fewer atomic states, only tens of transitions take place and the spectra can be resolved with far more ease. We have investigated optical emission lines in an electron-beam-ion-trap (EBIT), where we managed to charge-state resolve the spectra. Based on this technique and on a number of different ab initio techniques for calculating the level structure, the optical spectra could be assigned [1,2]. As a conclusion the assignments of EUV transitions in the literature require corrections. The EUV and optical spectra are measured simultaneously in the controlled conditions of the EBIT as well as in a droplet-based laser-produced plasma source providing information on the contribution of Sn^{q+} charge states to the EUV emission. [1] A. Windberger, F. Torretti, A. Borschevsky, A. Ryabtsev, S. Dobrodey, H. Bekker, E. Eliav, U. Kaldor, W. Ubachs, R. Hoekstra, J.R. Crespo Lopez-Urrutia, O.O. Versolato, Analysis of the fine structure of Sn^{11+} - Sn^{14+} ions by optical spectroscopy in an electron beam ion trap, Phys. Rev. A 94, 012506 (2016). [2] F. Torretti, A. Windberger, A. Ryabtsev, S. Dobrodey, H. Bekker, W. Ubachs, R. Hoekstra, E.V. Kahl, J.C. Berengut, J.R. Crespo Lopez-Urrutia, O.O. Versolato, Optical spectroscopy of complex open 4d-shell ions Sn^{7+} - Sn^{10+}, arXiv:1612.00747

High charge state carbon and oxygen ions in Earth's equatorial quasi-trapping region

NASA Technical Reports Server (NTRS)

Christon, S. P.; Hamilton, D. C.; Gloeckler, G.; Eastmann, T. E.

1994-01-01

Observations of energetic (1.5 - 300 keV/e) medium-to-high charge state (+3 less than or equal to Q less than or equal to +7) solar wind origin C and O ions made in the quasi-trapping region (QTR) of Earth's magnetosphere are compared to ion trajectories calculated in model equatorial magnetospheric magnetic and electric fields. These comparisons indicate that solar wind ions entering the QTR on the nightside as an energetic component of the plasma sheet exit the region on the dayside, experiencing little or no charge exchange on the way. Measurements made by the CHarge Energy Mass (CHEM) ion spectrometer on board the Active Magnetospheric Particle Tracer Explorer/Charge Composition Explorer (AMPTE/CCE) spacecraft at 7 less than L less than 9 from September 1984 to January 1989 are the source of the new results contained herein: quantitative long-term determination of number densities, average energies, energy spectra, local time distributions, and their variation with geomagnetic disturbance level as indexed by Kp. Solar wind primaries (ions with charge states unchanged) and their secondaries (ions with generally lower charge states produced from primaries in the magnetosphere via charge exchange)are observed throughout the QTR and have distinctly different local time variations that persist over the entire 4-year analysis interval. During Kp larger than or equal to 3 deg intervals, primary ion (e.g., O(+6)) densities exhibit a pronounced predawn maximum with average energy minimum and a broad near-local-noon density minimum with average energy maximum. Secondary ion (e.g., O(+5)) densities do not have an identifiable predawn peak, rather they have a broad dayside maximum peaked in local morning and a nightside minimum. During Kp less than or equal to 2(-) intervals, primary ion density peaks are less intense, broader in local time extent, and centered near midnight, while secondary ion density local time variations diminish. The long-time-interval baseline helps to refine and extend previous observations; for example, we show that ionospheric contribution to O(+3)) is negligible. Through comparison with model ion trajectories, we interpret the lack of pronounced secondary ion density peaks colocated with the primary density peaks to indicate that: (1) negligible charge exchange occurs at L greater than 7, that is, solar wind secondaries are produced at L less than 7, and (2) solar wind secondaries do not form a significant portion of the plasma sheet population injected into the QTR. We conclude that little of the energetic solar wind secondary ion population is recirculated through the magnetosphere.

Analysis of the saturation phenomena of the neutralization rate of positively charged 218Po in water vapor.

PubMed

Tan, Yanliang; Xiao, Detao; Shan, Jian; Zhou, Qingzhi; Qu, Jingnian

2014-09-01

Generally, 88% of the freshly generated 218Po ions decayed from 222Rn are positively charged. These positive ions become neutralized by recombination with negative ions, and the main source of the negative ions is the OH- ions formed by radiolysis of water vapor. However, the neutralization rate of positively charged 218Po versus the square root of the concentration of H2O will be a constant when the concentration of H2O is sufficiently high. Since the electron affinity of the hydroxyl radical formed by water vapor is high, the authors propose that the hydroxyl radical can grab an electron to become OH-. Because the average period of collision with other positively charged ions and the average life of the OH- are much longer than those of the electron, the average concentration of negative ions will grow when the water vapor concentration increases. The authors obtained a model to describe the growth of OH- ions. From this model, it was found that the maximum value of the OH- ion concentration is limited by the square root of the radon concentration. If the radon concentration is invariant, the OH- ion concentration should be approximately a constant when the water vapor concentration is higher than a certain value. The phenomenon that the neutralization rate of positively charged 218Po versus the square root of the water vapor concentration will be saturated when the water vapor concentration is sufficiently high can be explained by this mechanism. This mechanism can be used also to explain the phenomenon that the detection efficiency of a radon monitor based on the electrostatic collection method seems to be constant when the water vapor concentration is high.

On the upper bound in the Bohm sheath criterion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kotelnikov, I. A., E-mail: I.A.Kotelnikov@inp.nsk.su; Skovorodin, D. I., E-mail: D.I.Skovorodin@inp.nsk.su

2016-02-15

The question is discussed about the existence of an upper bound in the Bohm sheath criterion, according to which the Debye sheath at the interface between plasma and a negatively charged electrode is stable only if the ion flow velocity in plasma exceeds the ion sound velocity. It is stated that, with an exception of some artificial ionization models, the Bohm sheath criterion is satisfied as an equality at the lower bound and the ion flow velocity is equal to the speed of sound. In the one-dimensional theory, a supersonic flow appears in an unrealistic model of a localized ionmore » source the size of which is less than the Debye length; however, supersonic flows seem to be possible in the two- and three-dimensional cases. In the available numerical codes used to simulate charged particle sources with a plasma emitter, the presence of the upper bound in the Bohm sheath criterion is not supposed; however, the correspondence with experimental data is usually achieved if the ion flow velocity in plasma is close to the ion sound velocity.« less

Method and apparatus for selective filtering of ions

DOEpatents

Page, Jason S [Kennewick, WA; Tang, Keqi [Richland, WA; Smith, Richard D [Richland, WA

2009-04-07

An adjustable, low mass-to-charge (m/z) filter is disclosed employing electrospray ionization to block ions associated with unwanted low m/z species from entering the mass spectrometer and contributing their space charge to down-stream ion accumulation steps. The low-mass filter is made by using an adjustable potential energy barrier from the conductance limiting terminal electrode of an electrodynamic ion funnel, which prohibits species with higher ion mobilities from being transmitted. The filter provides a linear voltage adjustment of low-mass filtering from m/z values from about 50 to about 500. Mass filtering above m/z 500 can also be performed; however, higher m/z species are attenuated. The mass filter was evaluated with a liquid chromatography-mass spectrometry analysis of an albumin tryptic digest and resulted in the ability to block low-mass, "background" ions which account for 40-70% of the total ion current from the ESI source during peak elution.

Selective ion accumulation in an ICP/ITMS using a filtered noise field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eiden, G.C.; Barinaga, C.J.; Koppenaal, D.W.

1995-12-31

Selective accumulation of ions in an ion trap mass spectrometer (ITMS) has been characterized using both single frequency and broadband resonant excitation. The goal of this work is to enhance selective accumulation of ions from plasmas and other external ion sources. The charge capacity of the ITMS is 10{sup 6} to 10{sup 7} ions, although the mass spectrum is distorted at much lower space charge. Detection of trace ions necessitates selective detection schemes such as selective trapping or optical detection. The authors report results of selective trapping studies for Sr, Y, and Zr solutions (100 ppb Y and 1 ppbmore » each Sr, Zr). {open_quotes}Background{close_quotes} ions in mass channels adjacent to the channel of interest is a worst case situation with respect to selective ejection and abundance sensitivity. Real samples will often have matrix ion m/z values much further removed from the m/z of the ions of interest. Thus, the authors also give results for a multielement solution. Ions from an inductively coupled plasma ion source are endcap injected into the ITMS. Broadband waveforms were generated by an HST-1000 (Teledyne MEC) instrument, using the filtered noise field (FNF) method. The experiment is controlled by the ITMS electronics and ICMS software. The sequence of experimental events is: ion injection at q{sub z} = 0.4 (typical), collisionally cool ions, set trapping potential for resonant excitation (q{sub z} = 0.2 to 0.6), analysis rf ramp.« less

A new IBA-AMS laboratory at the Comenius University in Bratislava (Slovakia)

NASA Astrophysics Data System (ADS)

Povinec, Pavel P.; Masarik, Jozef; Kúš, Peter; Holý, Karol; Ješkovský, Miroslav; Breier, Robert; Staníček, Jaroslav; Šivo, Alexander; Richtáriková, Marta; Kováčik, Andrej; Szarka, Ján; Steier, Peter; Priller, Alfred

2015-01-01

A Centre for Nuclear and Accelerator Technologies (CENTA) has been established at the Comenius University in Bratislava comprising of a tandem laboratory designed for Ion Beam Analysis (IBA), Ion Beam Modification (IBM) of materials and Accelerator Mass Spectrometry (AMS). The main equipment of the laboratory, i.e. Alphatross and MC-SNICS ion sources, 3 MV Pelletron tandem accelerator, and analyzers of accelerated ions are described. Optimization of ion beam characteristics for different ion sources with gas and solid targets, for transmission of accelerated ions with different energy and charge state, for different parameters of the high-energy ion analyzers, as well as first AMS results are presented. The scientific program of the CENTA will be devoted mainly to nuclear, environmental, life and material sciences.

Development and Evaluation of a Reverse-Entry Ion Source Orbitrap Mass Spectrometer

NASA Astrophysics Data System (ADS)

Poltash, Michael L.; McCabe, Jacob W.; Patrick, John W.; Laganowsky, Arthur; Russell, David H.

2018-05-01

As a step towards development of a high-resolution ion mobility mass spectrometer using the orbitrap mass analyzer platform, we describe herein a novel reverse-entry ion source (REIS) coupled to the higher-energy C-trap dissociation (HCD) cell of an orbitrap mass spectrometer with extended mass range. Development of the REIS is a first step in the development of a drift tube ion mobility-orbitrap MS. The REIS approach retains the functionality of the commercial instrument ion source which permits the uninterrupted use of the instrument during development as well as performance comparisons between the two ion sources. Ubiquitin (8.5 kDa) and lipid binding to the ammonia transport channel (AmtB, 126 kDa) protein complex were used as model soluble and membrane proteins, respectively, to evaluate the performance of the REIS instrument. Mass resolution obtained with the REIS is comparable to that obtained using the commercial ion source. The charge state distributions for ubiquitin and AmtB obtained on the REIS are in agreement with previous studies which suggests that the REIS-orbitrap EMR retains native structure in the gas phase.

An Anomalous Composition in Slow Solar Wind as a Signature of Magnetic Reconnection in its Source Region

NASA Astrophysics Data System (ADS)

Zhao, L.; Landi, E.; Lepri, S. T.; Kocher, M.; Zurbuchen, T. H.; Fisk, L. A.; Raines, J. M.

2017-01-01

In this paper, we study a subset of slow solar winds characterized by an anomalous charge state composition and ion temperatures compared to average solar wind distributions, and thus referred to as an “Outlier” wind. We find that although this wind is slower and denser than normal slow wind, it is accelerated from the same source regions (active regions and quiet-Sun regions) as the latter and its occurrence rate depends on the solar cycle. The defining property of the Outlier wind is that its charge state composition is the same as that of normal slow wind, with the only exception being a very large decrease in the abundance of fully charged species (He2+, C6+, N7+, O8+, Mg12+), resulting in a significant depletion of the He and C element abundances. Based on these observations, we suggest three possible scenarios for the origin of this wind: (1) local magnetic waves preferentially accelerating non-fully stripped ions over fully stripped ions from a loop opened by reconnection; (2) depleted fully stripped ions already contained in the corona magnetic loops before they are opened up by reconnection; or (3) fully stripped ions depleted by Coulomb collision after magnetic reconnection in the solar corona. If any one of these three scenarios is confirmed, the Outlier wind represents a direct signature of slow wind release through magnetic reconnection.

Results from the Heavy Ions In Space (HIIS) experiment on the ionic charge state of solar energetic particles

NASA Technical Reports Server (NTRS)

Tylka, Allan J.; Boberg, Paul R.; Adams, James H., Jr.; Beahm, Lorraine P.; Kleis, Thomas

1995-01-01

It has long been known that low-energy solar energetic particles (SEP's) are partially-ionized. For example, in large, so-called 'gradual' solar energetic particle events, at approximately 1 MeV/nucleon the measured mean ionic charge state, Q, of Fe ions is 14.1 +/- 0.2, corresponding to a plasma temperature of approximately 2 MK in the coronal or solar-wind source material. Recent studies, which have greatly clarified the origin of solar energetic particles and their relation to solar flares, suggest that ions in these SEP events are accelerated not at a flare site, but by shocks propagating through relatively low-density regions in the interplanetary medium. As a result, the partially-ionized states observed at low energies are expected to continue to higher energies. However, up to now there have been no high-energy measurements of ionic charge states to confirm this notion. We report here HIIS observations of Fe-group ions at 50-600 MeV/nucleon, at energies and fluences which cannot be explained by fully-ionized galactic cosmic rays, even in the presence of severe geomagnetic cutoff suppression. Above approximately 200 MeV/nucleon, all features of our data -- fluence, energy spectrum, elemental composition, and arrival directions -- can be explained by the large SEP events of October 1989, provided that the mean ionic charge state at these high energies is comparable to the measured value at approximately 1 MeV/nucleon. By comparing the HIIS observations with measurements in interplanetary space in October 1989, we determine the mean ionic charge state of SEP Fe ions at approximately 200-600 MeV/nucleon to be Q = 13.4 plus or minus 1.0, in good agreement with the observed value at approximately 1 MeV/nucleon. The source of the ions below approximately 200 MeV/nucleon is not yet clear. Partially-ionized ions are less effectively deflected by the Earth's magnetic field than fully-ionized cosmic rays and therefore have greatly enhanced access to low-Earth orbit. Moreover, at the high energies observed in HIIS, these ions can penetrate typical amounts of shielding. We discuss the significance of the HIIS results for estimates of the radiation hazard posed by large SEP events to satellites in low-Earth orbit, including the proposed Space Station orbit. Finally, we comment on previous reports of low-energy below-cutoff Fe-group ions, which some authors have interpreted as evidence for partially-ionized galactic cosmic rays. The LDEF flux levels are much smaller than the corresponding fluxes in these previous reports, implying that the source of these ions has an unusual solar-cycle variation and/or strongly increases with decreasing altitude.

Measurement of visible and UV emission from Energetic Neutral Atom Precipitation (ENAP), on Spacelab

NASA Technical Reports Server (NTRS)

Tinsley, B. A.

1980-01-01

The charge exchange of plasmaspheric ions and exospheric H and O and of solar wind ions with exospheric and interplanetary H are sources of precipitating neutrals whose faint emission may be observed by the imaging spectrometric observatory during dark periods of the SL-1 orbit. Measurements of the interactions of these precipitating atoms with the thermosphere are needed to evaluate the heating and ionization effects on the atmosphere as well as the selective loss of i energetic ions from the sources (predominantly the ring current).

Volume Averaging Study of the Capacitive Deionization Process in Homogeneous Porous Media

DOE PAGES

Gabitto, Jorge; Tsouris, Costas

2015-05-05

Ion storage in porous electrodes is important in applications such as energy storage by supercapacitors, water purification by capacitive deionization, extraction of energy from a salinity difference and heavy ion purification. In this paper, a model is presented to simulate the charge process in homogeneous porous media comprising big pores. It is based on a theory for capacitive charging by ideally polarizable porous electrodes without faradaic reactions or specific adsorption of ions. A volume averaging technique is used to derive the averaged transport equations in the limit of thin electrical double layers. Transport between the electrolyte solution and the chargedmore » wall is described using the Gouy–Chapman–Stern model. The effective transport parameters for isotropic porous media are calculated solving the corresponding closure problems. Finally, the source terms that appear in the average equations are calculated using numerical computations. An alternative way to deal with the source terms is proposed.« less

Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics.

PubMed

Yorita, T; Hatanaka, K; Fukuda, M; Ueda, H; Yasuda, Y; Morinobu, S; Tamii, A; Kamakura, K

2014-02-01

An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.

Dense plasma focus (DPF) accelerated non radio isotopic radiological source

DOEpatents

Rusnak, Brian; Tang, Vincent

2017-01-31

A non-radio-isotopic radiological source using a dense plasma focus (DPF) to produce an intense z-pinch plasma from a gas, such as helium, and which accelerates charged particles, such as generated from the gas or injected from an external source, into a target positioned along an acceleration axis and of a type known to emit ionizing radiation when impinged by the type of accelerated charged particles. In a preferred embodiment, helium gas is used to produce a DPF-accelerated He2+ ion beam to a beryllium target, to produce neutron emission having a similar energy spectrum as a radio-isotopic AmBe neutron source. Furthermore, multiple DPFs may be stacked to provide staged acceleration of charged particles for enhancing energy, tunability, and control of the source.

Status of Charge Exchange Cross Section Measurements for Highly Charged Ions on Atomic Hydrogen

NASA Astrophysics Data System (ADS)

Draganic, I. N.; Havener, C. C.; Schultz, D. R.; Seely, D. G.; Schultz, P. C.

2011-05-01

Total cross sections of charge exchange (CX) for C5+, N6+, and O7+ ions on ground state atomic hydrogen are measured in an extended collision energy range of 1 - 20,000 eV/u. Absolute CX measurements are performed using an improved merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source mounted on a high voltage platform. In order to improve the problematic H+ signal collection for these exoergic CX collisions at low relative energies, a new double focusing electrostatic analyzer was installed. Experimental CX data are in good agreement with all previous H-oven relative measurements at higher collision energies. We compare our results with the most recent molecular orbital close-coupling (MOCC) and atomic orbital close-coupling (AOCC) theoretical calculations. Work supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, and the Office of Basic Energy Sciences of the U.S. DoE.

Dust Acoustic Solitary Waves in Dusty Plasma with Trapped Electrons Having Different Temperature Nonthermal Ions

NASA Astrophysics Data System (ADS)

Deka, Manoj Kr.

2016-12-01

In this report, a detailed investigation on the study of dust acoustics solitary waves solution with negatively dust charge fluctuation in dusty plasma corresponding to lower and higher temperature nonthermal ions with trapped electrons is presented. We consider temporal variation of dust charge as a source of dissipation term to derive the lower order modified Kadomtsev-Petviashvili equation by using the reductive perturbation technique. Solitary wave solution is obtained with the help of sech method in presence of trapped electrons and low (and high) temperature nonthermal ions. Both nonthermality of ions and trapped state of the electrons are found to have an imperative control on the nonlinear coefficient, dissipative coefficient as well as height of the wave potential.

Lithium ion beam divergence on SABRE extraction ion diode experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, D.L.; Cuneo, M.E.; Johnson, D.J.

Intense lithium beams are of particular interest for light ion inertial confinement fusion applications because lithium ions can be accelerated at high voltage in a single charge state (Li{sup +}) with a high mass-to-charge ratio and appropriate range for efficient focusing and heating of a hohlraum ICF target. Scaling to ion power densities adequate to drive high gain pellet implosions (600 TW at 30 MeV) will require a large number of beams transported, temporally bunched, and focused onto a target, with the necessary target standoff to ensure survival of the driver modules. For efficient long distance transport and focusing tomore » a small pellet, lithium beam divergence must be reduced to about 12 mrad or less (depending on the transport scheme). To support the eventual development of a light ion driver module for ICF applications, the authors are currently working to improve the composition, uniformity, and divergence of lithium ion beams produced by both passive LiF and active laser-generated lithium ion sources on extraction applied-B ion diodes on the SABRE accelerator (1 TW, 5 MV, 250 kA). While lithium beam divergence accounting and control are an essential goal of these experiments, divergence measurements for lithium beams present some unique problems not encountered to the same degree in divergence measurements on proton sources. To avoid these difficulties, the authors have developed a large aperture ion imaging diagnostic for time-resolved lithium divergence measurements. The authors will report on the operation of this lithium beam divergence diagnostic and on results of time-resolved divergence measurements in progress for passive LiF ion sources and laser-produced active lithium sources operated in diode configurations designed to control divergence growth. Comparisons will also be made with time-integrated divergence results obtained with small entrance aperture ultracompact pinhole cameras.« less

Towards a better comprehension of plasma formation and heating in high performances electron cyclotron resonance ion sources (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mascali, D.; Gammino, S.; Celona, L.

2012-02-15

Further improvements of electron cyclotron resonance ion sources (ECRIS) output currents and average charge state require a deep understanding of electron and ion dynamics in the plasma. This paper will discuss the most recent advances about modeling of non-classical evidences like the sensitivity of electron energy distribution function to the magnetic field detuning, the influence of plasma turbulences on electron heating and ion confinement, the coupling between electron and ion dynamics. All these issues have in common the non-homogeneous distribution of the plasma inside the source: the abrupt density drop at the resonance layer regulates the heating regimes (from collectivemore » to turbulent), the beam formation mechanism and emittance. Possible means to boost the performances of future ECRIS will be proposed. In particular, the use of Bernstein waves, in preliminary experiments performed at Laboratori Nazionali del Sud (LNS) on MDIS (microwave discharge ion sources)-type sources, has permitted to sustain largely overdense plasmas enhancing the warm electron temperature, which will make possible in principle the construction of sources for high intensity multicharged ions beams with simplified magnetic structures.« less

Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toivanen, V., E-mail: ville.aleksi.toivanen@cern.ch; Küchler, D.

2016-02-15

The 14.5 GHz GTS-LHC Electron Cyclotron Resonance Ion Source (ECRIS) provides multiply charged heavy ion beams for the CERN experimental program. The GTS-LHC beam formation has been studied extensively with lead, argon, and xenon beams with varied beam extraction conditions using the ion optical code IBSimu. The simulation model predicts self-consistently the formation of triangular and hollow beam structures which are often associated with ECRIS ion beams, as well as beam loss patterns which match the observed beam induced markings in the extraction region. These studies provide a better understanding of the properties of the extracted beams and a waymore » to diagnose the extraction system performance and limitations, which is otherwise challenging due to the lack of direct diagnostics in this region and the limited availability of the ion source for development work.« less

Status of the SPIRAL2 injector commissioning

NASA Astrophysics Data System (ADS)

Thuillier, T.; Angot, J.; Barué, C.; Bertrand, P.; Biarrotte, J. L.; Canet, C.; Denis, J.-F.; Ferdinand, R.; Flambard, J.-L.; Jacob, J.; Jardin, P.; Lamy, T.; Lemagnen, F.; Maunoury, L.; Osmond, B.; Peaucelle, C.; Roger, A.; Sole, P.; Touzery, R.; Tuske, O.; Uriot, D.

2016-02-01

The SPIRAL2 injector, installed in its tunnel, is currently under commissioning at GANIL, Caen, France. The injector is composed of two low energy beam transport lines: one is dedicated to the light ion beam production, the other to the heavy ions. The first light ion beam, created by a 2.45 GHz electron cyclotron resonance ion source, has been successfully produced in December 2014. The first beam of the PHOENIX V2 18 GHz heavy ion source was analyzed on 10 July 2015. A status of the SPIRAL2 injector commissioning is given. An upgrade of the heavy ion source, named PHOENIX V3 aimed to replace the V2, is presented. The new version features a doubled plasma chamber volume and the high charge state beam intensity is expected to increase by a factor of 1.5 to 2 up to the mass ˜50. A status of its assembly is proposed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thuillier, T., E-mail: thuillier@lpsc.in2p3.fr; Angot, J.; Jacob, J.

The SPIRAL2 injector, installed in its tunnel, is currently under commissioning at GANIL, Caen, France. The injector is composed of two low energy beam transport lines: one is dedicated to the light ion beam production, the other to the heavy ions. The first light ion beam, created by a 2.45 GHz electron cyclotron resonance ion source, has been successfully produced in December 2014. The first beam of the PHOENIX V2 18 GHz heavy ion source was analyzed on 10 July 2015. A status of the SPIRAL2 injector commissioning is given. An upgrade of the heavy ion source, named PHOENIX V3more » aimed to replace the V2, is presented. The new version features a doubled plasma chamber volume and the high charge state beam intensity is expected to increase by a factor of 1.5 to 2 up to the mass ∼50. A status of its assembly is proposed.« less

Status of the SPIRAL2 injector commissioning.

PubMed

Thuillier, T; Angot, J; Barué, C; Bertrand, P; Biarrotte, J L; Canet, C; Denis, J-F; Ferdinand, R; Flambard, J-L; Jacob, J; Jardin, P; Lamy, T; Lemagnen, F; Maunoury, L; Osmond, B; Peaucelle, C; Roger, A; Sole, P; Touzery, R; Tuske, O; Uriot, D

2016-02-01

The SPIRAL2 injector, installed in its tunnel, is currently under commissioning at GANIL, Caen, France. The injector is composed of two low energy beam transport lines: one is dedicated to the light ion beam production, the other to the heavy ions. The first light ion beam, created by a 2.45 GHz electron cyclotron resonance ion source, has been successfully produced in December 2014. The first beam of the PHOENIX V2 18 GHz heavy ion source was analyzed on 10 July 2015. A status of the SPIRAL2 injector commissioning is given. An upgrade of the heavy ion source, named PHOENIX V3 aimed to replace the V2, is presented. The new version features a doubled plasma chamber volume and the high charge state beam intensity is expected to increase by a factor of 1.5 to 2 up to the mass ∼50. A status of its assembly is proposed.

Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

PubMed

Toivanen, V; Küchler, D

2016-02-01

The 14.5 GHz GTS-LHC Electron Cyclotron Resonance Ion Source (ECRIS) provides multiply charged heavy ion beams for the CERN experimental program. The GTS-LHC beam formation has been studied extensively with lead, argon, and xenon beams with varied beam extraction conditions using the ion optical code IBSimu. The simulation model predicts self-consistently the formation of triangular and hollow beam structures which are often associated with ECRIS ion beams, as well as beam loss patterns which match the observed beam induced markings in the extraction region. These studies provide a better understanding of the properties of the extracted beams and a way to diagnose the extraction system performance and limitations, which is otherwise challenging due to the lack of direct diagnostics in this region and the limited availability of the ion source for development work.

Highly sensitive solids mass spectrometer uses inert-gas ion source

NASA Technical Reports Server (NTRS)

1966-01-01

Mass spectrometer provides a recorded analysis of solid material surfaces and bulk. A beam of high-energy inert-gas ions bombards the surface atoms of a sample and converts a percentage into an ionized vapor. The mass spectrum analyzer separates the vapor ionic constituents by mass-to-charge ratio.

Single event mass spectrometry

DOEpatents

Conzemius, Robert J.

1990-01-16

A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

Modeling of the charge-state separation at ITEP experimental facility for material science based on a Bernas ion source.

PubMed

Barminova, H Y; Saratovskyh, M S

2016-02-01

The experiment automation system is supposed to be developed for experimental facility for material science at ITEP, based on a Bernas ion source. The program CAMFT is assumed to be involved into the program of the experiment automation. CAMFT is developed to simulate the intense charged particle bunch motion in the external magnetic fields with arbitrary geometry by means of the accurate solution of the particle motion equation. Program allows the consideration of the bunch intensity up to 10(10) ppb. Preliminary calculations are performed at ITEP supercomputer. The results of the simulation of the beam pre-acceleration and following turn in magnetic field are presented for different initial conditions.

Modeling of the charge-state separation at ITEP experimental facility for material science based on a Bernas ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barminova, H. Y., E-mail: barminova@bk.ru; Saratovskyh, M. S.

2016-02-15

The experiment automation system is supposed to be developed for experimental facility for material science at ITEP, based on a Bernas ion source. The program CAMFT is assumed to be involved into the program of the experiment automation. CAMFT is developed to simulate the intense charged particle bunch motion in the external magnetic fields with arbitrary geometry by means of the accurate solution of the particle motion equation. Program allows the consideration of the bunch intensity up to 10{sup 10} ppb. Preliminary calculations are performed at ITEP supercomputer. The results of the simulation of the beam pre-acceleration and following turnmore » in magnetic field are presented for different initial conditions.« less

Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines.

PubMed

Jayaratne, E R; Ling, X; Morawska, L

2015-09-01

Overhead high-voltage power lines are known sources of corona ions. These ions rapidly attach to aerosols to form charged particles in the environment. Although the effect of ions and charged particles on human health is largely unknown, much attention has focused on the increasing exposure as a result of the expanding power network in urban residential areas. However, it is not widely known that a large number of charged particles in urban environments originate from motor vehicle emissions. In this study, for the first time, we compare the concentrations of charged nanoparticles near busy roads and overhead power lines. We show that large concentrations of both positive and negative charged nanoparticles are present near busy roadways and that these concentrations commonly exceed those under high-voltage power lines. We estimate that the concentration of charged nanoparticles found near two freeways carrying around 120 vehicles per minute exceeded the corresponding maximum concentrations under two corona-emitting overhead power lines by as much as a factor of 5. The difference was most pronounced when a significant fraction of traffic consisted of heavy-duty diesel vehicles which typically have high particle and charge emission rates. Copyright © 2015 Elsevier B.V. All rights reserved.

Combined distance-of-flight and time-of-flight mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enke, Christie G; Ray, Steven J; Graham, Alexander W

2014-02-11

A combined distance-of-flight mass spectrometry (DOFMS) and time-of-flight mass spectrometry (TOFMS) instrument includes an ion source configured to produce ions having varying mass-to-charge ratios, a first detector configured to determine when each of the ions travels a predetermined distance, a second detector configured to determine how far each of the ions travels in a predetermined time, and a detector extraction region operable to direct portions of the ions either to the first detector or to the second detector.

The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarvainen, O., E-mail: olli.tarvainen@jyu.fi; Orpana, J.; Kronholm, R.

2016-09-15

The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system andmore » the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. The results of such cavity tuning experiments conducted with the JYFL 14 GHz ECRIS are reported here. The cavity properties were adjusted by inserting a conducting tuner rod axially into the plasma chamber. The extracted beam currents of oxygen charge states O{sup 3+}–O{sup 7+} were recorded at various tuner positions and frequencies in the range of 14.00–14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited “mode-hopping” between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances.« less

Medium-energy heavy-ion single-event-burnout imaging of power MOSFETs

NASA Astrophysics Data System (ADS)

Musseau, O.; Torres, A.; Campbell, A. B.; Knudson, A. R.; Buchner, S.; Fischer, B.; Schlogl, M.; Briand, P.

1999-12-01

We present the first experimental determination of the SEB sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. We used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a nondestructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a sudden change in the charge collection image. "Hot spots" are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEB sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation.

Dynamics of ion beam charge neutralization by ferroelectric plasma sources

DOE PAGES

Stepanov, Anton D.; Gilson, Erik P.; Grisham, Larry R.; ...

2016-04-27

Ferroelectric Plasma Sources (FEPSs) can generate plasma that provides effective space-charge neutralization of intense high-perveance ion beams, as has been demonstrated on the Neutralized Drift Compression Experiment NDCX-I and NDCX-II. This article presents experimental results on charge neutralization of a high-perveance 38 keV Ar + beam by a plasma produced in a FEPS discharge. By comparing the measured beam radius with the envelope model for space-charge expansion, it is shown that a charge neutralization fraction of 98% is attainable with sufficiently dense FEPS plasma. The transverse electrostatic potential of the ion beam is reduced from 15V before neutralization to 0.3more » V, implying that the energy of the neutralizing electrons is below 0.3 eV. Measurements of the time-evolution of beam radius show that near-complete charge neutralization is established similar to –5 μs after the driving pulse is applied to the FEPS and can last for 35 μs. It is argued that the duration of neutralization is much longer than a reasonable lifetime of the plasma produced in the sub-mu s surface discharge. Measurements of current flow in the driving circuit of the FEPS show the existence of electron emission into vacuum, which lasts for tens of mu s after the high voltage pulse is applied. Lastly, it is argued that the beam is neutralized by the plasma produced by this process and not by a surface discharge plasma that is produced at the instant the high-voltage pulse is applied.« less

Spectroscopic method to study low charge state ion and cold electron population in ECRIS plasma

NASA Astrophysics Data System (ADS)

Kronholm, R.; Kalvas, T.; Koivisto, H.; Tarvainen, O.

2018-04-01

The results of optical emission spectroscopy experiments probing the cold electron population of a 14 GHz Electron Cyclotron Resonance Ion Source (ECRIS) are reported. The study has been conducted with a high resolution spectrometer and data acquisition setup developed specifically for the diagnostics of weak emission line characteristic to ECRIS plasmas. The optical emission lines of low charge state ions and neutral atoms of neon have been measured and analyzed with the line-ratio method. The aforementioned electron population temperature of the cold electron population (Te < 100 eV) is determined for Maxwell-Boltzmann and Druyvesteyn energy distributions to demonstrate the applicability of the method. The temperature was found to change significantly when the extraction voltage of the ion source is turned on/off. In the case of the Maxwellian distribution, the temperature of the cold electron population is 20 ± 10 eV when the extraction voltage is off and 40 ± 10 eV when it is on. The optical emission measurements revealed that the extraction voltage also affects both neutral and ion densities. Based on the rate coefficient analysis with the aforementioned temperatures, switching the extraction voltage off decreases the rate coefficient of neutral to 1+ ionization to 42% and 1+ to 2+ ionization to 24% of the original. This suggests that switching the extraction voltage on favors ionization to charge states ≥2+ and, thus, the charge state distributions of ECRIS plasmas are probably different with the extraction voltage on/off. It is therefore concluded that diagnostics results of ECRIS plasmas obtained without the extraction voltage are not depicting the plasma conditions in normal ECRIS operation.

Lunar Hydrospheric Explorer (HYDROX)

NASA Technical Reports Server (NTRS)

Cooper, J. F.; Paschalidis, N.; Sittler, E. C., Jr.; Jones, S. L.; Stubbs, T. J.; Sarantos, M.; Khurana, K. K.; Angelopoulos, V.; Jordan, A. P.; Schwadron, N. A.

2015-01-01

The Lunar Hydrospheric Explorer (HYDROX) is a 6U CubeSat designed to further confirm the existence of lunar exospheric water, and to determine source processes and surface sites, through ion mass spectrometer measurements of water group (O+, OH+, H2O+) and related ions at energy charge up to 2 keV/e. and mass/charge 1-40amu/e. HYDROX would follow up on the now-concluded exospheric compositional measurements by the Neutral Mass Spectrometer on the NASA LADEE mission and on other remote sensing surface and exospheric measurements (LADEE,LRO, etc.).

EBQ code: Transport of space-charge beams in axially symmetric devices

NASA Astrophysics Data System (ADS)

Paul, A. C.

1982-11-01

Such general-purpose space charge codes as EGUN, BATES, WODF, and TRANSPORT do not gracefully accommodate the simulation of relativistic space-charged beams propagating a long distance in axially symmetric devices where a high degree of cancellation has occurred between the self-magnetic and self-electric forces of the beam. The EBQ code was written specifically to follow high current beam particles where space charge is important in long distance flight in axially symmetric machines possessing external electric and magnetic field. EBQ simultaneously tracks all trajectories so as to allow procedures for charge deposition based on inter-ray separations. The orbits are treated in Cartesian geometry (position and momentum) with z as the independent variable. Poisson's equation is solved in cylindrical geometry on an orthogonal rectangular mesh. EBQ can also handle problems involving multiple ion species where the space charge from each must be included. Such problems arise in the design of ion sources where different charge and mass states are present.

Shedding light on the mercury mass discrepancy by weighing Hg 52+ ions in a Penning trap

NASA Astrophysics Data System (ADS)

Fritioff, T.; Bluhme, H.; Schuch, R.; Bergström, I.; Björkhage, M.

2003-07-01

In their nuclear tables Audi and Wapstra have pointed out a serious mass discrepancy between their extrapolated values for the mercury isotopes and those from a direct measurement by the Manitoba group. The values deviate by as much as 85 ppb from each other with claimed uncertainties of about 16 and 7 ppb, respectively. In order to decide which values are correct the masses of the 198Hg and 204Hg isotopes have been measured in the Stockholm Penning trap mass spectrometer SMILETRAP using 52+ ions. This charge state corresponds to a filled Ni electron configuration for which the electron binding energy can be accurately calculated. The mass values obtained are 197.966 768 44(43) u for 198Hg and 203.973 494 10(39) u for 204Hg. These values agree with those measured by the Manitoba group, with a 3 times lower uncertainty. This measurement was made possible through the implementation of a cooling technique of the highly charged mercury ions during charge breeding in the electron beam ion source used for producing the Hg 52+ ions.

Production of highly charged heavy ions by 18 GHz superconducting electron cyclotron resonance at Research Center for Nuclear Physics.

PubMed

Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

2010-02-01

An 18 GHz superconducting electron cyclotron resonance ion source has been installed as a subject of the azimuthally varying field cyclotron upgrade project (K. Hatanaka et al., in Proceedings of the 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18-22 October 2004, pp. 115-117), in order to increase beam currents and to extend the variety of ions. The production development of several ions has been performed since 2006 and some of them have already been used for user experiments [T. Yorita et al., Rev. Sci. Instrum. 79, 02A311 (2008)]. Further optimizations for each component such as the material of plasma electrode, material, and shape of bias probe and mirror field have been continued and more intense ion beams have been obtained for O, N, and Ar. For the purpose of obtaining highly charged Xe with several microamperes, the optimization of position and shape of plasma electrode and bias disk has also been done and highly charged Xe(32+) beam has been obtained successfully.

Back-streaming ion emission and beam focusing on high power linear induction accelerator

NASA Astrophysics Data System (ADS)

Zhu, Jun; Chen, Nan; Yu, Haijun; Jiang, Xiaoguo; Wang, Yuan; Dai, Wenhua; Gao, Feng; Wang, Minhong; Li, Jin; Shi, Jinshui

2011-08-01

Ions released from target surfaces by impact of a high intensity and current electron beam can be accelerated and trapped in the beam potential, and further destroy the beam focus. By solving the 2D Poisson equation, we found that the charge neutralization factor of the ions to the beam under space charge limited condition is 1/3, which is large enough to disrupt the spot size. Therefore, the ion emission at the target in a single-pulse beam/target system must be source limited. Experimental results on the time-resolved beam profile measurement have also proven that. A new focus scheme is proposed in this paper to focus the beam to a small spot size with the existence of back-streaming ions. We found that the focal spot will move upstream as the charge neutralization factor increases. By comparing the theoretical and experimental focal length of the Dragon-I accelerator (20 MeV, 2.5 kA, 60 ns flattop), we found that the average neutralization factor is about 5% in the beam/target system.

Studies on space charge neutralization and emittance measurement of beam from microwave ion source.

PubMed

Misra, Anuraag; Goswami, A; Sing Babu, P; Srivastava, S; Pandit, V S

2015-11-01

A 2.45 GHz microwave ion source together with a beam transport system has been developed at VECC to study the problems related with the injection of high current beam into a compact cyclotron. This paper presents the results of beam profile measurement of high current proton beam at different degrees of space charge neutralisation with the introduction of neon gas in the beam line using a fine leak valve. The beam profiles have been measured at different pressures in the beam line by capturing the residual gas fluorescence using a CCD camera. It has been found that with space charge compensation at the present current level (∼5 mA at 75 keV), it is possible to reduce the beam spot size by ∼34%. We have measured the variation of beam profile as a function of the current in the solenoid magnet under the neutralised condition and used these data to estimate the rms emittance of the beam. Simulations performed using equivalent Kapchinsky-Vladimirsky beam envelope equations with space charge neutralization factor are also presented to interpret the experimental results.

Studies on space charge neutralization and emittance measurement of beam from microwave ion source

NASA Astrophysics Data System (ADS)

Misra, Anuraag; Goswami, A.; Sing Babu, P.; Srivastava, S.; Pandit, V. S.

2015-11-01

A 2.45 GHz microwave ion source together with a beam transport system has been developed at VECC to study the problems related with the injection of high current beam into a compact cyclotron. This paper presents the results of beam profile measurement of high current proton beam at different degrees of space charge neutralisation with the introduction of neon gas in the beam line using a fine leak valve. The beam profiles have been measured at different pressures in the beam line by capturing the residual gas fluorescence using a CCD camera. It has been found that with space charge compensation at the present current level (˜5 mA at 75 keV), it is possible to reduce the beam spot size by ˜34%. We have measured the variation of beam profile as a function of the current in the solenoid magnet under the neutralised condition and used these data to estimate the rms emittance of the beam. Simulations performed using equivalent Kapchinsky-Vladimirsky beam envelope equations with space charge neutralization factor are also presented to interpret the experimental results.

Installation and Characterization of Charged Particle Sources for Space Environmental Effects Testing

NASA Technical Reports Server (NTRS)

Skevington, Jennifer L.

2010-01-01

Charged particle sources are integral devices used by Marshall Space Flight Center s Environmental Effects Branch (EM50) in order to simulate space environments for accurate testing of materials and systems. By using these sources inside custom vacuum systems, materials can be tested to determine charging and discharging properties as well as resistance to sputter damage. This knowledge can enable scientists and engineers to choose proper materials that will not fail in harsh space environments. This paper combines the steps utilized to build a low energy electron gun (The "Skevington 3000") as well as the methods used to characterize the output of both the Skevington 3000 and a manufactured Xenon ion source. Such characterizations include beam flux, beam uniformity, and beam energy. Both sources were deemed suitable for simulating environments in future testing.

Tunable Ionization Modes of a Flowing Atmospheric-Pressure Afterglow (FAPA) Ambient Ionization Source.

PubMed

Badal, Sunil P; Michalak, Shawn D; Chan, George C-Y; You, Yi; Shelley, Jacob T

2016-04-05

Plasma-based ambient desorption/ionization sources are versatile in that they enable direct ionization of gaseous samples as well as desorption/ionization of analytes from liquid and solid samples. However, ionization matrix effects, caused by competitive ionization processes, can worsen sensitivity or even inhibit detection all together. The present study is focused on expanding the analytical capabilities of the flowing atmospheric-pressure afterglow (FAPA) source by exploring additional types of ionization chemistry. Specifically, it was found that the abundance and type of reagent ions produced by the FAPA source and, thus, the corresponding ionization pathways of analytes, can be altered by changing the source working conditions. High abundance of proton-transfer reagent ions was observed with relatively high gas flow rates and low discharge currents. Conversely, charge-transfer reagent species were most abundant at low gas flows and high discharge currents. A rather nonpolar model analyte, biphenyl, was found to significantly change ionization pathway based on source operating parameters. Different analyte ions (e.g., MH(+) via proton-transfer and M(+.) via charge-transfer) were formed under unique operating parameters demonstrating two different operating regimes. These tunable ionization modes of the FAPA were used to enable or enhance detection of analytes which traditionally exhibit low-sensitivity in plasma-based ADI-MS analyses. In one example, 2,2'-dichloroquaterphenyl was detected under charge-transfer FAPA conditions, which were difficult or impossible to detect with proton-transfer FAPA or direct analysis in real-time (DART). Overall, this unique mode of operation increases the number and range of detectable analytes and has the potential to lessen ionization matrix effects in ADI-MS analyses.

The influence of ambipolarity on plasma confinement and on the performance of electron cyclotron resonance ion sources.

PubMed

Schachter, L; Dobrescu, S; Stiebing, K E; Thuillier, T; Lamy, T

2008-02-01

Charge diffusion in an electron cyclotron resonance ion source (ECRIS) discharge is usually characterized by nonambipolar behavior. While the ions are transported to the radial walls, electrons are lost axially from the magnetic trap. Global neutrality is maintained via compensating currents in the conducting walls of the vacuum chamber. It is assumed that this behavior reduces the ion breeding times compared to a truly ambipolar plasma. We have carried out a series of dedicated experiments in which the ambipolarity of the ECRIS plasma was influenced by inserting special metal-dielectric structures (MD layers) into the plasma chamber of the Frankfurt 14 GHz ECRIS. The measurements demonstrate the positive influence on the source performance when the ECR plasma is changed toward more ambipolar behavior.

Effect of Coulomb collision on the negative ion extraction mechanism in negative ion sources.

PubMed

Goto, I; Miyamoto, K; Nishioka, S; Mattei, S; Lettry, J; Abe, S; Hatayama, A

2016-02-01

To improve the H(-) ion beam optics, it is necessary to understand the energy relaxation process of surface produced H(-) ions in the extraction region of Cs seeded H(-) ion sources. Coulomb collisions of charged particles have been introduced to the 2D3V-PIC (two dimension in real space and three dimension in velocity space particle-in-cell) model for the H(-) extraction by using the binary collision model. Due to Coulomb collision, the lower energy part of the ion energy distribution function of H(-) ions has been greatly increased. The mean kinetic energy of the surface produced H(-) ions has been reduced to 0.65 eV from 1.5 eV. It has been suggested that the beam optics of the extracted H(-) ion beam is strongly affected by the energy relaxation process due to Coulomb collision.

Collison nebulizer as a new soft ionization source for mass spectrometry

NASA Astrophysics Data System (ADS)

Pervukhin, V. V.; Sheven', D. G.; Kolomiets, Yu. N.

2016-08-01

We have proposed that a Collison-type nebulizer be used as an ionization source for mass spectrometry with ionization under atmospheric pressure. This source does not require the use of electric voltage, radioactive sources, heaters, or liquid pumps. It has been shown that the number of ions produced by the 63Ni radioactive source is three to four times larger than the number of ions produced by acoustic ionization sources. We have considered the possibility of using a Collison-type nebulizer in combination with a vortex focusing system as an ion source for extractive ionization of compounds under atmospheric pressure. The ionization of volatile substances in crossflows of a charged aerosol and an analyte (for model compounds of the amine class, viz., diethylaniline, triamylamine, and cocaine) has been investigated. It has been shown that the limit of detecting cocaine vapor by this method is on the level of 4.6 × 10-14 g/cm3.

Design and Preliminary Performance Testing of Electronegative Gas Plasma Thruster

NASA Technical Reports Server (NTRS)

Liu, Thomas M.; Schloeder, Natalie R.; Walker, Mitchell L. R.; Polzin, Kurt A.; Dankanich, John W.; Aanesland, Ane

2014-01-01

In classical gridded electrostatic ion thrusters, positively charged ions are generated from a plasma discharge of noble gas propellant and accelerated to provide thrust. To maintain overall charge balance on the propulsion system, a separate electron source is required to neutralize the ion beam as it exits the thruster. However, if high-electronegativity propellant gases (e.g., sulfur hexafluoride) are instead used, a plasma discharge can result consisting of both positively and negatively charged ions. Extracting such electronegative plasma species for thrust generation (e.g., with time-varying, bipolar ion optics) would eliminate the need for a separate neutralizer cathode subsystem. In addition for thrusters utilizing a RF plasma discharge, further simplification of the ion thruster power system may be possible by also using the RF power supply to bias the ion optics. Recently, the PEGASES (Plasma propulsion with Electronegative gases) thruster prototype successfully demonstrated proof-of-concept operations in alternatively accelerating positively and negatively charged ions from a RF discharge of a mixture of argon and sulfur hexafluoride.i In collaboration with NASA Marshall Space Flight Center (MSFC), the Georgia Institute of Technology High-Power Electric Propulsion Laboratory (HPEPL) is applying the lessons learned from PEGASES design and testing to develop a new thruster prototype. This prototype will incorporate design improvements and undergo gridless operational testing and diagnostics checkout at HPEPL in April 2014. Performance mapping with ion optics will be conducted at NASA MSFC starting in May 2014. The proposed paper discusses the design and preliminary performance testing of this electronegative gas plasma thruster prototype.

Greatly Increasing Trapped Ion Populations for Mobility Separations Using Traveling Waves in Structures for Lossless Ion Manipulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Liulin; Ibrahim, Yehia M.; Garimella, Sandilya V. B.

The initial use of traveling waves (TW) for ion mobility (IM) separations using a structures for lossless ion manipulations (SLIM) employed an ion funnel trap (IFT) to accumulate ions from a continuous electrospray ionization source, and limited to injected ion populations of ~106 charges due to the onset of space charge effects in the trapping region. Additional limitations arise due to the loss of resolution for the injection of ions over longer periods (e.g. in extended pulses). In this work a new SLIM ‘flat funnel’ (FF) module has been developed and demonstrated to enable the accumulation of much larger ionmore » populations and their injection for IM separations. Ion current measurements indicate a capacity of ~3.2×108 charges for the extended trapping volume, over an order of magnitude greater than the IFT. The orthogonal ion injection into a funnel shaped separation region can greatly reduce space charge effects during the initial IM separation stage, and the gradually reduced width of the path allows the ion packet to be increasingly compressed in the lateral dimension as the separation progresses, allowing e.g. efficient transmission through conductance limits or compatibility with subsequent ion manipulations. This work examined the TW, RF, and DC confining field SLIM parameters involved in ion accumulation, injection, transmission and separation in the FF IM module using both direct ion current and MS measurements. Wide m/z range ion transmission is demonstrated, along with significant increases in signal to noise (S/N) ratios due to the larger ion populations injected. Additionally, we observed a reduction in the chemical background, which was attributed to more efficient desolvation of solvent related clusters over the extended ion accumulation periods. The TW SLIM FF IM module is anticipated to be especially effective as a front end for long path SLIM IM separation modules.« less

Development and Evaluation of a Reverse-Entry Ion Source Orbitrap Mass Spectrometer.

PubMed

Poltash, Michael L; McCabe, Jacob W; Patrick, John W; Laganowsky, Arthur; Russell, David H

2018-05-23

As a step towards development of a high-resolution ion mobility mass spectrometer using the orbitrap mass analyzer platform, we describe herein a novel reverse-entry ion source (REIS) coupled to the higher-energy C-trap dissociation (HCD) cell of an orbitrap mass spectrometer with extended mass range. Development of the REIS is a first step in the development of a drift tube ion mobility-orbitrap MS. The REIS approach retains the functionality of the commercial instrument ion source which permits the uninterrupted use of the instrument during development as well as performance comparisons between the two ion sources. Ubiquitin (8.5 kDa) and lipid binding to the ammonia transport channel (AmtB, 126 kDa) protein complex were used as model soluble and membrane proteins, respectively, to evaluate the performance of the REIS instrument. Mass resolution obtained with the REIS is comparable to that obtained using the commercial ion source. The charge state distributions for ubiquitin and AmtB obtained on the REIS are in agreement with previous studies which suggests that the REIS-orbitrap EMR retains native structure in the gas phase. Graphical Abstract ᅟ.

Ultra-low current beams in UMER to model space-charge effects in high-energy proton and ion machines

NASA Astrophysics Data System (ADS)

Bernal, S.; Beaudoin, B.; Baumgartner, H.; Ehrenstein, S.; Haber, I.; Koeth, T.; Montgomery, E.; Ruisard, K.; Sutter, D.; Yun, D.; Kishek, R. A.

2017-03-01

The University of Maryland Electron Ring (UMER) has operated traditionally in the regime of strong space-charge dominated beam transport, but small-current beams are desirable to significantly reduce the direct (incoherent) space-charge tune shift as well as the tune depression. This regime is of interest to model space-charge effects in large proton and ion rings similar to those used in nuclear physics and spallation neutron sources, and also for nonlinear dynamics studies of lattices inspired on the Integrable Optics Test Accelerator (IOTA). We review the definitions of beam vs. space-charge intensities and discuss three methods for producing very small beam currents in UMER. We aim at generating 60µA - 1.0mA, 100 ns, 10 keV beams with normalized rms emittances of the order of 0.1 - 1.0µm.

Timeframe Dependent Fragment Ions Observed in In-Source Decay Experiments with β-Casein Using MALDI MS.

PubMed

Sekiya, Sadanori; Nagoshi, Keishiro; Iwamoto, Shinichi; Tanaka, Koichi; Takayama, Mitsuo

2015-09-01

The fragment ions observed with time-of-flight (TOF) and quadrupole ion trap (QIT) TOF mass spectrometers (MS) combined with matrix-assisted laser desorption/ionization in-source decay (MALDI-ISD) experiments of phosphorylated analytes β-casein and its model peptide were compared from the standpoint of the residence timeframe of analyte and fragment ions in the MALDI ion source and QIT cell. The QIT-TOF MS gave fragment c-, z'-, z-ANL, y-, and b-ions, and further degraded fragments originating from the loss of neutrals such as H(2)O, NH(3), CH(2)O (from serine), C2H4O (from threonine), and H(3)PO(4), whereas the TOF MS merely showed MALDI source-generated fragment c-, z'-, z-ANL, y-, and w-ions. The fragment ions observed in the QIT-TOF MS could be explained by the injection of the source-generated ions into the QIT cell or a cooperative effect of a little internal energy deposition, a long residence timeframe (140 ms) in the QIT cell, and specific amino acid effects on low-energy CID, whereas the source-generated fragments (c-, z'-, z-ANL, y-, and w-ions) could be a result of prompt radical-initiated fragmentation of hydrogen-abundant radical ions [M + H + H](+) and [M + H - H](-) within the 53 ns timeframe, which corresponds to the delayed extraction time. The further degraded fragment b/y-ions produced in the QIT cell were confirmed by positive- and negative-ion low-energy CID experiments performed on the source-generated ions (c-, z'-, and y-ions). The loss of phosphoric acid (98 u) from analyte and fragment ions can be explained by a slow ergodic fragmentation independent of positive and negative charges.

Timeframe Dependent Fragment Ions Observed in In-Source Decay Experiments with β-Casein Using MALDI MS

NASA Astrophysics Data System (ADS)

Sekiya, Sadanori; Nagoshi, Keishiro; Iwamoto, Shinichi; Tanaka, Koichi; Takayama, Mitsuo

2015-09-01

The fragment ions observed with time-of-flight (TOF) and quadrupole ion trap (QIT) TOF mass spectrometers (MS) combined with matrix-assisted laser desorption/ionization in-source decay (MALDI-ISD) experiments of phosphorylated analytes β-casein and its model peptide were compared from the standpoint of the residence timeframe of analyte and fragment ions in the MALDI ion source and QIT cell. The QIT-TOF MS gave fragment c-, z'-, z-ANL, y-, and b-ions, and further degraded fragments originating from the loss of neutrals such as H2O, NH3, CH2O (from serine), C2H4O (from threonine), and H3PO4, whereas the TOF MS merely showed MALDI source-generated fragment c-, z'-, z-ANL, y-, and w-ions. The fragment ions observed in the QIT-TOF MS could be explained by the injection of the source-generated ions into the QIT cell or a cooperative effect of a little internal energy deposition, a long residence timeframe (140 ms) in the QIT cell, and specific amino acid effects on low-energy CID, whereas the source-generated fragments (c-, z'-, z-ANL, y-, and w-ions) could be a result of prompt radical-initiated fragmentation of hydrogen-abundant radical ions [M + H + H]+ and [M + H - H]- within the 53 ns timeframe, which corresponds to the delayed extraction time. The further degraded fragment b/y-ions produced in the QIT cell were confirmed by positive- and negative-ion low-energy CID experiments performed on the source-generated ions (c-, z'-, and y-ions). The loss of phosphoric acid (98 u) from analyte and fragment ions can be explained by a slow ergodic fragmentation independent of positive and negative charges.

Dianion diagnostics in DESIREE: High-sensitivity detection of Cn2 - from a sputter ion source

NASA Astrophysics Data System (ADS)

Chartkunchand, K. C.; Stockett, M. H.; Anderson, E. K.; Eklund, G.; Kristiansson, M. K.; Kamińska, M.; de Ruette, N.; Blom, M.; Björkhage, M.; Källberg, A.; Löfgren, P.; Reinhed, P.; Rosén, S.; Simonsson, A.; Zettergren, H.; Schmidt, H. T.; Cederquist, H.

2018-03-01

A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, Cn2 -, with n = 7-24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot Cn2 - dianions injected into the ring yielded Cn- anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90° analyzing magnet on the ion injection line reflect the production of internally hot C72 - - C242 - dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C62 - was found while there was a clear C72 - signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C62 - signal that is two orders-of-magnitude smaller than that for C72 -. In addition, CnO2- and CnCu2- dianions were detected.

Study of interactions between metal ions and protein model compounds by energy decomposition analyses and the AMOEBA force field

NASA Astrophysics Data System (ADS)

Jing, Zhifeng; Qi, Rui; Liu, Chengwen; Ren, Pengyu

2017-10-01

The interactions between metal ions and proteins are ubiquitous in biology. The selective binding of metal ions has a variety of regulatory functions. Therefore, there is a need to understand the mechanism of protein-ion binding. The interactions involving metal ions are complicated in nature, where short-range charge-penetration, charge transfer, polarization, and many-body effects all contribute significantly, and a quantitative description of all these interactions is lacking. In addition, it is unclear how well current polarizable force fields can capture these energy terms and whether these polarization models are good enough to describe the many-body effects. In this work, two energy decomposition methods, absolutely localized molecular orbitals and symmetry-adapted perturbation theory, were utilized to study the interactions between Mg2+/Ca2+ and model compounds for amino acids. Comparison of individual interaction components revealed that while there are significant charge-penetration and charge-transfer effects in Ca complexes, these effects can be captured by the van der Waals (vdW) term in the AMOEBA force field. The electrostatic interaction in Mg complexes is well described by AMOEBA since the charge penetration is small, but the distance-dependent polarization energy is problematic. Many-body effects were shown to be important for protein-ion binding. In the absence of many-body effects, highly charged binding pockets will be over-stabilized, and the pockets will always favor Mg and thus lose selectivity. Therefore, many-body effects must be incorporated in the force field in order to predict the structure and energetics of metalloproteins. Also, the many-body effects of charge transfer in Ca complexes were found to be non-negligible. The absorption of charge-transfer energy into the additive vdW term was a main source of error for the AMOEBA many-body interaction energies.

Negative ion source

DOEpatents

Delmore, James E.

1987-01-01

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Gas-phase synthesis of singly and multiply charged polyoxovanadate anions employing electrospray ionization and collision induced dissociation.

PubMed

Al Hasan, Naila M; Johnson, Grant E; Laskin, Julia

2013-09-01

Electrospray ionization mass spectrometry (ESI-MS) combined with in-source fragmentation and tandem mass spectrometry (MS/MS) experiments were used to generate a wide range of singly and multiply charged vanadium oxide cluster anions including VxOy(n-) and VxOyCl(n-) ions (x = 1-14, y = 2-36, n = 1-3), protonated clusters, and ligand-bound polyoxovanadate anions. The cluster anions were produced by electrospraying a solution of tetradecavanadate, V14O36Cl(L)5 (L = Et4N(+), tetraethylammonium), in acetonitrile. Under mild source conditions, ESI-MS generates a distribution of doubly and triply charged VxOyCl(n-) and VxOyCl(L)((n-1)-) clusters predominantly containing 14 vanadium atoms as well as their protonated analogs. Accurate mass measurement using a high-resolution LTQ/Orbitrap mass spectrometer (m/Δm = 60,000 at m/z 410) enabled unambiguous assignment of the elemental composition of the majority of peaks in the ESI-MS spectrum. In addition, high-sensitivity mass spectrometry allowed the charge state of the cluster ions to be assigned based on the separation of the major from the much less abundant minor isotope of vanadium. In-source fragmentation resulted in facile formation of smaller VxOyCl((1-2)-) and VxOy ((1-2)-) anions. Collision-induced dissociation (CID) experiments enabled systematic study of the gas-phase fragmentation pathways of the cluster anions originating from solution and from in-source CID. Surprisingly simple fragmentation patterns were obtained for all singly and doubly charged VxOyCl and VxOy species generated through multiple MS/MS experiments. In contrast, cluster anions originating directly from solution produced comparatively complex CID spectra. These results are consistent with the formation of more stable structures of VxOyCl and VxOy anions through low-energy CID. Furthermore, our results demonstrate that solution-phase synthesis of one precursor cluster anion combined with gas-phase CID is an efficient approach for the top-down synthesis of a wide range of singly and multiply charged gas-phase metal oxide cluster anions for subsequent investigations of structure and reactivity using mass spectrometry and ion spectroscopy techniques.

Gas-Phase Synthesis of Singly and Multiply Charged Polyoxovanadate Anions Employing Electrospray Ionization and Collision Induced Dissociation

NASA Astrophysics Data System (ADS)

Al Hasan, Naila M.; Johnson, Grant E.; Laskin, Julia

2013-09-01

Electrospray ionization mass spectrometry (ESI-MS) combined with in-source fragmentation and tandem mass spectrometry (MS/MS) experiments were used to generate a wide range of singly and multiply charged vanadium oxide cluster anions including VxOy n- and VxOyCln- ions (x = 1-14, y = 2-36, n = 1-3), protonated clusters, and ligand-bound polyoxovanadate anions. The cluster anions were produced by electrospraying a solution of tetradecavanadate, V14O36Cl(L)5 (L = Et4N+, tetraethylammonium), in acetonitrile. Under mild source conditions, ESI-MS generates a distribution of doubly and triply charged VxOyCln- and VxOyCl(L)(n-1)- clusters predominantly containing 14 vanadium atoms as well as their protonated analogs. Accurate mass measurement using a high-resolution LTQ/Orbitrap mass spectrometer (m/Δm = 60,000 at m/z 410) enabled unambiguous assignment of the elemental composition of the majority of peaks in the ESI-MS spectrum. In addition, high-sensitivity mass spectrometry allowed the charge state of the cluster ions to be assigned based on the separation of the major from the much less abundant minor isotope of vanadium. In-source fragmentation resulted in facile formation of smaller VxOyCl(1-2)- and VxOy (1-2)- anions. Collision-induced dissociation (CID) experiments enabled systematic study of the gas-phase fragmentation pathways of the cluster anions originating from solution and from in-source CID. Surprisingly simple fragmentation patterns were obtained for all singly and doubly charged VxOyCl and VxOy species generated through multiple MS/MS experiments. In contrast, cluster anions originating directly from solution produced comparatively complex CID spectra. These results are consistent with the formation of more stable structures of VxOyCl and VxOy anions through low-energy CID. Furthermore, our results demonstrate that solution-phase synthesis of one precursor cluster anion combined with gas-phase CID is an efficient approach for the top-down synthesis of a wide range of singly and multiply charged gas-phase metal oxide cluster anions for subsequent investigations of structure and reactivity using mass spectrometry and ion spectroscopy techniques.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers.

PubMed

Alejo, A; Kar, S; Ahmed, H; Krygier, A G; Doria, D; Clarke, R; Fernandez, J; Freeman, R R; Fuchs, J; Green, A; Green, J S; Jung, D; Kleinschmidt, A; Lewis, C L S; Morrison, J T; Najmudin, Z; Nakamura, H; Nersisyan, G; Norreys, P; Notley, M; Oliver, M; Roth, M; Ruiz, J A; Vassura, L; Zepf, M; Borghesi, M

2014-09-01

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C(6+), O(8+), etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

NASA Astrophysics Data System (ADS)

Alejo, A.; Kar, S.; Ahmed, H.; Krygier, A. G.; Doria, D.; Clarke, R.; Fernandez, J.; Freeman, R. R.; Fuchs, J.; Green, A.; Green, J. S.; Jung, D.; Kleinschmidt, A.; Lewis, C. L. S.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Nersisyan, G.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Ruiz, J. A.; Vassura, L.; Zepf, M.; Borghesi, M.

2014-09-01

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C6 +, O8 +, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Modulation of terrestrial ion escape flux composition /by low-altitude acceleration and charge exchange chemistry/

NASA Technical Reports Server (NTRS)

Moore, T. E.

1980-01-01

Motivated by recent observations of highly variable hot plasma composition in the magnetosphere, control of the ionospheric escape flux composition by low-altitude particle dynamics and ion chemistry has been investigated for an e(-), H(+), O(+) ionosphere. It is found that the fraction of the steady state escape flux which is O(+) can be controlled very sensitively by the occurrence of parallel or transverse ion acceleration at altitudes below the altitude where the neutral oxygen density falls rapidly below the neutral hydrogen density and the ionospheric source of O(+) tends to be rapidly converted by charge exchange to H(+). The acceleration is required both to overcome the gravitational confinement of O(+) and to violate charge exchange equilibrium so that the neutral hydrogen atmosphere appears 'optically' thin to escaping O(+). Constraints are placed on the acceleration processes, and it is shown that O(+) escape is facilitated by observed ionospheric responses to magnetic activity.

Rocket-borne time-of-flight mass spectrometry

NASA Technical Reports Server (NTRS)

Reiter, R. F.

1976-01-01

Theoretical and numerical analyses are made of planar, cylindrical and spherical-electrode two-field time-of-flight mass spectrometers in order to optimize their operating conditions. A method is introduced which can improve the resolving power of these instruments by a factor of 7.5. Potential barrier gating in time-of-flight mass spectrometers is also analyzed. Experimental studies of a miniature cylindrical-electrode and a hemispherical-electrode time-of-flight mass spectrometer are presented. Their sensitivity and ability to operate at D-region pressures with an open source make them ideal instruments for D-region ion composition measurements. A sounding rocket experiment package carrying a cylindrical electrode time-of-flight mass spectrometer was launched. The data indicate that essentially 100% of the positive electric charge on positive ions is carried by ions with mass-to-charge ratios greater than 500 below an altitude of 92 km. These heavy charge carriers were present at altitudes up to about 100 km.

Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yorita, T., E-mail: yorita@rcnp.osaka-u.ac.jp; Hatanaka, K.; Fukuda, M.

2014-02-15

An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] andmore » the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.« less

Detection method for dissociation of multiple-charged ions

DOEpatents

Smith, Richard D.; Udseth, Harold R.; Rockwood, Alan L.

1991-01-01

Dissociations of multiple-charged ions are detected and analyzed by charge-separation tandem mass spectrometry. Analyte molecules are ionized to form multiple-charged parent ions. A particular charge parent ion state is selected in a first-stage mass spectrometer and its mass-to-charge ratio (M/Z) is detected to determine its mass and charge. The selected parent ions are then dissociated, each into a plurality of fragments including a set of daughter ions each having a mass of at least one molecular weight and a charge of at least one. Sets of daughter ions resulting from the dissociation of one parent ion (sibling ions) vary in number but typically include two to four ions, one or more multiply-charged. A second stage mass spectrometer detects mass-to-charge ratio (m/z) of the daughter ions and a temporal or temporo-spatial relationship among them. This relationship is used to correlate the daughter ions to determine which (m/z) ratios belong to a set of sibling ions. Values of mass and charge of each of the sibling ions are determined simultaneously from their respective (m/z) ratios such that the sibling ion charges are integers and sum to the parent ion charge.

A high flux source of swift oxygen atoms

NASA Technical Reports Server (NTRS)

Fink, M.; Kohl, D. A.; Keto, J. W.; Antoniewicz, P.

1987-01-01

A source of swift oxygen atoms is described which has several unique features. A high current ion beam is produced by a microwave discharge, accelerated to 10 keV and the mass selected by a modified Du Pont 21-110 mass spectrometer. The O(+) beam exciting the mass spectrometer is focused into a rectangular shape with an energy spread of less than 1 eV. The next section of the machine decelerates the ion beam into a counterpropagating electron beam in order to minimize space charge effects. After deceleration, the ion beam intersects at 90 deg, a neutral oxygen atom beam, which via resonant charge exchange produces a mixture of O(+) and O. Any remaining O(+) are swept out of the beam by an electric field and differentially pumped away while the desired O beam, collimated by slits, impinges on the target. In situ monitoring of the target surface is done by X-ray photoelectron or Auger spectroscopy. Faraday cups provide flux measurements in the ion sections while the neutral flux is determined by a special torsion balance or by a quadrupole mass spectrometer specially adapted for swift atoms. While the vacuum from the source through the mass spectrometer is maintained by diffusion pumps, the rest of the machine is UHV.

A tandem mass spectrometer for crossed-beam irradiation of mass-selected molecular systems by keV atomic ions

NASA Astrophysics Data System (ADS)

Schwob, Lucas; Lalande, Mathieu; Chesnel, Jean-Yves; Domaracka, Alicja; Huber, Bernd A.; Maclot, Sylvain; Poully, Jean-Christophe; Rangama, Jimmy; Rousseau, Patrick; Vizcaino, Violaine; Adoui, Lamri; Méry, Alain

2018-04-01

In the present paper, we describe a new home-built crossed-beam apparatus devoted to ion-induced ionization and fragmentation of isolated biologically relevant molecular systems. The biomolecular ions are produced by an electrospray ionization source, mass-over-charge selected, accumulated in a 3D ion trap, and then guided to the extraction region of an orthogonal time-of-flight mass spectrometer. Here, the target molecular ions interact with a keV atomic ion beam produced by an electron cyclotron resonance ion source. Cationic products from the collision are detected on a position sensitive detector and analyzed by time-of-flight mass spectrometry. A detailed description of the operation of the setup is given, and early results from irradiation of a protonated pentapeptide (leucine-enkephalin) by a 7 keV He+ ion beam are presented as a proof-of-principle.

Integrated development facility for the calibration of low-energy charged particle flight instrumentation

NASA Technical Reports Server (NTRS)

Biddle, A. P.; Reynolds, J. M.

1986-01-01

The design of a low-energy ion facility for development and calibration of thermal ion instrumentation is examined. A directly heated cathode provides the electrons used to produce ions by impact ionization and an applied magnetic field increases the path length followed by the electrons. The electrostatic and variable geometry magnetic mirror configuration in the ion source is studied. The procedures for the charge neutralization of the beam and the configuration and function of the 1.4-m drift tube are analyzed. A microcomputer is utilized to control and monitor the beam energy and composition, and the mass- and angle-dependent response of the instrument under testing. The facility produces a high-quality ion beam with an adjustable range of energies up to 150 eV; the angular divergence and uniformity of the beam is obtained from two independent retarding potential analyzers. The procedures for calibrating the instrument being developed are described.

Li-Like CX

NASA Astrophysics Data System (ADS)

Dorsey, Zachary

2018-06-01

A fantastic discovery in 1996 caused an epiphany when it was realized that the charge exchange (CX) process was an important source of X-ray emission from comets. Over the last two decades, CX induced X-ray emission has been detected in a wide variety of solar and extra-solar sources. Recently, our group developed the Kronos database which contains CX cross sections and emission spectra for all H-like and most He-Like ions up to iron, based primarily on multichannel Landau-Zener calculations. Here we present preliminary results for extending Kronos to Li-like ions. Due to the incompleteness of highly-charged Li-like atomic structure data, we estimate missing energy levels and transition probabilities with a quantum defect approach and the package Autostructure.This work was support by NASA grants NNX13AF31G.

Investigation of Dusts Effect and Negative Ion in DC Plasmas by Electric Probes

NASA Astrophysics Data System (ADS)

Oh, Hye Taek; Kang, Inje; Bae, Min-Keun; Park, Insun; Lee, Seunghwa; Jeong, Seojin; Chung, Kyu-Sun

2017-10-01

Dust is typically negatively charged by electron attachment whose thermal velocities are fast compared to that of the heavier ions. The negatively charged particles can play a role of negative ions which affect the quasi-neutrality of background plasma. To investigate effect of metal dusts and negative ion on plasma and materials, metal dusts are injected into background Ar plasma which is generated by tungsten filament using dust dispenser on Cubical Plasma Device (CPD). The CPD has following conditions: size =24x24x24cm3, plasma source =DC filament plasma (ne 1x10x1010, Te 2eV), background gas =Ar, dusts =tungsten powder (diameter 1.89micron). The dust dispenser is developed to quantitate of metal dust by ultrasonic transducer. Electronegative plasmas are generated by adding O2 + Ar plasma to compare negative ion and dust effect. A few grams of micron-sized dusts are placed in the dust dispenser which is located at the upper side of the Cubical Plasma Device. The falling particles by dust dispenser are mainly charged up by the collection of the background plasma. The change in parameters due to negative ion production are characterized by measuring the floating and plasma potential, electron temperature and negative ion density using electric probes.

Characterization of xenon ion and neutral interactions in a well-characterized experiment

NASA Astrophysics Data System (ADS)

Patino, Marlene I.; Wirz, Richard E.

2018-06-01

Interactions between fast ions and slow neutral atoms are commonly dominated by charge-exchange and momentum-exchange collisions, which are important to understanding and simulating the performance and behavior of many plasma devices. To investigate these interactions, this work developed a simple, well-characterized experiment that accurately measures the behavior of high energy xenon ions incident on a background of xenon neutral atoms. By using well-defined operating conditions and a simple geometry, these results serve as canonical data for the development and validation of plasma models and models of neutral beam sources that need to ensure accurate treatment of angular scattering distributions of charge-exchange and momentum-exchange ions and neutrals. The energies used in this study are relevant for electric propulsion devices ˜1.5 keV and can be used to improve models of ion-neutral interactions in the plume. By comparing these results to both analytical and computational models of ion-neutral interactions, we discovered the importance of (1) accurately treating the differential cross-sections for momentum-exchange and charge-exchange collisions over a large range of neutral background pressures and (2) properly considering commonly overlooked interactions, such as ion-induced electron emission from nearby surfaces and neutral-neutral ionization collisions.

Experiments in charge control at geosynchronous orbit - ATS-5 and ATS-6

NASA Technical Reports Server (NTRS)

Olsen, R. C.

1985-01-01

In connection with existing theoretical concepts, it was difficult to explain the negative potentials found in sunlight, first on Applied Technology Satellite-5 (ATS-5) and then on ATS-6. The problem became important when an association between spacecraft charging and anomalies in spacecraft behavior was observed. A study of daylight charging phenomena on ATS-6 was conducted, and an investigation was performed with the objective to determine effective methods of charge control, taking into account the feasibility to utilize the ATS-5 and ATS-6 ion engines as current sources. In the present paper, data and analysis for the ion engine experiments on ATS-5 and ATS-6 are presented. It is shown that electron emission from a satellite with insulating surfaces is not an effective method of charge control because the increase in differential charging which results limits the effectiveness of electron emitters and increases the possibility of electrostatic discharges between surfaces at different potentials.

Probing Trapped Ion Energies Via Ion-Molecule Reaction Kinetics: Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

DTIC Science & Technology

1992-05-28

ORGANIZATION (if applicable) Office of Naval Research N00014-87- j - 1248 Bc. ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS 800 N. Quincy St...RESEARCH Grant NOOO14-87- J -1248 R & T Code 4134052 TECHNICAL REPORT NO. 36 Probing Trapped Ion Energies Via Ion-Molecule Reaction Kinetics: Fourier...reactivity (for charge transfer with N2) of the higher energy J =1/2 state is approximately three times that of the J =3/2 state at collision energies

Study of negative ion transport phenomena in a plasma source

NASA Astrophysics Data System (ADS)

Riz, D.; Paméla, J.

1996-07-01

NIETZSCHE (Negative Ions Extraction and Transport ZSimulation Code for HydrogEn species) is a negative ion (NI) transport code developed at Cadarache. This code calculates NI trajectories using a 3D Monte-Carlo technique, taking into account the main destruction processes, as well as elastic collisions (H-/H+) and charge exchanges (H-/H0). It determines the extraction probability of a NI created at a given position. According to the simulations, we have seen that in the case of volume production, only NI produced close to the plasma grid (PG) can be extracted. Concerning the surface production, we have studied how NI produced on the PG and accelerated by the plasma sheath backward into the source could be extracted. We demonstrate that elastic collisions and charge exchanges play an important role, which in some conditions dominates the magnetic filter effect, which acts as a magnetic mirror. NI transport in various conditions will be discussed: volume/surface production, high/low plasmas density, tent filter/transverse filter.

Design of a high-bunch-charge 112-MHz superconducting RF photoemission electron source

NASA Astrophysics Data System (ADS)

Xin, T.; Brutus, J. C.; Belomestnykh, Sergey A.; Ben-Zvi, I.; Boulware, C. H.; Grimm, T. L.; Hayes, T.; Litvinenko, Vladimir N.; Mernick, K.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Severino, F.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Xiao, B.; Xie, H.; Zaltsman, A.

2016-09-01

High-bunch-charge photoemission electron-sources operating in a continuous wave (CW) mode are required for many advanced applications of particle accelerators, such as electron coolers for hadron beams, electron-ion colliders, and free-electron lasers. Superconducting RF (SRF) has several advantages over other electron-gun technologies in CW mode as it offers higher acceleration rate and potentially can generate higher bunch charges and average beam currents. A 112 MHz SRF electron photoinjector (gun) was developed at Brookhaven National Laboratory to produce high-brightness and high-bunch-charge bunches for the coherent electron cooling proof-of-principle experiment. The gun utilizes a quarter-wave resonator geometry for assuring beam dynamics and uses high quantum efficiency multi-alkali photocathodes for generating electrons.

High-pressure ion source combined with an in-axis ion trap mass spectrometer. 1. Instrumentation and applications

PubMed

Mathurin; Faye; Brunot; Tabet; Wells; Fuche

2000-10-15

A new combination of a dual EI/CI ion source with a quadrupole ion trap mass spectrometer has been realized in order to efficiently produce negative ions in the reaction cell. Analysis of volatile compounds was performed under negative ion chemical ionization (NICI) during a reaction period where selected reactant negative ions, previously produced in the external ion source, were allowed to interact with molecules, introduced by hyphenated techniques such as gas chromatography. The O2*-, CH3O-, and Cl- reactant ions were used in this study to ensure specific ion/molecule interactions such as proton transfer, nucleophilic displacement, or charge exchange processes, respectively leading to even-electron species, i.e., deprotonated [M - H]- molecules, diagnostic [M - R]- ions, or odd-electron M*- molecular species. The reaction orientation depends on the thermochemistry of reactions within kinetic controls. First analytical results are presented here for the trace-level detection of several contaminants under NICI/Cl- conditions. Phosphorus-containing compounds (malathion, ethyl parathion, and methyl parathion as representative for pesticides) and nitro-containing compounds (2,4,6-trinitrotoluene for explosive material) have been chosen in order to explore the analytical ability of this promising instrumental coupling.

Systematic Variability of the He+ Pickup Ion Velocity Distribution Function Observed with SOHO/CELIAS/CTOF

NASA Astrophysics Data System (ADS)

Taut, A.; Drews, C.; Berger, L.; Wimmer-Schweingruber, R. F.

2015-12-01

The 1D Velocity Distribution Function (VDF) of He+ pickup ions shows two distinct populations that reflect the sources of these ions. The highly suprathermal population is the result of the ionization and pickup of almost resting interstellar neutrals that are injected into the solar wind as a highly anisotropic torus distribution. The nearly thermalized population is centered around the solar wind bulk speed and is mainly attributed to inner-source pickup ions that originate in the inner heliosphere. It is generally believed that the initial torus distribution of interstellar pickup ions is rapidly isotropized by resonant wave-particle interactions, but recent observations by Drews et al. (2015) of a torus-like VDF strongly limit this isotropization. This in turn means that more observational data is needed to further characterize the kinetic behavior of pickup ions. In this study we use data from the Charge-Time-Of-Flight sensor on-board SOHO. As this sensor offers unrivaled counting statistics for He+ together with a sufficient mass-per-charge resolution it is well-suited for investigating the He+ VDF on comparatively short timescales. We combine this data with the high resolution magnetic field data from WIND via an extrapolation to the location of SOHO. With this combination of instruments we investigate the He+ VDF for time periods of different solar wind speeds, magnetic field directions, and wave power. We find a systematic trend of the short-term He+ VDF with these parameters. Especially by varying the considered magnetic field directions we observe a 1D projection of the anisotropic torus-like VDF. In addition, we investigate stream interaction regions and coronal mass ejections. In the latter we observe an excess of inner-source He+ that is accompanied by a significant increase of heavy pickup ion count rates. This may be linked to the as yet ill understood production mechanism of inner-source pickup ions.

Space-charge compensation measurements in electron cyclotron resonance ion source low energy beam transport lines with a retarding field analyzer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winklehner, D.; Leitner, D., E-mail: leitnerd@nscl.msu.edu; Cole, D.

2014-02-15

In this paper we describe the first systematic measurement of beam neutralization (space charge compensation) in the ECR low energy transport line with a retarding field analyzer, which can be used to measure the potential of the beam. Expected trends for the space charge compensation levels such as increase with residual gas pressure, beam current, and beam density could be observed. However, the overall levels of neutralization are consistently low (<60%). The results and the processes involved for neutralizing ion beams are discussed for conditions typical for ECR injector beam lines. The results are compared to a simple theoretical beammore » plasma model as well as simulations.« less

A small electron beam ion trap/source facility for electron/neutral–ion collisional spectroscopy in astrophysical plasmas

NASA Astrophysics Data System (ADS)

Liang, Gui-Yun; Wei, Hui-Gang; Yuan, Da-Wei; Wang, Fei-Lu; Peng, Ji-Min; Zhong, Jia-Yong; Zhu, Xiao-Long; Schmidt, Mike; Zschornack, Günter; Ma, Xin-Wen; Zhao, Gang

2018-01-01

Spectra are fundamental observation data used for astronomical research, but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations. Different models give different insights for understanding a specific object. Hence, laboratory benchmarks for these theoretical models become necessary. An electron beam ion trap is an ideal facility for spectroscopic benchmarks due to its similar conditions of electron density and temperature compared to astrophysical plasmas in stellar coronae, supernova remnants and so on. In this paper, we will describe the performance of a small electron beam ion trap/source facility installed at National Astronomical Observatories, Chinese Academy of Sciences.We present some preliminary experimental results on X-ray emission, ion production, the ionization process of trapped ions as well as the effects of charge exchange on the ionization.

Interpretation of the ion mass spectra in the mass per charge range 25-35 amu/e obtained in the inner coma of Halley's comet by the HIS-sensor of the Giotto IMS experiment

NASA Technical Reports Server (NTRS)

Geiss, J.; Altwegg, K.; Anders, E.; Balsiger, H.; Meier, A.; Shelley, E. G.; Ip, W.-H.; Rosenbauer, H.; Neugebauer, M.

1991-01-01

The IMS-HIS double-focusing mass spectrometer that flew on the Giotto spacecraft covered the mass per charge range from 12 to 56 (amu/e). By comparing flight data, calibration data and results of model calculations of the ion population in the inner coma, the absolute mass scale is established, and ions in the mass range 25 to 35 are identified. Ions resulting from protonation of molecules with high proton affinity are relatively abundant, enabling us to estimate relative source strengths for H2CO, CH3OH, HCN, and H2S, providing for the first time a positive in situ measurement of methanol. Also, upper limits for NO and some hydrocarbons are derived.

Two possible improvements for mass spectrometry analysis of intact biomolecules.

PubMed

Raznikov, Valeriy V; Zelenov, Vladislav V; Aparina, Elena V; Pikhtelev, Alexander R; Sulimenkov, Ilia V; Raznikova, Marina O

2017-08-01

The goals of our study were to investigate abilities of two approaches to eliminate possible errors in electrospray mass spectrometry measurements of biomolecules. Passing of a relatively dense supersonic gas jet through ionization region followed by its hitting the spray of the analyzed solution in low vacuum may be effective to keep an initial biomolecule structure in solution. Provided that retention of charge carriers for some sites in the biomolecule cannot be changed noticeably in electrospray ion source, decomposition and separation of charge-state distributions of electrosprayed ions may give additional information about native structure of biomolecules in solution.

Low-energy ion beamline scattering apparatus for surface science investigations

NASA Astrophysics Data System (ADS)

Gordon, M. J.; Giapis, K. P.

2005-08-01

We report on the design, construction, and performance of a high current (monolayers/s), mass-filtered ion beamline system for surface scattering studies using inert and reactive species at collision energies below 1500 eV. The system combines a high-density inductively coupled plasma ion source, high-voltage floating beam transport line with magnet mass-filter and neutral stripping, decelerator, and broad based detection capabilities (ions and neutrals in both mass and energy) for products leaving the target surface. The entire system was designed from the ground up to be a robust platform to study ion-surface interactions from a more global perspective, i.e., high fluxes (>100μA/cm2) of a single ion species at low, tunable energy (50-1400±5eV full width half maximum) can be delivered to a grounded target under ultrahigh vacuum conditions. The high current at low energy problem is solved using an accel-decel transport scheme where ions are created at the desired collision energy in the plasma source, extracted and accelerated to high transport energy (20 keV to fight space charge repulsion), and then decelerated back down to their original creation potential right before impacting the grounded target. Scattered species and those originating from the surface are directly analyzed in energy and mass using a triply pumped, hybrid detector composed of an electron impact ionizer, hemispherical electrostatic sector, and rf/dc quadrupole in series. With such a system, the collision kinematics, charge exchange, and chemistry occurring on the target surface can be separated by fully analyzing the scattered product flux. Key design aspects of the plasma source, beamline, and detection system are emphasized here to highlight how to work around physical limitations associated with high beam flux at low energy, pumping requirements, beam focusing, and scattered product analysis. Operational details of the beamline are discussed from the perspective of available beam current, mass resolution, projectile energy spread, and energy tunability. As well, performance of the overall system is demonstrated through three proof-of-concept examples: (1) elastic binary collisions at low energy, (2) core-level charge exchange reactions involving Ne+20 with Mg /Al/Si/P targets, and (3) reactive scattering of CF2+/CF3+ off Si. These studies clearly demonstrate why low, tunable incident energy, as well as mass and energy filtering of products leaving the target surface is advantageous and often essential for studies of inelastic energy losses, hard-collision charge exchange, and chemical reactions that occur during ion-surface scattering.

Electrostatic ion thruster optics calculations

NASA Technical Reports Server (NTRS)

Whealton, John H.; Kirkman, David A.; Raridon, R. J.

1992-01-01

Calculations have been performed which encompass both a self-consistent ion source extraction plasma sheath and the primary ion optics including sheath and electrode-induced aberrations. Particular attention is given to the effects of beam space charge, accelerator geometry, and properties of the downstream plasma sheath on the position of the electrostatic potential saddle point near the extractor electrode. The electron blocking potential blocking is described as a function of electrode thickness and secondary plasma processes.

Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jang, Hyojae, E-mail: lkcom@ibs.re.kr; Jin, Hyunchang; Jang, Ji-Ho

2016-02-15

A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, developmentmore » of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.« less

Laboratory Measurements of Solar-Wind/Comet X-Ray Emission and Charge Exchange Cross Sections

NASA Technical Reports Server (NTRS)

Chutjian, A.; Cadez, I.; Greenwood, J. B.; Mawhorter, R. J.; Smith, S. J.; Lozano, J.

2002-01-01

The detection of X-rays from comets such as Hyakutake, Hale-Bopp, d Arrest, and Linear as they approach the Sun has been unexpected and exciting. This phenomenon, moreover, should be quite general, occurring wherever a fast solar or stellar wind interacts with neutrals in a comet, a planetary atmosphere, or a circumstellar cloud. The process is, O(+8) + H2O --> O(+7*) + H2O(+), where the excited O(+7*) ions are the source of the X-ray emissions. Detailed modeling has been carried out of X-ray emissions in charge-transfer collisions of heavy solar-wind Highly Charged Ions (HCIs) and interstellar/interplanetary neutral clouds. In the interplanetary medium the solar wind ions, including protons, can charge exchange with interstellar H and He. This can give rise to a soft X-ray background that could be correlated with the long-term enhancements seen in the low-energy X-ray spectrum of ROSAT. Approximately 40% of the soft X-ray background detected by Exosat, ROSAT, Chandra, etc. is due to Charge Exchange (CXE): our whole heliosphere is glowing in the soft X-ray due to CXE.

Source abundances of ultra heavy elements derived from UHCRE measurements.

PubMed

Domingo, C; Font, J; Baixeras, C; Fernandez, F

1996-11-01

A total of 205 tracks have been located, measured, and positively identified as originating from Ultra Heavy (Z > or = 65) cosmic ray ions with energies over 2 GeV/amu in the 10 UHCRE plastic track detector (mainly Lexan polycarbonate) stacks studied by our Group. About 40 values of reduced etch rate S have been obtained along each of these tracks. A method based on determining the gradient of S, together with calibration in accelerators, is used to determine the charge of each ion resulting in one of such tracks to obtain the charge spectrum of the recorded Ultra Heavy ions. The abundance ratio of ions with 87 < or = Z < or = 100 to those with 74 < or = Z < or = 86 as well as that of ions with 81 < or = Z < or = 86 to those with 74 < or = Z < or = 80 are calculated at 0.016 and 0.32, respectively, which agree with the values obtained from measurements in the HEAO-3 and Ariel-6 experiments. The abundance ratio of ions with 70 < or = Z < or = 73 to those with 74 < or = Z < or = 86 is also calculated, but its value (0.074) did not seem to be significant because of our detectors' low registration efficiency in the charge range 70 < or = Z < or = 73. A computer program developed by our Group, based on the Leaky Box cosmic ray propagation model, has been used to determine the source abundances of cosmic ray nuclei with Z > or = 65 inferred from the abundances measured in the UHCRE. It appeared that r-process synthesized elements were overabundant compared to the Solar System abundances, as predicted by other authors.

Spectroscopic determination of the composition of a 50 kV hydrogen diagnostic neutral beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, X.; Nornberg, M. D., E-mail: mdnornberg@wisc.edu; Den Hartog, D. J.

2016-11-15

A grating spectrometer with an electron multiplying charge-coupled device camera is used to diagnose a 50 kV, 5 A, 20 ms hydrogen diagnostic neutral beam. The ion source density is determined from Stark broadened H{sub β} emission and the spectrum of Doppler-shifted H{sub α} emission is used to quantify the fraction of ions at full, half, and one-third beam energy under a variety of operating conditions including fueling gas pressure and arc discharge current. Beam current is optimized at low-density conditions in the ion source while the energy fractions are found to be steady over most operating conditions.

Ion Storage with the High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James; Lewis, Raymond; Chakrabarti, Suman; Pearson, Boise

2002-01-01

The matter antimatter reaction represents the densest form of energy storage/release known to modern physics: as such it offers one of the most compact sources of power for future deep space exploration. To take the first steps along this path, NASA-Marshall Space Flight Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a goal of maintaining 10(exp 12) particles for up to 18 days. Experiments have been performed with this hardware using normal matter (positive hydrogen ions) to assess the device's ability to hold charged particles. These ions are currently created using an electron gun method to ionize background gas; however, this technique is limited by the quantity that can be captured. To circumvent this issue, an ion source is currently being commissioned which will greatly increase the number of ions captured and more closely simulate actual operations expected at an antiproton production facility. Ions have been produced, stored for various time intervals, and then extracted against detectors to measure species, quantity and energy. Radio frequency stabilization has been tested as a method to prolong ion lifetime: results show an increase in the baseline 1/e lifetime of trapped particles from hours to days. Impurities in the residual background gas (typically carbon-containing species CH4, CO, CO2, etc.) present a continuing problem by reducing the trapped hydrogen population through the mechanism of ion charge exchange.

Medium-energy heavy-ion single-event-burnout imaging of power MOSFETs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musseau, O.; Torres, A.; Campbell, A.B.

The authors present the first experimental determination of the SEB sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. They used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a non-destructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a suddenmore » change in the charge collection image. Hot spots are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEB sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation.« less

Influence of the electron cyclotron resonance plasma confinement on reducing the bremsstrahlung production of an electron cyclotron resonance ion source with metal-dielectric structures.

PubMed

Schachter, L; Stiebing, K E; Dobrescu, S

2009-01-01

The influence of metal-dielectric (MD) layers (MD structures) inserted into the plasma chamber of an electron cyclotron resonance ion source (ECRIS) onto the production of electron bremsstrahlung radiation has been studied in a series of dedicated experiments at the 14 GHz ECRIS of the Institut für Kernphysik der Universität Frankfurt. The IKF-ECRIS was equipped with a MD liner, covering the inner walls of the plasma chamber, and a MD electrode, covering the plasma-facing side of the extraction electrode. On the basis of similar extracted currents of highly charged ions, significantly reduced yields of bremsstrahlung radiation for the "MD source" as compared to the standard (stainless steel) source have been measured and can be explained by the significantly better plasma confinement in a MD source as compared to an "all stainless steel" ECRIS.

Modeling of negative ion transport in a plasma source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riz, David; Departement de Recherches sur la Fusion Controelee CE Cadarache, 13108 St Paul lez Durance; Pamela, Jerome

1998-08-20

A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The ion trajectory is calculated by numerically solving the 3-D motion equation, while the atomic processes of destruction, of elastic collision H{sup -}/H{sup +} and of charge exchange H{sup -}/H{sup 0} are handled at each time step by a Monte-Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have allowed to explain, either quantitatively or qualitatively, severalmore » phenomena observed in negative ion sources, such as the isotopic H{sup -}/D{sup -} effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm{sup -3}), negative ions can reach the extraction region provided if they are produced at a distance lower than 2 cm from the plasma grid in the case of 'volume production' (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.« less

Modeling of negative ion transport in a plasma source

NASA Astrophysics Data System (ADS)

Riz, David; Paméla, Jérôme

1998-08-01

A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The ion trajectory is calculated by numerically solving the 3-D motion equation, while the atomic processes of destruction, of elastic collision H-/H+ and of charge exchange H-/H0 are handled at each time step by a Monte-Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have allowed to explain, either quantitatively or qualitatively, several phenomena observed in negative ion sources, such as the isotopic H-/D- effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm-3), negative ions can reach the extraction region provided if they are produced at a distance lower than 2 cm from the plasma grid in the case of «volume production» (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.

Plasma shape control by pulsed solenoid on laser ion source

NASA Astrophysics Data System (ADS)

Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

2015-09-01

A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

Plasma shape control by pulsed solenoid on laser ion source

DOE PAGES

Sekine, M.; Ikeda, S.; Romanelli, M.; ...

2015-05-28

A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. It was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled bymore » the pulsed magnetic field. Thus, this approach may also be useful to reduce beam emittance of a LIS.« less

Development of Remote Sampling ESI Mass Spectrometry for the Rapid and Automatic Analysis of Multiple Samples

PubMed Central

Yamada, Yuki; Ninomiya, Satoshi; Hiraoka, Kenzo; Chen, Lee Chuin

2016-01-01

We report on combining a self-aspirated sampling probe and an ESI source using a single metal capillary which is electrically grounded and safe for use by the operator. To generate an electrospray, a negative H.V. is applied to the counter electrode of the ESI emitter to operate in positive ion mode. The sampling/ESI capillary is enclosed within another concentric capillary similar to the arrangement for a standard pneumatically assisted ESI source. The suction of the liquid sample is due to the Venturi effect created by the high-velocity gas flow near the ESI tip. In addition to serving as the mechanism for suction, the high-velocity gas flow also assists in the nebulization of charged droplets, thus producing a stable ion signal. Even though the potential of the ion source counter electrode is more negative than the mass spectrometer in the positive ion mode, the electric field effect is not significant if the ion source and the mass spectrometer are separated by a sufficient distance. Ion transmission is achieved by the viscous flow of the carrier gas. Using the present arrangement, the user can hold the ion source in a bare hand and the ion signal appears almost immediately when the sampling capillary is brought into contact with the liquid sample. The automated analysis of multiple samples can also be achieved by using motorized sample stage and an automated ion source holder. PMID:28616373

Development of Remote Sampling ESI Mass Spectrometry for the Rapid and Automatic Analysis of Multiple Samples.

PubMed

Yamada, Yuki; Ninomiya, Satoshi; Hiraoka, Kenzo; Chen, Lee Chuin

2016-01-01

We report on combining a self-aspirated sampling probe and an ESI source using a single metal capillary which is electrically grounded and safe for use by the operator. To generate an electrospray, a negative H.V. is applied to the counter electrode of the ESI emitter to operate in positive ion mode. The sampling/ESI capillary is enclosed within another concentric capillary similar to the arrangement for a standard pneumatically assisted ESI source. The suction of the liquid sample is due to the Venturi effect created by the high-velocity gas flow near the ESI tip. In addition to serving as the mechanism for suction, the high-velocity gas flow also assists in the nebulization of charged droplets, thus producing a stable ion signal. Even though the potential of the ion source counter electrode is more negative than the mass spectrometer in the positive ion mode, the electric field effect is not significant if the ion source and the mass spectrometer are separated by a sufficient distance. Ion transmission is achieved by the viscous flow of the carrier gas. Using the present arrangement, the user can hold the ion source in a bare hand and the ion signal appears almost immediately when the sampling capillary is brought into contact with the liquid sample. The automated analysis of multiple samples can also be achieved by using motorized sample stage and an automated ion source holder.

Ion mobility spectrometer with virtual aperture grid

DOEpatents

Pfeifer, Kent B.; Rumpf, Arthur N.

2010-11-23

An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

Diagnostics of Particles emitted from a Laser generated Plasma: Experimental Data and Simulations

NASA Astrophysics Data System (ADS)

Costa, Giuseppe; Torrisi, Lorenzo

2018-01-01

The charge particle emission form laser-generated plasma was studied experimentally and theoretically using the COMSOL simulation code. The particle acceleration was investigated using two lasers at two different regimes. A Nd:YAG laser, with 3 ns pulse duration and 1010 W/cm2 intensity, when focused on solid target produces a non-equilibrium plasma with average temperature of about 30-50 eV. An Iodine laser with 300 ps pulse duration and 1016 W/cm2 intensity produces plasmas with average temperatures of the order of tens keV. In both cases charge separation occurs and ions and electrons are accelerated at energies of the order of 200 eV and 1 MeV per charge state in the two cases, respectively. The simulation program permits to plot the charge particle trajectories from plasma source in vacuum indicating how they can be deflected by magnetic and electrical fields. The simulation code can be employed to realize suitable permanent magnets and solenoids to deflect ions toward a secondary target or detectors, to focalize ions and electrons, to realize electron traps able to provide significant ion acceleration and to realize efficient spectrometers. In particular it was applied to the study two Thomson parabola spectrometers able to detect ions at low and at high laser intensities. The comparisons between measurements and simulation is presented and discussed.

New progress of high current gasdynamic ion source (invited).

PubMed

Skalyga, V; Izotov, I; Golubev, S; Sidorov, A; Razin, S; Vodopyanov, A; Tarvainen, O; Koivisto, H; Kalvas, T

2016-02-01

The experimental and theoretical research carried out at the Institute of Applied Physics resulted in development of a new type of electron cyclotron resonance ion sources (ECRISs)-the gasdynamic ECRIS. The gasdynamic ECRIS features a confinement mechanism in a magnetic trap that is different from Geller's ECRIS confinement, i.e., the quasi-gasdynamic one similar to that in fusion mirror traps. Experimental studies of gasdynamic ECRIS were performed at Simple Mirror Ion Source (SMIS) 37 facility. The plasma was created by 37.5 and 75 GHz gyrotron radiation with power up to 100 kW. High frequency microwaves allowed to create and sustain plasma with significant density (up to 8 × 10(13) cm(-3)) and to maintain the main advantages of conventional ECRIS such as high ionization degree and low ion energy. Reaching such high plasma density relies on the fact that the critical density grows with the microwave frequency squared. High microwave power provided the average electron energy on a level of 50-300 eV enough for efficient ionization even at neutral gas pressure range of 10(-4)-10(-3) mbar. Gasdynamic ECRIS has demonstrated a good performance producing high current (100-300 mA) multi-charged ion beams with moderate average charge (Z = 4-5 for argon). Gasdynamic ECRIS has appeared to be especially effective in low emittance hydrogen and deuterium beams formation. Proton beams with current up to 500 emA and RMS emittance below 0.07 π ⋅ mm ⋅ mrad have been demonstrated in recent experiments.

Improving Charging-Breeding Simulations with Space-Charge Effects

NASA Astrophysics Data System (ADS)

Bilek, Ryan; Kwiatkowski, Ania; Steinbrügge, René

2016-09-01

Rare-isotope-beam facilities use Highly Charged Ions (HCI) for accelerators accelerating heavy ions and to improve measurement precision and resolving power of certain experiments. An Electron Beam Ion Trap (EBIT) is able to create HCI through successive electron impact, charge breeding trapped ions into higher charge states. CBSIM was created to calculate successive charge breeding with an EBIT. It was augmented by transferring it into an object-oriented programming language, including additional elements, improving ion-ion collision factors, and exploring the overlap of the electron beam with the ions. The calculation is enhanced with the effects of residual background gas by computing the space charge due to charge breeding. The program assimilates background species, ionizes and charge breeds them alongside the element being studied, and allows them to interact with the desired species through charge exchange, giving fairer overview of realistic charge breeding. Calculations of charge breeding will be shown for realistic experimental conditions. We reexamined the implementation of ionization energies, cross sections, and ion-ion interactions when charge breeding.

Correlation potential of a test ion near a strongly charged plate.

PubMed

Lu, Bing-Sui; Xing, Xiangjun

2014-03-01

We analytically calculate the correlation potential of a test ion near a strongly charged plate inside a dilute m:-n electrolyte. We do this by calculating the electrostatic Green's function in the presence of a nonlinear background potential, the latter having been obtained using the nonlinear Poisson-Boltzmann theory. We consider the general case where the dielectric constants of the plate and the electrolyte are distinct. The following generic results emerge from our analyses: (1) If the distance to the plate Δz is much larger than a Gouy-Chapman length, the plate surface will behave effectively as an infinitely charged surface, and the dielectric constant of the plate effectively plays no role. (2) If Δz is larger than a Gouy-Chapman length but shorter than a Debye length, the correlation potential can be interpreted in terms of an image charge that is three times larger than the source charge. This behavior is independent of the valences of the ions. (3) The Green's function vanishes inside the plate if the surface charge density is infinitely large; hence the electrostatic potential is constant there. In this respect, a strongly charged plate behaves like a conductor plate. (4) If Δz is smaller than a Gouy-Chapman length, the correlation potential is dominated by the conventional image charge due to the dielectric discontinuity at the interface. (5) If Δz is larger than a Debye length, the leading order behavior of the correlation potential will depend on the valences of the ions in the electrolyte. Furthermore, inside an asymmetric electrolyte, the correlation potential is singly screened, i.e., it undergoes exponential decay with a decay width equal to the Debye length.

Ion Current Rectification, Limiting and Overlimiting Conductances in Nanopores

PubMed Central

van Oeffelen, Liesbeth; Van Roy, Willem; Idrissi, Hosni; Charlier, Daniel; Lagae, Liesbet; Borghs, Gustaaf

2015-01-01

Previous reports on Poisson-Nernst-Planck (PNP) simulations of solid-state nanopores have focused on steady state behaviour under simplified boundary conditions. These are Neumann boundary conditions for the voltage at the pore walls, and in some cases also Donnan equilibrium boundary conditions for concentrations and voltages at both entrances of the nanopore. In this paper, we report time-dependent and steady state PNP simulations under less restrictive boundary conditions, including Neumann boundary conditions applied throughout the membrane relatively far away from the nanopore. We simulated ion currents through cylindrical and conical nanopores with several surface charge configurations, studying the spatial and temporal dependence of the currents contributed by each ion species. This revealed that, due to slow co-diffusion of oppositely charged ions, steady state is generally not reached in simulations or in practice. Furthermore, it is shown that ion concentration polarization is responsible for the observed limiting conductances and ion current rectification in nanopores with asymmetric surface charges or shapes. Hence, after more than a decade of collective research attempting to understand the nature of ion current rectification in solid-state nanopores, a relatively intuitive model is retrieved. Moreover, we measured and simulated current-voltage characteristics of rectifying silicon nitride nanopores presenting overlimiting conductances. The similarity between measurement and simulation shows that overlimiting conductances can result from the increased conductance of the electric double-layer at the membrane surface at the depletion side due to voltage-induced polarization charges. The MATLAB source code of the simulation software is available via the website http://micr.vub.ac.be. PMID:25978328

Systematic Variability of the He+ Pickup Ion Velocity Distribution Function Observed with SOHO/CELIAS/CTOF

NASA Astrophysics Data System (ADS)

Taut, Andreas; Drews, Christian; Berger, Lars; Wimmer-Schweingruber, Robert

2016-04-01

The 1D Velocity Distribution Function (VDF) of He+ pickup ions shows two distinct populations that reflect the sources of these ions. The highly suprathermal population is the result of the ionization and pickup of almost resting interstellar neutrals that are injected into the solar wind as a highly anisotropic torus distribution. The nearly thermalized population is centered around the solar wind bulk speed and is mainly attributed to inner-source pickup ions that originate in the inner heliosphere. Current pickup ion models assume a rapid isotropization of the initial VDF by resonant wave-particle interactions, but recent observations by Drews et al. (2015) of a torus-like VDF strongly limit this isotropization. This in turn means that more observational data is needed to further characterize the kinetic behavior of pickup ions. The Charge-Time-Of-Flight sensor on-board SOHO offers unrivaled counting statistics for He+ and a sufficient mass-per-charge resolution. Thus, the He+ VDF can be observed on comparatively short timescales. We combine this data with the magnetic field data from WIND via an extrapolation to the location of SOHO. On the one hand we investigate the 1D VDF of He+ pickup ions with respect to different magnetic field orientations. Our findings complement on previous studies with other instruments that show an anisotropy of the VDF that is linked to the initial torus VDF. On the other hand we find a significant modification of the VDF during stream-interaction region. This may be linked to a different cooling behaviour in these regions and/or the absence of inner-source He+ during these times. Here, we report on our preliminary results.

Correlating DMSP and NOAA Ion Precipitation Observations with Low Altitude ENA Emissions During the Declining Phase of Solar Cycle 23

NASA Astrophysics Data System (ADS)

Mackler, D. A.; Jahn, J. M.; Perez, J. D.; Pollock, C. J.

2014-12-01

Plasma sheet particles with sufficiently low mirror points will interact with thermospheric neutrals through charge exchange. The resulting ENAs are no longer magnetically bound and can therefore be detected by remote platforms outside the ionosphere/lower atmosphere. These ENAs closely associated with ion precipitation are termed Low Altitude Emissions (LAEs). They are non-isotropic in velocity space and mimic the corresponding ion pitch angle distribution. In this study we present a statistical correlation between remote observations of the LAE emission characteristics and ion precipitation maps determined in situ over the declining phase of solar cycle 23 (2000-2005). We discuss the strength and derived location (MLT, iMLAT) of LAEs as a function of geomagnetic activity levels in relation to the simultaneously measured strength, location, and spectral characteristics of in situ ion precipitation. These comparisons may allow us to use ENA images to assess where and how much energy is deposited during any type of enhanced geomagnetic activity. The precipitating ion differential directional flux maps are built up from combining NOAA-14/15/16 TED and DMSP-13/14/15 SSJ4 data. Low altitude ENA source locations are identified algorithmically using IMAGE/MENA images. ENA flux maps are derived by computing the LAE source locations assuming an ENA emission altitude (h) of 650 km, then projecting each image pixel onto a sphere with radius Re+h to determine the local time and latitude extent of the ENA source. The IGRF magnetic field model is used in combination with the Solar Magnetic coordinates of LAE pixels to compute the pitch angle of the escaping neutrals (previously ion before charge exchanging). Pitch angles larger than 90° will have a mirror point further into the atmosphere than the assumed emission altitude.

Modification of anisotropic plasma diffusion via auxiliary electrons emitted by a carbon nanotubes-based electron gun in an electron cyclotron resonance ion source.

PubMed

Malferrari, L; Odorici, F; Veronese, G P; Rizzoli, R; Mascali, D; Celona, L; Gammino, S; Castro, G; Miracoli, R; Serafino, T

2012-02-01

The diffusion mechanism in magnetized plasmas is a largely debated issue. A short circuit model was proposed by Simon, assuming fluxes of lost particles along the axial (electrons) and radial (ions) directions which can be compensated, to preserve the quasi-neutrality, by currents flowing throughout the conducting plasma chamber walls. We hereby propose a new method to modify Simon's currents via electrons injected by a carbon nanotubes-based electron gun. We found this improves the source performances, increasing the output current for several charge states. The method is especially sensitive to the pumping frequency. Output currents for given charge states, at different auxiliary electron currents, will be reported in the paper and the influence of the frequency tuning on the compensation mechanism will be discussed.

Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

PubMed

Toivanen, V; Bellodi, G; Dimov, V; Küchler, D; Lombardi, A M; Maintrot, M

2016-02-01

Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ion beams for the CERN experimental program. The ion beams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ion beam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT) section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented.

Ferroelectric Plasma Sources for Ion Beam Neutralization

NASA Astrophysics Data System (ADS)

Stepanov, A.; Gilson, E. P.; Grisham, L. R.; Davidson, R. C.

2014-10-01

A 40 keV Ar+ beam with a dimensionless perveance of 4 ×10-4 is propagated through a Ferroelectric Plasma Source (FEPS) to determine the effects of charge neutralization on the transverse beam profile. Neutralization is established 5 μs after the FEPS is triggered, and lasts between 10 and 35 μs. When the beam is fully neutralized, the profile has a Gaussian shape with a half-angle divergence of 0.87°, which is attributed to ion optics. The effects of the resistance and capacitance in the pulser circuit on the FEPS discharge are studied. The electron current emitted by the FEPS is calculated from measurements of the forward and return currents in the circuit. Electron emission typically begins 0.5 μs after the driving pulse, lasting for tens of μs, which is similar to the duration of ion beam neutralization. The total emitted charge does not depend significantly on the resistance, but depends strongly on the storage capacitance. Lowering the capacitance from 141 nF to 47 nF results in a near-complete shut-off of charge emission, although the amplitude of the applied voltage pulse is as high as when high-density plasma is produced. Overall, the data suggest that ferroelectric effects are significant in the physics of the FEPS discharge.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, A. L.; Chen, J. E.; State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871

Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Montemore » Carlo collision code which has been successfully applied to H{sup +} beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H{sup −} beam from a 2.45 GHz microwave driven H{sup −} ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.« less

Short-pulse, compressed ion beams at the Neutralized Drift Compression Experiment

DOE PAGES

Seidl, P. A.; Barnard, J. J.; Davidson, R. C.; ...

2016-05-01

We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory, with 1-mm beam spot size within 2.5 ns full-width at half maximum. The ion kinetic energy is 1.2 MeV. To enable the short pulse duration and mm-scale focal spot radius, the beam is neutralized in a 1.5-meter-long drift compression section following the last accelerator cell. A short-focal-length solenoid focuses the beam in the presence of the volumetric plasma that is near the target. In the accelerator, the line-charge density increases due to the velocity ramp imparted onmore » the beam bunch. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including select topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Below the transition to melting, the short beam pulses offer an opportunity to study the multi-scale dynamics of radiation-induced damage in materials with pump-probe experiments, and to stabilize novel metastable phases of materials when short-pulse heating is followed by rapid quenching. First experiments used a lithium ion source; a new plasma-based helium ion source shows much greater charge delivered to the target.« less

Development of stripper options for FRIB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marti, F.; Hershcovitch, A.; Momozaki, Y.

2010-09-12

The US Department of Energy Facility for Rare Isotope Beams (FRIB) at Michigan State University includes a heavy ion superconducting linac capable of accelerating all ions up to uranium with energies higher than 200 MeV/u and beam power up to 400 kW. To achieve these goals with present ion source performance it is necessary to accelerate simultaneously two charge states of uranium from the ion source in the first section of the linac. At an energy of approximately 16.5 MeV/u it is planned to strip the uranium beam to reduce the voltage needed in the rest of the linac tomore » achieve the final energy. Up to five different charge states are planned to be accelerated simultaneously after the stripper. The design of the stripper is a challenging problem due to the high power deposited (approximately 0.7 kW) in the stripper media by the beam in a small spot. To assure success of the project we have established a research and development program that includes several options: carbon or diamond foils, liquid lithium films, gas strippers and plasma strippers. We present in this paper the status of the different options.« less

Measurements of Electrical and Electron Emission Properties of Highly Insulating Materials

NASA Technical Reports Server (NTRS)

Dennison, J. R.; Brunson, Jerilyn; Hoffman, Ryan; Abbott, Jonathon; Thomson, Clint; Sim, Alec

2005-01-01

Highly insulating materials often acquire significant charges when subjected to fluxes of electrons, ions, or photons. This charge can significantly modify the materials properties of the materials and have profound effects on the functionality of the materials in a variety of applications. These include charging of spacecraft materials due to interactions with the severe space environment, enhanced contamination due to charging in Lunar of Martian environments, high power arching of cables and sources, modification of tethers and ion thrusters for propulsion, and scanning electron microscopy, to name but a few examples. This paper describes new techniques and measurements of the electron emission properties and resistivity of highly insulating materials. Electron yields are a measure of the number of electrons emitted from a material per incident particle (electron, ion or photon). Electron yields depend on incident species, energy and angle, and on the material. They determine the net charge acquired by a material subject to a give incident flu. New pulsed-beam techniques will be described that allow accurate measurement of the yields for uncharged insulators and measurements of how the yields are modified as charge builds up in the insulator. A key parameter in modeling charge dissipation is the resistivity of insulating materials. This determines how charge will accumulate and redistribute across an insulator, as well as the time scale for charge transport and dissipation. Comparison of new long term constant-voltage methods and charge storage methods for measuring resistivity of highly insulating materials will be compared to more commonly used, but less accurate methods.

A Versatile Ion Injector at KACST

NASA Astrophysics Data System (ADS)

El Ghazaly, M. O. A.; Behery, S. A.; Almuqhim, A. A.; Papash, A. I.; Welsch, C. P.

2011-10-01

A versatile ion-beam injector is presently being constructed at the National Centre for Mathematics and Physics (NCMP) at the King Abdul-Aziz City for Science and Technology (KACST), Saudi Arabia. This versatile injector will provide an electrostatic storage ring with high-quality ion beams of energies up to 30 keV per charge q. It will also allow for crossed-beams experiments in single-pass setups. The injector has been designed to include beams from two different ion sources, switched by a 90° deflection setup, and to allow for matching of the beam parameters to the Twiss parameters of the ring. The injector is equipped with two crossed beam-lines (inlets), with duplicated beam extraction and acceleration systems. As part of the initial setup, a simple electric discharge ion source has been developed for commissioning of the whole injector. In this paper, we report on the ion optics layout and the design parameters of the injector.

Status and outlook of CHIP-TRAP: The Central Michigan University high precision Penning trap

NASA Astrophysics Data System (ADS)

Redshaw, M.; Bryce, R. A.; Hawks, P.; Gamage, N. D.; Hunt, C.; Kandegedara, R. M. E. B.; Ratnayake, I. S.; Sharp, L.

2016-06-01

At Central Michigan University we are developing a high-precision Penning trap mass spectrometer (CHIP-TRAP) that will focus on measurements with long-lived radioactive isotopes. CHIP-TRAP will consist of a pair of hyperbolic precision-measurement Penning traps, and a cylindrical capture/filter trap in a 12 T magnetic field. Ions will be produced by external ion sources, including a laser ablation source, and transported to the capture trap at low energies enabling ions of a given m / q ratio to be selected via their time-of-flight. In the capture trap, contaminant ions will be removed with a mass-selective rf dipole excitation and the ion of interest will be transported to the measurement traps. A phase-sensitive image charge detection technique will be used for simultaneous cyclotron frequency measurements on single ions in the two precision traps, resulting in a reduction in statistical uncertainty due to magnetic field fluctuations.

High Power ECR Ion Thruster Discharge Characterization

NASA Technical Reports Server (NTRS)

Foster, John E.; Kamhawi, Hani; Haag, Thomas; Carpenter, Christian; Williams, George W.

2006-01-01

Electron cyclotron resonance (ECR) based ion thrusters with carbon based ion optics can potentially satisfy lifetime requirements for long duration missions (approximately 10 years) because grid erosion and cathode insert depletion issues are virtually eliminated. Though the ECR plasma discharge has been found to typically operate at slightly higher discharge losses than conventional DC ion thrusters (for high total thruster power applications), the discharge power fraction is small (less than 1 percent at 25 kW). In this regard, the benefits of increased life, low discharge plasma potentials, and reduced complexity are welcome tradeoffs for the associated discharge efficiency decrease. Presented here are results from discharge characterization of a large area ECR plasma source for gridded ion thruster applications. These measurements included load matching efficacy, bulk plasma properties via Langmuir probe, and plasma uniformity as measured using current probes distributed at the exit plane. A high degree of plasma uniformity was observed (flatness greater than 0.9). Additionally, charge state composition was qualitatively evaluated using emission spectroscopy. Plasma induced emission was dominated by xenon ion lines. No doubly charged xenon ions were detected.

Rechargeable magnesium-ion battery based on a TiSe2-cathode with d-p orbital hybridized electronic structure

PubMed Central

Gu, Yunpeng; Katsura, Yukari; Yoshino, Takafumi; Takagi, Hidenori; Taniguchi, Kouji

2015-01-01

Rechargeable ion-batteries, in which ions such as Li+ carry charges between electrodes, have been contributing to the improvement of power-source performance in a wide variety of mobile electronic devices. Among them, Mg-ion batteries are recently attracting attention due to possible low cost and safety, which are realized by abundant natural resources and stability of Mg in the atmosphere. However, only a few materials have been known to work as rechargeable cathodes for Mg-ion batteries, owing to strong electrostatic interaction between Mg2+ and the host lattice. Here we demonstrate rechargeable performance of Mg-ion batteries at ambient temperature by selecting TiSe2 as a model cathode by focusing on electronic structure. Charge delocalization of electrons in a metal-ligand unit through d-p orbital hybridization is suggested as a possible key factor to realize reversible intercalation of Mg2+ into TiSe2. The viewpoint from the electronic structure proposed in this study might pave a new way to design electrode materials for multivalent-ion batteries. PMID:26228263

Improved negative ion source

DOEpatents

Delmore, J.E.

1984-05-01

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

First results of 28 GHz superconducting electron cyclotron resonance ion source for KBSI accelerator.

PubMed

Park, Jin Yong; Lee, Byoung-Seob; Choi, Seyong; Kim, Seong Jun; Ok, Jung-Woo; Yoon, Jang-Hee; Kim, Hyun Gyu; Shin, Chang Seouk; Hong, Jonggi; Bahng, Jungbae; Won, Mi-Sook

2016-02-01

The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion for the linear accelerator at KBSI (Korea Basic Science Institute). The objective of this study is to generate fast neutrons with a proton target via a p(Li,n)Be reaction. The design and fabrication of the essential components of the ECR ion source, which include a superconducting magnet with a liquid helium re-condensed cryostat and a 10 kW high-power microwave, were completed. The waveguide components were connected with a plasma chamber including a gas supply system. The plasma chamber was inserted into the warm bore of the superconducting magnet. A high voltage system was also installed for the ion beam extraction. After the installation of the ECR ion source, we reported the results for ECR plasma ignition at ECRIS 2014 in Russia. Following plasma ignition, we successfully extracted multi-charged ions and obtained the first results in terms of ion beam spectra from various species. This was verified by a beam diagnostic system for a low energy beam transport system. In this article, we present the first results and report on the current status of the KBSI accelerator project.

First results of 28 GHz superconducting electron cyclotron resonance ion source for KBSI accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jin Yong; Lee, Byoung-Seob; Choi, Seyong

The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion for the linear accelerator at KBSI (Korea Basic Science Institute). The objective of this study is to generate fast neutrons with a proton target via a p(Li,n)Be reaction. The design and fabrication of the essential components of the ECR ion source, which include a superconducting magnet with a liquid helium re-condensed cryostat and a 10 kW high-power microwave, were completed. The waveguide components were connected with a plasma chamber including a gas supply system. The plasma chamber was inserted intomore » the warm bore of the superconducting magnet. A high voltage system was also installed for the ion beam extraction. After the installation of the ECR ion source, we reported the results for ECR plasma ignition at ECRIS 2014 in Russia. Following plasma ignition, we successfully extracted multi-charged ions and obtained the first results in terms of ion beam spectra from various species. This was verified by a beam diagnostic system for a low energy beam transport system. In this article, we present the first results and report on the current status of the KBSI accelerator project.« less

Injection of auxiliary electrons for increasing the plasma density in highly charged and high intensity ion sources.

PubMed

Odorici, F; Malferrari, L; Montanari, A; Rizzoli, R; Mascali, D; Castro, G; Celona, L; Gammino, S; Neri, L

2016-02-01

Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is not confined, has required an improvement of the gun design, in order to "screen" the cathode from the plasma particles. Experimental tests carried out on a plasma reactor show a boost of the plasma density, ranging from 10% to 90% when the electron guns are used, as explained by plasma diffusion models.

Dust Ion-Acoustic Shock Waves in a Multicomponent Magnetorotating Plasma

NASA Astrophysics Data System (ADS)

Kaur, Barjinder; Saini, N. S.

2018-02-01

The nonlinear properties of dust ion-acoustic (DIA) shock waves in a magnetorotating plasma consisting of inertial ions, nonextensive electrons and positrons, and immobile negatively charged dust are examined. The effects of dust charge fluctuations are not included in the present investigation, but the ion kinematic viscosity (collisions) is a source of dissipation, leading to the formation of stable shock structures. The Zakharov-Kuznetsov-Burgers (ZKB) equation is derived using the reductive perturbation technique, and from its solution the effects of different physical parameters, i.e. nonextensivity of electrons and positrons, kinematic viscosity, rotational frequency, and positron and dust concentrations, on the characteristics of shock waves are examined. It is observed that physical parameters play a very crucial role in the formation of DIA shocks. This study could be useful in understanding the electrostatic excitations in dusty plasmas in space (e.g. interstellar medium).

Plasma wave observations during ion gun experiments

NASA Astrophysics Data System (ADS)

Olsen, R. C.; Weddle, L. E.; Roeder, J. L.

1990-06-01

Experiments in charge control on the AF/NASA P78-2 (SCATHA) satellite were conducted with a plasma/ion source in the inner magnetosphere. These experiments were monitored with plasma wave instruments capable of high temporal and frequency resolution in the 0-6 kHz frequency range. Ion gun experiments revealed two distinct classes of behavior. Nonneutralized ion beam operation at 1 mA, 1kV resulted in arcing signatures (spiky in time, broad frequency range), coincident with induced satellite potentials of -600 to -900 V. This signature disappeared when the accelerating voltage was switched off or the beam was neutralized. The signal is attributed to arcing between differentially charged surfaces. An additional feature was noted in the 100-kHz channel of the wave receiver. During emission of dense, low-energy plasma, a signal is generated which may be at the upper hybrid, or plasma frequency for the local plasma.

Deceleration, precooling, and multi-pass stopping of highly charged ions in Be{sup +} Coulomb crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmöger, L., E-mail: lisa.schmoeger@mpi-hd.mpg.de; Schwarz, M.; Versolato, O. O.

2015-10-15

Preparing highly charged ions (HCIs) in a cold and strongly localized state is of particular interest for frequency metrology and tests of possible spatial and temporal variations of the fine structure constant. Our versatile preparation technique is based on the generic modular combination of a pulsed ion source with a cryogenic linear Paul trap. Both instruments are connected by a compact beamline with deceleration and precooling properties. We present its design and commissioning experiments regarding these two functionalities. A pulsed buncher tube allows for the deceleration and longitudinal phase-space compression of the ion pulses. External injection of slow HCIs, specificallymore » Ar{sup 13+}, into the linear Paul trap and their subsequent retrapping in the absence of sympathetic cooling is demonstrated. The latter proved to be a necessary prerequisite for the multi-pass stopping of HCIs in continuously laser-cooled Be{sup +} Coulomb crystals.« less

The development of a room temperature electron cyclotron resonance ion source (Lanzhou electron cyclotron resonance ion source No. 4) with evaporative cooling technology at Institute of Modern Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, W., E-mail: luwang@impcas.ac.cn; Sun, L. T.; Qian, C.

2015-04-15

LECR4 (Lanzhou electron cyclotron resonance ion source No. 4) has been successfully constructed at IMP and has also been connected with the Low Energy Beam Transport (LEBT) and Radio Frequency Quadrupole (RFQ) systems. These source magnet coils are cooled through evaporative cooling technology, which is the first attempt with an ECR ion source in the world. The maximum mirror field is 2.5 T (with iron plug) and the effective plasma chamber volume is 1.2 l. It was designed to be operated at 18 GHz and aimed to produce intense multiple charge state heavy ion beams for the linear injector projectmore » SSC-Linac at IMP. In February 2014, the first analyzed beam at 18 GHz was extracted. During about three months’ commissioning, some outstanding results have been achieved, such as 1.97 emA of O{sup 6+}, 1.7 emA of Ar{sup 8+}, 1.07 emA of Ar{sup 9+}, and 118 euA of Bi{sup 28+}. The source has also successfully delivered O{sup 5+} and Ar{sup 8+} ion beams for RFQ commissioning in April 2014. This paper will give a brief overview of the design of LECR4. Then, the latest results of this source at 18 GHz will be presented.« less

Development of an apparatus for obtaining molecular beams in the energy range from 2 to 200 eV

NASA Technical Reports Server (NTRS)

Clapier, R.; Devienne, F. M.; Roustan, A.; Roustan, J. C.

1985-01-01

The formation and detection of molecular beams obtained by charge exchange from a low-energy ion source is discussed. Dispersion in energy of the ion source was measured and problems concerning detection of neutral beams were studied. Various methods were used, specifically secondary electron emissivity of a metallic surface and ionization of a gas target with a low ionization voltage. The intensities of neutral beams as low as 10 eV are measured by a tubular electron multiplier and a lock-in amplifier.

LABORATORY MEASUREMENTS COMPELLINGLY SUPPORT A CHARGE-EXCHANGE MECHANISM FOR THE “DARK MATTER” ∼3.5 keV X-Ray LINE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, Chintan; Dobrodey, Stepan; Bernitt, Sven

2016-12-10

The reported observations of an unidentified X-ray line feature at ∼3.5 keV have driven a lively discussion about its possible dark matter origin. Motivated by this, we have measured the K-shell X-ray spectra of highly ionized bare sulfur ions following charge exchange with gaseous molecules in an electron beam ion trap, as a source of or a contributor to this X-ray line. We produced S{sup 16+} and S{sup 15+} ions and let them capture electrons in collision with those molecules with the electron beam turned off while recording X-ray spectra. We observed a charge-exchange-induced X-ray feature at the Lyman seriesmore » limit (3.47 ± 0.06 keV). The inferred X-ray energy is in full agreement with the reported astrophysical observations and supports the novel scenario proposed by Gu et al.« less

Protein and peptide cross sections and mass spectra in an electrostatic ion beam trap

NASA Astrophysics Data System (ADS)

Fradkin, Z.; Strasser, D.; Heber, O.; Rappaport, M. L.; Sharon, M.; Thomson, B. A.; Rahinov, I.; Toker, Y.; Zajfman, D.

2017-05-01

Among the advantages of an electrostatic ion beam trap (EIBT), which is based on purely electrostatic fields, are mass-unlimited trapping and ease of operation. We have developed a new system that couples an electrospray ion source to an EIBT. Between the source and EIBT there is a Paul trap in which the ions are accumulated before being extracted and accelerated. After the ion bunch has entered the EIBT, the ions are trapped by rapidly raising the voltages on the entrance mirror. The oscillations of the bunch are detected by amplifying the charge induced on a pickup ring in the center of the trap, the ion mass being directly proportional to the square of the oscillation period. The trapping of biomolecules in the RF-bunching mode of the EIBT is used for measurement of mass spectra and collision cross sections. Coalescence of bunches of ions of nearby mass in the self-bunching mode is also demonstrated.

Tests of positive ion beams from a microwave ion source for AMS

NASA Astrophysics Data System (ADS)

Schneider, R. J.; von Reden, K. F.; Hayes, J. M.; Wills, J. S. C.; Kern, W. G. E.; Kim, S.-W.

2000-10-01

A test facility has been constructed to evaluate high-current positive ion beams from small gaseous samples for AMS applications. The major components include a compact permanent magnet microwave ion source built at the AECL Chalk River Laboratory and now on loan from the University of Toronto, and a double-focusing spectrometer magnet on loan from Argonne National Laboratory. Samples are introduced by means of a silica capillary injection system. Loop injection into a carrier gas provides a stable feed for the microwave driven plasma. The magnetic analysis system is utilized to isolate carbon ions derived from CO 2 samples from other products of the plasma discharge, including argon ions of the carrier gas. With a smaller discharge chamber, we hope to exceed a conversion efficiency of 14% for carbon ions produced per atom, which we reported at AMS-7. The next step will be to construct an efficient charge-exchange cell, to produce negative ions for injection into the WHOI recombinator injector.

Spacelab energetic ion mass spectrometer

NASA Technical Reports Server (NTRS)

Whalen, B. A.; Mcdiarmid, I. B.; Burrows, J. R.; Sharp, R. D.; Johnson, R. G.; Shelley, E. G.

1980-01-01

Basic design criteria are given for an ion mass spectrometer for use in studying magnetospheric ion populations. The proposed instrument is composed of an electrostatic analyzer followed by a magnetic spectrometer and simultaneously measures the energy per unit and mass per unit charge of the ion species. An electromagnet is used for momentum analysis to extend the operational energy range over a much wider domain than is possible with the permanent magnets used in previous flights. The energetic ion source regions, ion energization mechanisms, field line tracing, coordinated investigations, and orbit considerations are discussed and operations of the momentum analyzer and of the electrostatic energy analyzer are examined.

Gas-Phase Synthesis of Singly and Multiply Charged Polyoxovanadate Anions Employing Electrospray Ionization and Collision Induced Dissociation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al Hasan, Naila M.; Johnson, Grant E.; Laskin, Julia

2013-07-02

Electrospray ionization mass spectrometry (ESI-MS) combined with in-source fragmentation and tandem mass spectrometry (MS/MS) experiments were used to generate a wide range of singly and multiply charged vanadium oxide cluster anions including V xO y n– and V xO yCl n– ions (x = 1–14, y = 2–36, n = 1–3), protonated clusters, and ligand-bound polyoxovanadate anions. The cluster anions were produced by electrospraying a solution of tetradecavanadate, V 14O 36Cl(L) 5 (L = Et 4N +, tetraethylammonium), in acetonitrile. Under mild source conditions, ESI-MS generates a distribution of doubly and triply charged V xO yCl n– and V xOmore » yCl(L) (n–1)– clusters predominantly containing 14 vanadium atoms as well as their protonated analogs. Accurate mass measurement using a high-resolution LTQ/Orbitrap mass spectrometer (m/Δm = 60,000 at m/z 410) enabled unambiguous assignment of the elemental composition of the majority of peaks in the ESI-MS spectrum. In addition, high-sensitivity mass spectrometry allowed the charge state of the cluster ions to be assigned based on the separation of the major from the much less abundant minor isotope of vanadium. In-source fragmentation resulted in facile formation of smaller V xO yCl (1–2)– and V xO y (1–2)– anions. Collision-induced dissociation (CID) experiments enabled systematic study of the gas-phase fragmentation pathways of the cluster anions originating from solution and from in-source CID. Surprisingly simple fragmentation patterns were obtained for all singly and doubly charged V xO yCl and V xO y species generated through multiple MS/MS experiments. In contrast, cluster anions originating directly from solution produced comparatively complex CID spectra. These results are consistent with the formation of more stable structures of V xO yCl and V xO y anions through low-energy CID. Finally and furthermore, our results demonstrate that solution-phase synthesis of one precursor cluster anion combined with gas-phase CID is an efficient approach for the top-down synthesis of a wide range of singly and multiply charged gas-phase metal oxide cluster anions for subsequent investigations of structure and reactivity using mass spectrometry and ion spectroscopy techniques.« less

Probing anode degradation in automotive Li-ion batteries

NASA Astrophysics Data System (ADS)

Kwon, Ou Jung

The lithium-ion battery is drawing attention as a power source for future clean and fuel-efficient vehicles. Although the Li-ion battery presently shows best performance for energy density and power density compared to other rechargeable batteries, some degradation problems still remain as key challenges for long-term durability in automotive applications. Among those problems, Li deposition is well known for causing permanent capacity loss. Fundamental mechanisms of Li deposition in the carbon anode are, however, not fully understood, especially at subzero temperature and/or under high rate charge. This dissertation introduces comprehensive study of Li deposition using automotive 18650 Li-ion cells. The mechanism and relevant diagnostic methods as well as preventive charging protocol are discussed. In part one, a new diagnostic tool is introduced utilizing 3-electrode cell system, which measures thermodynamic and kinetic parameters of cathode and anode, respectively, as a function of temperature and SOC (state of charge): open circuit potential (OCP); Li diffusion coefficient in active particles; and internal resistance. These data are employed to understand electrochemical reaction and its thermal interaction under charging conditions that result in Li deposition. Part two provides a threshold parameter for the onset of Li deposition, which is not commonly used anode potential but charge capacity, or more specifically the amount of Li+ ions participating in intercalation reaction without Li deposition at given charging circumstances. This is called the critical charge capacity in this thesis, beyond which capacity loss at normal operating condition is observed, which becomes more serious as temperature is lowered and/or charge C-rate increases. Based on these experimental results, the mechanism of Li deposition is proposed as the concept of anode particle surface saturation, meaning that once the anode particle surface is saturated with Li in any charging circumstances, no more Li+ ions can be intercalated but should be reduced to metallic form on the anode particle surface. This is validated by calculating the distribution of Li concentration inside the anode particle with electrochemical modeling. In part three, a novel pulse charge protocol is developed, which consists of two steps. First high current charge/discharge pulses increase the cell temperature from a subzero temperature up to above room temperature in a short time, and next, high current charge provides the net charge capacity. Sluggish Li diffusion at low temperature becomes fast thanks to cell temperature elevation by high current pulses (1st step), which plays a role of preventing surface saturation during high current charge (2nd step). Thus, this charge protocol is not only Li deposition-free but also leads to rapid charge at subzero temperatures.

Interaction of slow highly charged ions with hard dental tissue: studies of fluoride uptake and reminalization efficacy

NASA Astrophysics Data System (ADS)

Daskalova, A.; Kasperski, G.; Rousseau, P.; Domaracka, A.; Lawicki, A.

2014-05-01

TOF-SIMS mass spectroscopy data are presented on ion irradiation of hard dental tissue using a beam of 129Xe20+ (15 kV) ions delivered in the ARIBE facility by an ECR source. The investigation was focused on the mass distribution of the fragment ions. A comparison is made between the mass spectra from hard dental tissue treated by olaflur-(C27H60F2N2O3) and untreated hard dental tissue obtained under irradiation by low-energy highly-charged ions (HCIs). We found significant differences between the mass spectra of enamel after introducing amine fluoride (olaflur) and the mass spectra of pure untreated enamel. Further, we separated out the effects caused by radiation induced in the tooth enamel from those induced in dentin, which has not been performed before. In order to conduct a further detailed analysis, it is necessary to extend the research scope to include the influence of fluorine compounds on enamel and dentin.

Review of particle-in-cell modeling for the extraction region of large negative hydrogen ion sources for fusion

NASA Astrophysics Data System (ADS)

Wünderlich, D.; Mochalskyy, S.; Montellano, I. M.; Revel, A.

2018-05-01

Particle-in-cell (PIC) codes are used since the early 1960s for calculating self-consistently the motion of charged particles in plasmas, taking into account external electric and magnetic fields as well as the fields created by the particles itself. Due to the used very small time steps (in the order of the inverse plasma frequency) and mesh size, the computational requirements can be very high and they drastically increase with increasing plasma density and size of the calculation domain. Thus, usually small computational domains and/or reduced dimensionality are used. In the last years, the available central processing unit (CPU) power strongly increased. Together with a massive parallelization of the codes, it is now possible to describe in 3D the extraction of charged particles from a plasma, using calculation domains with an edge length of several centimeters, consisting of one extraction aperture, the plasma in direct vicinity of the aperture, and a part of the extraction system. Large negative hydrogen or deuterium ion sources are essential parts of the neutral beam injection (NBI) system in future fusion devices like the international fusion experiment ITER and the demonstration reactor (DEMO). For ITER NBI RF driven sources with a source area of 0.9 × 1.9 m2 and 1280 extraction apertures will be used. The extraction of negative ions is accompanied by the co-extraction of electrons which are deflected onto an electron dump. Typically, the maximum negative extracted ion current is limited by the amount and the temporal instability of the co-extracted electrons, especially for operation in deuterium. Different PIC codes are available for the extraction region of large driven negative ion sources for fusion. Additionally, some effort is ongoing in developing codes that describe in a simplified manner (coarser mesh or reduced dimensionality) the plasma of the whole ion source. The presentation first gives a brief overview of the current status of the ion source development for ITER NBI and of the PIC method. Different PIC codes for the extraction region are introduced as well as the coupling to codes describing the whole source (PIC codes or fluid codes). Presented and discussed are different physical and numerical aspects of applying PIC codes to negative hydrogen ion sources for fusion as well as selected code results. The main focus of future calculations will be the meniscus formation and identifying measures for reducing the co-extracted electrons, in particular for deuterium operation. The recent results of the 3D PIC code ONIX (calculation domain: one extraction aperture and its vicinity) for the ITER prototype source (1/8 size of the ITER NBI source) are presented.

Modeling of negative ion transport in a plasma source (invited)

NASA Astrophysics Data System (ADS)

Riz, David; Paméla, Jérôme

1998-02-01

A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The H-/D- trajectory is calculated by numerically solving the 3D motion equation, while the atomic processes of destruction, of elastic collision with H+/D+ and of charge exchange with H0/D0 are handled at each time step by a Monte Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have been allowed to explain, either quantitatively or qualitatively, several phenomena observed in negative ion sources, such as the isotopic H-/D- effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that, in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm-3), negative ions can reach the extraction region provided they are produced at a distance lower than 2 cm from the plasma grid in the case of volume production (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.

High-intensity polarized H- ion source for the RHIC SPIN physics

NASA Astrophysics Data System (ADS)

Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Kolmogorov, A.; Davydenko, V.

2017-08-01

A novel polarization technique had been successfully implemented for the RHIC polarized H- ion source upgrade to higher intensity and polarization. In this technique a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. The use of high-brightness primary beam and large cross-sections of charge-exchange cross-sections resulted in production of high intensity H- ion beam of 85% polarization. High beam brightness and polarization resulted in 75% polarization at 23 GeV out of AGS and 60-65% beam polarization at 100-250 GeV colliding beams in RHIC. The status of un-polarized magnetron type (Cs-vapour loaded) BNL source is also discussed.

An Investigation of Low Biofouling Copper-charged Membranes

NASA Astrophysics Data System (ADS)

Asapu, Sunitha

Water is essential for the survival of life on Earth, but pollutants in water can cause dangerous diseases and fatalities. The need for purified water has been increasing with increasing world population; however, natural sources of water such as rivers, lakes and streams, are progressively falling shorter and shorter of meeting water needs. The provision of clean, drinkable water to people is a key factor for the development of novel and alternative water purification technologies, such as membrane separations. Nanofiltration (NF) is a membrane separations technology that purifies water from lower quality sources, such as brackish water, seawater and wastewater. During the filtration of such sources, materials that are rejected by the membrane may accumulate on the surface of the membrane to foul it. Such materials include organic and inorganic matter, colloids, salts and microorganisms. The former four can often be controlled via pretreatment; however, the accumulation of microorganisms is more problematic to membranes. Biofouling is the accumulation and growth of microorganisms on the surface of membranes and on feed spacers. After attachment, microorganisms excrete extracellular polymeric substances (EPS), which form a matrix around the organism's outer surface as biofilm. These biofilms are detrimental and result in irreversible membrane fouling. Copper and silver ions inactivate the bacterial cells and prevent the DNA replication in microbial cells. Previous studies using copper-charged feed spacers have shown the ability of copper to control biofouling without a significant amount of copper leaching from copper-charged polypropylene (PP) feed spacers during crossflow filtration. Also, filtration using unmodified speed facers experienced almost 70% flux decline, while filtration using copper-charged feed spacers displayed only 25% flux decline. These intriguing results led to the hypothesis that the polymer chemistry could be extrapolated to produce membranes with increased biofouling resistance. The goal of this project was to develop low-biofouling nanofiltration cellulose acetate (CA) membranes through functionalization with metal chelating ligands charged with biocidal metal ions, i.e. copper ions. To this end, glycidyl methacrylate (GMA), an epoxy, was used to attach a chelating agent, iminodiacetic acid (IDA) to facilitate the charging of copper to the membrane surface. Both CA and CA-GMA membranes were cast using the phase-inversion method. The CA-GMA membranes were then charged with copper ions to make them low biofouling. Pore size distribution analysis of CA and copper charged membranes were conducted using various molecular weights of polyethylene glycol (PEG). CA and copper-charged membranes were characterized using Fourier Transform Infrared (FTIR), contact angle to measure hydrophilicity changes, and using scanning electron microscope (SEM) coupled with X-ray energy dispersive spectroscopy EDS to monitor copper leaching. Permeation experiments were conducted with distilled (DI) water, protein solutions, and synthetic brackish water containing microorganisms. The DI water permeation of the copper-charged membranes was initially lower than the CA membranes. The membranes were then subjected to bovine serum albumin (BSA) and lipase filtration. The copper-charged membranes showed higher pure water flux values for both proteins as compared to CA membranes. The rejection of BSA and lipase was the same for both the copper charged and CA membranes. The filtration with the synthetic brackish water showed that copper-charged membranes had higher flux values as compared to CA membranes, and biofouling analysis showed more bacteria on the CA membranes as compared to copper-charged membranes. Therefore, the copper-charged membranes made here have shown a potential to be used as low-biofouling membranes in the future.

Upgrade of the BATMAN test facility for H- source development

NASA Astrophysics Data System (ADS)

Heinemann, B.; Fröschle, M.; Falter, H.-D.; Fantz, U.; Franzen, P.; Kraus, W.; Nocentini, R.; Riedl, R.; Ruf, B.

2015-04-01

The development of a radio frequency (RF) driven source for negative hydrogen ions for the neutral beam heating devices of fusion experiments has been successfully carried out at IPP since 1996 on the test facility BATMAN. The required ITER parameters have been achieved with the prototype source consisting of a cylindrical driver on the back side of a racetrack like expansion chamber. The extraction system, called "Large Area Grid" (LAG) was derived from a positive ion accelerator from ASDEX Upgrade (AUG) using its aperture size (ø 8 mm) and pattern but replacing the first two electrodes and masking down the extraction area to 70 cm2. BATMAN is a well diagnosed and highly flexible test facility which will be kept operational in parallel to the half size ITER source test facility ELISE for further developments to improve the RF efficiency and the beam properties. It is therefore planned to upgrade BATMAN with a new ITER-like grid system (ILG) representing almost one ITER beamlet group, namely 5 × 14 apertures (ø 14 mm). Additionally to the standard three grid extraction system a repeller electrode upstream of the grounded grid can optionally be installed which is positively charged against it by 2 kV. This is designated to affect the onset of the space charge compensation downstream of the grounded grid and to reduce the backstreaming of positive ions from the drift space backwards into the ion source. For magnetic filter field studies a plasma grid current up to 3 kA will be available as well as permanent magnets embedded into a diagnostic flange or in an external magnet frame. Furthermore different source vessels and source configurations are under discussion for BATMAN, e.g. using the AUG type racetrack RF source as driver instead of the circular one or modifying the expansion chamber for a more flexible position of the external magnet frame.

Study of negative ion transport phenomena in a plasma source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riz, D.; Pamela, J.

1996-07-01

NIETZSCHE (Negative Ions Extraction and Transport ZSimulation Code for HydrogEn species) is a negative ion (NI) transport code developed at Cadarache. This code calculates NI trajectories using a 3D Monte-Carlo technique, taking into account the main destruction processes, as well as elastic collisions (H{sup {minus}}/H{sup +}) and charge exchanges (H{sup {minus}}/H{sup 0}). It determines the extraction probability of a NI created at a given position. According to the simulations, we have seen that in the case of volume production, only NI produced close to the plasma grid (PG) can be extracted. Concerning the surface production, we have studied how NImore » produced on the PG and accelerated by the plasma sheath backward into the source could be extracted. We demonstrate that elastic collisions and charge exchanges play an important role, which in some conditions dominates the magnetic filter effect, which acts as a magnetic mirror. NI transport in various conditions will be discussed: volume/surface production, high/low plasmas density, tent filter/transverse filter. {copyright} {ital 1996 American Institute of Physics.}« less

Dielectric particle injector for material processing

NASA Technical Reports Server (NTRS)

Leung, Philip L. (Inventor)

1992-01-01

A device for use as an electrostatic particle or droplet injector is disclosed which is capable of injecting dielectric particles or droplets. The device operates by first charging the dielectric particles or droplets using ultraviolet light induced photoelectrons from a low work function material plate supporting the dielectric particles or droplets, and then ejecting the charged particles or droplets from the plate by utilizing an electrostatic force. The ejected particles or droplets are mostly negatively charged in the preferred embodiment; however, in an alternate embodiment, an ion source is used instead of ultraviolet light to eject positively charged dielectric particles or droplets.

The new ClusterTrap setup

NASA Astrophysics Data System (ADS)

Martinez, F.; Marx, G.; Schweikhard, L.; Vass, A.; Ziegler, F.

2011-07-01

ClusterTrap has been designed to investigate properties of atomic clusters in the gas phase with particular emphasis on the dependence on the cluster size and charge state. The combination of cluster source, Penning trap and time-of-flight mass spectrometry allows a variety of experimental schemes including collision-induced dissociation, photo-dissociation, further ionization by electron impact, and electron attachment. Due to the storage capability of the trap extended-delay reaction experiments can be performed. Several recent modifications have resulted in an improved setup. In particular, an electrostatic quadrupole deflector allows the coupling of several sources or detectors to the Penning trap. Furthermore, a linear radio-frequency quadrupole trap has been added for accumulation and ion bunching and by switching the potential of a drift tube the kinetic energy of the cluster ions can be adjusted on their way towards or from the Penning trap. Recently, experiments on multiply negatively charged clusters have been resumed.

Fragmentation of organic ions bearing fixed multiple charges observed in MALDI MS.

PubMed

Lou, Xianwen; Li, Bao; de Waal, Bas F M; Schill, Jurgen; Baker, Matthew B; Bovee, Ralf A A; van Dongen, Joost L J; Milroy, Lech-Gustav; Meijer, E W

2018-01-01

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) was used to analyze a series of synthetic organic ions bearing fixed multiple charges. Despite the multiple intrinsic charges, only singly charged ions were recorded in each case. In addition to the pseudo-molecular ions formed by counterion adduction, deprotonation and electron capture, a number of fragment ions were also observed. Charge splitting by fragmentation was found to be a viable route for charge reduction leading to the formation of the observed singly charged fragment ions. Unlike multivalent metal ions, organic ions can rearrange and/or fragment during charge reduction. This fragmentation process will evidently complicate the interpretation of the MALDI MS spectrum. Because MALDI MS is usually considered as a soft ionization technique, the fragment ion peaks can easily be erroneously interpreted as impurities. Therefore, the awareness and understanding of the underlying MALDI-induced fragmentation pathways is essential for a proper interpretation of the corresponding mass spectra. Due to the fragment ions generated during charge reduction, special care should be taken in the MALDI MS analysis of multiply charged ions. In this work, the possible mechanisms by which the organic ions bearing fixed multiple charges fragment are investigated. With an improved understanding of the fragmentation mechanisms, MALDI TOF MS should still be a useful technique for the characterization of organic ions with fixed multiple charges. Copyright © 2017 John Wiley & Sons, Ltd.

Applications of high-energy heavy-ions from superconducting cyclotrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grimm, T. L.

1999-06-10

The superconducting cyclotrons of the National Superconducting Cyclotron Laboratory (NSCL), a major nuclear physics facility, can provide ions of any element from hydrogen to uranium. A major upgrade to the NSCL is underway and will consist of an electron cyclotron resonance (ECR) ion source followed by two large superconducting cyclotrons (K500 and K1200). Ions can be extracted at any point along this chain allowing a large range of energies and charge states. The ion energies range from a few keV to over 20 GeV, and charge states up to fully stripped {sup 197}Au{sup 79+} and two electron {sup 238}U{sup 90+}more » are possible. The long range of the high-energy heavy-ions allows them to penetrate deeply into a target that is placed in air, outside a vacuum chamber. The ion beams have already been used for a number of applications including; ion implantation, atomic physics, single event effects in integrated circuits, DNA radiation studies, radiation detector studies, flux pinning in high-T{sub c} superconductors, calibration of a space-based spectrometer, isotropic ratio measurements, material wear studies, and continuous positron emission tomography imaging.« less

Excluded volume and ion-ion correlation effects on the ionic atmosphere around B-DNA: Theory, simulations, and experiments

PubMed Central

Ovanesyan, Zaven; Fenley, Marcia O.; Guerrero-García, Guillermo Iván; Olvera de la Cruz, Mónica

2014-01-01

The ionic atmosphere around a nucleic acid regulates its stability in aqueous salt solutions. One major source of complexity in biological activities involving nucleic acids arises from the strong influence of the surrounding ions and water molecules on their structural and thermodynamic properties. Here, we implement a classical density functional theory for cylindrical polyelectrolytes embedded in aqueous electrolytes containing explicit (neutral hard sphere) water molecules at experimental solvent concentrations. Our approach allows us to include ion correlations as well as solvent and ion excluded volume effects for studying the structural and thermodynamic properties of highly charged cylindrical polyelectrolytes. Several models of size and charge asymmetric mixtures of aqueous electrolytes at physiological concentrations are studied. Our results are in good agreement with Monte Carlo simulations. Our numerical calculations display significant differences in the ion density profiles for the different aqueous electrolyte models studied. However, similar results regarding the excess number of ions adsorbed to the B-DNA molecule are predicted by our theoretical approach for different aqueous electrolyte models. These findings suggest that ion counting experimental data should not be used alone to validate the performance of aqueous DNA-electrolyte models. PMID:25494770

2001 Tom W. Bonner Prize in Nuclear Physics Lecture

NASA Astrophysics Data System (ADS)

Geller, Richard

2001-04-01

As long as the Highly Charged Ions (HCI) were obtained with a hot cathode ion source and foil strippers the reliability of the accelerators remained poor. Therefore in 1973, I thought of an ion source based an Electron Cyclotron Resonance (ECR) plasmas trapped inside magnetic mirrors since such devices deliver stable confinement plasmas with energetic electrons and cold ions which are the main ingredients for HCI production. In addition ECR eliminates the use of hot cathodes and this improves considerably their reliability. In 1974 we transformed a voluminous and obsolete " min B fusion mirror device " into an ECR Ion Source (ECRIS) delivering excellent HCI beams. However due to its large size it used too much electrical power (3 MW). To be practical we had to launch a smaller ECRIS with permanent magnets and such an ECRIS worked in 1979 at Grenoble. Between 1980-90 we developed half a dozen of increasingly performing prototypes and many accelerator groups followed the trend. This world wide success is a clear recognition of its reliability and its ability to yield intense HCI beams. However for these very reasons one rarely speaks about ECRIS ; in addition the ECRIS is far away from the targets so it is invisible and moreover it is unsubstantial since it is just an empty cavity filled with 3 invisible components : a) rarefied gas b) microwaves c) specific magnetic field lines… These components must be tuned to create a central ECR zone (where the Larmor frequency equals the microwave frequency) to ignite the plasma inside its magnetic mirror trap ; then one has to adjust accurately the parameters a) b) c) in order to prevent the on-set of always possible plasma instabilities. A well tuned ECRIS is ready to yield intense HCI beams without interruption for weeks and months, in continuous or pulsed regimes. At present an ECRIS has become a " must " for : (i) Nuclear reactions with very small cross-sections - where one has no other solution than to increase the incident ion dose (ex : superheavies - rare isotopes, etc.). (ii) Long duration runs with extreme heavy ion energy on existing machines (ex. CERN : 33 TeV Pb ions, for gluon quark plasma). (iii) Cancer therapy with heavy ions where the physicians require extremely reproducible doses for therapy protocols. The future of ECRIS will depend on further applications : for instance the production of very short life (1+) isotope ions delivered by ISOL systems in continuous regime. For this we developed in 1995 the so called (1+/N+) ECRIS charge booster which catches the (1+) ions before they are adsorpted on the walls. Moreover for pulsed accelerators we developed in 1998 an ECRIT (ECR Ion Trap) charge booster which is simultaneously a (1+) ions accumulator and HCI beam buncher.

Current density distributions and sputter marks in electron cyclotron resonance ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panitzsch, Lauri; Peleikis, Thies; Boettcher, Stephan

2013-01-15

Most electron cyclotron resonance ion sources use hexapolar magnetic fields for the radial confinement of the plasma. The geometry of this magnetic structure is then-induced by charged particles-mapped onto the inner side of the plasma electrode via sputtering and deposition. The resulting structures usually show two different patterns: a sharp triangular one in the central region which in some cases is even sputtered deep into the material (referred to as thin groove or sharp structure), and a blurred but still triangular-like one in the surroundings (referred to as broad halo). Therefore, both patterns seem to have different sources. To investigatemore » their origins we replaced the standard plasma electrode by a custom-built plasma electrode acting as a planar, multi-segment current-detector. For different biased disc voltages, detector positions, and source biases (referred to the detector) we measured the electrical current density distributions in the plane of the plasma electrode. The results show a strong and sharply confined electron population with triangular shape surrounded by less intense and spatially less confined ions. Observed sputter- and deposition marks are related to the analysis of the results. Our measurements suggest that the two different patterns (thin and broad) indeed originate from different particle populations. The thin structures seem to be caused by the hot electron population while the broad marks seem to stem from the medium to highly charged ions. In this paper we present our measurements together with theoretical considerations and substantiate the conclusions drawn above. The validity of these results is also discussed.« less

Parametric study of ion heating in a burnout device (HIP-1)

NASA Technical Reports Server (NTRS)

Sigman, D. R.; Reinmann, J. J.; Lauver, M. R.

1974-01-01

Results of further studies on the Lewis Research Center hot-ion plasma source (HIP-1) are reported. Changes have been made in both the electrode geometry and materials to produce higher ion temperatures. Ion temperature increased significantly with increased vacuum pumping speed. The best ion temperatures achieved, so far, for H(+), D(+), and He(+) plasmas are estimated to be equal to, or greater than 0.6, equal to, or greater than 0.9, and equal to, greater than 2.0 keV, respectively. Electrode pairs produced high ion temperatures whether on the magnetic axis or off it by 5.5 cm. Multiple sources, one on-axis and one off-axis, were run simultaneously from a single power supply by using independent gas feed rates. A momentum analyzer has been added to the charge-exchange neutral particle analyzer to identify particles according to mass, as well as energy. Under any given plasma condition, the higher mass ions have higher average energies but not by as much as the ratio of their respective masses.

Design of a high-bunch-charge 112-MHz superconducting RF photoemission electron source

DOE PAGES

Xin, T.; Brutus, J. C.; Belomestnykh, Sergey A.; ...

2016-09-01

High-bunch-charge photoemission electron-sources operating in a continuous wave (CW) mode are required for many advanced applications of particle accelerators, such as electron coolers for hadron beams, electron-ion colliders, and free-electron lasers (FELs). Superconducting RF (SRF) has several advantages over other electron-gun technologies in CW mode as it offers higher acceleration rate and potentially can generate higher bunch charges and average beam currents. A 112 MHz SRF electron photoinjector (gun) was developed at Brookhaven National Laboratory (BNL) to produce high-brightness and high-bunch-charge bunches for the Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment. Lastly, the gun utilizes a quarter-wave resonator (QWR) geometrymore » for assuring beam dynamics, and uses high quantum efficiency (QE) multi-alkali photocathodes for generating electrons.« less

New progress of high current gasdynamic ion source (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalyga, V., E-mail: skalyga@ipfran.ru; Sidorov, A.; Vodopyanov, A.

2016-02-15

The experimental and theoretical research carried out at the Institute of Applied Physics resulted in development of a new type of electron cyclotron resonance ion sources (ECRISs)—the gasdynamic ECRIS. The gasdynamic ECRIS features a confinement mechanism in a magnetic trap that is different from Geller’s ECRIS confinement, i.e., the quasi-gasdynamic one similar to that in fusion mirror traps. Experimental studies of gasdynamic ECRIS were performed at Simple Mirror Ion Source (SMIS) 37 facility. The plasma was created by 37.5 and 75 GHz gyrotron radiation with power up to 100 kW. High frequency microwaves allowed to create and sustain plasma withmore » significant density (up to 8 × 10{sup 13} cm{sup −3}) and to maintain the main advantages of conventional ECRIS such as high ionization degree and low ion energy. Reaching such high plasma density relies on the fact that the critical density grows with the microwave frequency squared. High microwave power provided the average electron energy on a level of 50-300 eV enough for efficient ionization even at neutral gas pressure range of 10{sup −4}–10{sup −3} mbar. Gasdynamic ECRIS has demonstrated a good performance producing high current (100-300 mA) multi-charged ion beams with moderate average charge (Z = 4-5 for argon). Gasdynamic ECRIS has appeared to be especially effective in low emittance hydrogen and deuterium beams formation. Proton beams with current up to 500 emA and RMS emittance below 0.07 π ⋅ mm ⋅ mrad have been demonstrated in recent experiments.« less

Ion-ion charge exchange processes. Final technical report, June 1, 1977-May 31, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poe, R.T.; Choi, B.H.

Under the auspices of ERDA, we have undertaken a vigorous study of ion-ion charge exchange process pertinent to the storage-ring configurations in the heavy-ion fusion program. One particular reaction, singly charged helium charge exchange, was investigated in detail. General trend of the singly charged heavy-ion charge exchange reaction can be inferred from the present study. Some of our results were presented at Proceedings of the Heavy-Ion Fusion Workshop, Argonne National Laboratory (September 1978) as a paper entitled Charge Exchange Between Singly Ionized Helium Ions, by B.H. Choi, R.T. Poe and K.T. Tang. Here, we briefly describe our method and reportmore » the results.« less

Simultaneous Chandra X-ray, HST Ultraviolet, and Ulysses Radio Observations of Jupiter's Aurora

NASA Technical Reports Server (NTRS)

Elsner, R. F.; Lugaz, N.; Waite, J. H., Jr.; Cravens, T. E.; Gladstone, G. R.; Ford, P.; Grodent, D.; Bhardwaj, A.; MacDowall, R. J.

2004-01-01

Observations of Jupiter carried out by the Chandra ACIS-S instrument over 24-26 February, 2003, show that the auroral X-ray spectrum consists of line emission consistent with high-charge states of precipitating ions, and not a continuum as might be expected from bremsstrahlung. The part of the spectrum due to oxygen peaks around 650 eV, which indicates a high fraction of fully-stripped oxygen in the precipitating ion flux. A combination of the OVIII emission lines at 653 eV and 774 eV, as well as the OVII emission lines at 561 eV and 666 eV, are evident in the measure auroral spectrum. There is also line emission at lower energies in the spectral region extending from 250 to 350 eV, which could be from sulfur and/or carbon. The Jovian auroral X- ray spectra are significantly different from the X-ray spectra of comets. The charge state distribution of the oxygen ions implied by the measured auroral X-ray spectra strongly suggests that, independent of the source of the energetic ions - magnetospheric or solar wind - the ions have undergone additional acceleration. This spectral evidence for ion acceleration is also consistent with the relatively high intensities of the X-rays compared to the available phase space density of the (unaccelerated) source populations of solar wind or magnetospheric ions at Jupiter, which are orders of magnitude too small to explain the observed emissions. The Chandra X-ray observations were executed simultaneously with observations at ultraviolet wavelengths by the Hubble Space Telescope and at radio wavelengths by the Ulysses spacecraft. These additional data sets suggest that the source of the X-rays is magnetospheric in origin, and that the precipitating particles are accelerated by strong field-aligned electric fields, which simultaneously create both the several-MeV energetic ion population and the relativistic electrons observed in situ by Ulysses that are correlated with approximately 40 minute quasi-periodic radio outbursts.

Wakes and precursor soliton excitations by a moving charged object in a plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar Tiwari, Sanat, E-mail: sanat-tiwari@uiowa.edu; Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242; Sen, Abhijit, E-mail: senabhijit@gmail.com

2016-02-15

We study the evolution of nonlinear ion acoustic wave excitations due to a moving charged source in a plasma. Our numerical investigations of the full set of cold fluid equations go beyond the usual weak nonlinearity approximation and show the existence of a rich variety of solutions including wakes, precursor solitons, and “pinned” solitons that travel with the source velocity. These solutions represent a large amplitude generalization of solutions obtained in the past for the forced Korteweg deVries equation and can find useful applications in a variety of situations in the laboratory and in space, wherever there is a largemore » relative velocity between the plasma and a charged object.« less

Simultaneous Chandra X-ray, HST UV, and Ulysses Radio Observations of Jupiter's Aurora

NASA Technical Reports Server (NTRS)

R. Elsner; Bhardwaj, A.; Waite, H.; Lugaz, N.; Majeed, T.; Cravens, T.; Gladstone, G.; Ford, P.; Grodent, D.; MacDowell, R.

2004-01-01

Observations of Jupiter carried out by the Chandra ACIS-S instrument over 24-26 February, 2003, show that the auroral X-ray spectrum consists of line emission consistent with high-charge states of precipitating ions, and not a continuum as might be expected from remsstrahlung. The part of the spectrum due to oxygen peaks around 650 eV, which indicates a high fraction of fully-stripped oxygen in the precipitating ion flux. The OVIII emission lines at 653 eV and 774 eV, as well as the OVII emission lines at 561 eV and 666 eV, are clearly identified. There is also line emission at lower energies in the spectral region extending from 250 to 350 eV for which sulfur and carbon lines are possible candidates. The Jovian auroral spectra differ significantly from measured cometary X-ray spectra. The charge state distribution of the oxygen ion emission evident in the measured auroral spectra strongly suggests that, independent of the source of the energetic ions (magnetospheric or solar wind) the ions have undergone additional acceleration. For the magnetospheric case, acceleration to energies exceeding 10 MeV is apparently required. The ion acceleration also helps to explain the high intensities of the X-rays observed. The phase space densities of unaccelerated source populations of either solar wind or magnetospheric ions are orders of magnitude too small to explain the observed emissions. The Chandra X-ray observations were executed simultaneously with observations at ultraviolet wavelengths by the Hubble Space Telescope and at radio wavelengths by the Ulysses spacecraft. These additional data sets provide interesting hints as to the location of the source region and the acceleration characteristics of the generation mechanism. The combined observations suggest that the source of the X rays is magnetospheric in origin, and that strong field-aligned electric fields are present which simultaneously create both the several-MeV energetic ion population and the relativistic electrons believed to be responsible for the generation of approximately 40 minute quasi-periodic radio outbursts.

Highly charged ion beams and their applications

NASA Astrophysics Data System (ADS)

Marler, Joan

2018-01-01

While much previous work with highly charged ions has been performed with the ions in the plasma state in which they were formed, beams of highly charged ions hold promise for exciting new experiments. Specifically low energy beams with a high degree of charge state purity are a prerequisite for momentum resolved cross section measurements and for efficient loading of highly charged ions into UHV traps for spectroscopy. The Clemson University facility is optimized for the delivery of such beams of highly charged ions with low kinetic energies. Near term experiments include energy resolved charge exchange with neutral targets.

Injection of auxiliary electrons for increasing the plasma density in highly charged and high intensity ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odorici, F., E-mail: fabrizio.odorici@bo.infn.it; Malferrari, L.; Montanari, A.

Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is not confined, has required an improvement of the gun design, in order to “screen” the cathode from the plasma particles. Experimental tests carried out on a plasma reactor show a boost of the plasma density, ranging from 10% to 90% when the electron guns are used,more » as explained by plasma diffusion models.« less

Discrimination of ionic species from broad-beam ion sources

NASA Technical Reports Server (NTRS)

Anderson, J. R.

1993-01-01

The performance of a broad-beam, three-grid, ion extraction system incorporating radio frequency (RF) mass discrimination was investigated experimentally. This testing demonstrated that the system, based on a modified single-stage Bennett mass spectrometer, can discriminate between ionic species having about a 2-to-1 mass ratio while producing a broad-beam of ions with low kinetic energy (less than 15 eV). Testing was conducted using either argon and krypton ions or atomic and diatomic oxygen ions. A simple one-dimensional model, which ignores magnetic field and space-charge effects, was developed to predict the species separation capabilities as well as the kinetic energies of the extracted ions. The experimental results correlated well with the model predictions. This RF mass discrimination system can be used in applications where both atomic and diatomic ions are produced, but a beam of only one of the species is desired. An example of such an application is a 5 eV atomic oxygen source. This source would produce a beam of atomic oxygen with 5 eV kinetic energy, which would be directed onto a material specimen, to simulate the interaction between the surface of a satellite and the rarefied atmosphere encountered in low-Earth orbit.

Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toivanen, V., E-mail: ville.aleksi.toivanen@cern.ch; Bellodi, G.; Dimov, V.

2016-02-15

Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ion beams for the CERN experimental program. The ion beams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ion beam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT)more » section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented.« less

EUV emission spectra in collisions of highly charged tantalum ions with nitrogen and oxygen molecules

NASA Astrophysics Data System (ADS)

Tanuma, Hajime; Numadate, Naoki; Uchikura, Yoshiyuki; Shimada, Kento; Akutsu, Takuto; Long, Elaine; O'Sullivan, Gerry

2017-10-01

We have performed ion beam collision experiments using multiply charged tantalum ions and observed EUV (extreme ultra-violet) emission spectra in collisions of ions with molecular targets, N2 and O2. Broad UTAs (un-resolved transition arrays) from multiply charged Ta ions were observed, and the mean wavelengths of the UTAs shifted and became shorter at higher charge statea of Ta ions. These UTAs may be attributed to the 4f-5d and 4f-5g transitions. Not only the UTA emission from incident ions, but also the sharp emission lines from multiply charged fragment atomic ions were observed. Production of temporary highly charged molecular ions, their kinetic energy and fragmentation processes have been investigated with coincident detection technique. However, the observation of emission from the fragments might be for the first time. The formation mechanisms of the multiply charged fragment atomic ions from target molecules are discussed.

High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region.

PubMed

Hirano, Y; Kiyama, S; Fujiwara, Y; Koguchi, H; Sakakita, H

2015-11-01

A high current density (≈3 mA/cm(2)) hydrogen ion beam source operating in an extremely low-energy region (E(ib) ≈ 150-200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E(ib) is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.

Nb3Sn superconducting magnets for electron cyclotron resonance ion sources.

PubMed

Ferracin, P; Caspi, S; Felice, H; Leitner, D; Lyneis, C M; Prestemon, S; Sabbi, G L; Todd, D S

2010-02-01

Electron cyclotron resonance (ECR) ion sources are an essential component of heavy-ion accelerators. Over the past few decades advances in magnet technology and an improved understanding of the ECR ion source plasma physics have led to remarkable performance improvements of ECR ion sources. Currently third generation high field superconducting ECR ion sources operating at frequencies around 28 GHz are the state of the art ion injectors and several devices are either under commissioning or under design around the world. At the same time, the demand for increased intensities of highly charged heavy ions continues to grow, which makes the development of even higher performance ECR ion sources a necessity. To extend ECR ion sources to frequencies well above 28 GHz, new magnet technology will be needed in order to operate at higher field and force levels. The superconducting magnet program at LBNL has been developing high field superconducting magnets for particle accelerators based on Nb(3)Sn superconducting technology for several years. At the moment, Nb(3)Sn is the only practical conductor capable of operating at the 15 T field level in the relevant configurations. Recent design studies have been focused on the possibility of using Nb(3)Sn in the next generation of ECR ion sources. In the past, LBNL has worked on the VENUS ECR, a 28 GHz source with solenoids and a sextupole made with NbTi operating at fields of 6-7 T. VENUS has now been operating since 2004. We present in this paper the design of a Nb(3)Sn ECR ion source optimized to operate at an rf frequency of 56 GHz with conductor peak fields of 13-15 T. Because of the brittleness and strain sensitivity of Nb(3)Sn, particular care is required in the design of the magnet support structure, which must be capable of providing support to the coils without overstressing the conductor. In this paper, we present the main features of the support structure, featuring an external aluminum shell pretensioned with water-pressurized bladders, and we analyze the expected coil stresses with a two-dimensional finite element mechanical model.

ION ROCKET ENGINE

DOEpatents

Ehlers, K.W.; Voelker, F. III

1961-12-19

A thrust generating engine utilizing cesium vapor as the propellant fuel is designed. The cesium is vaporized by heat and is passed through a heated porous tungsten electrode whereby each cesium atom is fonized. Upon emergfng from the tungsten electrode, the ions are accelerated rearwardly from the rocket through an electric field between the tungsten electrode and an adjacent accelerating electrode grid structure. To avoid creating a large negative charge on the space craft as a result of the expulsion of the positive ions, a source of electrons is disposed adjacent the ion stream to neutralize the cesium atoms following acceleration thereof. (AEC)

Experimental Evidence for Space-Charge Effects between Ions of the Same Mass-to-Charge in Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry

PubMed Central

Wong, Richard L.; Amster, I. Jonathan

2009-01-01

It is often stated that ions of the same mass-to-charge do not induce space-charge frequency shifts among themselves in an ion cyclotron resonance mass spectrometry measurement. Here, we demonstrate space-charge induced frequency shifts for ions of a single mass-to-charge. The monoisotopic atomic ion, Cs+, was used for this study. The measured frequency is observed to decrease linearly with an increase in the number of ions, as has been reported previously for space-charge effects between ions of different mass-to-charge. The frequency shift between ions of the same m/z value are compared to that induced between ions of different m/z value, and is found to be 7.5 times smaller. Control experiments were performed to ensure that the observed space-charge effects are not artifacts of the measurement or of experimental design. The results can be rationalized by recognizing that the electric forces between ions in a magnetic field conform to the weak form of the Newton's third law, where the action and reaction forces do not cancel exactly. PMID:19562102

Circuit for Full Charging of Series Lithium-Ion Cells

NASA Technical Reports Server (NTRS)

Ott, William E.; Saunders, David L.

2007-01-01

An advanced charger has been proposed for a battery that comprises several lithium-ion cells in series. The proposal is directed toward charging the cells in as nearly an optimum manner as possible despite unit-to-unit differences among the nominally identical cells. The particular aspect of the charging problem that motivated the proposal can be summarized as follows: During bulk charging (charging all the cells in series at the same current), the voltages of individual cells increase at different rates. Once one of the cells reaches full charge, bulk charging must be stopped, leaving other cells less than fully charged. To make it possible to bring all cells up to full charge once bulk charging has been completed, the proposed charger would include a number of top-off chargers one for each cell. The top-off chargers would all be powered from the same DC source, but their outputs would be DC-isolated from each other and AC-coupled to their respective cells by means of transformers, as described below. Each top-off charger would include a flyback transformer, an electronic switch, and an output diode. For suppression of undesired electromagnetic emissions, each top-off charger would also include (1) a resistor and capacitor configured to act as a snubber and (2) an inductor and capacitor configured as a filter. The magnetic characteristics of the flyback transformer and the duration of its output pulses determine the energy delivered to the lithium-ion cell. It would be necessary to equip the cell with a precise voltage monitor to determine when the cell reaches full charge. In response to a full-charge reading by this voltage monitor, the electronic switch would be held in the off state. Other cells would continue to be charged similarly by their top-off chargers until their voltage monitors read full charge.

Model of the dust-loaded ionospheres of Mars and Titan

NASA Astrophysics Data System (ADS)

Witasse, Olivier; Cardnell, Sandy; Molina-Cuberos, Gregorio; Michael, Mary; Tripathi, Sachi; Deprez, Gregoire; Montmessin, Franck; O'Brien, Keran

2016-10-01

The ionization of lower atmospheres of celestial bodies and the presence of charged species are fundamental in the understanding of atmospheric electricity phenomena, such as electric discharges, large scale electric currents and Schumann resonances. On January 14, 2005, the Huygens Probe measured the electric conductivity of Titan's atmosphere from 140 km down to the surface. Micro-ARES, the electric field and conductivity sensor on board the ExoMars 2016 Schiaparelli lander, will conduct the very first measurement and characterization of Martian atmospheric electricity. The landing is scheduled for October 19, 2016 and the measurements will be performed over 2-4 sols.The present photochemical model is developed to compute the concentration of the most abundant charged species (cluster-ions, electrons and charged aerosols) and electric conductivity in the lower atmospheres of Mars (0-70 km) and Titan (0-145 km). For both cases, the main source of ionization is galactic cosmic rays. In addition, during daytime, photoionization of aerosols due to solar UV radiation is important at Mars. Ion and electron attachment to aerosols is another major source of aerosol charging, which can vary between -50 and +200 elementary charges for Mars and -55 and -25 for Titan. The steady state concentration of charged species is computed by solving the respective balance equations, which include the source and sink terms of the photochemical reactions. Since the amount of suspended dust in the Martian atmosphere can vary considerably and it has an important effect on the atmospheric properties, several dust scenarios, in addition to the day-night variations, are considered to characterize the variability of the concentration of charged species.The agreement between with the results of the model for Titan and the Huygens data suggests an improvement with respect to previous models. This gives confidence in the results of the model for Mars, which characterize the predicted electric environment in which Micro-ARES will operate, being essential to its data analysis and interpretation.

Millimeter wave detection of nuclear radiation: an alternative detection mechanism.

PubMed

Gopalsami, N; Chien, H T; Heifetz, A; Koehl, E R; Raptis, A C

2009-08-01

We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.

ETD in a traveling wave ion guide at tuned Z-spray ion source conditions allows for site-specific hydrogen/deuterium exchange measurements.

PubMed

Rand, Kasper D; Pringle, Steven D; Morris, Michael; Engen, John R; Brown, Jeffery M

2011-10-01

The recent application of electron transfer dissociation (ETD) to measure the hydrogen exchange of proteins in solution at single-residue resolution (HX-ETD) paves the way for mass spectrometry-based analyses of biomolecular structure at an unprecedented level of detail. The approach requires that activation of polypeptide ions prior to ETD is minimal so as to prevent undesirable gas-phase randomization of the deuterium label from solution (i.e., hydrogen scrambling). Here we explore the use of ETD in a traveling wave ion guide of a quadrupole-time-of-flight (Q-TOF) mass spectrometer with a "Z-spray" type ion source, to measure the deuterium content of individual residues in peptides. We systematically identify key parameters of the Z-spray ion source that contribute to collisional activation and define conditions that allow ETD experiments to be performed in the traveling wave ion guide without gas-phase hydrogen scrambling. We show that ETD and supplemental collisional activation in a subsequent traveling wave ion guide allows for improved extraction of residue-specific deuterium contents in peptides with low charge. Our results demonstrate the feasibility, and illustrate the advantages of performing HX-ETD experiments on a high-resolution Q-TOF instrument equipped with traveling wave ion guides. Determination of parameters of the Z-spray ion source that contribute to ion heating are similarly pertinent to a growing number of MS applications that also rely on an energetically gentle transfer of ions into the gas-phase, such as the analysis of biomolecular structure by native mass spectrometry in combination with gas-phase ion-ion/ion-neutral reactions or ion mobility spectrometry. © American Society for Mass Spectrometry, 2011

Laser and optical system for laser assisted hydrogen ion beam stripping at SNS

DOE PAGES

Liu, Y.; Rakhman, A.; Menshov, A.; ...

2016-12-01

A high-efficiency laser assisted hydrogen ion (H-) beam stripping was recently successfully carried out in the Spallation Neutron Source (SNS) accelerator. The experiment was not only an important step toward foil-less H- stripping for charge exchange injection, it also set up a first example of using megawatt ultraviolet (UV) laser source in an operational high power proton accelerator facility. This study reports in detail the design, installation, and commissioning result of a macro-pulsed multi-megawatt UV laser system and laser beam transport line for the laser stripping experiment.

Laser and optical system for laser assisted hydrogen ion beam stripping at SNS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Y.; Rakhman, A.; Menshov, A.

A high-efficiency laser assisted hydrogen ion (H-) beam stripping was recently successfully carried out in the Spallation Neutron Source (SNS) accelerator. The experiment was not only an important step toward foil-less H- stripping for charge exchange injection, it also set up a first example of using megawatt ultraviolet (UV) laser source in an operational high power proton accelerator facility. This study reports in detail the design, installation, and commissioning result of a macro-pulsed multi-megawatt UV laser system and laser beam transport line for the laser stripping experiment.

Experimental observation of ion beams in the Madison Helicon eXperiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiebold, Matt; Sung, Yung-Ta; Scharer, John E.

2011-06-15

Argon ion beams up to E{sub b} = 165 eV at P{sub rf} = 500 W are observed in the Madison Helicon eXperiment (MadHeX) helicon source with a magnetic nozzle. A two-grid retarding potential analyzer (RPA) is used to measure the ion energy distribution, and emissive and rf-filtered Langmuir probes measure the plasma potential, electron density, and temperature. The supersonic ion beam (M = v{sub i}/c{sub s} up to 5) forms over tens of Debye lengths and extends spatially for a few ion-neutral charge-exchange mean free paths. The parametric variation of the ion beam energy is explored, including flow rate,more » rf power, and magnetic field dependence. The beam energy is equal to the difference in plasma potentials in the Pyrex chamber and the grounded expansion chamber. The plasma potential in the expansion chamber remains near the predicted eV{sub p} {approx} 5kT{sub e} for argon, but the upstream potential is much higher, likely due to wall charging, resulting in accelerated ion beam energies E{sub b} = e[V{sub beam} - V{sub plasma}] > 10kT{sub e}.« less

Alternate operating scenarios for NDCX-II

NASA Astrophysics Data System (ADS)

Sharp, W. M.; Friedman, A.; Grote, D. P.; Cohen, R. H.; Lund, S. M.; Vay, J.-L.; Waldron, W. L.

2014-01-01

NDCX-II is a newly completed accelerator facility at LBNL, built to study ion-heated warm dense matter, as well as aspects of ion-driven targets and intense-beam dynamics for inertial-fusion energy. The baseline design calls for using 12 induction cells to accelerate 30-50 nC of Li+ ions to 1.2 MeV. During commissioning, though, we plan to extend the source lifetime by extracting less total charge. Over time, we expect that NDCX-II will be upgraded to substantially higher energies, necessitating the use of heavier ions to keep a suitable deposition range in targets. For operational flexibility, the option of using a helium plasma source is also being investigated. Each of these options requires development of an alternate acceleration schedule. The schedules here are worked out with a fast-running 1-D particle-in-cell code ASP.

Temporal behavior of unresolved transition array emission in water window soft x-ray spectral region from multiply charged ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dinh, Thanh-Hung, E-mail: dinh@cc.utsunomiya-u.ac.jp; Suzuki, Yuhei; Arai, Goki

2015-09-21

We have characterized the spectral structure and the temporal history of the laser-produced high-Z multi-charged ion plasmas for the efficient water window soft x-ray sources. Strong unresolved transition array emission was observed due to 4d–4f and 4f–5g transitions from Au, Pb, and Bi plasmas in the 280–700 eV photon energy region. The temporal behavior of the emission was essentially similar of that of the laser pulse with a slight delay between different transitions. These results provide feedback for accurate modeling of the atomic processes with the radiative hydrodynamic simulations.

Laboratory Measurements Of Charge-exchange Produced X-ray Emission From K-shell Transitions In Hydrogenic And Helium-like Fe

NASA Astrophysics Data System (ADS)

Brown, Gregory V.; Beiersdorfer, P.; Boyce, K. R.; Chen, H.; Gu, M. F.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Thorn, D.; Wargelin, B.

2006-09-01

We have used a microcalorimeter and solid state detectors to measure x-ray emission produced by charge exchange reactions between bare and hydrogenic Fe colliding with neutral helium, hydrogen, and nitrogen gas. We show the measured spectral signature produced by different neutral donors and compare our results to theory where available. We also compare our results to measurements of the Fe K line emission from the Galactic Center measured by the XIS on the Suzaku x-ray observatory. This comparison shows that charge exchange recombination between highly charged ions (either cosmic rays or thermal ions) and neutral gas is probably not the dominant source of diffuse line emission in the Galactic Center. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48, and is also supported by NASA APRA grants to LLNL, GSFC, Harvard-Smithsonian CfA, and Stanford University.

A comprehensive model of ion diffusion and charge exchange in the cold Io torus

NASA Technical Reports Server (NTRS)

Barbosa, D. D.; Moreno, M. A.

1988-01-01

A comprehensive analytic model of radial diffusion in the cold Io torus is developed. The model involves a generalized molecular cloud theory of SO2 and its dissociation fragments SO, O2, S, and O, which are formed at a relatively large rate by solar UV photodissociation of SO2. The key component of the new theory is SO, which can react with S(+) through a near-resonant charge exchange process that is exothermic. This provides a mechanism for the rapid depletion of singly ionized sulfur in the cold torus and can account for the large decrease in the total flux tube content inward of Io's orbit. The model is used to demonstrate quantitatively the effects of radial diffusion in a charge exchange environment that acts as a combined source and sink for ions in various charge states. A detailed quantitative explanation for the O(2+) component of the cold torus is given, and insight is derived into the workings of the so-called plasma 'ribbon'.

Tuning extreme ultraviolet emission for optimum coupling with multilayer mirrors for future lithography through control of ionic charge states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohashi, Hayato, E-mail: ohashi@cc.utsunomiya-u.ac.jp; Higashiguchi, Takeshi, E-mail: higashi@cc.utsunomiya-u.ac.jp; Suzuki, Yuhei

2014-01-21

We report on the identification of the optimum plasma conditions for a laser-produced plasma source for efficient coupling with multilayer mirrors at 6.x nm for beyond extreme ultraviolet lithography. A small shift to lower energies of the peak emission for Nd:YAG laser-produced gadolinium plasmas was observed with increasing laser power density. Charge-defined emission spectra were observed in electron beam ion trap (EBIT) studies and the charge states responsible identified by use of the flexible atomic code (FAC). The EBIT spectra displayed a larger systematic shift of the peak wavelength of intense emission at 6.x nm to longer wavelengths with increasingmore » ionic charge. This combination of spectra enabled the key ion stage to be confirmed as Gd{sup 18+}, over a range of laser power densities, with contributions from Gd{sup 17+} and Gd{sup 19+} responsible for the slight shift to longer wavelengths in the laser-plasma spectra. The FAC calculation also identified the origin of observed out-of-band emission and the charge states responsible.« less

Photoionization study of the F2+ ion via the screening constant by unit nuclear charge method

NASA Astrophysics Data System (ADS)

Dieng, M.; Tine, M.; Sow, M.; Diop, B.; Guèye, M.; Faye, M.; Sakho, I.; Biaye, M.; Wagué, A.

2014-03-01

In this paper, we have tabulated energy resonances of the 2s22p2 (1D)nd (2L), 2s22p2 (1S)nd (2L) and 2s22p3 (3D)np Rydberg series originating from the 2s22p3(2Po) and from the 2s22p3 (2Do) metastable states of F2+. In addition, energy resonances of the 2s2p3(5So)np (4P) Rydberg series originating from the 2s22p3 (4So) ground-state of F2+are also reported. Calculations are performed using the Screening constant by unit nuclear charge (SCUNC) method. Analysis of the present data is achieved by calculating the quantum defects and the effective nuclear charges for each series. The present results agree very well with the Advanced Light Source experiments on F2+ (Aguilar et al., 2005). Upto n=30, the present quantum defects are almost constant and the effective charge decreases regularly toward the electric charge of the F3+ core ion along each series.

Measurements of Metastable Lifetimes of Highly-Charged Ions

NASA Astrophysics Data System (ADS)

Smith, Steven J.; Chutjian, A.; Lozano, J.

2002-11-01

Measurements have been made of the lifetimes and f -values of metastable levels of singly- and highly-charged positive ions (HCI). These contribute to the optical absorption, emission and energy balance in the ISM, stellar and solar atmospheres, etc. These ions and charge states are important for interpretations of data obtained from HST, EUVE, FUSE, Chandra and Newton missions. The vast majority of the millions of transition probabilities are presently being calculated by theory. However, the use of theory alone, unchecked by experimental verification, can lead to orders of magnitude error in the calculated electron densities and temperatures determined from diagnostic line ratios. The experimental lifetime measurements are carried out using the 14.0 GHz electron cyclotron ion source at the JPL facility. [1,2] The ECR ion source provides microampere current of ions such as O(1-6)+ and Mg(1-6)+. Ions are injected into a Kingdon ion trap and stored for times longer than the metastable lifetimes. Decay channels include intercombination, E2, M1 and 2E transitions. The UV photons are filtered by an interference filter and detected by a UV grade photomultiplier tube using a UV grade optical system. For wavelengths less than 180 nm, a cesium-iodide coated microchannel plate enhanced for UV performance is used. The Kingdon trap was constructed in collaboration with Texas A & M University. [3] Base vacuum is 4 x 10-10 Torr, hence quenching corrections are negligible. We have previously reported [1] lifetimes for the 2Po-4P intercombination transitions of C+ and have recently presented lifetime measurements of the 1S0 M1 transition of O2+ at 232 nm. [4] The measured lifetime of 541 ± 40 ms is in good agreement with previous measurements and a number of theoretical calculations. Additional metastable lifetimes have been measured and will be presented for Mg+6 , Fe9+, Fe10+ and Fe13+ metastable states. Additional lifetime measurements are planned for SIII, Ne V, Fe II and Fe XIII This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, and was supported by the National Aeronautics and Space Administration.

Method and source for producing a high concentration of positively charged molecular hydrogen or deuterium ions

DOEpatents

Ehlers, K.W.; Leung, K.N.

1983-07-26

One principal object of the present invention is to provide a novel method and apparatus for generating a high concentration of H/sub 2//sup +/ or D/sub 2//sup +/ ions by using a new and improved multicusp ion source. The basic principle in achieving a high percentage of H/sub 2//sup +/ or D/sub 2//sup +/ ions is to extract them from the source as soon as they are produced. Otherwise they will react with background gas molecules to form tri-atomic ions H/sub 3//sup +/ or D/sub 3//sup +/ or be dissociated by electrons. The former reaction H/sub 2//sup +/ + H/sub 2/ ..-->.. H/sub 3//sup +/ + H can have a very short mean free path length lambda. Assuming a background neutral gas density of approximately 3.3 x 10/sup 13/ cm/sup -3/ and a cross-section sigma of approximately 6 x 10/sup -15/ cm/sup 2/, lambda = (n/sub 0/ sigma)/sup -1/ is estimated to be about 5 cm. Thus the distance traversed by the H/sub 2//sup +/ ion before it arrives at the extractor electrode cannot exceed this value. This in turn sets a limit on the length of the source chamber.

Emittance of short-pulsed high-current ion beams formed from the plasma of the electron cyclotron resonance discharge sustained by high-power millimeter-wave gyrotron radiation.

PubMed

Razin, S; Zorin, V; Izotov, I; Sidorov, A; Skalyga, V

2014-02-01

We present experimental results on measuring the emittance of short-pulsed (≤100 μs) high-current (80-100 mA) ion beams of heavy gases (Nitrogen, Argon) formed from a dense plasma of an ECR source of multiply charged ions (MCI) with quasi-gas-dynamic mode of plasma confinement in a magnetic trap of simple mirror configuration. The discharge was created by a high-power (90 kW) pulsed radiation of a 37.5-GHz gyrotron. The normalized emittance of generated ion beams of 100 mA current was (1.2-1.3) π mm mrad (70% of ions in the beams). Comparing these results with those obtained using a cusp magnetic trap, it was concluded that the structure of the trap magnetic field lines does not exert a decisive influence on the emittance of ion beams in the gas-dynamic ECR source of MCI.

Emittance of short-pulsed high-current ion beams formed from the plasma of the electron cyclotron resonance discharge sustained by high-power millimeter-wave gyrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Razin, S., E-mail: sevraz@appl.sci-nnov.ru; Zorin, V.; Izotov, I.

2014-02-15

We present experimental results on measuring the emittance of short-pulsed (≤100 μs) high-current (80–100 mA) ion beams of heavy gases (Nitrogen, Argon) formed from a dense plasma of an ECR source of multiply charged ions (MCI) with quasi-gas-dynamic mode of plasma confinement in a magnetic trap of simple mirror configuration. The discharge was created by a high-power (90 kW) pulsed radiation of a 37.5-GHz gyrotron. The normalized emittance of generated ion beams of 100 mA current was (1.2–1.3) π mm mrad (70% of ions in the beams). Comparing these results with those obtained using a cusp magnetic trap, it was concluded thatmore » the structure of the trap magnetic field lines does not exert a decisive influence on the emittance of ion beams in the gas-dynamic ECR source of MCI.« less

Micro structure processing on plastics by accelerated hydrogen molecular ions

NASA Astrophysics Data System (ADS)

Hayashi, H.; Hayakawa, S.; Nishikawa, H.

2017-08-01

A proton has 1836 times the mass of an electron and is the lightest nucleus to be used for accelerator in material modification. We can setup accelerator with the lowest acceleration voltage. It is preferable characteristics of Proton Beam Writer (PBW) for industrial applications. On the contrary ;proton; has the lowest charge among all nuclei and the potential impact to material is lowest. The object of this research is to improve productivity of the PBW for industry application focusing on hydrogen molecular ions. These ions are generated in the same ion source by ionizing hydrogen molecule. There is no specific ion source requested and it is suitable for industrial use. We demonstrated three dimensional (3D) multilevel micro structures on polyester base FPC (Flexible Printed Circuits) using proton, H2+ and H3+. The reactivity of hydrogen molecular ions is much higher than that of proton and coincident with the level of expectation. We can apply this result to make micro devices of 3D multilevel structures on FPC.

Investigation of the boundary layer during the transition from volume to surface dominated H- production at the BATMAN test facility

NASA Astrophysics Data System (ADS)

Wimmer, C.; Schiesko, L.; Fantz, U.

2016-02-01

BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 1/8 scale H- source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H- production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H- density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H- density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (jH-, je) exists with the Cs emission.

Investigation of the boundary layer during the transition from volume to surface dominated H⁻ production at the BATMAN test facility.

PubMed

Wimmer, C; Schiesko, L; Fantz, U

2016-02-01

BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 18 scale H(-) source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H(-) production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H(-) density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H(-) density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (j(H(-)), j(e)) exists with the Cs emission.

Investigating the error sources of the online state of charge estimation methods for lithium-ion batteries in electric vehicles

NASA Astrophysics Data System (ADS)

Zheng, Yuejiu; Ouyang, Minggao; Han, Xuebing; Lu, Languang; Li, Jianqiu

2018-02-01

Sate of charge (SOC) estimation is generally acknowledged as one of the most important functions in battery management system for lithium-ion batteries in new energy vehicles. Though every effort is made for various online SOC estimation methods to reliably increase the estimation accuracy as much as possible within the limited on-chip resources, little literature discusses the error sources for those SOC estimation methods. This paper firstly reviews the commonly studied SOC estimation methods from a conventional classification. A novel perspective focusing on the error analysis of the SOC estimation methods is proposed. SOC estimation methods are analyzed from the views of the measured values, models, algorithms and state parameters. Subsequently, the error flow charts are proposed to analyze the error sources from the signal measurement to the models and algorithms for the widely used online SOC estimation methods in new energy vehicles. Finally, with the consideration of the working conditions, choosing more reliable and applicable SOC estimation methods is discussed, and the future development of the promising online SOC estimation methods is suggested.

Ion Beam Facilities at the National Centre for Accelerator based Research using a 3 MV Pelletron Accelerator

NASA Astrophysics Data System (ADS)

Trivedi, T.; Patel, Shiv P.; Chandra, P.; Bajpai, P. K.

A 3.0 MV (Pelletron 9 SDH 4, NEC, USA) low energy ion accelerator has been recently installed as the National Centre for Accelerator based Research (NCAR) at the Department of Pure & Applied Physics, Guru Ghasidas Vishwavidyalaya, Bilaspur, India. The facility is aimed to carried out interdisciplinary researches using ion beams with high current TORVIS (for H, He ions) and SNICS (for heavy ions) ion sources. The facility includes two dedicated beam lines, one for ion beam analysis (IBA) and other for ion implantation/ irradiation corresponding to switching magnet at +20 and -10 degree, respectively. Ions with 60 kV energy are injected into the accelerator tank where after stripping positively charged ions are accelerated up to 29 MeV for Au. The installed ion beam analysis techniques include RBS, PIXE, ERDA and channelling.

Ion-ion correlation, solvent excluded volume and pH effects on physicochemical properties of spherical oxide nanoparticles.

PubMed

Ovanesyan, Zaven; Aljzmi, Amal; Almusaynid, Manal; Khan, Asrar; Valderrama, Esteban; Nash, Kelly L; Marucho, Marcelo

2016-01-15

One major source of complexity in the implementation of nanoparticles in aqueous electrolytes arises from the strong influence that biological environments has on their physicochemical properties. A key parameter for understanding the molecular mechanisms governing the physicochemical properties of nanoparticles is the formation of the surface charge density. In this article, we present an efficient and accurate approach that combines a recently introduced classical solvation density functional theory for spherical electrical double layers with a surface complexation model to account for ion-ion correlation and excluded volume effects on the surface titration of spherical nanoparticles. We apply the proposed computational approach to account for the charge-regulated mechanisms on the surface chemistry of spherical silica (SiO2) nanoparticles. We analyze the effects of the nanoparticle size, as well as pH level and electrolyte concentration of the aqueous solution on the nanoparticle's surface charge density and Zeta potential. We validate our predictions for 580Å and 200Å nanoparticles immersed in acid, neutral and alkaline mono-valent aqueous electrolyte solutions against experimental data. Our results on mono-valent electrolyte show that the excluded volume and ion-ion correlations contribute significantly to the surface charge density and Zeta potential of the nanoparticle at high electrolyte concentration and pH levels, where the solvent crowding effects and electrostatic screening have shown a profound influence on the protonation/deprotonation reactions at the liquid/solute interface. The success of this approach in describing physicochemical properties of silica nanoparticles supports its broader application to study other spherical metal oxide nanoparticles. Copyright © 2015 Elsevier Inc. All rights reserved.

Plasma Ion Sources for Atmospheric Pressure Ionization Mass Spectrometry.

NASA Astrophysics Data System (ADS)

Zhao, Jian-Guo

1994-01-01

Atmospheric pressure ionization (API) sources using direct-current (DC) and radio-frequency (RF) plasma have been developed in this thesis work. These ion sources can provide stable discharge currents of ~ 1 mA, 2-3 orders of magnitude larger than that of the corona discharge, a widely used API source. The plasmas can be generated and maintained in 1 atm of various buffer gases by applying -500 to -1000 V (DC plasma) or 1-15 W with a frequency of 165 kHz (RF plasma) on the needle electrode. These ion sources have been used with liquid injection to detect various organic compounds of pharmaceutical, biotechnological and environmental interest. Key features of these ion sources include soft ionization with the protonated molecule as the largest peak, and superb sensitivity with detection limits in the low picogram or femtomole range and a linear dynamic range over ~4 orders of magnitude. The RF plasma has advantages over the DC plasma in its ability to operate in various buffer gases and to produce a more stable plasma. Factors influencing the performance of the ion sources have been studied, including RF power level, liquid flow rate, chamber temperature, solvent composition, and voltage affecting the collision induced dissociation (CID). Ionization of hydrocarbons by the RF plasma API source was also studied. Soft ionization is generally produced. To obtain high sensitivity, the ion source must be very dry and the needle-to-orifice distance must be small. Nitric oxide was used to enhance the sensitivity. The RF plasma source was then used for the analysis of hydrocarbons in auto emissions. Comparisons between the corona discharge and the RF plasma have been made in terms of discharge current, ion residence time, and the ion source model. The RF plasma source provides larger linear dynamic range and higher sensitivity than the corona discharge, due to its much larger discharge current. The RF plasma was also observed to provide longer ion residence times and was not limited by space-charge effect as in the corona source.

Detection of Radiation-Exposure Biomarkers by Differential Mobility Prefiltered Mass Spectrometry (DMS-MS)

PubMed Central

Coy, Stephen L.; Krylov, Evgeny V.; Schneider, Bradley B.; Covey, Thomas R.; Brenner, David J.; Tyburski, John B.; Patterson, Andrew D.; Krausz, Kris W.; Fornace, Albert J.; Nazarov, Erkinjon G.

2010-01-01

Technology to enable rapid screening for radiation exposure has been identified as an important need, and, as a part of a NIH / NIAD effort in this direction, metabolomic biomarkers for radiation exposure have been identified in a recent series of papers. To reduce the time necessary to detect and measure these biomarkers, differential mobility spectrometry – mass spectrometry (DMS-MS) systems have been developed and tested. Differential mobility ion filters preselect specific ions and also suppress chemical noise created in typical atmospheric-pressure ionization sources (ESI, MALDI, and others). Differential-mobility-based ion selection is based on the field dependence of ion mobility, which, in turn, depends on ion characteristics that include conformation, charge distribution, molecular polarizability, and other properties, and on the transport gas composition which can be modified to enhance resolution. DMS-MS is able to resolve small-molecule biomarkers from nearly-isobaric interferences, and suppresses chemical noise generated in the ion source and in the mass spectrometer, improving selectivity and quantitative accuracy. Our planar DMS design is rapid, operating in a few milliseconds, and analyzes ions before fragmentation. Depending on MS inlet conditions, DMS-selected ions can be dissociated in the MS inlet expansion, before mass analysis, providing a capability similar to MS/MS with simpler instrumentation. This report presents selected DMS-MS experimental results, including resolution of complex test mixtures of isobaric compounds, separation of charge states, separation of isobaric biomarkers (citrate and isocitrate), and separation of nearly-isobaric biomarker anions in direct analysis of a bio-fluid sample from the radiation-treated group of a mouse-model study. These uses of DMS combined with moderate resolution MS instrumentation indicate the feasibility of field-deployable instrumentation for biomarker evaluation. PMID:20305793

Efficient acceleration of neutral atoms in laser produced plasma

DOE PAGES

Dalui, M.; Trivikram, T. M.; Colgan, James Patrick; ...

2017-06-20

Recent advances in high-intensity laser-produced plasmas have demonstrated their potential as compact charge particle accelerators. Unlike conventional accelerators, transient quasi-static charge separation acceleration fields in laser produced plasmas are highly localized and orders of magnitude larger. Manipulating these ion accelerators, to convert the fast ions to neutral atoms with little change in momentum, transform these to a bright source of MeV atoms. The emittance of the neutral atom beam would be similar to that expected for an ion beam. Since intense laser-produced plasmas have been demonstrated to produce high-brightness-low-emittance beams, it is possible to envisage generation of high-flux, low-emittance, highmore » energy neutral atom beams in length scales of less than a millimeter. Here, we show a scheme where more than 80% of the fast ions are reduced to energetic neutral atoms and demonstrate the feasibility of a high energy neutral atom accelerator that could significantly impact applications in neutral atom lithography and diagnostics.« less

Low charge state heavy ion production with sub-nanosecond laser.

PubMed

Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

2016-02-01

We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

Low charge state heavy ion production with sub-nanosecond laser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanesue, T., E-mail: tkanesue@bnl.gov; Okamura, M.; Kumaki, M.

2016-02-15

We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the differencemore » of generated plasma using the Zirconium target.« less

Are clusters important in understanding the mechanisms in atmospheric pressure ionization? Part 1: Reagent ion generation and chemical control of ion populations.

PubMed

Klee, Sonja; Derpmann, Valerie; Wißdorf, Walter; Klopotowski, Sebastian; Kersten, Hendrik; Brockmann, Klaus J; Benter, Thorsten; Albrecht, Sascha; Bruins, Andries P; Dousty, Faezeh; Kauppila, Tiina J; Kostiainen, Risto; O'Brien, Rob; Robb, Damon B; Syage, Jack A

2014-08-01

It is well documented since the early days of the development of atmospheric pressure ionization methods, which operate in the gas phase, that cluster ions are ubiquitous. This holds true for atmospheric pressure chemical ionization, as well as for more recent techniques, such as atmospheric pressure photoionization, direct analysis in real time, and many more. In fact, it is well established that cluster ions are the primary carriers of the net charge generated. Nevertheless, cluster ion chemistry has only been sporadically included in the numerous proposed ionization mechanisms leading to charged target analytes, which are often protonated molecules. This paper series, consisting of two parts, attempts to highlight the role of cluster ion chemistry with regard to the generation of analyte ions. In addition, the impact of the changing reaction matrix and the non-thermal collisions of ions en route from the atmospheric pressure ion source to the high vacuum analyzer region are discussed. This work addresses such issues as extent of protonation versus deuteration, the extent of analyte fragmentation, as well as highly variable ionization efficiencies, among others. In Part 1, the nature of the reagent ion generation is examined, as well as the extent of thermodynamic versus kinetic control of the resulting ion population entering the analyzer region.

Pure Material Vapor Source by Induction Heating Evaporator for an Electron Cyclotron Resonance Ion Source

NASA Astrophysics Data System (ADS)

Matsui, Y.; Watanabe, T.; Satani, T.; Muramatsu, M.; Tanaka, K.; Kitagawa, A.; Yoshida, Y.; Sato, F.; Kato, Y.; Iida, T.

2008-11-01

Multiply charged iron ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with the induction coil which is made from bare molybdenum wire and surrounding the pure iron rod. We optimize the shape of induction heating coil and operation of rf power supply. We conduct experiment to investigate reproducibility and stability in the operation and heating efficiency. Induction heating evaporator produces pure material vapor, because materials directly heated by eddy currents have non-contact with insulated materials which are impurity gas sources. The power and the frequency of the induction currents range from 100 to 900 W and from 48 to 23 kHz, respectively. The working pressure is about 10-4 to 10-3 Pa. We measure temperature of iron rod and film deposition rate by depositing iron vapor to crystal oscillator. We confirm stability and reproducibility of evaporator enough to conduct experiment in ECR ion source. We can obtain required temperature of iron under maximum power of power supply. We are aiming the evaporator higher melting point material than iron.

Performance and Safety of Lithium Ion Cells

NASA Technical Reports Server (NTRS)

Ratnakumar, B. V.; Smart, M. C.; Whitcanack, L.; Surampudi, S.; Marsh, R.

2001-01-01

This report evaluates the performance and safety of Lithium Ion (Li-Ion) cells when used in batteries. Issues discussed include the cycle life, energy efficiency, tolerance to higher charge voltage, tolerance to extended tapered charge voltage, charge on cycling, specific energy, low temperature discharge, low temperature charge, various charge characteristics, storage characteristics, and more of Li-Ion cells.

Spectroscopic investigations of beam-plasma interactions in an ion plume

NASA Technical Reports Server (NTRS)

Ruyten, W. M.; Friedly, V. J.; Peng, X.; Celenza, J. A.; Keefer, D.

1993-01-01

We report the results of spectroscopic investigations of beam-plasma interactions in the plume from a 3 cm ion source operated on argon. Ion-electron, ion-neutral, and electron-neutral scattering are identified by studying the dependence of neutral and ion emission intensities on chamber pressure and mass flow rate, and by analyzing the emission lineshapes at a non-orthogonal angle to the plume axis. Through the Doppler shift, we are able to separate contributions from fast beam ions and fast charge-exchange neutrals on the one hand, and of slow neutrals and slow ions on the other. We discuss the application of this new technique to the characterization of beam plasma interactions in the downstream region of ion thruster engines, and its potential for identifying the processes which lead to grid erosion.

Methylene blue, curcumin and ion pairing nanoparticles effects on photodynamic therapy of MDA-MB-231 breast cancer cell.

PubMed

Hosseinzadeh, Reza; Khorsandi, Khatereh

2017-06-01

The aim of current study was to use methylene blue-curcumin ion pair nanoparticles and single dyes as photosensitizer for comparison of photodynamic therapy (PDT) efficacy on MDA-MB-231 cancer cells, also various light sources effect on activation of photosensitizer (PS) was considered. Ion pair nanoparticles were synthesized using opposite charge ions precipitation and lyophilized. The PDT experiments were designed and the effect of PSs and light sources (Red LED (630nm; power density: 30mWcm -2 ) and blue LED (465nm; power density: 34mWcm -2 )) on the human breast cancer cell line were examined. The effect of PS concentration (0-75μg.mL -1 ), incubation time, irradiation time and light sources, and priority in irradiation of blue or red lights were determined. The results show that the ion pairing of methylene blue and curcumin enhance the photodynamic activity of both dyes and the cytotoxicity of ion pair nanoparticles on the MDA-231 breast cancer cell line. Blue and red LED light sources were used for photo activation of photosensitizers. The results demonstrated that both dyes can activate using red light LED better than blue light LED for singlet oxygen producing. Nano scale ion pair precipitating of methylene blue-curcumin enhanced the cell penetrating and subsequently cytotoxicity of both dyes together. Copyright © 2017 Elsevier B.V. All rights reserved.

The Plasma Wake Downstream of Lunar Topographic Obstacles: Preliminary Results from 2D Particle Simulations

NASA Technical Reports Server (NTRS)

Zimmerman, Michael I.; Farrell, W. M.; Snubbs, T. J.; Halekas, J. S.

2011-01-01

Anticipating the plasma and electrical environments in permanently shadowed regions (PSRs) of the moon is critical in understanding local processes of space weathering, surface charging, surface chemistry, volatile production and trapping, exo-ion sputtering, and charged dust transport. In the present study, we have employed the open-source XOOPIC code [I] to investigate the effects of solar wind conditions and plasma-surface interactions on the electrical environment in PSRs through fully two-dimensional pattic1e-in-cell simulations. By direct analogy with current understanding of the global lunar wake (e.g., references) deep, near-terminator, shadowed craters are expected to produce plasma "mini-wakes" just leeward of the crater wall. The present results (e.g., Figure I) are in agreement with previous claims that hot electrons rush into the crater void ahead of the heavier ions, fanning a negative cloud of charge. Charge separation along the initial plasma-vacuum interface gives rise to an ambipolar electric field that subsequently accelerates ions into the void. However, the situation is complicated by the presence of the dynamic lunar surface, which develops an electric potential in response to local plasma currents (e.g., Figure Ia). In some regimes, wake structure is clearly affected by the presence of the charged crater floor as it seeks to achieve current balance (i.e. zero net current to the surface).

Transport and emittance study for 18 GHz superconducting-ECR ion source at RCNP.

PubMed

Yorita, T; Hatanaka, K; Fukuda, M; Ueda, H; Kibayashi, M; Morinobu, S; Tamii, A

2012-02-01

As the upgrade program of the azimuthally varying field (AVF) cyclotron is at the cyclotron facility of the RCNP, Osaka University for the improvement of the quality, stability, and intensity of accelerated beams, an 18 GHz superconducting (SC) ECR ion source has been installed to increase beam currents and to extend the variety of ions, especially for highly charged heavy ions which can be accelerated by RCNP AVF cyclotron. The production development of several ions such as B, O, N, Ne, Ar, Ni, Kr, and Xe has been performed by Yorita et al. [Rev. Sci. Instrum. 79, 02A311(2008); 81, 02A332 (2010)]. Further studies for the beam transport have been done in order to improve the beam current more for injection of cyclotron. The effect of field leakage of AVF main coil is not negligible and additional steering magnet has been installed and then beam transmission has been improved. The emittance monitor has also been developed for the purpose of investigating correlation between emittance of beam from ECR ion sources and injection efficiency. The monitor consists with BPM82 with rotating wire for fast measurement for efficient study.

Optimization of power and energy densities in supercapacitors

NASA Astrophysics Data System (ADS)

Robinson, David B.

Supercapacitors use nanoporous electrodes to store large amounts of charge on their high surface areas, and use the ions in electrolytes to carry charge into the pores. Their high power density makes them a potentially useful complement to batteries. However, ion transport through long, narrow channels still limits power and efficiency in these devices. Proper design can mitigate this. Current collector geometry must also be considered once this is done. Here, De Levie's model for porous electrodes is applied to quantitatively predict device performance and to propose optimal device designs for given specifications. Effects unique to nanoscale pores are considered, including that pores may not have enough salt to fully charge. Supercapacitors are of value for electric vehicles, portable electronics, and power conditioning in electrical grids with distributed renewable sources, and that value will increase as new device fabrication methods are developed and proper design accommodates those improvements. Example design outlines for vehicle applications are proposed and compared.

Neoclassical parallel flow calculation in the presence of external parallel momentum sources in Heliotron J

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishioka, K.; Nakamura, Y.; Nishimura, S.

A moment approach to calculate neoclassical transport in non-axisymmetric torus plasmas composed of multiple ion species is extended to include the external parallel momentum sources due to unbalanced tangential neutral beam injections (NBIs). The momentum sources that are included in the parallel momentum balance are calculated from the collision operators of background particles with fast ions. This method is applied for the clarification of the physical mechanism of the neoclassical parallel ion flows and the multi-ion species effect on them in Heliotron J NBI plasmas. It is found that parallel ion flow can be determined by the balance between themore » parallel viscosity and the external momentum source in the region where the external source is much larger than the thermodynamic force driven source in the collisional plasmas. This is because the friction between C{sup 6+} and D{sup +} prevents a large difference between C{sup 6+} and D{sup +} flow velocities in such plasmas. The C{sup 6+} flow velocities, which are measured by the charge exchange recombination spectroscopy system, are numerically evaluated with this method. It is shown that the experimentally measured C{sup 6+} impurity flow velocities do not contradict clearly with the neoclassical estimations, and the dependence of parallel flow velocities on the magnetic field ripples is consistent in both results.« less

Ion energy distributions and densities in the plume of Enceladus

NASA Astrophysics Data System (ADS)

Sakai, Shotaro; Cravens, Thomas E.; Omidi, Nojan; Perry, Mark E.; Waite, J. Hunter

2016-10-01

Enceladus has a dynamic plume that is emitting gas, including water vapor, and dust. The gas is ionized by solar EUV radiation, charge exchange, and electron impact and extends throughout the inner magnetosphere of Saturn. The charge exchange collisions alter the plasma composition. Ice grains (dust) escape from the vicinity of Enceladus and form the E ring, including a portion that is negatively charged by the local plasma. The inner magnetosphere within 10 RS (Saturn radii) contains a complex mixture of plasma, neutral gas, and dust that links back to Enceladus. In this paper we investigate the energy distributions, ion species and densities of water group ions in the plume of Enceladus using test particle and Monte Carlo methods that include collisional processes such as charge exchange and ion-neutral chemical reactions. Ion observations from the Cassini Ion and Neutral Mass Spectrometer (INMS) for E07 are presented for the first time. We use the modeling results to interpret observations made by the Cassini Plasma Spectrometer (CAPS) and the INMS. The low energy ions, as observed by CAPS, appear to be affected by a vertical electric field (EZ=-10 μV/m) in the plume. The EZ field may be associated with the charged dust and/or the pressure gradient of plasma. The model results, along with the results of earlier models, show that H3O+ ions created by chemistry are predominant in the plume, which agrees with INMS and CAPS data, but the INMS count rate in the plume for the model is several times greater than the data, which we do not fully understand. This composition and the total ion count found in the plume agree with INMS and CAPS data. On the other hand, the Cassini Langmuir Probe measured a maximum plume ion density more than 30,000 cm-3, which is far larger than the maximum ion density from our model, 900 cm-3. The model results also demonstrate that most of the ions in the plume are from the external magnetospheric flow and are not generated by local ionization. The origin of the ions in the plume was investigated using two different velocity models. Most ions were created by the interaction with background magnetospheric plasma and by photoionization. INMS and CAPS also detected water cluster ions. We will interpret these observations as a result of ion collisions with neutral water clusters, (H2O)n, originating in the tiger stripe vents as suggested by Tokar et al. (2009). We also estimated the process of generating cluster ions based on the INMS observations. We suggest that the most likely source is reaction of H3O+ with neutral water clusters or dimers such as (H2O)2 formed in the plume vents.

Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi

2016-02-15

An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs—Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed “on-line” during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and themore » beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure.« less

Glow plasma trigger for electron cyclotron resonance ion sources.

PubMed

Vodopianov, A V; Golubev, S V; Izotov, I V; Nikolaev, A G; Oks, E M; Savkin, K P; Yushkov, G Yu

2010-02-01

Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 micros and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 10(12) cm(-3), required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to T(e) approximately = 20 eV.

Improved liquid chromatography-MS/MS of heparan sulfate oligosaccharides via chip-based pulsed makeup flow.

PubMed

Huang, Yu; Shi, Xiaofeng; Yu, Xiang; Leymarie, Nancy; Staples, Gregory O; Yin, Hongfeng; Killeen, Kevin; Zaia, Joseph

2011-11-01

Microfluidic chip-based hydrophilic interaction chromatography (HILIC) is a useful separation system for liquid chromatography-mass spectrometry (LC-MS) in compositional profiling of heparan sulfate (HS) oligosaccharides; however, ions observed using HILIC LC-MS are low in charge. Tandem MS of HS oligosaccharide ions with low charge results in undesirable losses of SO(3) from precursor ions during collision induced dissociation. One solution is to add metal cations to stabilize sulfate groups. Another is to add a nonvolatile, polar compound such as sulfolane, a molecule known to supercharge proteins, to produce a similar effect for oligosaccharides. We demonstrate use of a novel pulsed makeup flow (MUF) HPLC-chip. The chip enables controlled application of additives during specified chromatographic time windows and thus minimizes the extent to which nonvolatile additives build up in the ion source. The pulsed MUF system was applied to LC-MS/MS of HS oligosaccharides. Metal cations and sulfolane were tested as additives. The most promising results were obtained for sulfolane, for which supercharging of the oligosaccharide ions increased their signal strengths relative to controls. Tandem MS of these supercharged precursor ions showed decreased abundances of product ions from sulfate losses yet more abundant product ions from backbone cleavages.

Photoionization and Photofragmentation of Carbon Fullerene Molecular Ions

NASA Astrophysics Data System (ADS)

Baral, Kiran Kumar

Cross sections are reported for single and double photoionization accompanied by the loss of as many as seven pairs of C atoms of C60 + and C70+ fullerene molecular ions in the photon energy range 18 eV to 150 eV. These measurements were performed at the Advanced Light Source (ALS) by merging a mass-selected ion beam with a beam of monochromatized synchrotron radiation. Threshold energies were determined for the formation of doubly and triply charged fragment ions from parent ions C60+ and C70+. The energy dependences of cross-sections for direct photoionization yielding C60 2+ and C702+ are compared with those for forming different doubly and triply charged fullerene fragment ions. Two-dimensional product ion scans were measured and quantified at four discrete photon energies: 35 eV, 65 eV, 105 eV and 140 eV, in the vacuum ultraviolet region, providing a comprehensive mapping of the product channels involving single ionization of fullerene ions C60+ and C 70+ accompanied by fragmentation. Since fullerenes are composed of even numbers of carbon atoms, the fragmentation occurs by the loss of differing numbers of carbon atom pairs. In addition to pure ionization, fragmentation product channels become relatively more important at higher photon energies.

Analytical Performance of a Venturi-assisted Array of Micromachined UltraSonic Electrosprays (AMUSE) Coupled to Ion Trap Mass Spectrometry for the Analysis of Peptides and Proteins

PubMed Central

Hampton, Christina Y.; Forbes, Thomas P.; Varady, Mark J.; Meacham, J. Mark; Fedorov, Andrei G.; Degertekin, F. Levent; Fernández, Facundo M.

2008-01-01

The analytical characterization of a novel ion source for mass spectrometry named Array of Micromachined UltraSonic Electrosprays (AMUSE) is presented here. This is a fundamentally different type of ion generation device, consisting of three major components: 1) a piezoelectric transducer that creates ultrasonic waves at one of the resonant frequencies of the sample-filled device, 2) an array of pyramidally-shaped nozzles micromachined on a silicon wafer, and 3) a spacer which prevents contact between the array and transducer ensuring the transfer of acoustic energy to the sample. A high pressure gradient generated at the apices of the nozzle pyramids forces the periodic ejection of multiple droplet streams from the device. With this device, the processes of droplet formation and droplet charging are separated, hence, the limitations of conventional electrospray-type ion sources, including the need for high charging potentials and the addition of organic solvent to decrease surface tension can be avoided. In this work, a Venturi device is coupled with AMUSE in order to increase desolvation, droplet focusing, and signal stability. Results show that ionization of model peptides and small tuning molecules is possible with DC charging potentials of 100 VDC or less. Ionization in RF-only mode (without DC biasing) was also possible. It was observed that, when combined with AMUSE, the Venturi device provides a 10-fold gain in signal-to-noise ratio for 90% aqueous sample solutions. Further reduction in the diameter of the orifices of the micromachined arrays, led to an additional signal gain of at least 3 orders of magnitude, a 2- to 10-fold gain in the signal-to-noise ratio, and an improvement in signal stability from 47% to 8.5% RSD. The effectiveness of this device for the soft ionization of model proteins in aqueous media, such as cytochrome C was also examined, yielding spectra with an average charge state of 8.8 when analyzed with a 100 VDC charging potential. Ionization of model proteins was also possible in RF-only mode. PMID:17914864

A Study of Fermi Acceleration of Suprathermal Solar Wind Ions

NASA Astrophysics Data System (ADS)

Freeman, Theodore James

The Wind spacecraft has observed numerous sunward bursts of ~2 MeV ions upstream of the Earth's bow shock. The bursts typically last several minutes at the highest energies, but they can last for tens of minutes at intermediate energies (tens to hundreds of keV). The MeV ions are not protons or alpha particles, and are probably oxygen ions. There are two possible sources of these particles: Fermi acceleration of solar wind ions, and ring current particles which have escaped from the Earth's magnetosphere. In this dissertation, Wind observations and numerical particle simulations of Fermi acceleration are presented which demonstrate that suprathermal solar wind O6+ ions are the most likely source of these bursts. Since the Fermi mechanism accelerates all ions to approximately the same ratio of energy to charge, H+ and He2+ ions are accelerated to much lower energies than O6+ ions. In this model, suprathermal ions are reflected between the bow shock and rotations in the interplanetary magnetic field (IMF) upstream of the shock, gaining energy due to the relative motion of the reflecting magnetic structures. Each burst either coincides with or is closely followed by a large IMF rotation. By using measured magnetic field data, the timing of the bursts detected by Wind is precisely reproduced in the simulation. The energy spectra observed by Wind are also reproduced by adding H+ , He2+ , and O6+ fluxes together, and assuming that there is an increase of ~2 orders of magnitude in the high energy tail of the solar wind oxygen distribution. An enhancement of this order of magnitude in CNO group ions was measured by the ion composition experiment on Wind in association with these bursts. An examination of the magnetospheric escape model shows that while escaping O+ ions can account for some features of the data, such as the longer bursts of intermediate energy ions, it cannot account for the short duration ~2 MeV bursts themselves, because O+ ions scatter diffusively in the solar wind. This study concludes by predicting that ion composition and charge state measurements will show these bursts to be solar wind O6+ ions.

Use of .sup.3 He.sup.30 + ICRF minority heating to simulate alpha particle heating

DOEpatents

Post, Jr., Douglass E.; Hwang, David Q.; Hovey, Jane

1986-04-22

Neutron activation due to high levels of neutron production in a first heated deuterium-tritium plasma is substantially reduced by using Ion Cyclotron Resonance Frequency (ICRF) heating of energetic .sup.3 He.sup.++ ions in a second deuterium-.sup.3 He.sup.++ plasma which exhibit an energy distribution and density similar to that of alpha particles in fusion reactor experiments to simulate fusion alpha particle heating in the first plasma. The majority of the fast .sup.3 He.sup.++ ions and their slowing down spectrum can be studied using either a modulated hydrogen beam source for producing excited states of He.sup.+ in combination with spectrometers or double charge exchange with a high energy neutral lithium beam and charged particle detectors at the plasma edge. The maintenance problems thus associated with neutron activation are substantially reduced permitting energetic alpha particle behavior to be studied in near term large fusion experiments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, L.; Landi, E.; Lepri, S. T.

In this paper, we study a subset of slow solar winds characterized by an anomalous charge state composition and ion temperatures compared to average solar wind distributions, and thus referred to as an “Outlier” wind. We find that although this wind is slower and denser than normal slow wind, it is accelerated from the same source regions (active regions and quiet-Sun regions) as the latter and its occurrence rate depends on the solar cycle. The defining property of the Outlier wind is that its charge state composition is the same as that of normal slow wind, with the only exceptionmore » being a very large decrease in the abundance of fully charged species (He{sup 2+}, C{sup 6+}, N{sup 7+}, O{sup 8+}, Mg{sup 12+}), resulting in a significant depletion of the He and C element abundances. Based on these observations, we suggest three possible scenarios for the origin of this wind: (1) local magnetic waves preferentially accelerating non-fully stripped ions over fully stripped ions from a loop opened by reconnection; (2) depleted fully stripped ions already contained in the corona magnetic loops before they are opened up by reconnection; or (3) fully stripped ions depleted by Coulomb collision after magnetic reconnection in the solar corona. If any one of these three scenarios is confirmed, the Outlier wind represents a direct signature of slow wind release through magnetic reconnection.« less

Incorporation of membrane potential into theoretical analysis of electrogenic ion pumps.

PubMed Central

Reynolds, J A; Johnson, E A; Tanford, C

1985-01-01

The transport rate of an electrogenic ion pump, and therefore also the current generated by the pump, depends on the potential difference (delta psi) between the two sides of the membrane. This dependence arises from at least three sources: (i) charges carried across the membrane by the transported ions; (ii) protein charges in the ion binding sites that alternate between exposure to (and therefore electrical contact with) the two sides of the membrane; (iii) protein charges or dipoles that move within the domain of the membrane as a result of conformational changes linked to the transport cycle. Quantitative prediction of these separate effects requires presently unavailable molecular information, so that there is great freedom in assigning voltage dependence to individual steps of a transport cycle when one attempts to make theoretical calculations of physiological behavior for an ion pump for which biochemical data (mechanism, rate constants, etc.) are already established. The need to make kinetic behavior consistent with thermodynamic laws, however, limits this freedom, and in most cases two points on a curve of rate versus delta psi will be fixed points independent of how voltage dependence is assigned. Theoretical discussion of these principles is illustrated by reference to ATP-driven Na,K pumps. Physiological data for this system suggest that all three of the possible mechanisms for generating voltage dependence do in fact make significant contributions. PMID:2413447

Conducting ion tracks generated by charge-selected swift heavy ions

NASA Astrophysics Data System (ADS)

Gupta, Srashti; Gehrke, H. G.; Krauser, J.; Trautmann, C.; Severin, D.; Bender, M.; Rothard, H.; Hofsäss, H.

2016-08-01

Conducting ion tracks in tetrahedral amorphous carbon (ta-C) thin films were generated by irradiation with swift heavy ions of well-defined charge state. The conductivity of tracks and the surface topography of the films, showing characteristic hillocks at each track position, were investigated using conductive atomic force microscopy measurements. The dependence of track conductivity and hillock size on the charge state of the ions was studied using 4.6 MeV/u Pb ions of charge state 53+, 56+ and 60+ provided by GANIL, as well as 4.8 MeV/u Bi and Au ions of charge state from 50+ to 61+ and 4.2 MeV/u 238U ions in equilibrium charge state provided by UNILAC of GSI. For the charge state selection at GSI, an additional stripper-foil system was installed at the M-branch that now allows routine irradiations with ions of selected charge states. The conductivity of tracks in ta-C increases significantly when the charge state increases from 51+ to 60+. However, the conductivity of individual tracks on the same sample still shows large variations, indicating that tracks formed in ta-C are either inhomogeneous or the conductivity is limited by the interface between ion track and Si substrate.

Space charge effect in spectrometers of ion mobility increment with cylindrical drift chamber.

PubMed

Elistratov, A A; Sherbakov, L A

2007-01-01

We have amplified the model for the drift of ions under a non-uniform high-frequency electric field by taking space charge effect into account. By this means, we have investigated the effect of space charge on the dynamics of a single type of ions in a spectrometer of ion mobility increment with a cylindrical drift chamber. The counteraction of the space charge effect and the focusing effect is investigated. The output ion current saturation caused by the effect of the space charge is observed. The shape of the ion peak taking into consideration the space charge effect has been obtained. We show that the effect of the space charge is sufficient for the relative ion density greater than 10 ppt by order of magnitude (for a cylindrical geometry spectrometer with typical parameters).

Generalization of the Child-Langmuir law to the alternate extraction of positive and negative ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lafleur, T., E-mail: trevor.lafleur@lpp.polytechnique.fr; ONERA-The French Aerospace Lab, 91120 Palaiseau; Aanesland, A.

Using a combined analytical and simulation approach, we investigate positive and negative ion extraction between two electrodes from an ion-ion plasma source. With a square voltage waveform applied to the electrodes, we obtain approximate analytical solutions for the time-averaged extracted current densities, which are given simply by: J{sub p}{sup ac}=[α−fL√((M{sub p})/(q{sub p}V{sub 0}) )]J{sub p}{sup dc}, and J{sub n}{sup ac}=[(1−α)−fL√((M{sub n})/(q{sub n}V{sub 0}) )]J{sub n}{sup dc}, where J{sup ac} is the time-averaged current density, α is the square waveform duty cycle, f is the frequency, L is the electrode gap length, M is the ion mass, q is the ionmore » charge, V{sub 0} is the applied voltage amplitude, J{sup dc} is the dc extracted current density, and the subscripts p and n refer to positive and negative ions, respectively. In particular, if J{sup dc} is the dc space-charge limited current density, then these equations describe the square waveform generalization of the Child-Langmuir law.« less

Gated charged-particle trap

DOEpatents

Benner, W.H.

1999-03-09

The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector. 5 figs.

Charged particle measurements on a 30-CM diameter mercury ion engine thrust beam

NASA Technical Reports Server (NTRS)

Sellen, J. M., Jr.; Komatsu, G. K.; Hoffmaster, D. K.; Kemp, R. F.

1974-01-01

Measurements of both thrust ions and charge exchange ions were made in the beam of a 30 centimeter diameter electron bombardment mercury ion thruster. A qualitative model is presented which describes magnitudes of charge exchange ion formation and motions of these ions in the weak electric field structure of the neutralized thrust beam plasma. Areas of agreement and discrepancy between observed and modeled charge exchange properties are discussed.

Isobar separation at very low energy for AMS

NASA Astrophysics Data System (ADS)

Litherland, A. E.; Tomski, I.; Zhao, X.-L.; Cousins, Lisa M.; Doupé, J. P.; Javahery, G.; Kieser, W. E.

2007-06-01

The separation of atomic and molecular isobars, prior to injection into a tandem accelerator for Accelerator Mass Spectrometry (AMS), is discussed. To accomplish this separation, the anions from a standard sputter ion source are retarded to eV energy. The advantages of using very low energy (eV) for this purpose are twofold. The ionic reactions in gases can be isobar specific and the multiple scattering of the eV ions, unlike that at higher energy, can be controlled in linear radio-frequency multipoles. An example of current interest to AMS practice, the suppression of the S- isobar ions from negative ion sources generating mainly Cl- ions, will be described. It will be argued that this is a universal method for isobar separation prior to AMS, which is applicable to atomic anions and cations as well as their molecular counterparts. This procedure should be applicable to the AMS analysis of most rare radioactive species, as atomic or molecular ions, starting with either anions or cations, with appropriate charge changing. In some cases the ions may be analysable without AMS.

High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirano, Y., E-mail: y.hirano@aist.go.jp, E-mail: hirano.yoichi@phys.cst.nihon-u.ac.jp; College of Science and Technologies, Nihon University, Chiyodaku, Tokyo 101-0897; Kiyama, S.

2015-11-15

A high current density (≈3 mA/cm{sup 2}) hydrogen ion beam source operating in an extremely low-energy region (E{sub ib} ≈ 150–200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E{sub ib} is being reduced. The radial profiles of the ion beam current density and the low temperature ion current densitymore » can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.« less

MULTIPLE ELECTRON BEAM ION PUMP AND SOURCE

DOEpatents

Ellis, R.E.

1962-02-27

A vacuum pump is designed which operates by ionizing incoming air and by withdrawing the ions from the system by means of electrical fields. The apparatus comprises a cylindrical housing communicable with the vessel to be evacuated and having a thin wall section in one end. Suitable coils provide a longitudinal magnetic field within the cylinder. A broad cathode and an anode structure is provided to establish a plurality of adjacent electron beams which are parallel to the cylinder axis. Electron reflector means are provided so that each of the beams constitutes a PIG or reflex discharge. Such structure provides a large region in which incoming gas molecules may be ionized by electron bombardment. A charged electrode assembly accelerates the ions through the thin window, thereby removing the gas from the system. The invention may also be utilized as a highly efficient ion source. (AEC)

High Resolution X-ray Measurements Following Charge Exchange with Atomic H: Data for a New Observational Window on Diffuse Astrophysical Sources

NASA Astrophysics Data System (ADS)

Havener, Charles

It is rapidly being realized that many X-ray astronomical investigations are being affected in one way or another by charge exchange emission. Metal abundance measurements in supernova remnants and in outflows from star-forming galaxies need to be corrected for this additional process, and all X-ray observations of low surface brightness objects, such as the outskirts of clusters, galactic halos, the intergalactic medium, and plasma emission from hot interstellar gas are seriously compromised by a highly variable and largely unpredictable foreground from the exchange of solar wind ions on interstellar neutrals within the Solar system. At the same time, charge exchange provides a new sensitivity to mixing at interfaces between hot and cold gas, including direct measurements of relative velocities. The new generation of facilities with microcalorimeter detectors, starting with Astro-H in 2015, will provide the energy resolution and throughput for extended sources required to take advantage of this process. But analysis requires accurate partial cross sections for the production of individual lines, and even the most sophisticated of current charge exchange models do not do this with adequate precision. We propose an inexpensive modification of the Wisconsin high-throughput XQC microcalorimeter instrument so that it can be used on the merged beam facility at Oak Ridge to make direct measurement of lines of interest from collisions between an assortment of heavy ions with neutral atomic hydrogen. In this beam-beam system, the entire range of astrophysically interesting relative velocities can be investigated. We will work closely with modelers to use these results to tune their models to give accurate results for additional ions.

Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malapit, Giovanni M.; Department of Physical Sciences, University of the Philippines Baguio, Baguio City 2600; Mahinay, Christian Lorenz S.

2012-02-15

A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into themore » data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.« less

The Colorado Solar Wind Experiment

NASA Astrophysics Data System (ADS)

Munsat, Tobin; Han, Jia; Horanyi, Mihaly; Ulibarri, Zach; Wang, Xu; Yeo, Lihsia

2016-10-01

The Colorado Solar Wind Experiment (CSWE) is a new device developed at the Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) at the University of Colorado. This large ion source is for studies of the interaction of solar wind plasma with planetary surfaces and cosmic dust, and for the investigation of plasma wake physics. With a plasma beam diameter of 12 cm at the source, ion energies of up to 1 keV, and ion flows of up to 1 mA/cm2, a large cross-section Kaufman Ion Source is used to create steady state plasma flow to model the solar wind in an experimental vacuum chamber. Chamber pressure can be reduced to 3e-5 Torr under operating conditions to suppress ion-neutral collisions and create a uniform ion velocity distribution. Diagnostic instruments such as a double Langmuir probe and an ion energy analyzer are mounted on a two-dimensional translation stage that allow the beam to be characterized throughout the chamber. Early experiments include the measurement of dust grain charging from the interaction with flowing plasma, and measurements of the plasma sheath created by the interaction of the flowing plasma impinging on a surface with a dipole magnetic field. This poster will describe the facility and the scientific results obtained to date.

Lateral charge transport from heavy-ion tracks in integrated circuit chips

NASA Technical Reports Server (NTRS)

Zoutendyk, J. A.; Schwartz, H. R.; Nevill, L. R.

1988-01-01

A 256K DRAM has been used to study the lateral transport of charge (electron-hole pairs) induced by direct ionization from heavy-ion tracks in an IC. The qualitative charge transport has been simulated using a two-dimensional numerical code in cylindrical coordinates. The experimental bit-map data clearly show the manifestation of lateral charge transport in the creation of adjacent multiple-bit errors from a single heavy-ion track. The heavy-ion data further demonstrate the occurrence of multiple-bit errors from single ion tracks with sufficient stopping power. The qualitative numerical simulation results suggest that electric-field-funnel-aided (drift) collection accounts for single error generated by an ion passing through a charge-collecting junction, while multiple errors from a single ion track are due to lateral diffusion of ion-generated charge.

Lithium-Ion Cell Charge-Control Unit Developed

NASA Technical Reports Server (NTRS)

Reid, Concha M.; Manzo, Michelle A.; Buton, Robert M.; Gemeiner, Russel

2005-01-01

A lithium-ion (Li-ion) cell charge-control unit was developed as part of a Li-ion cell verification program. This unit manages the complex charging scheme that is required when Li-ion cells are charged in series. It enables researchers to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and reduces test costs substantially in comparison to individual cell testing.

Interaction of highly charged ions with carbon nano membranes

NASA Astrophysics Data System (ADS)

Gruber, Elisabeth; Wilhelm, Richard A.; Smejkal, Valerie; Heller, René; Facsko, Stefan; Aumayr, Friedrich

2015-09-01

Charge state and energy loss measurements of slow highly charged ions (HCIs) after transmission through nanometer and sub-nanometer thin membranes are presented. Direct transmission measurements through carbon nano membranes (CNMs) show an unexpected bimodal exit charge state distribution, accompanied by charge exchange dependent energy loss. The energy loss of ions in CNMs with large charge loss shows a quadratic dependency on the incident charge state, indicating charge state dependent stopping force values. Another access to the exit charge state distribution is given by irradiating stacks of CNMs and investigating each layer of the stack with high resolution imaging techniques like transmission electron microscopy (TEM) and helium ion microscopy (HIM) independently. The observation of pores created in all of the layers confirms the assumption derived from the transmission measurements that the two separated charge state distributions reflect two different impact parameter regimes, i.e. close collision with large charge exchange and distant collisions with weak ion-target interaction.

Edge effects in vertically-oriented graphene based electric double-layer capacitors

NASA Astrophysics Data System (ADS)

Yang, Huachao; Yang, Jinyuan; Bo, Zheng; Zhang, Shuo; Yan, Jianhua; Cen, Kefa

2016-08-01

Vertically-oriented graphenes (VGs) have been demonstrated as a promising active material for electric double-layer capacitors (EDLCs), partially due to their edge-enriched structure. In this work, the 'edge effects', i.e., edges as the promoters of high capacitance, in VG based EDLCs are investigated with experimental research and numerical simulations. VGs with diverse heights (i.e., edge-to-basal ratios) and edge densities are prepared with varying the plasma-enabled growth time and employing different plasma sources. Electrochemical measurements show that the edges play a predominant role on the charge storage behavior of VGs. A simulation is further conducted to unveil the roles of the edges on the separation and adsorption of ions within VG channels. The initial charge distribution of a VG plane is obtained with density functional theory (DFT) calculations, which is subsequently applied to a molecular dynamics (MD) simulation system to gain the insights into the microscope EDLC structures. Compared with the basal planes, the edges present higher initial charge density (by 4.2 times), higher ion packing density (by 2.6 times), closer ion packing location (by 0.8 Å), and larger ion separation degree (by 14%). The as-obtained findings will be instructive in designing the morphology and structure of VGs for enhanced capacitive performances.

The Solar Wind Ion Composition Spectrometer

NASA Technical Reports Server (NTRS)

Gloeckler, G.; Geiss, J.; Balsiger, H.; Bedini, P.; Cain, J. C.; Fisher, J.; Fisk, L. A.; Galvin, A. B.; Gliem, F.; Hamilton, D. C.

1992-01-01

The Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses is designed to determine uniquely the elemental and ionic-charge composition, and the temperatures and mean speeds of all major solar-wind ions, from H through Fe, at solar wind speeds ranging from 175 km/s (protons) to 1280 km/s (Fe(8+)). The instrument, which covers an energy per charge range from 0.16 to 59.6 keV/e in about 13 min, combines an electrostatic analyzer with postacceleration, followed by a time-of-flight and energy measurement. The measurements made by SWICS will have an impact on many areas of solar and heliospheric physics, in particular providing essential and unique information on: (1) conditions and processes in the region of the corona where the solar wind is accelerated; (2) the location of the source regions of the solar wind in the corona; (3) coronal heating processes; (4) the extent and causes of variations in the composition of the solar atmosphere; (5) plasma processes in the solar wind; (6) the acceleration of energetic particles in the solar wind; (7) the thermalization and acceleration of interstellar ions in the solar wind, and their composition; and (8) the composition, charge states, and behavior of the plasma in various regions of the Jovian magnetosphere.