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1

Negative Ion Sources: Magnetron and Penning  

E-print Network

The history of the magnetron and Penning electrode geometry is briefly outlined. Plasma generation by electrical discharge-driven electron impact ionization is described and the basic physics of plasma and electrodes relevant to magnetron and Penning discharges are explained. Negative ions and their applications are introduced, along with their production mechanisms. Caesium and surface production of negative ions are detailed. Technical details of how to build magnetron and Penning surface plasma sources are given, along with examples of specific sources from around the world. Failure modes are listed and lifetimes compared.

Faircloth, D C

2013-01-01

2

Improved magnetron cold-cathode ion source  

NASA Technical Reports Server (NTRS)

Cold cathode ionization source generates smaller amounts of spurious gases and has a higher sensitivity than commonly used hot-filament ion sources. Photon and X-ray background noise are reduced below detectable levels.

Roehrig, J.; Torney, F.

1970-01-01

3

Magnetron-Discharge-Based Ion Source for Improvement of an Inertial Electrostatic Confinement Fusion Device  

Microsoft Academic Search

A magnetron discharge as a built-in ion source have studied both experimentally and numerically for a compact discharge-type fusion neutron source called IECF (Inertial Electrostatic Confinement Fusion). With this magnetron discharge, ions are produced in the vicinity of the vacuum chamber (anode) at negative electric potential. Therefore, produced ions are expected to have nearly full energy corresponding to the applied

Teruhisa Takamatsu; Kai Masuda; Kiyoshi Yoshikawa; Hisayuki Toku; Kazunobu Nagasaki; Toshiyuki Kyunai

2005-01-01

4

Magnetron-Discharge-Based Ion Source for Improvement of an Inertial Electrostatic Confinement Fusion Device  

SciTech Connect

A magnetron discharge as a built-in ion source have studied both experimentally and numerically for a compact discharge-type fusion neutron source called IECF (Inertial Electrostatic Confinement Fusion). With this magnetron discharge, ions are produced in the vicinity of the vacuum chamber (anode) at negative electric potential. Therefore, produced ions are expected to have nearly full energy corresponding to the applied voltage to the IECF cathode but slightly smaller energy preventing them from hitting the anode of the opposite end, eventually improving both fusion reaction rate and ion recirculation life. Also, the magnetron ion source was found to produce ample ion current for maintenance of the discharge. With the optimization of the configuration of the magnetron discharge, further improvement of the fusion reaction rate is found feasible.

Takamatsu, Teruhisa; Masuda, Kai; Yoshikawa, Kiyoshi; Toku, Hisayuki; Nagasaki, Kazunobu; Kyunai, Toshiyuki [Kyoto University (Japan)

2005-05-15

5

An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources  

NASA Astrophysics Data System (ADS)

An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 1010 cm-3 to 1 × 1011 cm-3, when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 1018 atoms/s for aluminum, which meets the demand for the production of a milliampere Al+ ion beam.

Weichsel, T.; Hartung, U.; Kopte, T.; Zschornack, G.; Kreller, M.; Silze, A.

2014-05-01

6

Joint functioning of a magnetron sputtering system and an end-hall ion source  

NASA Astrophysics Data System (ADS)

The features of joint operation of a magnetron sputtering system (MSS) and an end-Hall ion source (EHIS) are investigated. It is noted that the initiation of the magnetron discharge leads to partial or complete neutralization of the ion beam generated by the EHIS; in other words, in some regimes of the MSS, the ion source operates in the filament-free regime. In such a case, the magnetron discharge is the source of electrons required for sustaining the discharge and for compensating the ion beam from the EHIS. The dependences of the discharge characteristics of the EHIS and MSS are established when a filament neutralizer and MSS discharge are used for compensating the EHIS ion beam. The balance of currents in the ion source-magnetron sputtering system is considered by analyzing the joint functioning of the MSS and EHIS. It is shown that the maximal discharge current from the ion source for which the charge compensation condition is preserved depends on the unbalance and the magnetron discharge current.

Golosov, D. A.; Eungsun, Byon; Zavadski, S. M.

2014-09-01

7

Inertial electrostatic confinement fusion device with an ion source using a magnetron discharge  

Microsoft Academic Search

An inertial electrostatic confinement (IEC) fusion device is studied for a compact fusion neutron\\/proton source using a built-in magnetron ion source. The addition of an ion source to the IEC fusion device enhances fusion reactions by allowing a lower operating gas pressure and by providing a beam-like ion energy distribution. Under lower gas pressures, charge exchange collisions are reduced, resulting

T. Takamatsu; K. Masuda; T. Kyunai; H. Toku; K. Yoshikawa

2006-01-01

8

Characteristics of end Hall ion source with magnetron hollow cathode discharge  

NASA Astrophysics Data System (ADS)

An end Hall ion source with magnetron hollow cathode discharge is described. The source is suitable for high current, low energy ion beam applications such as Hall current plasma accelerators. The end Hall ion source is based on an anode layer thruster with closed drift electrons that move in a closed path in the E × B field. Only a simple magnetron power supply is used in the ion source. The special configuration enables uninterrupted and expanded operation with oxygen as well as other reactive gases because of the absence of an electron source in the ion source. In our evaluation, the ion beam current was measured by a circular electrostatic probe and the energy distribution of the ion beam was measured by a retarding potential analyzer (RPA). An ion beam current density of up to 10 mA/cm 2 was obtained at a mean ion energy of 100-250 eV using Ar or O 2. The ion source can be operated in a stable fashion at a discharge voltage between 200 and 500 V and without additional electron triggering. The discharge power of the ion source can be easily changed by adjusting the gas flow rate and anode voltage. No water cooling is needed for power from 500 W to 2 kW. The simple and rugged ion source is suitable for industrial applications such as deposition of thin films with enhanced adhesion. The operational characteristics of the ion source are experimentally determined and discussed.

Tang, Deli; Wang, Lisheng; Pu, Shihao; Cheng, Changming; Chu, Paul K.

2007-04-01

9

Magnetron sputtering source  

DOEpatents

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal.

Makowiecki, Daniel M. (Livermore, WA); McKernan, Mark A. (Livermore, CA); Grabner, R. Fred (Brentwood, CA); Ramsey, Philip B. (Livermore, CA)

1994-01-01

10

Magnetron sputtering source  

DOEpatents

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

1994-08-02

11

Sub microsecond notching of a negative hydrogen beam at low energy utilizing a magnetron ion source with a split extractor  

SciTech Connect

A technique for sub-microsecond beam notching is being developed at 20 keV utilizing a Magnetron ion source with a slit extraction system and a split extractor. Each half of the extractor is treated as part of a 50 ohm transmission line which can be pulsed at {+-}700 volts creating a 1400 volt gradient. This system along with the associated electronics is electrically floated on top of a pulsed extraction voltage. A beam reduction of 95% has been observed at the end of the Fermilab 400 MeV Linac and 35% notching has recently been achieved in the Booster.

Moehs, Douglas; /Fermilab

2004-12-01

12

Cathode grid current dependence of D(d, n)3He reaction rates in an inertial electrostatic confinement device driven by a ring-shaped magnetron ion source  

Microsoft Academic Search

We present D(d, n)3 He reaction rates for a new inertial electrostatic confinement (IEC) device which aims to overcome neutralization (charge exchange) of accelerating ions by operating at D2 gas pressures of just 5-10 mPa with the aid of an internal ring-shaped magnetron ion source. Initial experiments with a voltage of -60 kV applied to a central spherical cathode grid

K. Masuda; T. Nakagawa; J. Kipritidis; T. Kajiwara; Y. Yamagaki; H. Zen; K. Yoshikawa; K. Nagasaki

2010-01-01

13

Modeling the time variation of beam-grid fusion reaction rates in an Inertial Electrostatic Confinement device driven by a ring-shaped magnetron ion source  

Microsoft Academic Search

We use the two-dimensional analysis code KUAD2 to simulate D^{+_{2}} trajectories in an Inertial Electrostatic Confinement (IEC) device driven by a ring-shaped magnetron ion source (RS-MIS). This aims to maximize the path length lambdaCX for ion-gas charge exchange by operating at just units of mPa D2 gas pressures; however, under these conditions simulations reveal a surprisingly small path length for

J. Kipritidis; K. Masuda; T. Kajiwara; Y. Yamagaki; K. Nagasaki

2011-01-01

14

High power impulse magnetron sputtering and related discharges: scalable plasma sources for plasma-based ion implantation and deposition  

SciTech Connect

High power impulse magnetron sputtering (HIPIMS) and related self-sputtering techniques are reviewed from a viewpoint of plasma-based ion implantation and deposition (PBII&D). HIPIMS combines the classical, scalable sputtering technology with pulsed power, which is an elegant way of ionizing the sputtered atoms. Related approaches, such as sustained self-sputtering, are also considered. The resulting intense flux of ions to the substrate consists of a mixture of metal and gas ions when using a process gas, or of metal ions only when using `gasless? or pure self-sputtering. In many respects, processing with HIPIMS plasmas is similar to processing with filtered cathodic arc plasmas, though the former is easier to scale to large areas. Both ion implantation and etching (high bias voltage, without deposition) and thin film deposition (low bias, or bias of low duty cycle) have been demonstrated.

Anders, Andre

2009-09-01

15

Ion-acoustic solitary waves in a high power pulsed magnetron sputtering discharge  

Microsoft Academic Search

We report on the creation and propagation of ion-acoustic solitary waves in a high power pulsed magnetron sputtering discharge. A dense localized plasma is created by applying high energy pulses (4–12 J) of length ?70 µs, at a repetition frequency of 50 pulses per second, to a planar magnetron sputtering source. The temporal behaviour of the electron density, measured by

K B Gylfason; J Alami; U. Helmersson; J T Gudmundsson

2005-01-01

16

Faceted Magnetron Device Using Discrete Current Sources  

NASA Astrophysics Data System (ADS)

A faceted magnetron concept has a cathode structure comprised of field emitters instead of the traditional thermionic cathode. The faceted magnetron structure has been modeled using the 3D particle-in-cell codes VORPAL 5.2 and ICEPIC. The two-dimensional particle trajectory simulation Lorentz2E has been used to model the electron injection from gated field emitters in a slit type structure. The sensitivity of the electron injection into the device was studied using Lorentz2E with the variation in the operating voltages in the cathode structure -as well as the location of the pusher electrode. Volume electron charge was considered in the sensitivity analysis. Surface charge was not included. Together with this work a model of a ten cavity rising sun magnetron was developed using VORPAL 5.2. A cylindrical and pentagonal-shaped cathode was modeled to study the variation of results due to the cathode shape. The results of this model are used to compare with results obtained from ICEPIC. Discrete current sources were also modeled to come from each facet of the pentagon-shaped cathode to study its effect on the magnetron operation. It is planned to generate velocity distributions of the electrons for the VORPAL input by using results generated with Lorentz2E.

Fernandez-Gutierrez, Sulmer; Browning, Jim; Smithe, David; Watrous, Jack

2012-10-01

17

Ion source  

DOEpatents

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01

18

Ion-acoustic solitary waves in a high power pulsed magnetron sputtering discharge  

Microsoft Academic Search

We report on the creation and propagation of ion-acoustic solitary waves in a high power pulsed magnetron sputtering discharge. A dense localized plasma is created by applying high energy pulses (4-12 J) of length ap70 µs, at a repetition frequency of 50 pulses per second, to a planar magnetron sputtering source. The temporal behaviour of the electron density, measured by

K. B. Gylfason; J. Alami; U. Helmersson; J. T. Gudmundsson

2005-01-01

19

Phase and Frequency Locked Magnetrons for SRF Sources  

SciTech Connect

Magnetrons are low-cost highly-efficient microwave sources, but they have several limitations, primarily centered about the phase and frequency stability of their output. When the stability requirements are low, such as for medical accelerators or kitchen ovens, magnetrons are the very efficient power source of choice. But for high energy accelerators, because of the need for frequency and phase stability - proton accelerators need 1-2 degrees source phase stability, and electron accelerators need .1-.2 degrees of phase stability - they have rarely been used. We describe a novel variable frequency cavity technique which will be utilized to phase and frequency lock magnetrons.

Neubauer, M.; Johnson, R.P.; /Muons Inc., Batavia; Popovic, M.; Moretti, A.; /Fermilab

2009-05-01

20

Improved negative ion source  

DOEpatents

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.

Delmore, J.E.

1984-05-01

21

The ion energy distributions and ion flux composition from a high power impulse magnetron sputtering discharge  

Microsoft Academic Search

The energy distribution of sputtered and ionized metal atoms as well as ions from the sputtering gas is reported for a high power impulse magnetron sputtering (HIPIMS) discharge. High power pulses were applied to a conventional planar circular magnetron Ti target. The peak power on the target surface was 1–2 kW\\/cm2 with a duty factor of about 0.5%. Time resolved, and

J. Bohlmark; M. Lattemann; J. T. Gudmundsson; A. P. Ehiasarian; Y. Aranda Gonzalvo; N. Brenning; U. Helmersson

2006-01-01

22

Ion-induced oxidation of aluminum during reactive magnetron sputtering  

NASA Astrophysics Data System (ADS)

Particle beam experiments were conducted in an ultra-high-vacuum vessel to mimic target poisoning during reactive magnetron sputtering of aluminum. Aluminum targets were exposed to quantified beams of argon ions, oxygen atoms and molecules, and aluminum vapour. The growth and etch rates were measured in situ by means of an Al-coated quartz crystal microbalance. The chemical state of the target surface was monitored in-situ by real-time Fourier transform infrared spectroscopy. The surface processes were modelled through a set of balance equations providing sputter yields and sticking coefficients. The results indicate that the oxygen uptake of the aluminum surface is enhanced by a factor 1 to 2 by knock-on implantation and that the deposition of aluminum is not affected by the oxidation state of the surface.

Kreiter, Oliver; Grosse-Kreul, Simon; Corbella, Carles; von Keudell, Achim

2013-04-01

23

Improved ion source  

DOEpatents

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species,

Leung, K.N.; Ehlers, K.W.

1982-05-04

24

High-power magnetron transmitter as an RF source for superconducting linear accelerators  

NASA Astrophysics Data System (ADS)

A concept of a high-power transmitter utilizing the Continuous Wave (CW) magnetrons, injection-locked by phase-modulated signals, and intended to operate within a wideband control feedback loop in phase and amplitude, is presented. This transmitter is proposed to drive Superconducting RF (SRF) cavities for intensity-frontier GeV-scale proton/ion linacs, such as the projected Fermilab proton linacs or linacs for Accelerator Driven System (ADS). The transmitter consists of two 2-cascade injection-locked magnetrons with outputs combined by a 3-dB hybrid. The transmitter performance was modelled using CW, S-Band, 1 kW magnetrons. A wideband dynamic control of magnetrons, required for the superconducting linacs, was realized using the magnetrons, injection-locked by the phase-modulated signals. The capabilities of the magnetrons injection-locked by the phase-modulated signals and adequateness for feeding of SRF cavities have been verified by measurements of the magnetrons phase performance, by measurements of the transfer function magnitude characteristics of single and 2-cascade magnetrons in the phase modulation domain, and by measurements of spectra of carrier frequency of the magnetron. At the ratio of power of locking signal to output power of ?-13 dB (in 2-cascade scheme per magnetron) a phase modulation bandwidth is over 1.0 MHz for injection-locked CW single magnetrons and a 2-cascade setup. The carrier frequency spectra (width of ~1 Hz at the level of -60 dBc) measured with the magnetron, injection-locked by a phase-modulated signal, did not demonstrate broadening at wide range of magnitude and frequency of the phase modulation. The wideband dynamic management of output power of the transmitter model has been first experimentally demonstrated using combined in power magnetrons, injection-locked by the phase-modulated signals. Experiments with the injection-locked magnetrons adequately emulated the wideband dynamic control with a feedback control system, which will allow to suppress all known parasitic modulation of the accelerating field in the SRF cavities. The magnetron transmitter concept, tests of the transmitter models and injection-locking of magnetrons by phase-modulated signals are discussed in this work.

Kazakevich, Grigory; Johnson, Rolland; Flanagan, Gene; Marhauser, Frank; Yakovlev, Vyacheslav; Chase, Brian; Lebedev, Valeri; Nagaitsev, Sergei; Pasquinelli, Ralph; Solyak, Nikolay; Quinn, Kenneth; Wolff, Daniel; Pavlov, Viatcheslav

2014-10-01

25

Radioactive Ion Sources  

E-print Network

This chapter provides an overview of the basic requirements for ion sources designed and operated in radioactive ion beam facilities. The facilities where these sources are operated exploit the isotope separation online (ISOL) technique, in which a target is combined with an ion source to maximize the secondary beam intensity and chemical element selectivity. Three main classes of sources are operated, namely surface-type ion sources, arc discharge-type ion sources, and finally radio-frequency-heated plasma-type ion sources.

Stora, T

2014-01-01

26

Microstructural comparisons of ultrathin Cu films deposited by ion-beam and dc-magnetron sputtering  

SciTech Connect

We report and contrast both the electrical resistance and the microstructure of copper thin films deposited in an oxygen-containing atmosphere by ion-beam and dc-magnetron sputtering. For films with thicknesses of 5 nm or less, the resistivity of the Cu films is minimized at oxygen concentrations ranging from 0.2% to 1% for dc-magnetron sputtering and 6%-10% for ion-beam sputtering. Films sputtered under both conditions show a similar decrease of interface roughness with increasing oxygen concentration, although the magnetron-deposited films are smoother. The dc-magnetron-produced films have higher resistivity, have smaller Cu grains, and contain a higher concentration of cuprous oxide particles. We discuss the mechanisms leading to the grain refinement and the consequent reduced resistivity in both types of films.

Prater, W.L.; Allen, E.L.; Lee, W.-Y.; Toney, M.F.; Kellock, A.; Daniels, J.S.; Hedstrom, J.A.; Harrell, T. [Chemical and Materials Engineering Department, San Jose State University, One Washington Square, San Jose, California 95192 (United States); Hitachi Global Storage Technologies, 5600 Cottle Road, San Jose, California 95193 (United States); Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); International Business Machines Corporation (IBM) Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States)

2005-05-01

27

Ion-assisted pulsed magnetron sputtering deposition of taC films  

Microsoft Academic Search

The process of ion-assisted deposition of ta-C films by pulsed magnetron sputtering of a graphite target has been investigated. Probe measurements of the magnetron discharge plasma have been performed and its space- and time-dependent characteristics have been obtained as functions of the sputtering parameters and the bias voltage applied to the substrate. It has been shown that the density of

S. P Bugaev; V. G Podkovyrov; K. V Oskomov; S. V Smaykina; N. S Sochugov

2001-01-01

28

A self-sputtering ion source: A new approach to quiescent metal ion beams  

SciTech Connect

A new metal ion source is presented based on sustained self-sputtering plasma in a magnetron discharge. Metals exhibiting high self-sputtering yield such as Cu, Ag, Zn, and Bi can be used in a high-power impulse magnetron sputtering discharge such that the plasma almost exclusively contains singly charged metal ions of the target material. The plasma and extracted ion beam are quiescent. The ion beams consist mostly of singly charged ions with a space-charge limited current density which reached about 10 mA/cm{sup 2} at an extraction voltage of 45 kV and a first gap spacing of 12 mm.

Oks, Efim [High Current Electronics Institute, Russian Academy of Sciences, 2/3 Academichesky Ave., Tomsk 634055 (Russian Federation); Anders, Andre [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

2010-02-15

29

Spatial and temporal evolution of ion energies in high power impulse magnetron sputtering plasma discharge  

NASA Astrophysics Data System (ADS)

High power impulse magnetron sputtering (HIPIMS) is a novel deposition technology successfully implemented on full scale industrial machines. HIPIMS utilizes short pulses of high power delivered to the target in order to generate high amount of metal ions. The life-span of ions between the pulses and their energy distribution could strongly influence the properties and characteristics of the deposited coating. In modern industrial coating machines the sample rotates on a substrate holder and changes its position and distance with regard to the magnetron. Time resolved measurements of the ion energy distribution function (IEDF) at different distances from the magnetron have been performed to investigate the temporal evolution of ions at various distances from target. The measurements were performed using two pressures, 1 and 3 Pa to investigate the influence of working gas pressure on IEDF. Plasma sampling energy-resolved mass spectroscopy was used to measure the IEDF of Ti1+, Ti2+, Ar1+, and Ar2+ ions in HIPIMS plasma discharge with titanium (Ti) target in Ar atmosphere. The measurements were done over a full pulse period and the distance between the magnetron and the orifice of the mass spectrometer was changed from 25 to 215 mm.

Hecimovic, A.; Ehiasarian, A. P.

2010-09-01

30

Vacuum Arc Ion Sources  

E-print Network

The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the source has grown, so also have the operational characteristics been improved in a variety of different ways. Here we review the principles, design, and performance of vacuum arc ion sources.

Brown, I

2014-01-01

31

Ion sources for accelerators  

NASA Astrophysics Data System (ADS)

A survey of different types of ion sources used for accelerator applications is given. Typical problems like the source life time, or the special need for technical solutions for specific elements will demonstrate the advantage of each type of ion source. In any case reliability is a main topic. Besides the plasma generation of the desired element, beam formation and beam transport to the accelerator are discussed. The influence of space charge on the beam transport can be of great importance if there is no space-charge compensation. Typical results achieved at GSI will be given for the following source types: Penning Ion Source (PIG), Electron Cyclotron Resonance (ECR), Cold or Hot Reflex Discharge Ion Source (CHORDIS), Multicusp Ion Source (MUCIS) and MEVVA.

Spädtke, P.; Bossler, J.; Emig, H.; Leible, K. D.; Mühle, C.; Schulte, H.; Tinschert, K.

1998-04-01

32

Compact microwave ion source  

SciTech Connect

A small microwave ion source has been fabricated from a quartz tube with one end enclosed by a two grid accelerator. The source is also enclosed by a cavity operated at a frequency of 2.45 GHz. Microwave power as high as 500 W can be coupled to the source plasma. The source has been operated with and without multicusp fields for different gases. In the case of hydrogen, ion current density of 200 mA/cm/sup -2/ with atomic ion species concentration as high as 80% has been extracted from the source.

Leung, K.N.; Walther, S.; Owren, H.W.

1985-05-01

33

High current ion sources  

SciTech Connect

The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be high', while in another area a current of 10 Amperes could low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely eclipsed by better performance and higher current output within a short period of time. Within their fields of application, there is a large number of kinds of ion sources that can justifiably be called high current. Thus, as a very limited example only, PIGs, Freemen sources, ECR sources, duoplasmatrons, field emission sources, and a great many more all have their high current variants. High current ion beams of gaseous and metallic species can be generated in a number of different ways. Ion sources of the kind developed at various laboratories around the world for the production of intense neutral beams for controlled fusion experiments are used to form large area proton deuteron beams of may tens of Amperes, and this technology can be used for other applications also. There has been significant progress in recent years in the use of microwave ion sources for high current ion beam generation, and this method is likely to find wide application in various different field application. Finally, high current beams of metal ions can be produced using metal vapor vacuum arc ion source technology. After a brief consideration of high current ion source design concepts, these three particular methods are reviewed in this paper.

Brown, I.G.

1989-06-01

34

Magnetron Discharge Characteristics for Improvement of an Inertial Electrostatic Confinement Neutron\\/Proton Source  

Microsoft Academic Search

A magnetron discharge was adopted in the inertial-electrostatic confinement (IEC) fusion device for drastic improvement of fusion reaction rate. With this discharge in the vicinity of the vacuum chamber, a substantial number of ions produced there are expected to have almost full energy corresponding to the applied voltage to the transparent IEC cathode under relatively low pressures compared with the

K. Yoshikawa; H. Toku; K. Masuda; T. Mizutani; A. Nagafuchi; M. Imoto; T. Takamatsu; K. Nagasaki

2003-01-01

35

Classification of Ion Sources  

E-print Network

In this chapter, the anatomy of an ion source is briefly described, as well as a few features of particle motion in electric and magnetic fields, and of particle dynamics and plasmas. Using this information, different types of ion sources are described, highlighting their main mode of operation.

Scrivens, R

2013-01-01

36

Magnetron Discharge Characteristics for Improvement of an Inertial Electrostatic Confinement Neutron/Proton Source  

SciTech Connect

A magnetron discharge was adopted in the inertial-electrostatic confinement (IEC) fusion device for drastic improvement of fusion reaction rate. With this discharge in the vicinity of the vacuum chamber, a substantial number of ions produced there are expected to have almost full energy corresponding to the applied voltage to the transparent IEC cathode under relatively low pressures compared with the conventional glow discharge. The magnetron discharge is found to occur even for the pressure of 0.07 mTorr (H{sub 2}) in the present configuration of the experiment, compared with 5 mTorr in the glow discharge.

Yoshikawa, K.; Toku, H.; Masuda, K.; Mizutani, T.; Nagafuchi, A.; Imoto, M.; Takamatsu, T.; Nagasaki, K. [Kyoto University (Japan)

2003-09-15

37

Pulsed ion beam source  

DOEpatents

An improved magnetically-confined anode plasma pulsed ion beam source. Beam rotation effects and power efficiency are improved by a magnetic design which places the separatrix between the fast field flux structure and the slow field structure near the anode of the ion beam source, by a gas port design which localizes the gas delivery into the gap between the fast coil and the anode, by a pre-ionizer ringing circuit connected to the fast coil, and by a bias field means which optimally adjusts the plasma formation position in the ion beam source.

Greenly, John B. (Lansing, NY)

1996-01-01

38

Selective ion source  

DOEpatents

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P{sup +} from PH{sub 3}. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P{sup +}, As{sup +}, and B{sup +} without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices. 6 figs.

Leung, K.N.

1996-05-14

39

Selective ion source  

DOEpatents

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01

40

Structure and adhesion of ZrN films formed by reactive magnetron sputtering ion plating and dynamic ion mixing  

NASA Astrophysics Data System (ADS)

Ceramic coatings of zirconium nitride have been fabricated on nickel, silicon, and M2 high-speed steel by methods of reactive magnetron sputtering ion plating (RMSP) and the dynamic ion mixing (DIM). The microhardness values of ZrN film prepared by RMSP with different nitrogen partial pressure have been discussed. The scratch tests provide that the adhesion of ZrN film produced by dynamic ion mixing is better than that by reactive magnetron sputtering ion plating. Auger electron spectroscopy analysis is used to analyze the composition distribution of ZrN film prepared by DIM and indicates that there is a transitional layer between the ZrN film and substrate. Meanwhile, by cross-sectional and the plan-view transmission electron microscopy, it is observed that the interlayer of amorphous structure exists in the interface zone between ZrN film and substrate. According to the analysis of energy-dispersive x-ray analysis patterns, the composition of this amorphous region fabricated by RMSP is Ni51Zr49 (?NiZr), as is that fabricated by DIM. (Up to now it has not been reported that the amorphous transitional layer occurs in reactive magnetron sputtering ion plating). The reason why the adhesion of coating by DIM is better than that by RMSP is not the formation of the transitional layer in ion-beam-assisted deposition but the particle bombardment effects on the bulk of the thin film.

Jin, S.; Wen, X. Y.; Gong, Z. X.; Zhu, Y. C.

1993-08-01

41

Industrial ion source technology  

NASA Technical Reports Server (NTRS)

In reactive ion etching of Si, varying amounts of O2 were added to the CF4 background. The experimental results indicated an etch rate less than that for Ar up to an O2 partial pressure of about .00006 Torr. Above this O2 pressure, the etch rate with CF4 exceeded that with Ar alone. For comparison the random arrival rate of O2 was approximately equal to the ion arrival rate at a partial pressure of about .00002 Torr. There were also ion source and ion pressure gauge maintenance problems as a result of the use of CF4. Large scale (4 sq cm) texturing of Si was accomplished using both Cu and stainless steel seed. The most effective seeding method for this texturing was to surround the sample with large inclined planes. Designing, fabricating, and testing a 200 sq cm rectangular beam ion source was emphasized. The design current density was 6 mA/sq cm with 500 eV argon ions, although power supply limitations permitted operation to only 2 mA/sq cm. The use of multiple rectangular beam ion sources for continuous processing of wider areas than would be possible with a single source was also studied. In all cases investigated, the most uniform coverage was obtained with 0 to 2 cm beam overlay. The maximum departure from uniform processing at optimum beam overlap was found to be +15%.

Kaufman, H. R.; Robinson, R. S.

1979-01-01

42

Negative hydrogen ion source research and beam parameters for accelerators  

Microsoft Academic Search

H beams are useful for multi-turn charge-exchange stripping injection into circular accelerators. Studies on a modified ion source for this purpose are presented. This paper includes some theory about a H magnetron discharge, ion-electron emission, emittance and problems linked with emittance measurement and calculations. Investigated parameters of the emittance probe for optimal performance give a screen voltage of 150 V

Timofey V. Zolkin

2006-01-01

43

Requirements for Ion Sources  

E-print Network

Ion sources produce beams for a large variety of different physical experiments, industrial processes and medical applications. In order to characterize the beam delivered by them, a list of requirements is necessary. In this chapter the list of principal requirements is specified and definitions for them are given.

Scrivens, R

2013-01-01

44

Industrial ion source technology  

NASA Technical Reports Server (NTRS)

An analytical model was developed to describe the development of a coned surface texture with ion bombardment and simultaneous deposition of an impurity. A mathematical model of sputter deposition rate from a beveled target was developed in conjuction with the texturing models to provide an important input to that model. The establishment of a general procedure that will allow the treatment of manay different sputtering configurations is outlined. Calculation of cross sections for energetic binary collisions was extened to Ar, Kr.. and Xe with total cross sections for viscosity and diffusion calculated for the interaction energy range from leV to 1000eV. Physical sputtering and reactive ion etching experiments provided experimental data on the operating limits of a broad beam ion source using CF4 as a working gas to produce reactive species in a sputtering beam. Magnetic clustering effects are observed when Al is seeded with Fe and sputtered with Ar(?) ions. Silicon was textured at a micron scale by using a substrate temperature of 600 C.

Kaufman, H. R.; Robinson, R. S.

1978-01-01

45

C/CrC nanocomposite coating deposited by magnetron sputtering at high ion irradiation conditions  

SciTech Connect

CrC with the fcc NaCl (B1) structure is a metastable phase that can be obtained under the non-equilibrium conditions of high ion irradiation. A nano-composite coating consisting of amorphous carbon embedded in a CrC matrix was prepared via the unbalanced magnetron sputtering of graphite and Cr metal targets in Ar gas with a high ionized flux (ion-to-neutral ratio Ji/Jn = 6). The nanoscale amorphous carbon clusters self-assembled into layers alternated by CrC, giving the composite a multilayer structure. The phase, microstructure, and composition of the coating were characterized using x-ray diffraction, transmission electron microscopy, and aberration corrected scanning transmission electron microscopy coupled with electron energy loss spectroscopy. The interpretation of the true coating structure, in particular the carbide type, is discussed.

Zhou, Z.; Rainforth, W. M. [Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD (United Kingdom); Gass, M. H.; Bleloch, A. [SuperSTEM at Daresbury Laboratory, Daresbury, Cheshire, WA4 4AD (United Kingdom); Ehiassarian, A. P.; Hovsepian, P. Eh. [Materials Engineering Research Institute, Sheffield Hallam University, Sheffield, S1 1WB (United Kingdom)

2011-10-01

46

Optical properties of ITO films obtained by high-frequency magnetron sputtering with accompanying ion treatment  

SciTech Connect

A variation in the properties of indium-tin-oxide (ITO) films obtained by the method of reactive magnetron sputtering with simultaneous ion treatment is reported. The ITO films feature the following parameters in the optical range of 450-1100 nm: a transmission coefficient of 80%, band gap of 3.50-3.60 eV, and a refractive index of 1.97-2.06. All characteristics of the films depend on the ion-treatment current. The latter, during the course of deposition, reduces the resistivity of the ITO films with the smallest value of the resistivity being equal to 2 Multiplication-Sign 10{sup -3} {Omega} cm. The degradation of films with a high resistivity when kept in air is observed.

Krylov, P. N., E-mail: ftt@uni.udm.ru; Zakirova, R. M.; Fedotova, I. V. [Udmurt State University (Russian Federation)] [Udmurt State University (Russian Federation)

2013-10-15

47

Negative oxygen ion formation in reactive magnetron sputtering processes for transparent conductive oxides  

SciTech Connect

Reactive d.c. magnetron sputtering in Ar/O{sub 2} gas mixtures has been investigated with energy-resolved mass spectrometry. Different metal targets (Mg, Ti, Zn, In, InSn, and Sn), which are of importance for transparent conductive oxide thin film deposition, have been used to study the formation of negative ions, mainly high-energetic O{sup -}, which are supposed to induce radiation damage in thin films. Besides their energy distribution, the ions have been particularly investigated with respect to their intensity in comparison of the different target materials. To realize the comparability, various calibration factors had to be introduced. After their application, major differences in the negative ion production have been observed for the target materials. The intensity, especially of O{sup -}, differs by about two orders of magnitude. It is shown that this difference results almost exclusively from ions that gain their energy in the target sheath. Those may gain additional energy from the sputtering process or reflection at the target. Low-energetic negative ions are, however, less affected by changes of the target material. The results concerning O{sup -} formation are discussed in term of the sputtering rate from the target and are compared to models for negative ion formation.

Welzel, Thomas; Ellmer, Klaus [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Institut Solare Brennstoffe, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)

2012-11-15

48

Effect of ion bombarding energies on photocatalytic TiO{sub 2} films growing in a pulsed dual magnetron discharge  

SciTech Connect

Photocatalytic crystalline TiO{sub 2} films were deposited by a pulsed dc dual magnetron system. The depositions were performed using two unbalanced magnetrons with planar titanium targets of 50 mm diameter in Ar+O{sub 2} gas mixtures at a total pressure of 0.9 Pa with oxygen partial pressures ranging from 0.2 to 0.9 Pa. The maximum substrate surface temperature was 160 deg. C Both magnetrons operated in the same asymmetric bipolar mode at the repetition frequencies of 100 and 350 kHz with a fixed 50% duty cycle and the average target power densities of 52-74 W cm{sup -2} in the negative voltage phase of the pulses, but the magnetron operations were shifted by a half of the period. Time-averaged energy-resolved mass spectroscopy was performed at a substrate position located 100 mm from the targets. The measured structure of the ion energy distributions was correlated with the distinct pulse phases of the magnetron discharges. A decrease in the energy delivered by fast ions (E{>=}10 eV) to the unit volume of the growing films, together with possible effects of plasma-chemical processes, during the depositions at the oxygen partial pressures of 0.5-0.75 Pa and the repetition frequency of 350 kHz resulted in a strong predominance of the highly photoactive crystalline anatase phase in the TiO{sub 2} films.

Novak, Ondrej; Vlcek, Jaroslav [Department of Physics, University of West Bohemia, Univerzitni 22, 306 14 Plzen (Czech Republic)

2011-05-15

49

Size-selected cluster beam source based on radio frequency magnetron plasma sputtering and gas condensation  

SciTech Connect

We report on a source for producing size-selected nanoclusters based on the combination of radio frequency magnetron plasma sputtering and gas condensation. The use of plasma sputtering to vaporize a target is applicable to a large range of materials; Ag, Au, Cu, and Si have been attempted to date. The source, combined with a time-of-flight mass filter, can produce clusters in the size range from 2 up to at least 70 000 atoms, depending on the target material, with a constant mass (M) resolution (M/{delta}M{approx}25) at an intensity that produces atomic monolayer coverage in as little as a few minutes. The source is also attached to an ultrahigh vacuum analysis chamber, which allows in situ surface chemical and structural analysis. Examples of cluster deposition experiments with the source are also presented.

Pratontep, S.; Carroll, S.J.; Xirouchaki, C.; Streun, M.; Palmer, R.E. [Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

2005-04-01

50

High current ion source  

SciTech Connect

This patent describes an ion source utilizing a vacuum enclosure. It comprises: a cathode; an anode, the anode spaced apart from the cathode, within a first region in the vacuum enclosure; means for producing an electrical arc between the cathode and anode sufficient to vaporize and ionize a portion of the cathode to form a plasma in the first region and to permit travel of the plasma to a second region in the vacuum enclosure, the second region defined to permit physical expansion of the plasma transversely relative to a line between the first and second region, the second region of the vacuum enclosure including a first portion adjacent the first region and a second portion located further outwardly from the first region than the first portion of the second region, the second portion of the second region having a larger transverse dimension than the first portion of second region; means for producing a magnetic field in the second region which flattened the density profile of the plasma in the second region, the magnetic field producing means for including at least one magnetic member extending along the periphery of the second region, the magnetic member being electrically linked to the anode; and means for extracting ions from the expanded plasma in a third region.

Brown, I.G.; MacGill, R.A.; Galvin, J.E.

1990-08-28

51

ULTRA-LOW-ENERGY HIGH-CURRENT ION SOURCE  

SciTech Connect

The technical objective of the project was to develop an ultra-low-energy, high-intensity ion source (ULEHIIS) for materials processing in high-technology fields including semiconductors, micro-magnetics and optics/opto-electronics. In its primary application, this ion source can be incorporated into the 4Wave thin-film deposition technique called biased target ion-beam deposition (BTIBD), which is a deposition technique based on sputtering (without magnetic field, i.e., not the typical magnetron sputtering). It is a technological challenge because the laws of space charge limited current (Child-Langmuir) set strict limits of how much current can be extracted from a reservoir of ions, such as a suitable discharge plasma. The solution to the problem was an innovative dual-discharge system without the use of extraction grids.

Anders, Andre; Yushkov, Georgy Yu.; Baldwin, David A.

2009-11-20

52

Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation  

SciTech Connect

Linac4 accelerator of Centre Europeen de Recherches Nucleaires is under construction and a RF-driven H{sup -} ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H{sup -}, electrons, and Cs{sup -} ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

Lettry J.; Alessi J.; Faircloth, D.; Gerardin, A.; Kalvas, T.; Pereira, H.; Sgobba, S.

2012-02-23

53

Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation  

SciTech Connect

Linac4 accelerator of Centre Europeen de Recherches Nucleaires is under construction and a RF-driven H{sup -} ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H{sup -}, electrons, and Cs{sup -} ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

Lettry, J.; Gerardin, A.; Pereira, H.; Sgobba, S. [CERN, 1211 Geneva 23 (Switzerland); Alessi, J. [BNL, P.O. Box 5000, Upton, New York 11973-5000 (United States); Faircloth, D. [RAL, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Kalvas, T. [University of Jyvaskyla, P.O.Box 35, FI-40014 (Finland)

2012-02-15

54

Reducing the impurity incorporation from residual gas by ion bombardment during high vacuum magnetron sputtering  

SciTech Connect

The influence of ion energy on the hydrogen incorporation has been investigated for alumina thin films, deposited by reactive magnetron sputtering in an Ar/O{sub 2}/H{sub 2}O environment. Ar{sup +} with an average kinetic energy of {approx}5 eV was determined to be the dominating species in the plasma. The films were analyzed with x-ray diffraction, x-ray photoelectron spectroscopy, and elastic recoil detection analysis, demonstrating evidence for amorphous films with stoichiometric O/Al ratio. As the substrate bias potential was increased from -15 V (floating potential) to -100 V, the hydrogen content decreased by {approx}70%, from 9.1 to 2.8 at. %. Based on ab initio calculations, these results may be understood by thermodynamic principles, where a supply of energy enables surface diffusion, H{sub 2} formation, and desorption [Rosen et al., J. Phys.: Condens. Matter 17, L137 (2005)]. These findings are of importance for the understanding of the correlation between ion energy and film composition and also show a pathway to reduce impurity incorporation during film growth in a high vacuum ambient.

Rosen, Johanna; Widenkvist, Erika; Larsson, Karin; Kreissig, Ulrich; Mraz, Stanislav; Martinez, Carlos; Music, Denis; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Department of Materials Chemistry, Angstroem Laboratory, Uppsala University, Box 538, 751 21 Uppsala (Sweden); Institute of Ion Beam Physics and Materials Research, Research Center Rossendorf, P.O. Box 510119, D-01314 Dresden (Germany); Materials Chemistry, RWTH Aachen University, D-52056 Aachen (Germany)

2006-05-08

55

Three chamber negative ion source  

DOEpatents

It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

1983-11-10

56

Optical properties of magnetron sputtered Tb3+ ions containing thin dielectric films for thin film solar cells applications  

Microsoft Academic Search

Results are presented on the deposition and characterization of thin SiO2 and Al2O3 films containing Tb3+ ions developed for application as spectral converters. The films are prepared by RF magnetron co-sputtering. The photoluminescence (PL) is measured at room temperature using the 488 nm line of an Ar laser. The dependence is studied of the PL intensity on the Tb concentration

M. Sendova-Vassileva; K. Baumgartner; O. Angelov; B. Holländer; D. Dimova-Malinovska; R. Carius

2010-01-01

57

Negative ion source  

DOEpatents

An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.

Leung, K.N.; Ehlers, K.W.

1982-08-06

58

Negative ion source  

DOEpatents

An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01

59

Negative ion source  

DOEpatents

An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field. 14 figs.

Leung, K.N.; Ehlers, K.W.

1984-12-04

60

Properties of All-Solid Lithium-Ion Rechargeable Batteries Deposited by RF Magnetron Sputtering  

NASA Astrophysics Data System (ADS)

Amorphous V2O5, LiPON and Li2Mn2O4 thin films were fabricated by RF magnetron sputtering methods and the morphology of thin films were characterized by scanning electron microscopy. Then with these three materials deposited as the anode, solid electrolyte, cathode, and vanadium as current collector, a rocking-chair type of all-solid-state thin-film-type Lithium-ion rechargeable battery was prepared by using the same sputtering parameters on stainless steel substrates. Electrochemical studies show that the thin film battery has a good charge-discharge characteristic in the voltage range of 0.3-3.5 V, and after 30 cycles the cell performance turned to become stabilized with the charge capacity of 9 ?Ah/cm2, and capacity loss of single-cycle of about 0.2%. At the same time, due to electronic conductivity of the electrolyte film, self-discharge may exist, resulting in approximately 96.6% Coulombic efficiency.

Zhu, R. J.; Ren, Y.; Geng, L. Q.; Chen, T.; Li, L. X.; Yuan, C. R.

2013-08-01

61

Vacuum Technology for Ion Sources  

E-print Network

The basic notions of vacuum technology for ion sources are presented, with emphasis on pressure profile calculation and choice of pumping technique. A Monte Carlo code (Molflow+) for the evaluation of conductances and the vacuum-electrical analogy for the calculation of time-dependent pressure variations are introduced. The specific case of the Linac4 H- source is reviewed.

Chiggiato, P

2013-01-01

62

Optimal Position of Ion Source for High Performance of IEC  

SciTech Connect

An inertial electrostatic confinement (IEC) fusion device is possibly used for portable neutron sources. R. L. Hirsh reported that D-D the neutrons of 1.8 x 10{sup 8} n/s were produced. Recently, the similar amounts of fusion reactions are observed to occur in IEC devices In the most of IEC devices, since gas pressure is so high that the ions lose their energy by the frequent collisions with the neutral gas. The conditions of the high voltage and the low pressure are preferable because the energy of beam ions is kept very high and used for the fusion reaction more efficiently. It, however, is difficult to produce enough amounts of ions through a glow discharge at the low pressure. One of the solutions is to equip the ion source such as a magnetron near the anode. We have made three-dimensional orbit following code to evaluate the life of the ions produced near the anode surface. The code includes atomic collisions with background neutral gas and indicates the optimal positions to equip ion source which gives longer life of accelerated ions.

Osawa, Hodaka [Kansai University (Japan); Ishibashi, Takayuki [Kansai University (Japan); Ohnishi, Masami [Kansai University (Japan); Yoshikawa, Kiyoshi [Kyoto University (Japan)

2005-05-15

63

Negative hydrogen ion source research and beam parameters for accelerators  

SciTech Connect

H{sup -} beams are useful for multi-turn charge-exchange stripping injection into circular accelerators. Studies on a modified ion source for this purpose are presented. This paper includes some theory about a H{sup -} magnetron discharge, ion-electron emission, emittance and problems linked with emittance measurement and calculations. Investigated parameters of the emittance probe for optimal performance give a screen voltage of 150 V and a probe step of about 5 mil. Normalized 90% emittance obtained for this H{sup -} source is 0.22 {pi} mm-mr, for an extraction voltage of 18 kV at a beam energy of 30 keV and a beam current of 11 mA.

Zolkin, Timofey V.; /Fermilab

2006-09-01

64

Solenoid and monocusp ion source  

DOEpatents

An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

Brainard, John Paul (Albuquerque, NM); Burns, Erskine John Thomas (Albuquerque, NM); Draper, Charles Hadley (Albuquerque, NM)

1997-01-01

65

Solenoid and monocusp ion source  

DOEpatents

An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures. 6 figs.

Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

1997-10-07

66

STATUS OF ITEP DECABORANE ION SOURCE PROGRAM.  

SciTech Connect

The joint research and development program is continued to develop steady-state ion source of decaborane beam for ion implantation industry. Both Freeman and Bemas ion sources for decaborane ion beam generation were investigated. Decaborane negative ion beam as well as positive ion beam were generated and delivered to the output of mass separator. Experimental results obtained in ITEP are presented.

KULEVOY,T.V.; PETRENKO, S.V.; KUIBEDA, R.P.; SELEZNEV, D.N.; KOZLOV, A.V.; STASEVICH, YU.B.; SITNIKOV, A.L.; SHAMAILOV, I.M.; PERSHIN, V.I.; HERSHCOVITCH, A.; JOHNSON, B.M.; GUSHENETS, V.I.; OKS, E.M.; POOLE, H.J.; MASUNOV, E.S.; POLOZOV, S.M.

2007-08-26

67

The DCU laser ion source.  

PubMed

Laser ion sources are used to generate and deliver highly charged ions of various masses and energies. We present details on the design and basic parameters of the DCU laser ion source (LIS). The theoretical aspects of a high voltage (HV) linear LIS are presented and the main issues surrounding laser-plasma formation, ion extraction and modeling of beam transport in relation to the operation of a LIS are detailed. A range of laser power densities (I approximately 10(8)-10(11) W cm(-2)) and fluences (F=0.1-3.9 kJ cm(-2)) from a Q-switched ruby laser (full-width half-maximum pulse duration approximately 35 ns, lambda=694 nm) were used to generate a copper plasma. In "basic operating mode," laser generated plasma ions are electrostatically accelerated using a dc HV bias (5-18 kV). A traditional einzel electrostatic lens system is utilized to transport and collimate the extracted ion beam for detection via a Faraday cup. Peak currents of up to I approximately 600 microA for Cu(+) to Cu(3+) ions were recorded. The maximum collected charge reached 94 pC (Cu(2+)). Hydrodynamic simulations and ion probe diagnostics were used to study the plasma plume within the extraction gap. The system measured performance and electrodynamic simulations indicated that the use of a short field-free (L=48 mm) region results in rapid expansion of the injected ion beam in the drift tube. This severely limits the efficiency of the electrostatic lens system and consequently the sources performance. Simulations of ion beam dynamics in a "continuous einzel array" were performed and experimentally verified to counter the strong space-charge force present in the ion beam which results from plasma extraction close to the target surface. Ion beam acceleration and injection thus occur at "high pressure." In "enhanced operating mode," peak currents of 3.26 mA (Cu(2+)) were recorded. The collected currents of more highly charged ions (Cu(4+)-Cu(6+)) increased considerably in this mode of operation. PMID:20441334

Yeates, P; Costello, J T; Kennedy, E T

2010-04-01

68

Relating to monitoring ion sources  

SciTech Connect

The apparatus and method provide techniques for monitoring the position on alpha contamination in or on items or locations. The technique is particularly applicable to pipes, conduits and other locations to which access is difficult. The technique uses indirect monitoring of alpha emissions by detecting ions generated by the alpha emissions. The medium containing the ions is moved in a controlled manner frog in proximity with the item or location to the detecting unit and the signals achieved over time are used to generate alpha source position information.

Orr, Christopher Henry (Calderbridge, GB); Luff, Craig Janson (Calderbridge, GB); Dockray, Thomas (Calderbridge, GB); Macarthur, Duncan Whittemore (Los Alamos, NM); Bounds, John Alan (Los Alamos, NM)

2002-01-01

69

An ion source research facility  

SciTech Connect

As an ion source developer, D-Pace frequently faces the issue of needing access to a research facility to be able to test equipment or to develop our existing technology further. The closest facility to perform such tasks is hundreds of kilometers away, at TRIUMF, and it is not always feasible to make use of it on a timely basis. With a growing demand and a desire to enhance our products, the idea to create an ion source research facility in our region evolved. In this paper, we will discuss the approach that was chosen to reach our goal, the status of the project, the principle layout of the facility, and the different ways this facility could be utilized.

Roeder, M.; Dehnel, M.; Jackle, P.; Stewart, T.; Theroux, J. [D-Pace, Inc., P.O. Box 201, Nelson, British Columbia V1L 5P9 (Canada)

2008-02-15

70

An ion source research facility.  

PubMed

As an ion source developer, D-Pace frequently faces the issue of needing access to a research facility to be able to test equipment or to develop our existing technology further. The closest facility to perform such tasks is hundreds of kilometers away, at TRIUMF, and it is not always feasible to make use of it on a timely basis. With a growing demand and a desire to enhance our products, the idea to create an ion source research facility in our region evolved. In this paper, we will discuss the approach that was chosen to reach our goal, the status of the project, the principle layout of the facility, and the different ways this facility could be utilized. PMID:18315134

Roeder, M; Dehnel, M; Jackle, P; Stewart, T; Theroux, J

2008-02-01

71

Miniature high current metal ion source  

SciTech Connect

A small, simple ion source for the production of high brightness beams of metal ions is described. A metal vapor vacuum arc discharge is used to establish the high density plasma from which the ion beam is extracted. The source is finger-sized, and can produce pulsed metal ion beams with current up to the 10 ma range. 9 refs., 6 figs.

Brown, I.G.; Galvin, J.E.; MacGill, R.A.; Wright, R.T.

1986-04-01

72

Miniature high current metal ion source  

SciTech Connect

A small, simple ion source for the production of high brightness beams of metal ions is described. A metal vapor vacuum arc discharge is used to establish the high density plasma from which the ion beam is extracted. The source is finger sized, and can produce pulsed metal ion beams with current up to the 10-mA range.

Brown, I.G.; Galvin, J.E.; MacGill, R.A.; Wright, R.T.

1986-10-20

73

Modeling evaporation, ion-beam assist, and magnetron sputtering of thin metal films over realistic time scales  

NASA Astrophysics Data System (ADS)

A long-time-scale dynamics technique has been used to model the evaporation, ion-beam assist, and magnetron sputtering of thin metal films over realistic time scales. Two fcc metals have been investigated: silver and aluminum. We illustrate how the technique can be used to model growth of these films over experimental time scales, while investigating individual growth mechanisms and surface diffusion events. Long-time dynamics is achieved through an on-the-fly kinetic Monte Carlo method, which determines diffusion pathways and barriers, in parallel, with no prior knowledge of the involved transitions. It was found that Ag has the ability to grow smooth surfaces, using several mechanisms including multiple-atom concerted motion, exchange mechanisms, and damage and repair systems. Ag {111} and {100} grew dense, complete, and crystalline film when sputtering was simulated, whereas evaporation produced incomplete layers. The inclusion of Ar in the ion-beam-assisted evaporation of Ag {111} aided growth by transferring more energy to the surface atoms allowing increased diffusion. Al {111}, however, shows slightly different patterns; growth via evaporation and magnetron sputtering shows only slight differences and the inclusion of the ion-beam assist actually damages the film beyond repair, producing subsurface Ar clusters where Al atoms were displaced creating voids throughout the film. Al {100}, similar to Ag {100}, grows denser and more complete film when grown via sputtering rather than evaporation. Results show that the energy of the deposition method used plays a vital role in the resulting thin film and substrate quality.

Blackwell, S.; Smith, R.; Kenny, S. D.; Walls, J. M.

2012-07-01

74

Development of Electron Cyclotron Resonance Ion Source for Synthesis of Endohedral Metallofullerenes  

NASA Astrophysics Data System (ADS)

A new electron cyclotron resonance ion source (ECRIS) has been constructed for synthesis of endohedral metallofullerenes. The main purpose of the ion source is to produce new biological and medical materials. The design is based on ECRIS for production of multicharged ion beams with a traditional minimum-B magnetic field. An 8-10 GHz traveling wave tube (TWT) amplifier and a 2.45 GHz magnetron have been applied as microwave sources. Fullerene and metal vapor are introduced with a filament heating micro-oven and an induction heating oven, respectively. In preliminary ion-extraction test, Ar+ is 54 ?A. Many broken fullerenes such as C58 and C56 are observed in fullerene ion beams.

Tanaka, K.; Muramatsu, M.; Uchida, T.; Biri, S.; Asaji, T.; Shima, K.; Hanajiri, T.; Kitagawa, A.; Kato, Y.; Yoshida, Y.

2008-11-01

75

Performance characteristics of an inertial-electrostatic confinement fusion device with magnetron discharge  

Microsoft Academic Search

A magnetron discharge as a built-in ion source for an inertial-electrostatic confinement fusion (IECF) device was experimentally studied aiming at a drastic improvement of fusion reaction rate. With this discharge in the vicinity of the grounded vacuum chamber, produced ions are expected to have almost full energy corresponding to the voltage applied to the central transparent cathode. Also, the magnetron-glow

Kai Masuda; Kiyoshi Yoshikawa; Toshiyuki Mizutani; Teruhisa Takamatsu; Masaki Imoto; Kazunobu Nagasaki; Hisayuki Toku

2003-01-01

76

High current vacuum arc ion source for heavy ion fusion  

SciTech Connect

Heavy Ion fusion (HIF) is one of the approaches for the controlled thermonuclear power production. A source of heavy ions with charge states 1+ to 2+, in {approximately}0.5 A current beams with {approximately}20 {micro}s pulse widths and {approximately}10 Hz repetition rates are required. Thermionic sources have been the workhorse for the HIF program to date, but suffer from sloe turn-on, heating problems for large areas, are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1+. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum arc ion source. The vacuum arc ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states, in short and long pulse bursts, with low emittance and high beam currents. Under a Phase-I STTR from DOE, the feasibility of the vacuum arc ion source for the HIF applications is investigated. An existing ion source at LBNL was modified to produce {approximately}0.5 A, {approximately}60 keV Gd (A{approximately}158) ion beams. The experimental effort concentrated on beam noise reduction, pulse-to-pulse reproducibility and achieving low beam emittance at 0.5 A ion current level. Details of the source development will be reported.

Qi, N.; Schein, J.; Gensler, S.; Prasad, R.R.; Krishnan, M.; Brown, I.

1999-07-01

77

Developments at the CERN laser ion source  

Microsoft Academic Search

The high current, high charge-state ion beam which can be extracted from a laser produced plasma is well suited, after initial acceleration, for injection into synchrotrons. At CERN, the production of a heavy ion beam using a CO2 laser ion source is studied. The latest results of experiments with a tantalum ion beam with charge states up to 23+ and

H. Haseroth; H. Kugler; K. Langbein; N. Lisi; A. Lombardi; H. Magnusson; W. Pirkl; J. C. Schnuriger; R. Scrivens; J. Tambini; E. Tanke; S. Homenko; K. Makarov; V. Roerich; A. Stepanov; Y. Satov; S. Kondrashev; S. Savin; B. Sharkov; A. Shumshurov; J. Krása; L. Láska; M. Pfeifer; E. Woryna

1998-01-01

78

High Current Ion Source Development for Heavy Ion Fusion  

Microsoft Academic Search

We are developing high-current-density high-brightness sources for Heavy Ion Fusion applications. Heavy ion driven inertial fusion requires beams of high brightness in order to achieve high power density at the target for high target gain. At present, there are no existing ion source types that can readily meet all the driver HIF requirements, though sources exist which are adequate for

G A Westenskow; D P Grote; J W Kwan

2003-01-01

79

The Electron Beam Ion Source (EBIS)  

ScienceCinema

Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

Brookhaven Lab

2010-01-08

80

Summary: Gas Targets and Ion Sources  

SciTech Connect

The talks related to gas targets and ion sources are summarized. The main areas of interest were hydrogen and deuterium gas targets for storage rings, fed by atomic beam sources, and pulsed ion sources for injection into synchrotrons, both for the hydrogen isotopes and for fully stripped {sup 3}He. Impressive progress has been achieved in the last few years.

Steffens, Erhard [Physikalisches Institut, University of Erlangen-Nuernberg Erwin-Rommel-Str. 1, D-91058 Erlangen (Germany)

2008-02-06

81

Ion mass spectrometry investigations of the discharge during reactive high power pulsed and direct current magnetron sputtering of carbon in Ar and Ar/N{sub 2}  

SciTech Connect

Ion mass spectrometry was used to investigate discharges formed during high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) of a graphite target in Ar and Ar/N{sub 2} ambient. Ion energy distribution functions (IEDFs) were recorded in time-averaged and time-resolved mode for Ar{sup +}, C{sup +}, N{sub 2}{sup +}, N{sup +}, and C{sub x}N{sub y}{sup +} ions. An increase of N{sub 2} in the sputter gas (keeping the deposition pressure, pulse width, pulse frequency, and pulse energy constant) results for the HiPIMS discharge in a significant increase in C{sup +}, N{sup +}, and CN{sup +} ion energies. Ar{sup +}, N{sub 2}{sup +}, and C{sub 2}N{sup +} ion energies, in turn, did not considerably vary with the changes in working gas composition. The HiPIMS process showed higher ion energies and fluxes, particularly for C{sup +} ions, compared to DCMS. The time evolution of the plasma species was analyzed for HiPIMS and revealed the sequential arrival of working gas ions, ions ejected from the target, and later during the pulse-on time molecular ions, in particular CN{sup +} and C{sub 2}N{sup +}. The formation of fullerene-like structured CN{sub x} thin films for both modes of magnetron sputtering is explained by ion mass-spectrometry results and demonstrated by transmission electron microscopy as well as diffraction.

Schmidt, S.; Greczynski, G.; Jensen, J.; Hultman, L. [Thin Film Physics Div., Department of Physics (IFM), Linkoeping University, SE-581 83 (Sweden); Czigany, Zs. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Konkoly Thege Miklos ut 29-33. H-1121 Budapest (Hungary)

2012-07-01

82

Upgraded vacuum arc ion source for metal ion implantationa)  

NASA Astrophysics Data System (ADS)

Vacuum arc ion sources have been made and used by a large number of research groups around the world over the past twenty years. The first generation of vacuum arc ion sources (dubbed "Mevva," for metal vapor vacuum arc) was developed at Lawrence Berkeley National Laboratory in the 1980s. This paper considers the design, performance parameters, and some applications of a new modified version of this kind of source which we have called Mevva-V.Ru. The source produces broad beams of metal ions at an extraction voltage of up to 60 kV and a time-averaged ion beam current in the milliampere range. Here, we describe the Mevva-V.Ru vacuum arc ion source that we have developed at Tomsk and summarize its beam characteristics along with some of the applications to which we have put it. We also describe the source performance using compound cathodes.

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

2012-02-01

83

Upgraded vacuum arc ion source for metal ion implantation  

SciTech Connect

Vacuum arc ion sources have been made and used by a large number of research groups around the world over the past twenty years. The first generation of vacuum arc ion sources (dubbed ''Mevva,'' for metal vapor vacuum arc) was developed at Lawrence Berkeley National Laboratory in the 1980s. This paper considers the design, performance parameters, and some applications of a new modified version of this kind of source which we have called Mevva-V.Ru. The source produces broad beams of metal ions at an extraction voltage of up to 60 kV and a time-averaged ion beam current in the milliampere range. Here, we describe the Mevva-V.Ru vacuum arc ion source that we have developed at Tomsk and summarize its beam characteristics along with some of the applications to which we have put it. We also describe the source performance using compound cathodes.

Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Yushkov, G. Yu. [High Current Electronics Institute, Siberian Division of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Brown, I. G. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2012-02-15

84

Laser ion source for heavy ion synchrotrons (invited)  

Microsoft Academic Search

A status overview of the development of laser ion sources suited to heavy ion synchrotrons is presented. The results of experimental and theoretical studies, recently obtained at a number of laboratories, for laser-produced highly charged heavy ions are summarized for plasmas heated by long wavelength lasers. Design of a powerful repetition rate CO2 laser, target interaction chamber, and extraction system

B. Yu. Sharkov; S. Kondrashev; I. Roudskoy; S. Savin; A. Shumshurov; H. Haseroth; H. Kugler; K. Langbein; N. Lisi; H. Magnusson; R. Scrivens; J. C. Schnuringer; J. Tambini; S. Homenko; K. Makarov; V. Roerich; A. Stepanov; Yu. Satov

1998-01-01

85

Laser ion source for low charge heavy ion beams  

SciTech Connect

For heavy ion inertial fusion application, a combination of a laser ion source and direct plasma injection scheme into an RFQ is proposed. The combination might provide more than 100 mA of singly charged heavy ion beam from a single laser shot. A planned feasibility test with moderate current is also discussed.

Okamura,M.; Pikin, A.; Zajic, V.; Kanesue, T.; Tamura, J.

2008-08-03

86

Research of spectral description films of amorphous hydrogenated silicon received by a magnetron method with the use of an ionic source  

NASA Astrophysics Data System (ADS)

Spectral characteristics films of amorphous hydrogenated silicon received by a magnetron method with use of an ionic source are investigated. As results of researches of temperature dependences on a condition of hydrogen in argon-hydrogen plasma are resulted and a number of laws influencing on electric and optical properties amorphous films is revealed.

Slipchenko, Nicolay I.; Bykov, Mikhail A.; Mazinov, Alim S.

2008-05-01

87

Arc-Discharge Ion Sources for Heavy Ion Fusion  

SciTech Connect

A miniature multiple beamlet approach to an injector system was recently proposed in order to reduce the size, cost, and power requirements of the injector. The beamlets of very high current density are needed to meet the brightness requirement. Besides vacuum arc ion sources, cold-cathode gas ion sources are candidates for this application. Vacuum-arc metal ion sources and vacuum-arc-like gas ion sources are discussed. Experiments are presented that focus on the short-pulse plasma composition and ion charge state distribution. Mg and Sr have been identified as the most promising metals leading to mono-species beams when 20 {mu}s arc pulses are used. It is shown that the efficient production of gas ions requires the presence of a magnetic field.

Anders, A.; Kwan, J.W.

2000-03-01

88

New ion source design for ion propulsion application  

Microsoft Academic Search

A new broad beam ion source to be used as an ion thruster for small satellites in orbit maneuvering applications has been developed at the LABEN Proel Tecnologie Division. The source uses an rf electromagnetic field with frequency in the VHF range to generate and sustain the discharge. Preliminary theoretical investigations seem to indicate that the excitation of an e-m

M. Capacci; G. Noci

1998-01-01

89

High current vacuum arc ion source for heavy ion fusion  

Microsoft Academic Search

Summary form only given. Heavy Ion Fusion (HIF) is one of the approaches for the controlled thermonuclear power production. A source of heavy ions with charge states 1+ to 2+, in ≈0.5 A current beams with 20 ?s pulse widths and ~10 Hz repetition rates are required. Thermionic sources have been the workhorse for the HIF program to date, but

N. Qi; J. Schein; S. Gensler; R. R. Prasad; M. Krishnan; I. Brown

1999-01-01

90

Scanning transmission ion microscope with a field ion source.  

PubMed Central

Experiments with a low-resolution scanning transmission ion microscope, using hydrogen ions from a field ionization source, indicate that it will be feasible by this approach to aim at high-resolution ion microscopy. Micrographs of unstained biological specimens have been obtained by critical range absorption of a 55 keV hydrogen ion beam at a resolution of 2000 A. Images PMID:1057173

Escovitz, W H; Fox, T R; Levi-Setti, R

1975-01-01

91

Highly Polarized Ion Sources for Electron Ion Colliders (EIC)  

SciTech Connect

The operation of the RHIC facility at BNL and the Electron Ion Colliders (EIC) under development at Jefferson Laboratory and BNL need high brightness ion beams with the highest polarization. Charge exchange injection into a storage ring or synchrotron and Siberian snakes have the potential to handle the needed polarized beam currents, but first the ion sources must create beams with the highest possible polarization to maximize collider productivity, which is proportional to a high power of the polarization. We are developing one universal H-/D- ion source design which will synthesize the most advanced developments in the field of polarized ion sources to provide high current, high brightness, ion beams with greater than 90% polarization, good lifetime, high reliability, and good power efficiency. The new source will be an advanced version of an atomic beam polarized ion source (ABPIS) with resonant charge exchange ionization by negative ions. An integrated ABPIS design will be prepared based on new materials and an optimized magnetic focusing system. Polarized atomic and ion beam formation, extraction, and transport for the new source will be computer simulated.

V.G. Dudnikov, R.P. Johnson, Y.S. Derbenev, Y. Zhang

2010-03-01

92

CERN PS laser ion source development  

Microsoft Academic Search

CERN, together with ITEP and TRINITI (Russia), is developing a CO 2 laser ion source. The key design parameters are: 1.4×1010 ions of Pb25+ in a pulse of 5.5 ?s, with a 4-RMS emittance of 0.2×10-6 rad m, working at a repetition rate of 1 Hz. This device is considered as one candidate source for LHC heavy ion operation. The

P. Fournier; G. Gregoire; H. Haseroth; H. Kupler; N. Lisi; A. Lombardi; C. Meyer; P. Ostroumov; W. Pirkl; J.-C. Schnuriger; R. Scrivens; V. Tenishev; F. Varela-Rodriguez; S. Kondrashev; J. Roudskoy; B. Sharkov; A. Shumshurov; S. Khomenko; K. Makarov; V. Roerich; Y. Satov; A. Stepanov

1999-01-01

93

Adhesion and wear properties of TiN films deposited on martensitic stainless steel and Stellite by reactive magnetron sputter ion plating  

Microsoft Academic Search

TiN films were deposited onto the turbine blade materials, AISI 403 martensitic stainless steel and Stellite 6B, using reactive magnetron sputter ion plating. The hardness of the TiN film increases with the residual compressive stress and has a maximum value of 3400 kg\\/mm2 at the substrate bias of about ?75 V. In the scratch adhesion test, the critical loads for

Min Ku Lee; Whung Whoe Kim; Joung Soo Kim; Won Jong Lee

1998-01-01

94

Physics of Plasma-Based Ion Implantation & Deposition (PBIID) and High Power Impulse Magnetron Sputtering (HIPIMS): A Comparison  

E-print Network

G. Lister, Plasma Sources Science and Technology 6/4 (1997)established technology of Plasma Based Ion Implantation &technology emerged in the 1980s when Adler and Picraux [3] used (pulsed) metal plasma and

Anders, Andre

2008-01-01

95

ION SOURCES FOR ENERGY EXTREMES OF ION IMPLANTATION.  

SciTech Connect

For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques, which meet the two energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of Antimony and Phosphorous ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. For low energy ion implantation our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA of positive Decaborane ions were extracted at 10 keV and smaller currents of negative Decaborane ions were also extracted. Additionally, Boron current fraction of over 70% was extracted from a Bemas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources.

HERSCHCOVITCH,A.; JOHNSON, B.M.; BATALIN, V.A.; KROPACHEV, G.N.; KUIBEDA, R.P.; KULEVOY, T.V.; KOLOMIETS, A.A.; PERSHIN, V.I.; PETRENKO, S.V.; RUDSKOY, I.; SELEZNEV, D.N.; BUGAEV, A.S.; GUSHENETS, V.I.; LITOVKO, I.V.; OKS, E.M.; YUSHKOV, G. YU.; MASEUNOV, E.S.; POLOZOV, S.M.; POOLE, H.J.; STOROZHENKO, P.A.; SVAROVSKI, YA.

2007-08-26

96

Use of a duoplasmatron ion source for negative ion generation  

NASA Astrophysics Data System (ADS)

The use of electronegative species as primary ions considerably enhances the emission of positive secondary ions in SIMS. Considering furthermore that negative primary ions can be required due to instrumental configurations (e.g. the Cameca NanoSIMS 50 requires an opposite polarity of the primary and secondary ions), O - ion bombardment is employed in SIMS analysis. These O - ions are typically created in a duoplasmatron source, which suffers however from its low brightness and which is thus not suited for high resolution imaging applications. The development of new (electro)negative ion sources is thus necessary to optimize the analysis of electropositive elements in terms of lateral resolution and sensitivity. In this paper, we present the performance of a duoplasmatron ion source generating F -, Cl -, Br - and I - ion beams. In particular, we experimentally determine on a dedicated test bench the brightness of the source in the F -, Cl -, Br - and I - modes as a function of the gas pressure, the magnetic field strength and the arc current in the source. The obtained results are compared to the performances of the duoplasmatron in the standard O - mode. In this context, a five times higher brightness was found for F - (200 A/cm 2 sr) compared to the standard O - (42 A/cm 2 sr).

Pillatsch, L.; Wirtz, T.; Migeon, H.-N.; Scherrer, H.

2011-05-01

97

A Subnanosecond Ion Source for ?m-focused Ion Beams  

NASA Astrophysics Data System (ADS)

A new, compact design of an ion source delivers ns-pulsed ion beams with low emittance, which can be focused to ?m size. By using a high-power femtosecond (25 fs) laser pulse focused into a 10-6 mbar region, ions at very low temperatures are produced in the small focal volume (5 ?m diameter by 20 ?m length) through the simultaneous absorption of a high number of infrared photons. These ions are born in a cold environment and not in a hot plasma, and consequently have temperatures well below 10 K. The generated ion pulse (up to several thousand ions per bunch) is extracted from the source volume with ion optics that have been carefully tailored through simulations. Externally triggered, its subnanosecond duration and even smaller time jitter allows it to be superimposed with other pulses.

Höhr, C.; Fischer, D.; Moshammer, R.; Dorn, A.; Ullrich, J.

2007-06-01

98

Operation of the Relativistic Heavy Ion Collider Au- ion source  

NASA Astrophysics Data System (ADS)

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is beginning its second year of operation. A cesium sputter ion source injecting into a tandem Van de Graaff provides the gold ions for RHIC. The ion source is operated in the pulsed beam mode and produces a 500-?s-long pulse of Au- with a peak intensity of 290 ?A at the entrance of the tandem. After acceleration in the tandem and post-stripping, this results in a beam of Au+32 with an intensity of 80 ?A and an energy of 182 MeV. Over the last several years, a series of improvements have been made to increase the intensity of the pulsed beam from the ion source. Details of the source performance and improvements will be presented. In addition, an effort is under way to provide other beam species for RHIC collisions.

Steski, D. B.; Alessi, J.; Benjamin, J.; Carlson, C.; Manni, M.; Thieberger, P.; Wiplich, M.

2002-02-01

99

Pseudo ribbon metal ion beam source.  

PubMed

The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface. PMID:24593634

Stepanov, Igor B; Ryabchikov, Alexander I; Sivin, Denis O; Verigin, Dan A

2014-02-01

100

Ion sources for MedAustron  

SciTech Connect

The MedAustron Ion therapy center will be constructed in Wiener Neustadt (Austria) in the vicinity of Vienna. Its accelerator complex consists of four ion sources, a linear accelerator, a synchrotron, and a beam delivery system to the three medical treatment rooms and to the research irradiation room. The ion sources shall deliver beams of H{sub 3}{sup 1+}, C{sup 4+}, and light ions with utmost reliability and stability. This paper describes the features of the ion sources presently planned for the MedAustron facility, such as ion source main parameters, gas injection, temperature control, and cooling systems. A dedicated beam diagnostics technique is proposed in order to characterize electron cyclotron resonance (ECR) ion beams; in the first drift region after the ion source, a fraction of the mixed beam is selected via moveable aperture. With standard beam diagnostics, we then aim to produce position-dependant observables such as ion-current density, beam energy distribution, and emittance for each charge states to be compared to simulations of ECR e-heating, plasma simulation, beam formation, and transport.

Lettry, J. [AB Department, CERN, CH1211 Geneva (Switzerland); Penescu, L.; Wallner, J.; Sargsyan, E. [EBG MedAustron GmbH, Viktor Kaplan-Strasse 2, A-2700 Wiener Neustadt (Austria)

2010-02-15

101

Ion sources for MedAustron.  

PubMed

The MedAustron Ion therapy center will be constructed in Wiener Neustadt (Austria) in the vicinity of Vienna. Its accelerator complex consists of four ion sources, a linear accelerator, a synchrotron, and a beam delivery system to the three medical treatment rooms and to the research irradiation room. The ion sources shall deliver beams of H(3)(1+), C(4+), and light ions with utmost reliability and stability. This paper describes the features of the ion sources presently planned for the MedAustron facility, such as ion source main parameters, gas injection, temperature control, and cooling systems. A dedicated beam diagnostics technique is proposed in order to characterize electron cyclotron resonance (ECR) ion beams; in the first drift region after the ion source, a fraction of the mixed beam is selected via moveable aperture. With standard beam diagnostics, we then aim to produce position-dependant observables such as ion-current density, beam energy distribution, and emittance for each charge states to be compared to simulations of ECR e-heating, plasma simulation, beam formation, and transport. PMID:20192349

Lettry, J; Penescu, L; Wallner, J; Sargsyan, E

2010-02-01

102

Cold atomic beam ion source for focused ion beam applications  

NASA Astrophysics Data System (ADS)

We report measurements and modeling of an ion source that is based on ionization of a laser-cooled atomic beam. We show a high brightness and a low energy spread, suitable for use in next-generation, high-resolution focused ion beam systems. Our measurements of total ion current as a function of ionization conditions support an analytical model that also predicts the cross-sectional current density and spatial distribution of ions created in the source. The model predicts a peak brightness of 2 × 107 A m-2 sr-1 eV-1 and an energy spread less than 0.34 eV. The model is also combined with Monte-Carlo simulations of the inter-ion Coulomb forces to show that the source can be operated at several picoamperes with a brightness above 1 × 107 A m-2 sr-1 eV-1. We estimate that when combined with a conventional ion focusing column, an ion source with these properties could focus a 1 pA beam into a spot smaller than 1 nm. A total current greater than 5 nA was measured in a lower-brightness configuration of the ion source, demonstrating the possibility of a high current mode of operation.

Knuffman, B.; Steele, A. V.; McClelland, J. J.

2013-07-01

103

Cold atomic beam ion source for focused ion beam applications  

SciTech Connect

We report measurements and modeling of an ion source that is based on ionization of a laser-cooled atomic beam. We show a high brightness and a low energy spread, suitable for use in next-generation, high-resolution focused ion beam systems. Our measurements of total ion current as a function of ionization conditions support an analytical model that also predicts the cross-sectional current density and spatial distribution of ions created in the source. The model predicts a peak brightness of 2 × 10{sup 7} A m{sup ?2} sr{sup ?1} eV{sup ?1} and an energy spread less than 0.34 eV. The model is also combined with Monte-Carlo simulations of the inter-ion Coulomb forces to show that the source can be operated at several picoamperes with a brightness above 1 × 10{sup 7} A m{sup ?2} sr{sup ?1} eV{sup ?1}. We estimate that when combined with a conventional ion focusing column, an ion source with these properties could focus a 1 pA beam into a spot smaller than 1 nm. A total current greater than 5 nA was measured in a lower-brightness configuration of the ion source, demonstrating the possibility of a high current mode of operation.

Knuffman, B.; Steele, A. V. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States) [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Maryland Nanocenter, University of Maryland, College Park, Maryland 20742 (United States); zeroK NanoTech, Montgomery Village, Maryland 20886 (United States); McClelland, J. J. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)] [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

2013-07-28

104

Key issues in plasma source ion implantation  

SciTech Connect

Plasma source ion implantation (PSII) is a scaleable, non-line-of-sight method for the surface modification of materials. In this paper, we consider three important issues that should be addressed before wide-scale commercialization of PSII: (1) implant conformality; (2) ion sources; and (3) secondary electron emission. To insure uniform implanted dose over complex shapes, the ion sheath thickness must be kept sufficiently small. This criterion places demands on ion sources and pulsed-power supplies. Another limitation to date is the availability of additional ion species beyond B, C, N, and 0. Possible solutions are the use of metal arc vaporization sources and plasma discharges in high-vapor-pressure organometallic precursors. Finally, secondary electron emission presents a potential efficiency and x-ray hazard issue since for many metallurgic applications, the emission coefficient can be as large as 20. Techniques to suppress secondary electron emission are discussed.

Rej, D.J.; Faehl, R.J. [Los Alamos National Laboratory, NM (United States); Matossian, J.N. [Hughes Research Laboratory, Malibu, CA (United States)

1996-09-01

105

Ion source design for industrial applications  

NASA Technical Reports Server (NTRS)

The design of broad-beam industrial ion sources is described. The approach used emphasizes refractory metal cathodes and permanent-magnet multipole discharge chambers. Design procedures and sample calculations are given for the discharge chamber, ion optics, cathodes, and magnetic circuit. Hardware designs are included for the isolator, cathode supports, anode supports, pole-piece assembly, and ion-optics supports. There are other ways of designing most ion source components, but the designs presented are representative of current technology and adaptable to a wide range of configurations.

Kaufman, H. R.; Robinson, R. S.

1981-01-01

106

Inert gas ion source program  

NASA Technical Reports Server (NTRS)

THe original 12 cm hexagonal magneto-electrostatic containment discharge chamber has been optimized for argon and xenon operation. Argon mass utilization efficiencies of 65 to 77 percent were achieved at keeper-plus-main discharge energy consumptions of 200 to 458 eV/ion, respectively. Xenon performance of 84 to 96 percent mass utilization was realized at 203 to 350 eV/ion. The optimization process and test results are discussed.

Ramsey, W. D.

1978-01-01

107

Electrospray ion source with reduced analyte electrochemistry  

DOEpatents

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.

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

2011-08-23

108

Electrospray ion source with reduced analyte electrochemistry  

DOEpatents

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.

Kertesz, Vilmos; Van Berkel, Gary J

2013-07-30

109

Prototype negative ion sources for RIB generation  

SciTech Connect

Radioactive ion beams (RIBs) of {sup 17}F and {sup 18}F are of interest for investigation of astrophysical phenomena such as the hot CNO cycle and the rp stellar nuclear synthesis processes. In order to generate useful beam intensities of atomic F{sup {minus}}, the species must be efficiently and expediently released from the target material, thermally dissociated from fluoride release products during transport to the ionization chamber of the ion source, and efficiently ionized in the source upon arrival. The authors have conceived and evaluated two prototype negative ion sources for potential use for RIB generation: (1) a direct extraction source and (2) a kinetic ejection source. Both sources utilize Cs vapor to enhance F{sup {minus}} formation. The mechanical design features, operational parameters, ionization efficiencies for forming atomic F{sup {minus}} and delay times for transport of F and fluoride compounds for the respective sources are presented. The efficiency {eta} for formation and extraction of F{sup {minus}} for the direct extraction negative ion source is found to be {eta} {approximately} 1.0% while the characteristic delay time {tau} for transport of F and fluorides through the source is typically, {eta} {approximately} 120s; the analogous efficiencies and delay times for the kinetic ejection negative ion source are, respectively: {eta} = {approximately}3.2% and {tau} = {approximately}70s.

Alton, G.D.; Murray, S.N. [Oak Ridge National Lab., TN (United States); Welton, R.F.; Williams, C. [Oak Ridge National Lab., TN (United States); [Oak Ridge Inst. of Science and Engineering, TN (United States); Cui, B. [China Inst. of Atomic Energy, Beijing (China)

1997-12-01

110

State of the Art ECR Ion Sources  

SciTech Connect

Electron Cyclotron Resonance (ECR) ion source which produces highly-charged ions is used in heavy ion accelerators worldwide. Applications also found in atomic physics research and industry ion implantation. ECR ion source performance continues to improve, especially in the last few years with new techniques, such as multiple-frequency plasma heating and better methods to provide extra cold electrons, combined with higher magnetic mirror fields. So far more than 1 emA of multiply-charged ions such as He{sup 2+} and O{sup 6+}, and 30 e{mu}A of Au{sup 32+}, 1.1 e{mu}A of {sup 238}U{sup 48+}, and epA currents of very high charge states such as {sup 86}Kr{sup 35+} and {sup 238}U{sup 60+} have been produced.

Xie, Z.Q.

1997-05-01

111

Metal vapor vacuum arc ion sources  

SciTech Connect

We have developed a family of metal vapor vacuum are (MEVVA) high current metal ion sources. The sources were initially developed for the production of high current beams of metal ions for heavy ion synchrotron injection for basic nuclear physics research; more recently they have also been used for metal ion implantation. A number of different embodiments of the source have been developed for these specific applications. Presently the sources operate in a pulsed mode, with pulse width of order 1 ms and repetition rate up to 100 pps. Beam extraction voltage is up to 100 kV, and since the ions produced in the vacuum arc plasma are in general multiply ionized the ion energy is up to several hundred keV. Beam current is up to several Amperes peak and around 10 mA time averaged delivered onto target. Nearly all of the solid metals of the Periodic Table have been use to produce beam. A number of novel features have been incorporated into the sources, including multiple cathodes and the ability to switch between up to 18 separate cathode materials simply and quickly, and a broad beam source version as well as miniature versions. here we review the source designs and their performance. 45 refs., 7 figs.

Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; Godechot, X.; MacGill, R.A.

1990-06-01

112

Ionized physical vapor deposition (IPVD): magnetron sputtering discharges  

Microsoft Academic Search

Over the past decade, various magnetron sputtering techniques have appeared that provide a high degree of ionization of the sputtered vapor. Here, ionized physical vapor deposition (IPVD) magnetron sputtering systems are reviewed. The application of a secondary discharge to a magnetron sputtering discharge, either an inductively coupled plasma source (ICP-MS) or a microwave amplified magnetron sputtering, is currently widely used.

J T Gudmundsson

2008-01-01

113

Laser ion source development at Holifield Radioactive Ion Beam Facility  

SciTech Connect

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:sapphire lasers for nuclear physics and astrophysics research at Holifield Radioactive Ion Beam Facility. Three Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Liu, Y.; Havener, C. C.; Beene, J. R. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Gottwald, T.; Mattolat, C.; Vane, C. R.; Wendt, K. [Institute of Physics, University of Mainz, D-55099 Mainz (Germany); Howe, J. Y.; Kiggans, J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2012-02-15

114

Laser ion source development at Holifield Radioactive Ion Beam Facilitya)  

NASA Astrophysics Data System (ADS)

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:sapphire lasers for nuclear physics and astrophysics research at Holifield Radioactive Ion Beam Facility. Three Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Liu, Y.; Gottwald, T.; Havener, C. C.; Howe, J. Y.; Kiggans, J.; Mattolat, C.; Vane, C. R.; Wendt, K.; Beene, J. R.

2012-02-01

115

Ion production from solid state laser ion sources  

SciTech Connect

Laser ion sources based on resonant excitation and ionization of atoms are well-established tools for selective and efficient production of radioactive ion beams. Recent developments are focused on the use of the state-of-the-art all solid-state laser systems. To date, 35 elements of the periodic table are available from laser ion sources based on tunable Ti:sapphire lasers. Recent progress in this field regarding the establishment of suitable optical excitation schemes for Ti:sapphire lasers are reported.

Gottwald, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Havener, Charles C [ORNL; Lassen, J. [TRIUMF, Canada; Liu, Yuan [ORNL; Mattolat, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Raeder, S. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rothe, S. [CERN, Geneva, Switzerland; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2010-01-01

116

Ion production from solid state laser ion sources  

SciTech Connect

Laser ion sources based on resonant excitation and ionization of atoms are well-established tools for selective and efficient production of radioactive ion beams. Recent developments are focused on the use of the state-of-the-art all solid-state laser systems. To date, 35 elements of the periodic table are available from laser ion sources based on tunable Ti:sapphire lasers. Recent progress in this field regarding the establishment of suitable optical excitation schemes for Ti:sapphire lasers are reported.

Gottwald, T.; Mattolat, C.; Raeder, S.; Wendt, K. [Institute for Physics, University of Mainz, Staudinger Weg 7, 55128 Mainz (Germany); Havener, C.; Liu, Y. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Lassen, J. [TRIUMF-ISAC Division, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Rothe, S. [CERN, CH-1211 Geneve 23 (Switzerland)

2010-02-15

117

Simulation and analysis of solenoidal ion sources  

SciTech Connect

We present a detailed analysis and simulation of solenoidal, magnetically confined electron bombardment ion sources, aimed at molecular beam detection. The aim is to achieve high efficiency for singly ionized species while minimizing multiple ionization. Electron space charge plays a major role and we apply combined ray tracing and finite element simulations to determine the properties of a realistic geometry. The factors controlling electron injection and ion extraction are discussed. The results from simulations are benchmarked against experimental measurements on a prototype source.

Alderwick, A. R.; Jardine, A. P.; Hedgeland, H.; MacLaren, D. A.; Allison, W.; Ellis, J. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2008-12-15

118

Development of a polarized Helium-3 ion source for RHIC using the electron beam ion source  

E-print Network

This thesis presents my work on the design and development of a source of polarized Helium-3 ions for the Relativistic Heavy Ion Collider at Brookhaven National Lab, Upton, NY. The 3He atoms will be polarized using the ...

Epstein, Charles Samuel

2013-01-01

119

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

PubMed

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 ?A) 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. PMID:22380298

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

2012-02-01

120

Deposition of Al-doped ZnO thin-films with radio frequency magnetron sputtering for a source\\/drain electrode for pentacene thin-film transistor  

Microsoft Academic Search

Al-doped ZnO thin-films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers for a source\\/drain electrode in the pentacene thin-film transistor. With the increase in the deposition temperature and the decrease in the radio frequency sputtering power, the crystallinity was increased and the surface roughness was decreased, which lead to the decrease in the

Dong-Jin Yun; Shi-Woo Rhee

2009-01-01

121

High Pressure Discharge Negative Ion Source  

NASA Astrophysics Data System (ADS)

A high pressure discharge negative ion source has been developed with the goals of high duty cycle, high current, and good reliability, with the ultimate aim of providing a source for a facility such as the Spallation Neutron Source. The discharge itself has been characterized running on hydrogen and helium over pressure ranges of 10s to 100s of torr, with the pressure varied both by changing the flow rate and exit orifice diameter. A key part of the characterization was the power required for the E-H transition as a function of the pressure and gas flow. Running on hydrogen, a biased grid set has been used to extract negative current from a negative ion production region downstream from the discharge exit orifice and an electromagnet has been used to separate electrons from the negative ions. Initial measured efficiency for negative ion current has been in the range of 1-2 mA/kW.

Olson, Lynn; Blandino, John; Gatsonis, Nikolaos

2012-10-01

122

Permanent Magnet Helicon Source for Ion Propulsion  

Microsoft Academic Search

Helicon sources have been proposed by at least two groups for generating ions for space propulsion: the Helicon Double Layer Thruster (HDLT) concept at the Australian National University and the Variable Specific Impulse Magnetohydrodynamic Rocket (VASIMR) concept at the Johnson Space Center in Houston. These sources normally require a large electromagnet and power supply to produce the magnetic field. At

Francis F. Chen

2008-01-01

123

Influence of plasma-generated negative oxygen ion impingement on magnetron sputtered amorphous SiO{sub 2} thin films during growth at low temperatures  

SciTech Connect

Growth of amorphous SiO{sub 2} thin films deposited by reactive magnetron sputtering at low temperatures has been studied under different oxygen partial pressure conditions. Film microstructures varied from coalescent vertical column-like to homogeneous compact microstructures, possessing all similar refractive indexes. A discussion on the process responsible for the different microstructures is carried out focusing on the influence of (i) the surface shadowing mechanism, (ii) the positive ion impingement on the film, and (iii) the negative ion impingement. We conclude that only the trend followed by the latter and, in particular, the impingement of O{sup -} ions with kinetic energies between 20 and 200 eV, agrees with the resulting microstructural changes. Overall, it is also demonstrated that there are two main microstructuring regimes in the growth of amorphous SiO{sub 2} thin films by magnetron sputtering at low temperatures, controlled by the amount of O{sub 2} in the deposition reactor, which stem from the competition between surface shadowing and ion-induced adatom surface mobility.

Macias-Montero, M.; Garcia-Garcia, F. J.; Alvarez, R.; Gil-Rostra, J.; Gonzalez, J. C.; Gonzalez-Elipe, A. R.; Palmero, A. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, 41092 Seville (Spain); Cotrino, J. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, 41092 Seville (Spain); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Avda. Reina Mercedes, s/n, 42022 Seville (Spain)

2012-03-01

124

Status of CSNS H- ion source  

E-print Network

A new H^- ion source has been installed successfully and will be used to serve the China Spallation Neutron Source (CSNS). In this paper, we report various components of the ion source, including discharge chamber, temperature, cooling system, extraction electrodes, analyzing magnet, remote control system and so on. Compared to the previous experimental ion source, some improvements have been made to make the ion source more compact and convenient. In the present arrangement, the Penning field is generated by a pair of pole tip extensions on the analyzing magnet instead of by a separate circuit. For the remote control system, F3RP61-2L is applied to the accelerator online control system for the first time. In the running of the ion source, a stable pulse H- beam with a current of 50 mA at an energy of 50 keV is produced. The extraction frequency and pulse width is 25 Hz and 500microsecond, respectively. Furthermore, an emittance scanner has been installed and measurements are in progress.

Liu, Shengjin; Ouyang, Huafu; Zhao, Fuxiang; Xiao, Yongchuan; Lv, Yongjia; Cao, Xiuxia; Xue, Kangjia; Zhang, Junsong; Xu, Taoguang; Li, Fang; Lu, Yanhua; Li, Gang; Yang, Lei; Li, Yi

2014-01-01

125

CAS - CERN Accelerator School, Ion Sources  

E-print Network

These proceedings collate lectures given at the twenty-sixth specialized course organised by the CERN Accelerator School (CAS). The course was held in Senec, Slovakia from 29 May to 8 June 2012, in collaboration with the Slovak University of Technology, Bratislava. Following lectures on the background accelerator physics and the fundamental processes underlying the production of particle beams, the course covered the different types of ion sources and associated technological issues, and different applications for which sources are used. The participants pursued one of six case studies in order to get “hands-on” experience of the issues connected with the design of an ion source.

2013-01-01

126

Low temperature ion source for calutrons  

DOEpatents

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.

Veach, Allen M. (Oak Ridge, TN); Bell, Jr., William A. (Oak Ridge, TN); Howell, Jr., George D. (Clinton, TN)

1981-01-01

127

High Current Ion Source Development for Heavy Ion Fusion  

SciTech Connect

We are developing high-current-density high-brightness sources for Heavy Ion Fusion applications. Heavy ion driven inertial fusion requires beams of high brightness in order to achieve high power density at the target for high target gain. At present, there are no existing ion source types that can readily meet all the driver HIF requirements, though sources exist which are adequate for present experiments and which with further development may achieve driver requirements. Our two major efforts have been on alumino-silicate sources and RF plasma sources. Experiments being performed on a 10-cm alumino-silicate source are described. To obtain a compact system for a HIF driver we are studying RF plasma sources where low current beamlets are combined to produce a high current beam. A 80-kV 20-{micro}s source has produced up to 5 mA of Ar{sup +} in a single beamlet. The extraction current density was 100 mA/cm{sup 2}. We present measurements of the extracted current density as a function of RF power and gas pressure, current density uniformity, emittance, and energy dispersion (due to charge exchange).

Westenskow, G A; Grote, D P; Kwan, J W

2003-09-04

128

Highly Stripped Ion Sources for MeV Ion Implantation  

SciTech Connect

Original technical objectives of CRADA number PVI C-03-09 between BNL and Poole Ventura, Inc. (PVI) were to develop an intense, high charge state, ion source for MeV ion implanters. Present day high-energy ion implanters utilize low charge state (usually single charge) ion sources in combination with rf accelerators. Usually, a MV LINAC is used for acceleration of a few rnA. It is desirable to have instead an intense, high charge state ion source on a relatively low energy platform (de acceleration) to generate high-energy ion beams for implantation. This de acceleration of ions will be far more efficient (in energy utilization). The resultant implanter will be smaller in size. It will generate higher quality ion beams (with lower emittance) for fabrication of superior semiconductor products. In addition to energy and cost savings, the implanter will operate at a lower level of health risks associated with ion implantation. An additional aim of the project was to producing a product that can lead to long­ term job creation in Russia and/or in the US. R&D was conducted in two Russian Centers (one in Tomsk and Seversk, the other in Moscow) under the guidance ofPVI personnel and the BNL PI. Multiple approaches were pursued, developed, and tested at various locations with the best candidate for commercialization delivered and tested at on an implanter at the PVI client Axcelis. Technical developments were exciting: record output currents of high charge state phosphorus and antimony were achieved; a Calutron-Bemas ion source with a 70% output of boron ion current (compared to 25% in present state-of-the-art). Record steady state output currents of higher charge state phosphorous and antimony and P ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb {sup 4 +}, Sb{sup 5+}, and Sb{sup 6+} respectively. Ultimate commercialization goals did not succeed (even though a number of the products like high charge state phosphorus and antimony could have resulted in a lower power consumption of 30 kW/implanter) for the following reasons (which were discovered after R&D completion): record output of high charge state phosphorous would have thermally damage wafers; record high charge state of antimony requires tool (ion implanting machine in ion implantation jargon) modification, which did not make economic sense due to the small number of users. Nevertheless, BNL has benefited from advances in high-charge state ion generation, due to high charge state ions need for RHIC preinjection. High fraction boron ion was delivered to PVI client Axcelis for retrofit and implantation testing; the source could have reduced beam preinjector power consumption by a factor of 3.5. But, since the source generated some lithium (though in miniscule amounts); last minute decision was made not to employ the source in implanters. R&D of novel transport and gasless plasmaless deceleration, as well as decaborane molecular ion source to mitigate space charge problems in low energy shallow ion implantation was also conducted though results were not yet ready for commercialization. Future work should be focused on gasless plasmaless transport and deceleration as well as on molecular ions due to their significance to low energy, shallow implantation; which is the last frontier of ion implantation. To summarize the significant accomplishments: 1. Record steady state output currents of high charge state phosphorous, P, ions in particle milli-Ampere: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA). 2. Record steady state output currents of high charge state antimony, Sb, ions in particle milli-Ampere: Sb{sup 3+} (16.2 pmA), Sb{sup 4+} (7.6 pmA), Sb{sup 5+} (3.3 pmA), and Sb{sup 6+} (2.2 pmA). 3. 70% output of boron ion current (compared to 25% in present state-of-the-art) from a Calutron-Bemas ion source. These accomplishments have the potential of benefiting the semiconductor manufacturing industry by lowering power consumption by as much as 30 kW per ion implanter. Major problem w

Hershcovitch, Ady

2009-06-30

129

Metal versus rare-gas ion irradiation during Ti{sub 1-x}Al{sub x}N film growth by hybrid high power pulsed magnetron/dc magnetron co-sputtering using synchronized pulsed substrate bias  

SciTech Connect

Metastable NaCl-structure Ti{sub 1-x}Al{sub x}N is employed as a model system to probe the effects of metal versus rare-gas ion irradiation during film growth using reactive high-power pulsed magnetron sputtering (HIPIMS) of Al and dc magnetron sputtering of Ti. The alloy film composition is chosen to be x = 0.61, near the kinetic solubility limit at the growth temperature of 500 Degree-Sign C. Three sets of experiments are carried out: a -60 V substrate bias is applied either continuously, in synchronous with the full HIPIMS pulse, or in synchronous only with the metal-rich-plasma portion of the HIPIMS pulse. Alloy films grown under continuous dc bias exhibit a thickness-invariant small-grain, two-phase nanostructure (wurtzite AlN and cubic Ti{sub 1-x}Al{sub x}N) with random orientation, due primarily to intense Ar{sup +} irradiation leading to Ar incorporation (0.2 at. %), high compressive stress (-4.6 GPa), and material loss by resputtering. Synchronizing the bias with the full HIPIMS pulse results in films that exhibit much lower stress levels (-1.8 GPa) with no measureable Ar incorporation, larger grains elongated in the growth direction, a very small volume fraction of wurtzite AlN, and random orientation. By synchronizing the bias with the metal-plasma phase of the HIPIMS pulses, energetic Ar{sup +} ion bombardment is greatly reduced in favor of irradiation predominantly by Al{sup +} ions. The resulting films are single phase with a dense competitive columnar structure, strong 111 orientation, no measureable trapped Ar concentration, and even lower stress (-0.9 GPa). Thus, switching from Ar{sup +} to Al{sup +} bombardment, while maintaining the same integrated incident ion/metal ratio, eliminates phase separation, minimizes renucleation during growth, and reduces the high concentration of residual point defects, which give rise to compressive stress.

Greczynski, Grzegorz; Lu Jun; Jensen, Jens; Petrov, Ivan; Greene, Joseph E.; Bolz, Stephan; Koelker, Werner; Schiffers, Christoph; Lemmer, Oliver; Hultman, Lars [Department of Physics (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden); Department of Physics (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden) and Materials Science Department and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States); Department of Physics (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden); Materials Science Department and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States) and Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); CemeCon AG, Adenauerstr. 20 A4, D-52146 Wurselen (Germany); Department of Physics (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden)

2012-11-15

130

Laser micro-structuring of magnetron-sputtered SnO x thin films as anode material for lithium ion batteries  

Microsoft Academic Search

SnOx electrode thin films for lithium ion batteries were deposited by reactive and non-reactive rf magnetron sputtering of a SnO2 target in an argon–oxygen atmosphere. Amorphous and nano-crystalline SnOx films could be synthesized, with regard to the O2:Ar volume ratio in the sputter gas which was adjusted to 0, 3.5 or 10%. Laser micro-structuring using a KrF excimer laser\\u000a operating

R. Kohler; H. Besser; M. Hagen; J. Ye; C. Ziebert; S. Ulrich; J. Proell; W. Pfleging

2011-01-01

131

Low Z impurity ion extraction from TFTR ion sources  

SciTech Connect

TFTR deuterium neutral beams have been operated unintentionally with significant quantities of extracted water ions. Water has been observed with an Optical Multichannel Analyzer (OMA) during beam extraction when small water leaks were present within the arc chamber. These leaks were thermally induced with the contamination level increasing linearly with pulse length. 6% of the beam current was attributed to water ions for the worst leak, corresponding to an instantaneous value of 12% at the end of a 1.5 s pulse. A pre-calorimeter collimator was damaged as a result of this operation. A similar contamination is observed during initial operation of ion sources exposed to air. This latter contamination is attributed to the synthesis, from adsorbed air, of either D[sub 2]O or the indistinguishable ND[sub 3]. Initial operation of new ion sources typically produces a contamination level of [approximately]2%. These impurities are reduced to undetectable levels after 50 to 100 beam pulses. Once a water molecule is present in the plasma generator, it is predominantly ionized rather than dissociated, resulting in the extraction of only trace amounts of hydrogenated ions. The addition of water to the extracted beam also reduces the optimum perveance, moving the typical underdense operating point closer to optimum, causing the frequency of grid faults to increase. Close to 90% of the water extracted from ion sources with water leaks was deuterated, implying that the potential exists for the production of tritiated water during TFTR's forthcoming DT operation. Isotope exchange in the plasma generator takes place rapidly and is believed to be surface catalyzed. The primary concern is with O implanted into beam absorbers recombining with tritium, and the subsequent hold up of T[sub 2]O on cryopanels. Continuous surveillance with the OMA diagnostic during DT operation will ensure that ion sources with detectable water are not operated with tritium.

Kamperschroer, J.H.; Grisham, L.R.; Newman, R.A.; O'Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.; Wright, K.E.

1993-04-01

132

Low Z impurity ion extraction from TFTR ion sources  

SciTech Connect

TFTR deuterium neutral beams have been operated unintentionally with significant quantities of extracted water ions. Water has been observed with an Optical Multichannel Analyzer (OMA) during beam extraction when small water leaks were present within the arc chamber. These leaks were thermally induced with the contamination level increasing linearly with pulse length. 6% of the beam current was attributed to water ions for the worst leak, corresponding to an instantaneous value of 12% at the end of a 1.5 s pulse. A pre-calorimeter collimator was damaged as a result of this operation. A similar contamination is observed during initial operation of ion sources exposed to air. This latter contamination is attributed to the synthesis, from adsorbed air, of either D{sub 2}O or the indistinguishable ND{sub 3}. Initial operation of new ion sources typically produces a contamination level of {approximately}2%. These impurities are reduced to undetectable levels after 50 to 100 beam pulses. Once a water molecule is present in the plasma generator, it is predominantly ionized rather than dissociated, resulting in the extraction of only trace amounts of hydrogenated ions. The addition of water to the extracted beam also reduces the optimum perveance, moving the typical underdense operating point closer to optimum, causing the frequency of grid faults to increase. Close to 90% of the water extracted from ion sources with water leaks was deuterated, implying that the potential exists for the production of tritiated water during TFTR`s forthcoming DT operation. Isotope exchange in the plasma generator takes place rapidly and is believed to be surface catalyzed. The primary concern is with O implanted into beam absorbers recombining with tritium, and the subsequent hold up of T{sub 2}O on cryopanels. Continuous surveillance with the OMA diagnostic during DT operation will ensure that ion sources with detectable water are not operated with tritium.

Kamperschroer, J.H.; Grisham, L.R.; Newman, R.A.; O`Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.; Wright, K.E.

1993-04-01

133

Ion plating with an induction heating source  

NASA Technical Reports Server (NTRS)

Induction heating is introduced as an evaporation heat source in ion plating. A bare induction coil without shielding can be directly used in the glow discharge region with no arcing. The only requirement is to utilize an rf inductive generator with low operating frequency of 75 kHz. Mechanical simplicity of the ion plating apparatus and ease of operation is a great asset for industrial applications; practically any metal such as nickel, iron, and the high temperature refractories can be evaporated and ion plated.

Spalvins, T.; Brainard, W. A.

1976-01-01

134

rf improvements for Spallation Neutron Source H- ion source.  

PubMed

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering approximately 38 mA H(-) beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride (AlN) plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. PMID:20192394

Kang, Y W; Fuja, R; Goulding, R H; Hardek, T; Lee, S-W; McCarthy, M P; Piller, M C; Shin, K; Stockli, M P; Welton, R F

2010-02-01

135

ECR ion source with electron gun  

DOEpatents

An Advanced Electron Cyclotron Resonance ion source (10) having an electron gun (52) for introducing electrons into the plasma chamber (18) of the ion source (10). The ion source (10) has a injection enclosure (12) and a plasma chamber tank (14). The plasma chamber (18) is defined by a plurality of longitudinal magnets (16). The electron gun (52) injects electrons axially into the plasma chamber (18) such that ionization within the plasma chamber (18) occurs in the presence of the additional electrons produced by the electron gun (52). The electron gun (52) has a cathode (116) for emitting electrons therefrom which is heated by current supplied from an AC power supply (96) while bias potential is provided by a bias power supply (118). A concentric inner conductor (60) and Outer conductor (62) carry heating current to a carbon chuck (104) and carbon pusher (114) Which hold the cathode (116) in place and also heat the cathode (16). In the Advanced Electron Cyclotron Resonance ion source (10), the electron gun (52) replaces the conventional first stage used in prior art electron cyclotron resonance ion generators.

Xie, Zu Q. (El Cerrito, CA); Lyneis, Claude M. (Berkeley, CA)

1993-01-01

136

Laser Ion Source Development at HRIBF  

SciTech Connect

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:Sapphire lasers for nuclear physics and astrophysics research at HRIBF. Three Ti:Sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Liu, Yuan [ORNL; Beene, James R [ORNL; Havener, Charles C [ORNL; Howe, Jane Y [ORNL; Kiggans, Jim [ORNL; Vane, C Randy [ORNL; Mattolat, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Gottwald, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2012-01-01

137

Recent negative ion source activity at JYFL  

NASA Astrophysics Data System (ADS)

A filament-powered multicusp ion source for production of H- has been developed for the Jyväskylä Pelletron accelerator for use in ion beam lithography and particle induced X-ray emission applications. The source can be considered conventional with the exception of the filter field being created with an electric magnet for continuous adjustability. A permanent magnet dipoleantidipole electron dump is integrated in the puller electrode. The source provides 50 ?A H- beam at 10 keV energy with 0.019 mm mrad 95 % normalized rms emittance through a 2 mm aperture. Lower emittance is achievable by changing the plasma electrode insert to a smaller aperture one if application requires. A new commercial MCC30/15 cyclotron has been installed at the Jyväskylä accelerator laboratory providing 30MeV H+ and 15Mev D+ for use in nuclear physics experiments and applications. The ion source delivered with the cyclotron is a a filament-powered multicusp source capable of about 130 h continuous operation at 1 mA H- output between filament changes. The ion source is located in the cyclotron vault and therefore a significant waiting time for the vault cooldown is required before filament change is possible. This kind of operation is not acceptable as 350 h and longer experiments are expected. Therefore a project for developing a CW 13.56 MHz RF ion source has been initiated. A planar RF antenna replacing the filament back plate of the existing TRIUMF-type ion source has been used in the first tests with 240 ?A of H- and 21 mA of electrons measured at 1.5 kW of RF power. Tests with higher RF power levels were prevented by electron beam induced sparking. A new plasma chamber has been built and a new extraction is being designed for the RF ion source. The extraction code IBSimu has recently gone through a major update on how smooth electrode surfaces are implemented in the Poisson solvers. This has made it possible to implement a fast multigrid solver with low memory consumption. Also a method has been made to import 3D CAD geometries into simulations.

Kalvas, T.; Tarvainen, O.; Komppula, J.; Laitinen, M.; Sajavaara, T.; Koivisto, H.; Jokinen, A.; Dehnel, M. P.

2013-02-01

138

Negative ion source with low temperature transverse divergence optical system  

DOEpatents

A negative ion source is provided which has extremely low transverse divergence as a result of a unique ion focusing system in which the focal line of an ion beam emanating from an elongated, concave converter surface is outside of the ion exit slit of the source and the path of the exiting ions. The beam source operates with a minimum ion temperature which makes possible a sharply focused (extremely low transverse divergence) ribbon like negative ion beam.

Whealton, John H. (Oak Ridge, TN); Stirling, William L. (Oak Ridge, TN)

1986-01-01

139

Negative ion source with low temperature transverse divergence optical system  

DOEpatents

A negative ion source is provided which has extremely low transverse divergence as a result of a unique ion focusing system in which the focal line of an ion beam emanating from an elongated, concave converter surface is outside of the ion exit slit of the source and the path of the exiting ions. The beam source operates with a minimum ion temperature which makes possible a sharply focused (extremely low transverse divergence) ribbon like negative ion beam.

Whealton, J.H.; Stirling, W.L.

1985-03-04

140

Ion sources for induction linac driven heavy ion fusion  

SciTech Connect

The use of ion sources in induction linacs for heavy ion fusion is fundamentally different from their use in the rf linac-storage rings approach. Induction linacs require very high current, short pulse extraction usually with large apertures which are dictated by the injector design. One is faced with the problem of extracting beams in a pulsed fashion while maintaining high beam quality during the pulse (low-emittance). Four types of sources have been studied for this application. The vacuum arc and the rf cusp field source are the plasma types and the porous plug and hot alumino-silicate surface source are the thermal types. The hot alumino-silicate potassium source has proved to be the best candidate for the next generation of scaled experiments. The porous plug for potassium is somewhat more difficult to use. The vacuum arc suffers from noise and lifetime problems and the rf cusp field source is difficult to use with very short pulses. Operational experience with all of these types of sources is presented.

Rutkowski, H.L.; Eylon, S.; Chupp, W.W.

1993-08-01

141

Secondary electron ion source neutron generator  

DOEpatents

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter is disclosed. The target contains occluded deuterium, tritium, or a mixture thereof. 4 figs.

Brainard, J.P.; McCollister, D.R.

1998-04-28

142

Metal vapor vacuum arc ion source  

SciTech Connect

A high-current ion source is described in which a metal vapor vacuum arc is used to create the plasma from which the ion beam is extracted. An ion beam current of up to about 1 A has been measured at an extraction voltage of 25 kV for a range of metallic species spanning the periodic table from lithium to uranium. Multiply ionized charge states are seen up to as high as Q = 6+ in the case of uranium. In the metal vapor vacuum arc, regions of intense current concentration are formed at the cathode, and it is at these regions, the cathode spots, that the cathode material is vaporized and ionized to form a dense, quasi-neutral plasma which plumes away from the cathode surface. The plasma plume is caused to impinge upon a set of extractor grids, and the ion beam is extracted from the streaming metal plasma. A preliminary survey of the performance of the source has been made. We describe here the principle of operation of the source, the source design, and the results of those measurements that we have made to date.

Brown, I.G.; Galvin, J.E.; Gavin, B.F.; MacGill, R.A.

1986-06-01

143

Secondary electron ion source neutron generator  

DOEpatents

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof

Brainard, John P. (Albuquerque, NM); McCollister, Daryl R. (Albuquerque, NM)

1998-01-01

144

Vacuum arc ion sources-a brief historical review  

Microsoft Academic Search

The production of energetic metal ion beams by vacuum arc ion sources is a subfield of ion beam science and technology that has experienced rapid growth and a great deal of research activity in the last decade or so. Interest in this kind of ion source derives from the high current of metal ions that can be produced-these are the

Ian G. Brown; Efim M. Oks

1997-01-01

145

Adhesion and wear properties of TiN films deposited on martensitic stainless steel and Stellite by reactive magnetron sputter ion plating  

NASA Astrophysics Data System (ADS)

TiN films were deposited onto the turbine blade materials, AISI 403 martensitic stainless steel and Stellite 6B, using reactive magnetron sputter ion plating. The hardness of the TiN film increases with the residual compressive stress and has a maximum value of 3400 kg/mm 2 at the substrate bias of about -75 V. In the scratch adhesion test, the critical loads for cohesive failure and adhesive failure are sensitively governed by the film hardness. The wear rate decreases with increasing hardness and has a minimum value at about -75 V. The ion plated TiN has a superior wear resistance than the bare Stellite 6B and AISI 403 martensitic stainless steel.

Lee, Min Ku; Kim, Whung Whoe; Kim, Joung Soo; Lee, Won Jong

1998-03-01

146

Extracted current saturation in negative ion sources  

SciTech Connect

The extraction of negatively charged particles from a negative ion source is one of the crucial issues in the development of the neutral beam injector system for future experimental reactor ITER. Full 3D electrostatic particle-in-cell Monte Carlo collision code - ONIX [S. Mochalskyy et al., Nucl. Fusion 50, 105011 (2010)] - is used to simulate the hydrogen plasma behaviour and the extracted particle features in the vicinity of the plasma grid, both sides of the aperture. It is found that the contribution to the extracted negative ion current of ions born in the volume is small compared with that of ions created at the plasma grid walls. The parametric study with respect to the rate of negative ions released from the walls shows an optimum rate. Beyond this optimum, a double layer builds-up by the negative ion charge density close to the grid aperture surface reducing thus extraction probability, and therefore the extracted current. The effect of the extraction potential and magnetic field magnitudes on the extraction is also discussed. Results are in good agreement with available experimental data.

Mochalskyy, S.; Lifschitz, A. F.; Minea, T. [LPGP, University Paris-Sud 11, bat 210, 15 rue G. Clemenceau-Orsay, F91405 (France)

2012-06-01

147

Structural and electrical properties of half-Heusler La-Pt-Bi thin films grown by 3-source magnetron co-sputtering  

NASA Astrophysics Data System (ADS)

Half-Heusler La-Pt-Bi thin films have been deposited on YAlO3(001) substrate by 3-source magnetron co-sputtering. Control of the Bi content was the critical factor to obtain single phase, c-axis-oriented thin films. Generation of secondary phases was effectively prevented by precise control of the deposition rate for separate targets as well as adjustment of the deposition temperature. The realization of single-phase LaPtBi thin films will provide new potential applications to topological insulating devices based on Heusler alloys.

Miyawaki, Tetsuya; Sugimoto, Nozomi; Fukatani, Naoto; Yoshihara, Tatsuhiko; Ueda, Kenji; Tanaka, Nobuo; Asano, Hidefumi

2012-04-01

148

Note: development of ESS Bilbao's proton ion source: Ion Source Hydrogen positive.  

PubMed

The Ion Source Hydrogen positive is a 2.7 GHz off-resonance microwave discharge ion source. It uses four coils to generate an axial magnetic field in the plasma chamber around 0.1 T that exceeds the ECR resonance field. A new magnetic system was designed as a combination of the four coils and soft iron in order to increase the reliability of the source. The description of the simulations of the magnetic field and the comparison with the magnetic measurements are presented. Moreover, results of the initial commissioning of the source for extraction voltage until 50 kV will be reported. PMID:24593417

Miracoli, R; Feuchtwanger, J; Arredondo, I; Belver, D; Gonzalez, P J; Corres, J; Djekic, S; Echevarria, P; Eguiraun, M; Garmendia, N; Muguira, L

2014-02-01

149

The correlation between the radial distribution of high-energetic ions and the structural as well as electrical properties of magnetron sputtered ZnO:Al films  

SciTech Connect

The origin of the pronounced radial distributions of structural and electrical properties of magnetron sputtered ZnO:Al films has been investigated. The film properties were correlated with the radially resolved ion-distribution functions. While the positive ions exhibit low energies and a radial distribution with a maximum intensity opposite the center of the target, the negative ions can have energies up to several hundred eV, depending on the target potential, with a radial distribution with two maxima opposite the erosion tracks. The most prominent positive ion is that of the working gas (Ar{sup +}), while the highest flux of the negative ions is measured for negative oxygen O{sup ?}. The radial distribution of the flux of the high-energetic negative ions can clearly be related to the radial variations of the structural (c-axis lattice parameter, crystallite size) and electronic (resistivity) properties for sputtering from the planar target, which points to the decisive role of the high-energetic negative oxygen ions for the film quality. The relation between the negative ion bombardment and the structural as well as electronic properties can be explained by a qualitative model recently developed by us. The same target has also been investigated in the eroded state. In this case, the limited acceptance angle of the mass spectrometer leads to a misinterpretation of the radial distribution of the flux of the high-energetic negative ions. This effect can be explained by a simulation, based on the assumption that the high-energetic negative ions are mainly accelerated in the cathode (target) sheath perpendicular to the uneven substrate surface.

Bikowski, André; Welzel, Thomas; Ellmer, Klaus [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institute for Solar Fuels, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institute for Solar Fuels, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)

2013-12-14

150

Characterization of an iodine-based ionic liquid ion source and studies on ion fragmentation  

E-print Network

Electrosprays are a well studied source of charged droplets and ions. A specific subclass is the ionic liquid ion source (ILIS), which produce ion beams from the electrostatically stressed meniscus of ionic liquids. ILIS ...

Fedkiw, Timothy Peter

2010-01-01

151

Compact microwave ion source for industrial applications.  

PubMed

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams. PMID:22380346

Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok

2012-02-01

152

High-power magnetron transmitter as an RF source for the electron collider ring of the MEIC facility  

E-print Network

A novel concept of high-power transmitters utilizing the Continuous Wave (CW) magnetrons, frequency-locked by phase-modulated signals has been proposed to compensate energy losses caused by Synchrotron Radiation (SR) in the electron ring of the MEIC facility. At operating frequency of about 750 MHz the SR losses are ~2 MW. They can be compensated by some number of Superconducting RF (SRF) cavities at the feeding power of about 100-200 kW per cavity. A high-power CW transmitters, based on magnetrons, frequency-locked by phase-modulated signal, allowing a wide-band control in phase and power, and associated with a wide-band closed feedback loop are proposed to feed the SRF cavities to compensate the SR losses of the electron beam in the MEIC collider electron ring.

Kazakevich, G

2014-01-01

153

Field Ion Source Development for Neutron Generators  

SciTech Connect

An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption ({approx}20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with {approx}10,000 tip arrays have achieved deuterium ion currents of {approx}50 nA. Neutron production by field ionization has yielded {approx}10{sup 2} n/s from {approx}1 mm{sup 2} of array area using the deuterium-deuterium fusion reaction at 90 kV.

B. Bargsten Johnson; P. R. Schwoebel; C. E. Holland; P. J. Resnick; K. L. Hertz; D. L. Chichester

2012-01-01

154

Proton emission from a laser ion source.  

PubMed

At intensities of the order of 10(10) W?cm(2), ns pulsed lasers can be employed to ablate solid bulk targets in order to produce high emission of ions at different charge state and kinetic energy. A special interest is devoted to the production of protons with controllable energy and current from a roto-translating target irradiated in repetition rate at 1-10 Hz by a Nd:Yag pulsed laser beam. Different hydrogenated targets based on polymers and hydrates were irradiated in high vacuum. Special nanostrucutres can be embedded in the polymers in order to modify the laser absorption properties and the amount of protons to be accelerated in the plasma. For example, carbon nanotubes may increase the laser absorption and the hydrogen absorption to generate high proton yields from the plasma. Metallic nanostrucutres may increase the electron density of the plasma and the kinetic energy of the accelerated protons. Ion collectors, ion energy analyzer, and mass spectrometers, used in time-of-flight configuration, were employed to characterize the ion beam properties. A comparison with traditional proton ion source is presented and discussed. PMID:22380289

Torrisi, L; Cavallaro, S; Cutroneo, M; Margarone, D; Gammino, S

2012-02-01

155

Ion source with improved primary arc collimation  

DOEpatents

An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

Dagenhart, W.K.

1983-12-16

156

Development of a high current H(-) ion source for cyclotrons.  

PubMed

A multi-cusp DC H(-) ion source has been designed and fabricated for medical applications of cyclotrons. Optimization of the ion source is in progress, such as the improvement of the filament configuration, magnetic filter strength, extraction electrode's shape, configuration of electron suppression magnets, and plasma electrode material. A small quantity of Cs has been introduced into the ion source to enhance the negative ion beam current. The ion source produced 16 mA of DC H(-) ion beam with the Cs-seeded operation at a low arc discharge power of 2.8 kW. PMID:24593547

Etoh, H; Aoki, Y; Mitsubori, H; Arakawa, Y; Mitsumoto, T; Yajima, S; Sakuraba, J; Kato, T; Okumura, Y

2014-02-01

157

1+-n+ ECR ION SOURCE DEVELOPMENT TEST STAND  

SciTech Connect

A test stand for the investigation of 1+-n+ charge boosting using an ECR ion sources is currently being assembled at the Texas A&M Cyclotron Institute. The ultimate goal is to relate the charge-boosting of ions of stable species to possible charge-boosting of ions of radioactive species extracted from the diverse, low-charge-state ion sources developed for radioactive ion beams.

Donald P. May

2006-04-07

158

A PLASMA GUN DRIVER FOR THE SNS ION SOURCE  

Microsoft Academic Search

The original ion source developed for the Spallation Neutron Source* (SNS) was an RF-driven, multi-cusp source based on an internal antenna (plasma - immersed) and designed to produce ~ 40 mA of H - with a ~7% duty- factor. To date, the ion source has demonstrated very reliable operation during commissioning of the SNS accelerator and early operations at low

R. F. Welton; M. P. Stockli; S. N. Murray; J. Carr; J. R. Carmichael

159

Development of hollow anode penning ion source for laboratory application  

NASA Astrophysics Data System (ADS)

The research work presented here focuses for the development of miniature penning type ion source. One hollow anode penning type ion source was developed in our laboratory. The size of the ion source is 38 mm diameter and 55 mm length. The ion source consists of two cathodes, a hollow anode and one piece of rare earth permanent magnet. The plasma was created in the plasma region between cathodes and the hollow anode. The J × B force in the region helps for efficient ionization of the gas even in the high vacuum region˜1×10 -5 Torr. The ions were extracted in the axial direction with help of the potential difference between the electrodes and the geometry of the extraction angle. The effect of the extraction electrode geometry for efficient extraction of the ions from the plasma region was examined. This ion source is a self extracted ion source. The self extracted phenomena reduce the cost and the size of the ion source. The extracted ion current was measured by a graphite probe. An ion current of more than 200 ?A was observed at the probe placed 70 mm apart from the extraction electrode. In this paper, the structure of the ion source, effect of operating pressure, potential difference and the magnetic field on the extracted ion current is reported.

Das, B. K.; Shyam, A.; Das, R.; Rao, A. D. P.

2012-03-01

160

Progress of resonant ionization laser ion source development at GANIL.  

PubMed

SPIRAL2 (Système de Production d'Ions Radioactifs Accélérés en Ligne) is a research facility under construction at GANIL (Grand Accélérateur National d'Ions Lourds) for the production of radioactive ion beams by isotope separation on-line methods and low-energy in-flight techniques. A resonant ionization laser ion source will be one of the main techniques to produce the radioactive ion beams. GISELE (GANIL Ion Source using Electron Laser Excitation) is a test bench developed to study a fully operational laser ion source available for Day 1 operations at SPIRAL2 Phase 2. The aim of this project is to find the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results about the new ion source geometry will be presented. PMID:24593619

Henares, J L; Huguet, Y; Kron, T; Lecesne, N; Leroy, R; Osmond, B; Schneider, F; Sjödin, A M; Wendt, K

2014-02-01

161

The emittance and brightness characteristics of negative ion sources suitable for MeV ion implantation  

SciTech Connect

This paper provides the description and beam properties of ion sources suitable for use with ion implantation devices. Particular emphasis is placed on the emittance and brightness properties of state-of-the-art, high intensity, negative ion sources based on the cesium ion sputter principle. (WRF)

Alton, G.D.

1987-01-01

162

Vacuum arc ion sources: recent developments and applications  

Microsoft Academic Search

The vacuum arc ion source has evolved over the past 20 years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface

Ian Brown; Efim Oks

2005-01-01

163

Development of a lithium liquid metal ion source for MeV ion beam analysis  

SciTech Connect

Lithium liquid metal ion sources are an attractive complement to the existing gaseous ion sources that are extensively used for ion beam analysis. This is due in part to the high brightness of the liquid metal ion source and in part to the availability of a lithium ion beam. High brightness is of particular importance to MeV ion microprobes which are now approaching current density limitations on targets determined by the ion source. The availability of a lithium beam provides increased capabilities for hydrogen profiling and high resolution Rutherford backscattering spectrometry. This paper describes the design and performance of a lithium liquid metal ion source suitable for use on a 5MV Laddertron accelerator. Operational experience with the source and some of its uses for ion beam analysis are discussed. 8 refs., 2 figs.

Read, P.M.; Maskrey, J.T.; Alton, G.D.

1988-01-01

164

RF Ion Source-Driven IEC Design and Operation  

SciTech Connect

The next step needed to achieve higher neutron yields and improved neutron production efficiency with Inertial Electrostatic Confinement (IEC) sources requires operation with an external ion source so that the reaction chamber pressure is controlled separately for the source pressure. This paper presents recent progress in IEC research at the UIUC using a unique external ion source ILLIBS (Illinois Ion Beam Source). When filled with deuterium, the IEC provides {approx}10{sup 8} 2.5-MeV D-D fusion neutrons/sec at steady-state. The design and operation of a radiofrequency (RF) ion gun designed for this purpose is also discussed.

Miley, G.H.; Yang, Y.; Webber, J.; Shaban, Y.; Momota, H. [University of Illinois, Urbana-Champaign (United States)

2005-05-15

165

Photoionization of multiply charged ions at the advanced light source  

SciTech Connect

Photoionization of multiply charged ions is studied using the merged-beams technique at the Advanced Light Source. Absolute photoionization cross sections have been measured for a variety of ions along both isoelectronic and isonuclear sequences.

Schlachter, A.S.; Kilcoyne, A.L.D.; Aguilar, A.; Gharaibeh, M.F.; Emmons, E.D.; Scully, S.W.J.; Phaneuf, R.A.; Muller, A.; Schippers, S.; Alvarez, I.; Cisneros, C.; Hinojosa, G.; McLaughlin, B.M.

2004-10-07

166

Side extraction duoPIGatron-type ion source.  

SciTech Connect

We have designed and constructed a compact duoPIGatron-type ion source, for possible use in ion implanters, in such the ion can be extracted from side aperture in contrast to conventional duoPIGatron sources with axial ion extraction. The size of the side extraction aperture is 1x40 mm. The ion source was developed to study physical and technological aspects relevant to an industrial ion source. The side extraction duoPIGatron has stable arc, uniformly bright illumination, and dense plasma. The present work describes some of preliminary operating parameters of the ion source using Argon, BF3. The total unanalyzed beam currents are 23 mA using Ar at an arc current 5 A and 13 mA using BF3 gas at an arc current 6 A.

GUSHENETS,V.I.; OKS, E.M.; HERSCHOVITCH, A.; JOHNSON, B.M.

2007-08-26

167

Plasma studies on a duoPIGatron ion source  

Microsoft Academic Search

In an effort to develop a plasma source capable of producing a dense, quiescent, uniform plasma for extracting tens of amperes of hydrogen ions, experimental and theoretical studies on a duoPIGatron ion source have been pursued. A study of plasma generation in the duoPIGatron was begun and a discharge model was subsequently developed to explain observed source behavior. The discharge

C. C. Tsai; W. L. Stirling; P. M. Ryan

1977-01-01

168

Ion source for high-precision mass spectrometry  

DOEpatents

The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit. 2 figures, 3 tables.

Todd, P.J.; McKown, H.S.; Smith, D.H.

1982-04-26

169

Ion source for high-precision mass spectrometry  

DOEpatents

The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit.

Todd, Peter J. (Oak Ridge, TN); McKown, Henry S. (Oak Ridge, TN); Smith, David H. (Oak Ridge, TN)

1984-01-01

170

Fermilab HINS Proton Ion Source Beam Measurements  

SciTech Connect

The proton ion source for the High Intensity Neutrino Source (HINS) Linac front-end at Fermilab has been successfully commissioned. It produces a 50 keV, 3 msec beam pulse with a peak current greater than 20mA at 2.5Hz. The beam is transported to the radio-frequency quadrupole (RFQ) by a low energy beam transport (LEBT) that consists of two focusing solenoids, four steering dipole magnets and a beam current transformer. To understand beam transmission through the RFQ, it is important to characterize the 50 keV beam before connecting the LEBT to the RFQ. A wire scanner and a Faraday cup are temporarily installed at the exit of the LEBT to study the beam parameters. Beam profile measurements are made for different LEBT settings and results are compared to those from computer simulations. In lieu of direct emittance measurements, solenoid variation method based on profile measurements is used to reconstruct the beam emittance.

Tam, W.M.; Apollinari, G.; Chaurize, S.; Hays, S.; Romanov, G.; Scarpine, V.; Schmidt, C.; Webber, R.; /Fermilab

2009-05-01

171

A field evaporation deuterium ion source for neutron generators  

NASA Astrophysics Data System (ADS)

Proof-of-principle experiments have demonstrated an electrostatic field evaporation based deuterium ion source for use in compact, high-output deuterium-tritium neutron generators. The ion source produces principally atomic deuterium and titanium ions. More than 100 ML of deuterated titanium thin film can be removed and ionized from a single tip in less than 20 ns. The measurements indicate that with the use of microfabricated tip arrays the deuterium ion source could provide sufficient ion current to produce 109-1010 n/cm2 of tip array area.

Reichenbach, Birk; Solano, I.; Schwoebel, P. R.

2008-05-01

172

Double-layer ion acceleration triggered by ion magnetization in expanding radiofrequency plasma sources  

SciTech Connect

Ion energy distribution functions downstream of the source exit in magnetically expanding low-pressure plasmas are experimentally investigated for four source tube diameters ranging from about 5 to 15 cm. The magnetic-field threshold corresponding to a transition from a simple expanding plasma to a double layer-containing plasma is observed to increase with a decrease in the source tube diameter. The results demonstrate that for the four geometries, the double layer and the accelerated ion beam form when the ion Larmour radius in the source becomes smaller than the source tube radius, i.e., when the ions become magnetized in the source tube.

Takahashi, Kazunori [Department of Electrical and Electronic Engineering, Iwate University, Morioka 020-8551 (Japan); Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra 0200 (Australia); Charles, Christine; Boswell, Rod W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra 0200 (Australia); Fujiwara, Tamiya [Department of Electrical and Electronic Engineering, Iwate University, Morioka 020-8551 (Japan)

2010-10-04

173

A high brightness plasma sputter heavy negative ion source  

SciTech Connect

A high-intensity, pulsed-mode, plasma-sputter heavy negative ion source has been developed; this source holds promise for a number of uses, including tandem electrostatic accelerator/synchrotron injection applications. To date, the source has been used to generate mA intensities from more than 18 sputter probes. A brief description of the source and typical performance data for a number of ion species are given. In addition, basic ion source operational data, such as intensity versus cesium oven temperature, sputter probe voltage, and discharge pressure, along with emittance data, are presented. 12 refs., 11 figs., 2 tabs.

Alton, G.D.; Mori, Y.; Takagi, A.; Ueno, A.; Fukumoto, S.

1988-01-01

174

Negative ion source development for fusion application (invited).  

PubMed

Giant negative ion sources, producing high-current of several tens amps with high energy of several hundreds keV to 1 MeV, are required for a neutral beam injector (NBI) in a fusion device. The giant negative ion sources are cesium-seeded plasma sources, in which the negative ions are produced on the cesium-covered surface. Their characteristic features are discussed with the views of large-volume plasma production, large-area beam acceleration, and high-voltage dc holding. The international thermonuclear experimental reactor NBI employs a 1 MeV-40 A of deuterium negative ion source, and intensive development programs for the rf-driven source plasma production and the multistage electrostatic acceleration are in progress, including the long pulse operation for 3600 s. Present status of the development, as well as the achievements of the giant negative ion sources in the working injectors, is also summarized. PMID:20192420

Takeiri, Yasuhiko

2010-02-01

175

Ion source for tests of ion behavior in the Karlsruhe tritium neutrino experiment beam line  

NASA Astrophysics Data System (ADS)

An electron-impact ion source based on photoelectron emission was developed for ionization of gases at pressures below 10-4 mbar in an axial magnetic field in the order of 5 T. The ion source applies only dc fields, which makes it suitable for use in the presence of equipment sensitive to radio-frequency (RF) fields. The ion source was successfully tested under varying conditions regarding pressure, magnetic field, and magnetic-field gradient, and the results were studied with the help of simulations. The processes in the ion source are well understood, and possibilities for further optimization of generated ion currents are clarified.

Lukic, S.; Bornschein, B.; Drexlin, G.; Glück, F.; Kazachenko, O.; Schöppner, M.; Weinheimer, Ch.; Zoll, M. C. R.

2011-01-01

176

The effect of substrate bias voltages on impact resistance of CrAlN coatings deposited by modified ion beam enhanced magnetron sputtering  

NASA Astrophysics Data System (ADS)

CrAlN coatings were deposited on silicon and AISI H13 steel substrates using a modified ion beam enhanced magnetron sputtering system. The effect of substrate negative bias voltages on the impact property of the CrAlN coatings was studied. The X-ray diffraction (XRD) data show that all CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1), (2 0 0) (2 2 0) and (2 2 2) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing substrate bias voltage the coatings became more compact and denser, and the microhardness and fracture toughness of the coatings increased correspondingly. In the dynamic impact resistance tests, the CrAlN coatings displayed better impact resistance with the increase of bias voltage, due to the reduced emergence and propagation of the cracks in coatings with a very dense structure and the increase of hardness and fracture toughness in coatings.

Chunyan, Yu; Linhai, Tian; Yinghui, Wei; Shebin, Wang; Tianbao, Li; Bingshe, Xu

2009-01-01

177

Permanent magnet helicon source for ion propulsion Francis F. Chen  

E-print Network

Permanent magnet helicon source for ion propulsion Francis F. Chen Electrical Engineering by at least two groups for generating ions for space propulsion: the HDLT concept at the Australian National, emphasis has been on the plasma density and ion current that can be produced, but not much on the weight

Chen, Francis F.

178

Low energy spread ion source with a coaxial magnetic filter  

DOEpatents

Multicusp ion sources are capable of producing ions with low axial energy spread which are necessary in applications such as ion projection lithography (IPL) and radioactive ion beam production. The addition of a radially extending magnetic filter consisting of a pair of permanent magnets to the multicusp source reduces the energy spread considerably due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. A coaxial multicusp ion source designed to further reduce the energy spread utilizes a cylindrical magnetic filter to achieve a more uniform axial plasma potential distribution. The coaxial magnetic filter divides the source chamber into an outer annular discharge region in which the plasma is produced and a coaxial inner ion extraction region into which the ions radially diffuse but from which ionizing electrons are excluded. The energy spread in the coaxial source has been measured to be 0.6 eV. Unlike other ion sources, the coaxial source has the capability of adjusting the radial plasma potential distribution and therefore the transverse ion temperature (or beam emittance).

Leung, Ka-Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA)

2000-01-01

179

Characterization of an 8-cm Diameter Ion Source System  

NASA Technical Reports Server (NTRS)

Results of tests characterizing an 8-cm diameter ion source are presented. The tests were conducted in three separate vacuum test facilities at the University of Alabama-Huntsville, Colorado State University, and L3 Communications' ETI division. Standard ion optics tests describing electron backstreaming and total-voltage-limited impingement current behavior as a function of beam current were used as guidelines for selecting operating conditions where more detailed ion beam measurements were performed. The ion beam was profiled using an in-vacuum actuating probe system to determine the total ion current density and the ion charge state distribution variation across the face of the ion source. Both current density and ExB probes were utilized. The ion current density data were used to obtain integrated beam current, beam flatness parameters, and general beam profile shapes. The ExB probe data were used to determine the ratio of doubly to singly charged ion current. The ion beam profile tests were performed at over six different operating points that spanned the expected operating range of the DAWN thrusters being developed at L3. The characterization tests described herein reveal that the 8-cm ion source is suitable for use in (a) validating plasma diagnostic equipment, (b) xenon ion sputtering and etching studies of spacecraft materials, (c) plasma physics research, and (d) the study of ion thruster optics at varying conditions.

Li, Zhongmin; Hawk, C. W.; Hawk, Clark W.; Buttweiler, Mark S.; Williams, John D.; Buchholtz, Brett

2005-01-01

180

Volume and Surface-Enabled Volumne Negative Ion Sources  

SciTech Connect

H- volume sources and especially caesiated H- volume sources are important ion sources for generating high intensity proton beams, which then in turn generate large quantities of other particles. This paper discusses the physics and technology of the volume production and the caesium enhanced (surface) production of H- ions. Starting with Bacal s discovery of the H- volume production, the paper briefly recounts the development of some H- sources, which capitalized on this process to significantly increase the production of H- beams. Another significant increase was achieved in the 1990s by adding cesiated surfaces to supplement the volume produced ions with surface produced ions as illustrated with other H- sources. Finally the focus turns to some of the experience gained when such a source was successfully ramped up in H- output as well as in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source.

Stockli, Martin P [ORNL

2013-01-01

181

Volume and Surface-Enhanced Volume Negative Ion Sources  

E-print Network

H- volume sources and, especially, caesiated H- volume sources are important ion sources for generating high-intensity proton beams, which then in turn generate large quantities of other particles. This chapter discusses the physics and technology of the volume production and the caesium-enhanced (surface) production of H- ions. Starting with Bacal's discovery of the H- volume production, the chapter briefly recounts the development of some H- sources, which capitalized on this process to significantly increase the production of H- beams. Another significant increase was achieved in the 1990s by adding caesiated surfaces to supplement the volume-produced ions with surface-produced ions, as illustrated with other H- sources. Finally, the focus turns to some of the experience gained when such a source was successfully ramped up in H- output and in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source.

Stockli, M P

2013-01-01

182

A double-plasma source of continuous bipolar ion-ion beam  

SciTech Connect

A double-plasma source capable of the generation of a continuous bipolar ion-ion beam is described. The quasi-neutral ion-ion flow to an extraction electrode is formed in the system containing primary inductively coupled plasma separated from a secondary plasma by an electrostatic grid-type filter. The total current of each ion species to the 250 mm diameter extraction electrode is about 80 mA; the electron current does not exceed 30% of the ion current. Method of positive/negative ion current ratio control is proposed, allowing the ion currents ratio variation in wide range.

Dudin, S. V. [Department of Physics and Technology, V.N. Karazin Kharkiv National University, Kurchatova ave. 31, 61108 Kharkiv (Ukraine) [Department of Physics and Technology, V.N. Karazin Kharkiv National University, Kurchatova ave. 31, 61108 Kharkiv (Ukraine); Scientific Center of Physical Technologies, Svobody sq. 6, 61022 Kharkiv (Ukraine); Rafalskyi, D. V. [Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique, Palaiseau CEDEX 91128 (France)] [Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique, Palaiseau CEDEX 91128 (France)

2013-01-21

183

TOPICAL REVIEW: Physics and phenomena in pulsed magnetrons: an overview  

NASA Astrophysics Data System (ADS)

This paper reviews the contribution made to the observation and understanding of the basic physical processes occurring in an important type of magnetized low-pressure plasma discharge, the pulsed magnetron. In industry, these plasma sources are operated typically in reactive mode where a cathode is sputtered in the presence of both chemically reactive and noble gases typically with the power modulated in the mid-frequency (5-350 kHz) range. In this review, we concentrate mostly, however, on physics-based studies carried out on magnetron systems operated in argon. This simplifies the physical-chemical processes occurring and makes interpretation of the observations somewhat easier. Since their first recorded use in 1993 there have been more than 300 peer-reviewed paper publications concerned with pulsed magnetrons, dealing wholly or in part with fundamental observations and basic studies. The fundamentals of these plasmas and the relationship between the plasma parameters and thin film quality regularly have whole sessions at international conferences devoted to them; however, since many different types of magnetron geometries have been used worldwide with different operating parameters the important results are often difficult to tease out. For example, we find the detailed observations of the plasma parameter (particle density and temperature) evolution from experiment to experiment are at best difficult to compare and at worst contradictory. We review in turn five major areas of studies which are addressed in the literature and try to draw out the major results. These areas are: fast electron generation, bulk plasma heating, short and long-term plasma parameter rise and decay rates, plasma potential modulation and transient phenomena. The influence of these phenomena on the ion energy and ion energy flux at the substrate is discussed. This review, although not exhaustive, will serve as a useful guide for more in-depth investigations using the referenced literature and also hopefully as an inspiration for future studies.

Bradley, J. W.; Welzel, T.

2009-05-01

184

Versatile plasma ion source with an internal evaporator  

NASA Astrophysics Data System (ADS)

A novel construction of an ion source with an evaporator placed inside a plasma chamber is presented. The crucible is heated to high temperatures directly by arc discharge, which makes the ion source suitable for substances with high melting points. The compact ion source enables production of intense ion beams for wide spectrum of solid elements with typical separated beam currents of ˜100-150 ?A for Al +, Mn +, As + (which corresponds to emission current densities of 15-25 mA/cm 2) for the extraction voltage of 25 kV. The ion source works for approximately 50-70 h at 100% duty cycle, which enables high ion dose implantation. The typical power consumption of the ion source is 350-400 W. The paper presents detailed experimental data (e.g. dependences of ion currents and anode voltages on discharge and filament currents and magnetic flux densities) for Cr, Fe, Al, As, Mn and In. The discussion is supported by results of Monte Carlo method based numerical simulation of ionisation in the ion source.

Turek, M.; Prucnal, S.; Drozdziel, A.; Pyszniak, K.

2011-04-01

185

Emittance of compact microwave ion source for low energy application.  

PubMed

The emittance of the compact microwave ion source for low energy application was investigated. The source structure was slightly modified from the previously reported version. The extraction apertures of 3 mm and 4 mm were used to evaluate the emittance. It was found that the normalized emittance of the present ion source ranged from 6 × 10(-8) m?rad (3 mm extraction aperture) to 2 × 10(-7) m?rad (4 mm extraction aperture), which are similar to that of the original ion source. PMID:24593455

Gotoh, Yasuhito; Taguchi, Shuhei; Tsuji, Hiroshi; Ishikawa, Junzo; Sakai, Shigeki

2014-02-01

186

Selection and design of ion sources for use at the Holifield Radioactive Ion Beam Facility  

SciTech Connect

The Holifield Radioactive Ion beam Facility now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility. The choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. Although direct-extraction negative ion sources are clearly desirable, the ion formation efficiencies are often too low for practical consideration; for this situation, positive ion sources, in combination with charge exchange, are the logical choice. The high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the facility because of its low emittance, relatively high ionization efficiencies and species versatility, and because it has been engineered for remote installation, removal and servicing as required for safe handling in a high-radiation-level ISOL facility. The source will be primarily used to generate ion beams from elements with intermediate to low electron affinities. Prototype plasma-sputter negative ion sources and negative surface-ionization sources are under design consideration for generating radioactive ion beams from high-electron-affinity elements. The design features of these sources and expected efficiencies and beam qualities (emittances) will be described in this report.

Alton, G.D.; Haynes, D.L.; Mills, G.D.; Olsen, D.K.

1993-12-31

187

Plume characteristics of a multiple ion source thruster  

NASA Astrophysics Data System (ADS)

This report describes ion plume characteristics of a multiple ion source thruster that are important to propulsion subsystem, spacecraft system, and mission design engineers with respect to incorporation of the segmented ion thruster (SIT) within a space mission. These characteristics will address issues related to operational performance, lifetime, thruster interaction with a host spacecraft, multiple ion beam interaction, and repeatability of construction and operation. Information contained within this report can be helpful in evaluating subsystem / mission performance, and resolve possible thruster / spacecraft integration issues.Characteristics of the exhausted ion beam(s) were evaluated through two sets of experiments. The first involved measuring the two-dimensional ion current density distribution at several downstream locations from the thruster with concurrent operation of up to three ion sources. Assessments were made of plume symmetry, plume development as a function of downstream position, interactions between multiple ion beams, and beam divergence angles were calculated for individually operated ion sources. Ion beam asymmetries about the ion source centerline were observed. Construction of multiple ion source current density profiles through superposition of data obtained from operation of individual ions sources was attempted. Charge exchange effects appear to have impacted the analyses and some discrepancies between 'real' and 'constructed' results were observed. Beam divergence angles for R = 0.893 cases ranged from 10° to 18° and from 16° to 22° for R = 0.643 cases.The second set of experiments involved collection of ion charge state data with the use of an ExB mass spectrometer placed downstream of the thruster. Charge state data was collected along the ion source centerline for 3 fixed propellant flow rates and varible beam currents. Data was also collected for a fixed flow rate and beam current at positions located along the horizontal and vertical axes passing through the ion source centerline. Correction factors for thrust and propellant utilization based upon doubly charged ion production, as well as propellant backflow into the discharge chamber were determined. Asymmetries in the radial profiles, as well as inconsistencies between the profiles of singly and doubly charged ions and charge state ratio, were observed.

Tierney, C. Michael

1995-01-01

188

GISELE: A resonant ionization laser ion source for the production of radioactive ions at GANIL  

SciTech Connect

SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

Lecesne, N.; Alves-Conde, R.; De Oliveira, F.; Dubois, M.; Flambard, J. L.; Franberg, H.; Jardin, P.; Leroy, R.; Pacquet, J. Y.; Pichard, A.; Saint-Laurent, M. G. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Coterreau, E.; Le Blanc, F.; Olivier, A. [IPN Orsay, BP 1-91406 Orsay (France); Gottwald, T.; Mattolat, C.; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Staudinger Weg 7, 55099 Mainz (Germany); Lassen, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Rothe, S. [Department of Engineering, CERN, CH-1211 Geneva 23 (Switzerland)

2010-02-15

189

Extending Ion Source Life on High Current Ion Implant Tools with In-Situ Chemical Cleaning  

NASA Astrophysics Data System (ADS)

Ion source replacement is generally the most frequent maintenance activity on an ion implanter impacting both productivity and consumable costs. In this paper we review the different mechanisms responsible for ion source failure. We report on in-situ chemical cleaning tests conducted at Toshiba Oita, which have shown potential for significant extension in source life. Several factors impact the effectiveness of xenon difluoride including failure modes, cleaning time and flow rates.

Uvais, A.; Jinguji, M.; Sato, Y.; Yotsumoto, T.; Botet, A.

2011-01-01

190

Extending Ion Source Life on High Current Ion Implant Tools with In-Situ Chemical Cleaning  

SciTech Connect

Ion source replacement is generally the most frequent maintenance activity on an ion implanter impacting both productivity and consumable costs. In this paper we review the different mechanisms responsible for ion source failure. We report on in-situ chemical cleaning tests conducted at Toshiba Oita, which have shown potential for significant extension in source life. Several factors impact the effectiveness of xenon difluoride including failure modes, cleaning time and flow rates.

Uvais, A.; Botet, A. [ATMI, Danbury, CT (United States); Jinguji, M.; Sato, Y.; Yotsumoto, T. [Toshiba Corporation, Oita (Japan)

2011-01-07

191

Model for the description of ion beam extraction from electron cyclotron resonance ion sources.  

PubMed

The finite difference method trajectory code KOBRA3-INP has been developed now for 25 years to perform the simulation of ion beam extraction in three dimensions. Meanwhile, the code has been validated for different applications: high current ion beam extraction from plasma sources for ion implantation technology, neutral gas heating in fusion devices, or ion thrusters for space propulsion. One major issue of the development of this code was to improve the flexibility of the applied model for the simulation of different types of particle sources. Fixed emitter sources might be simulated with that code as well as laser ion sources, Penning ion sources, electron cyclotron resonance ion sources (ECRISs), or H(-) sources, which require the simulation of negative ions, negative electrons, and positive charges simultaneously. The model which has been developed for ECRIS has now been used to explore the conditions for the ion beam extraction from a still nonexisting ion source, a so called ARC-ECRIS [P. Suominen and F. Wenander, Rev. Sci. Instrum. 79, 02A305 (2008)]. It has to be shown whether the plasma generator has similar properties like regular ECRIS. However, the emittance of the extracted beam seems to be much better compared to an ECRIS equipped with a hexapole. PMID:20192465

Spädtke, P

2010-02-01

192

High brilliance negative ion and neutral beam source  

DOEpatents

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.

Compton, Robert N. (Oak Ridge, TN)

1991-01-01

193

Anode tufting, arc faulting and plasma nonuniformity in ion sources  

NASA Astrophysics Data System (ADS)

The observation of anode tufting in typical ion sources and the resulting source plasma inhomogeneity is reported. Plasma density and potential profiles across a stationary anode tuft, plasma density profiles in an experimental duopigatron ion source in the presence of a single anode tuft, plasma density profiles in the duopigatron in the absence of tufting, and current flow to the 'anode' and 'wall' of the duopigatron as a function of gas pressure are presented. Anode tufting in other experimental geometries is briefly described.

Jones, R.

1983-03-01

194

Measurement of beam characteristics from C(6+) laser ion source.  

PubMed

We developed a C(6+) laser ion source for a heavy-ion accelerator. A carbon target was irradiated with a Q-switched Nd:YAG laser (1064 nm wavelength, 1.4 J maximum laser energy, 10 ns pulse duration) to generate a high-density plasma. The laser ion source employed a rotating carbon target for continuous operation. Ion beams were extracted from the plasma through a drift space using a direct plasma injection scheme [B. Yu. Sharkov, A. V. Shumshurov, V. P. Dubenkow, O. B. Shamaev, and A. A. Golubev, Rev. Sci. Instrum. 63, 2841 (1992)] up to a maximum voltage of 40 kV. We measured the characteristics of the ion beams from the laser ion source and present the results of experiments here. PMID:24593626

Yamaguchi, A; Sako, K; Sato, K; Hayashizaki, N; Hattori, T

2014-02-01

195

Status of ion sources at National Institute of Radiological Sciencesa)  

NASA Astrophysics Data System (ADS)

The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.

Kitagawa, A.; Fujita, T.; Goto, A.; Hattori, T.; Hamano, T.; Hojo, S.; Honma, T.; Imaseki, H.; Katagiri, K.; Muramatsu, M.; Sakamoto, Y.; Sekiguchi, M.; Suda, M.; Sugiura, A.; Suya, N.

2012-02-01

196

Status of ion sources at National Institute of Radiological Sciences.  

PubMed

The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements. PMID:22380179

Kitagawa, A; Fujita, T; Goto, A; Hattori, T; Hamano, T; Hojo, S; Honma, T; Imaseki, H; Katagiri, K; Muramatsu, M; Sakamoto, Y; Sekiguchi, M; Suda, M; Sugiura, A; Suya, N

2012-02-01

197

Observation of Solitons in a Pulsed Magnetron Sputtering Discharge  

Microsoft Academic Search

We report on the formation of multiple ion acoustic solitons in an unipolar pulsed magnetron plasma.A high density plasma ( ˜ 10^18 cm-3) is created by applying a high power pulse (3 -- 7 J) with pulse length 100 mus and repetition frequency 50 Hz to a planar magnetron discharge. The temporal behaviour of the electron density measured by a

Jon Tomas Gudmundsson; Kristinn B. Gylfason; Jones Alami; Johan Böhlmark; Ulf Helmersson

2003-01-01

198

Sources and Losses of Ring Current Ions  

NASA Technical Reports Server (NTRS)

During geomagnetic quiet times, in-situ measurements of ring current energetic ions (few to few tens of keVs) from THEMIS spacecraft often exhibit multiple ion populations at discrete energies that extend from the inner magnetosphere to the magnetopause at dayside or plasma sheet at nightside. During geomagnetic storm times, the levels of fluxes as well as the mean energies of these ions elevated dramatically and the more smooth distributions in energies and distances during quiet times are disrupted into clusters of ion populations with more confined spatial extends. This reveals local plasma heating processes that might have come into play. Several processes have been proposed. Magnetotail dipolarization, sudden enhancement of field-aligned current, local current disruptions, and plasma waves are possible mechanisms to heat the ions locally as well as strong convections of energetic ions directly from the magnetotail due to reconnections. We will examine two geomagnetic storms on October 11, 2008 and July 22, 2009 to reveal possible heating mechanisms. We will analyze in-situ plasma and magnetic field measurements from THEMIS, GOES, and DMSP for the events to study the ion pitch angle distributions and magnetic field perturbations in the auroral ionosphere and inner magnetosphere where the plasma heating processes occur.

Chen, Sheng-Hsien; Fok, Mei-Ching H.; Angeloupoulos, Vassilis

2010-01-01

199

A novel surface ionization source for ion mobility spectrometer.  

PubMed

A surface ionization (SI) source is designed and prepared for ion mobility spectrometer (IMS). The source acts not only as an emitter but also an ion injector which can inject ions periodically into the drift region of drift tube. Using the dual-role source, the dimension of the drift tube can be decreased and the circuit for high voltage can be simplified efficiently. The IMS with the SI source has a response range of approximately 4 orders of magnitude and a good reproducibility to tri-ethylamine. Compared with radioactive ionization (RI), the ultra-short time for ion injection and the zero level base line of ion mobility spectrum are characteristics of the surface ionization. PMID:17386765

Hui-yong, Guo; Xiu-li, He; Xiao-guang, Gao; Jian, Jia; Jian-ping, Li

2007-03-21

200

Ion source and injection line for high intensity medical cyclotron.  

PubMed

A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 ?A/14 MeV was extracted from the cyclotron with a small multi-cusp H- ion source (CIAE-CH-I type) and a short injection line, which the H- ion source of 3 mA/25 keV H- beam with emittance of 0.3??mm?mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 ?A was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper. PMID:24593632

Jia, XianLu; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

2014-02-01

201

New ion source for KSTAR neutral beam injection system  

SciTech Connect

The neutral beam injection system (NBI-1) of the KSTAR tokamak can accommodate three ion sources; however, it is currently equipped with only one prototype ion source. In the 2010 and 2011 KSTAR campaigns, this ion source supplied deuterium neutral beam power of 0.7-1.6 MW to the KSTAR plasma with a beam energy of 70-100 keV. A new ion source will be prepared for the 2012 KSTAR campaign with a much advanced performance compared with the previous one. The newly designed ion source has a very large transparency ({approx}56%) without deteriorating the beam optics, which is designed to deliver a 2 MW injection power of deuterium beams at 100 keV. The plasma generator of the ion source is of a horizontally cusped bucket type, and the whole inner wall, except the cathode filaments and plasma grid side, functions as an anode. The accelerator assembly consists of four multi-circular aperture grids made of copper and four electrode flanges made of aluminum alloy. The electrodes are insulated using PEEK. The ion source will be completed and tested in 2011.

Kim, Tae-Seong; Jeong, Seung Ho; In, Sang-Ryul [Department of Nuclear Fusion Engineering Development, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

2012-02-15

202

New ion source for KSTAR neutral beam injection systema)  

NASA Astrophysics Data System (ADS)

The neutral beam injection system (NBI-1) of the KSTAR tokamak can accommodate three ion sources; however, it is currently equipped with only one prototype ion source. In the 2010 and 2011 KSTAR campaigns, this ion source supplied deuterium neutral beam power of 0.7-1.6 MW to the KSTAR plasma with a beam energy of 70-100 keV. A new ion source will be prepared for the 2012 KSTAR campaign with a much advanced performance compared with the previous one. The newly designed ion source has a very large transparency (˜56%) without deteriorating the beam optics, which is designed to deliver a 2 MW injection power of deuterium beams at 100 keV. The plasma generator of the ion source is of a horizontally cusped bucket type, and the whole inner wall, except the cathode filaments and plasma grid side, functions as an anode. The accelerator assembly consists of four multi-circular aperture grids made of copper and four electrode flanges made of aluminum alloy. The electrodes are insulated using PEEK. The ion source will be completed and tested in 2011.

Kim, Tae-Seong; Jeong, Seung Ho; In, Sang-Ryul

2012-02-01

203

Ion sources for initial use at the Holifield Radioactive Ion Beam Facility  

SciTech Connect

The Holifield Radioactive Ion Beam Facility (HRIBF) now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility; the choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. A high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the HRIBF because of its low emittance, relatively high ionization efficiencies and species versatility, and because it has been engineered for remote installation, removal and servicing as required for safe handling in a high-radiation-level ISOL facility. Prototype plasma-sputter negative ion sources and negative surface-ionization sources are also under design consideration for generating negative radioactive ion beams from high-electron-affinity elements. The design features of these sources and expected efficiencies and beam qualities (emittances) will be described in this report.

Alton, G.D.

1993-12-31

204

Electrohydrodynamically driven large-area liquid ion sources  

SciTech Connect

The patent describes a liquid ion source comprising means for generating, over a large area of the surface of a liquid capable of emitting ion, an electric field of a strength sufficient to induce emission of ions from the large area at a current density on the order of at least 5 kAcm/sup 2/, wherein the large area is on the order of at least 10 lambda/sup 2/ and lambda is the wavelength of an unstable surface wave generated in the ion source by the electric field.

Pregenzer, A.L.

1988-03-15

205

Expansion Discharge Source for Ion Beam Laser Spectroscopy of Cold Molecular Ions  

NASA Astrophysics Data System (ADS)

Molecular ions are important in several fields of research, and spectroscopy acts as a key tool in the study of these ions. However, problems such as low ion abundance, ion-neutral confusion, and spectral congestion due to high internal temperatures can hinder effective spectroscopic studies. To circumvent these problems, we are developing a technique called Sensitive, Cooled, Resolved, Ion BEam Spectroscopy (SCRIBES). This ion beam spectrometer will feature a continuous supersonic expansion discharge source to produce cold molecular ions, electrostatic ion optics to focus the ions into an ion beam and bend the beam away from co-produced neutral molecules, an overlap region for cavity enhanced spectroscopy, and a time-of-flight mass spectrometer. When completed, SCRIBES will be an effective tool for the study of large, fluxional, and complex molecular ions that are difficult to study with other means. The ion beam spectrometer has been successfully implemented with a hot ion source. This talk will focus on the work of integrating a supersonic expansion discharge source into the instrument. To better understand how the source would work in the whole ion beam instrument, characterization studies are being performed with spectroscopy of HN_2^+ in a section of the system to ascertain the rotational temperature of the ion expansion. Attempts are also underway to measure the ion current from a beam formed from the expansion. Once the source in this environment is properly understood, we will reintegrate it to the rest of the ion beam system, completing SCRIBES. A. A. Mills, B. M. Siller, M. W. Porambo, M. Perera, H. Kreckel and B. J. McCall J. Chem. Phys., 135, 224201, (2011). K. N. Crabtree, C. A. Kauffman and B. J. McCall Rev. Sci. Instrum. 81, 086103, (2010).

Porambo, Michael; Pearson, Jessica; Riccardo, Craig; McCall, Benjamin J.

2013-06-01

206

Cusp energetic ions: A bow shock source  

NASA Astrophysics Data System (ADS)

Recent interpretations of cusp energetic ions observed by the POLAR spacecraft have suggested a new energization process in the cusp [Chen et al., 1997; 1998]. Simultaneous enhancement of H+, He+2, and O>+2 fluxes indicates that they are of solar wind origin. In the present study, we examine H+ and He+2 energy spectra from 20 eV to several 100 keV measured by the Hydra, Toroidal Imaging Mass-Angle Spectrograph (TIMAS), and Charge and Mass Magnetospheric Ion Composition Experiment (CAMMICE) on POLAR. The combined spectrum for each species is shown to be continuous with a thermal distribution below 10 keV/e and an energetic component above 20 keV/e. Energetic ions with comparable fluxes and a similar spectral shape are commonly observed downstream from the Earth's quasi-parallel (Q?) bow shock. In addition to the similarity in the ion spectra, electric and magnetic field noise and turbulence detected in the cusp by the Plasma Wave Instrument (PWI) and Magnetic Field Experiment (MFE) onboard POLAR are similar to the previously reported observations at the bow shock. The waves appear to be coincidental to the cusp energetic ions rather than causal. We suggest that these ions are not accelerated locally in the cusp. Rather, they are accelerated at the Q? bow shock and enter the cusp along open magnetic field lines connecting both regions.

Chang, S.-W.; Scudder, J. D.; Fuselier, S. A.; Fennell, J. F.; Trattner, K. J.; Pickett, J. S.; Spence, H. E.; Menietti, J. D.; Peterson, W. K.; Lepping, R. P.; Friedel, R.

207

The influence of electrospray ion source design on matrix effects.  

PubMed

This study investigates to which extent the design of electrospray ion sources influences the susceptibility to matrix effects (MEs) in liquid chromatography-tandem mass spectrometry (LC-MS/MS). For this purpose, MEs were measured under comparable conditions (identical sample extracts, identical LC column, same chromatographic method and always positive ion mode) on four LC-MS/MS instrument platforms. The instruments were combined with five electrospray ion sources, viz. Turbo Ion Spray, Turbo V(TM) Source, Standard ESI, Jet Stream ESI and Standard Z-Spray Source. The comparison of MEs could be made at all retention times because the method of permanent postcolumn infusion was applied. The MEs ascertained for 45 pesticides showed for each electrospray ion source the same pattern, i.e. the same number of characteristic signal suppressions at equivalent retention times in the chromatogram. The Turbo Ion Spray (off-axis geometry), Turbo V(TM) Source (orthogonal geometry) and the Standard Z-Spray Source (double orthogonal geometry) did not differ much in their susceptibility to MEs. The Jet Stream ESI (orthogonal geometry) reaches a higher sensitivity by an additional heated sheath gas, but suffers at the same time from significantly stronger signal suppressions than the comparable Standard ESI (orthogonal geometry) without sheath gas. No relation between source geometry and extent of signal suppression was found in this study. PMID:22791255

Stahnke, Helen; Kittlaus, Stefan; Kempe, Günther; Hemmerling, Christlieb; Alder, Lutz

2012-07-01

208

Proposed laser ion source for the Columbia University microbeam  

E-print Network

: a high-power 100 Hz Nd:YAG laser, a source vacuum chamber and a 24° spherical electrostatic analyzer that will extend the linear energy transfer (LET) range of our experiments. This type of heavy ion source and the laser pulses will be guided to the source vacuum housing mounted at the accel- erator terminal

209

Pure radioactive Ga ion beams provided by new laser ion source for nuclear research at ORNL  

E-print Network

Pure radioactive Ga ion beams provided by new laser ion source for nuclear research at ORNL pure beams of radioactive nuclei far from stability. · Beams of neutron-rich Ga isotopes were delivered and intensity. · The -decay of the very exotic isotope 86Ga, delivered to LeRIBSS at the rate of several ions

210

High intensity metal ion beam production with ECR ion sources atthe Lawrence Berkeley National Laboratory  

Microsoft Academic Search

The large number of different experiments performed at the 88 Inch Cyclotron requires great variety and flexibility in the production of ion beams. This flexibility is provided by the two high performance electron cyclotron resonance (ECR) ion sources, the LBL ECR and the AECR-U, which can produce beams of ions as light as hydrogen and as heavy as uranium. With

D. Wutte; S. Abbott; M. A. Leitner; C. M. Lyneis

2001-01-01

211

High intensity metal ion beam production with ECR ion sources at the Lawrence Berkeley National Laboratory  

Microsoft Academic Search

The large number of different experiments performed at the 88 Inch Cyclotron requires great variety and flexibility in the production of ion beams. This flexibility is provided by the two high performance electron cyclotron resonance (ECR) ion sources, the LBL ECR and the AECR-U, which can produce beams of ions as light as hydrogen and as heavy as uranium. With

D. Wutte; S. Abbott; M. A. Leitner; C. M. Lyneis

2002-01-01

212

Novel Ion Traps for Enhanced Fluorescence Collections and Single Photon Sources Based on Barium Ions  

NASA Astrophysics Data System (ADS)

Efficient ion-photon interface is critical for ion-photon and ion-ion entanglement generation, which are the fundamental building blocks for loophole-free Bell inequality violation tests based on ion qubits, and for the quantum computer architecture based on ion-photon networks. As one approach to address the problem, the feasibility of integrating reflective optics into ion trap to increase free-space photon interception is studied. The development and operation of two novel ion traps are demonstrated: one integrates a spherical mirror with a linear quadrapole trap, and the other combines the optical surface with the RF electrode. The possibility of using aspherical optics to improve ion images is studied and partially implemented. A continuously excited single photon source based on 138Ba + ion is demonstrated and calibrated. Methods of scaling up current design are also discussed.

Shu, Gang

213

Production of molecular ion beams using an electron cyclotron resonance ion source  

NASA Astrophysics Data System (ADS)

An all-permanent magnet electron cyclotron resonance (ECR) ion source is tuned to create a variety of intense molecular ion beams for basic research. Based on simultaneous injection of several gases with spectroscopic high purity or enriched isotope content (e.g., H 2, D 2, N 2, O 2 or CO) and low power microwave heating, the ECR ion source produces diatomic molecular ion beams of H 2+, D 2+, HD +, HO +, DO +, NH +, ND + and more complex polyatomic molecular ions such as H 3+, D 3+, HD 2+, H 2O +, D 2O +, H 3O +, D 3O +, and NH n+, ND n+ with n=2,3,4 and possibly higher. Molecular ion beams have been produced with very high current intensities compared to other molecular beam sources. The recorded molecular ion beam spectra are discussed.

Dragani?, I. N.; Bannister, M. E.; Meyer, F. W.; Vane, C. R.; Havener, C. C.

2011-06-01

214

Neutral ion sources in precision manufacturing  

NASA Technical Reports Server (NTRS)

Ion figuring of optical components is a relatively new technology that can alleviate some of the problems associated with traditional contact polishing. Because the technique is non contacting, edge distortions and rib structure print through do not occur. This initial investigation was aimed at determining the effect of ion figuring on surface roughness of previously polished or ductile ground ceramic optical samples. This is the first step in research directed toward the combination of a pre-finishing process (ductile grinding or polishing) with ion figuring to produce finished ceramic mirrors. The second phase of the project is focusing on the development of mathematical algorithms that will deconvolve the ion beam profile from the surface figure errors so that these errors can be successfully removed from the optical components. In the initial phase of the project, multiple, chemical vapor deposited silicon carbide (CVD SiC) samples were polished or ductile ground to specular or near-specular roughness. These samples were then characterized to determine topographic surface information. The surface evaluation consisted of stylus profilometry, interferometry, and optical and scanning electron microscopy. The surfaces, were ion machined to depths from 0-5 microns. The finished surfaces were characterized to evaluate the effects of the ion machining process with respect to the previous processing methods and the pre-existing subsurface damage. The development of the control algorithms for figuring optical components has been completed. These algorithms have been validated with simulations and future experiments have been planned to verify the methods. This paper will present the results of the initial surface finish experiments and the control algorithms simulations.

Fawcett, Steven C.; Drueding, Thomas W.

1994-01-01

215

High current ion sources and injectors for induction linacs in heavy ion fusion  

Microsoft Academic Search

Heavy ion beam driven inertial fusion requires short ion beam pulses with high current and high brightness. Depending on the beam current and the number of beams in the driver system, the injector can use a large diameter surface ionization source or merge an array of small beamlets from a plasma source. In this paper, we review the scaling laws

Joe W. Kwan

2005-01-01

216

A review of ion sources for medical accelerators (invited)  

SciTech Connect

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 widespread 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.

Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

2012-02-15

217

A review of ion sources for medical accelerators (invited).  

PubMed

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 widespread since the 1990s. The energy and intensity are typically over 200 MeV and several 10(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(8) or 10(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. PMID:22380341

Muramatsu, M; Kitagawa, A

2012-02-01

218

Effect of resonant microwave power on a PIG ion source  

SciTech Connect

We have investigated the effect of applying microwave power at the electron cyclotron frequency on the characteristics of the ion beam extracted from a hotcathode PIG ion source. No change was seen in the ion charge state distribution. A small but significant reduction in the beam noise level was seen, and it is possible that the technique may find application in situations where beam quiescence is important.

Brown, I.G.; Galvin, B.F.; Galvin, J.E.; MacGill, R.A.

1985-10-01

219

An ion guide laser ion source for isobar-suppressed rare isotope beams.  

PubMed

Modern experiments at isotope separator on-line (ISOL) facilities like ISAC at TRIUMF often depend critically on the purity of the delivered rare isotope beams. Therefore, highly selective ion sources are essential. This article presents the development and successful on-line operation of an ion guide laser ion source (IG-LIS) for the production of ion beams free of isobaric contamination. Thermionic ions from the hot ISOL target are suppressed by an electrostatic potential barrier, while neutral radio nuclides effusing out are resonantly ionized by laser radiation within a quadrupole ion guide behind this barrier. The IG-LIS was developed through detailed thermal and ion optics simulation studies and off-line tests with stable isotopes. In a first on-line run with a SiC target a suppression of surface-ionized Na contaminants in the ion beam of up to six orders of magnitude was demonstrated. PMID:24689577

Raeder, Sebastian; Heggen, Henning; Lassen, Jens; Ames, Friedhelm; Bishop, Daryl; Bricault, Pierre; Kunz, Peter; Mjøs, Anders; Teigelhöfer, Andrea

2014-03-01

220

An ion guide laser ion source for isobar-suppressed rare isotope beams  

NASA Astrophysics Data System (ADS)

Modern experiments at isotope separator on-line (ISOL) facilities like ISAC at TRIUMF often depend critically on the purity of the delivered rare isotope beams. Therefore, highly selective ion sources are essential. This article presents the development and successful on-line operation of an ion guide laser ion source (IG-LIS) for the production of ion beams free of isobaric contamination. Thermionic ions from the hot ISOL target are suppressed by an electrostatic potential barrier, while neutral radio nuclides effusing out are resonantly ionized by laser radiation within a quadrupole ion guide behind this barrier. The IG-LIS was developed through detailed thermal and ion optics simulation studies and off-line tests with stable isotopes. In a first on-line run with a SiC target a suppression of surface-ionized Na contaminants in the ion beam of up to six orders of magnitude was demonstrated.

Raeder, Sebastian; Heggen, Henning; Lassen, Jens; Ames, Friedhelm; Bishop, Daryl; Bricault, Pierre; Kunz, Peter; Mjøs, Anders; Teigelhöfer, Andrea

2014-03-01

221

Conditioning of ion sources for mass spectrometry of plasmas  

SciTech Connect

Mass spectrometry is a useful diagnostic technique for monitoring plasma species and plasma-surface interactions. In order to maximize the sensitivity of measurements of hydrogen-fueled fusion plasmas or hydrogen-based discharge cleaning and etching plasmas, the ion sources of mass spectrometers are operated at or near the high pressure limit of 10/sup -4/ Torr (10/sup -2/ Pa). Such high ambient pressures of hydrogen give rise to high background levels of residual gases such as H/sub 2/O, CO, and CH/sub 4/, due to surface reactions on the ion source electrodes. For a commonly used ion source configuration, the residual gas production is a linear function of the ambient H/sub 2/ pressure. Hydrogen conditioning can reduce the absolute residual gas levels. Steady-state residual gas production is observed in a conditioned ion source, which is related to a balance of diffusion and sorption on the electrode surfaces.

Dylla, H.F.; Blanchard, W.R.

1983-02-01

222

Offline Ion Source Developments for the BECOLA Facility at NSCL  

NASA Astrophysics Data System (ADS)

Singly-charged beams of the stable isotope(s) of K, Ca, Mn, and Fe have been produced using either a commercial plasma ion source or a home-built electron ionization source for the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. For each element, collinear laser spectroscopy was performed to confirm the presence of the respective element. Production of stable ion beams for a given element is necessary to obtain reference hyperfine spectra of species with known electromagnetic moments before such nuclear properties can be deduced from the laser hyperfine-structure measurements of rare isotopes that are planned at NSCL. The results from the commissioning tests of the plasma and electron ionization sources will be presented, and development of a new Penning Ion Gauge (PIG) ion source will be discussed.

Klose, Andrew; Mantica, Paul; Minamisono, Kei

2013-04-01

223

Ion current detector for high pressure ion sources for monitoring separations  

DOEpatents

The present invention relates generally to any application involving the monitoring of signal arising from ions produced by electrospray or other high pressure (>100 torr) ion sources. The present invention relates specifically to an apparatus and method for the detection of ions emitted from a capillary electrophoresis (CE) system, liquid chromatography, or other small-scale separation methods. And further, the invention provides a very simple diagnostic as to the quality of the separation and the operation of an electrospray source. 7 figs.

Smith, R.D.; Wahl, J.H.; Hofstadler, S.A.

1996-08-13

224

Ion current detector for high pressure ion sources for monitoring separations  

DOEpatents

The present invention relates generally to any application involving the monitoring of signal arising from ions produced by electrospray or other high pressure (>100 torr) ion sources. The present invention relates specifically to an apparatus and method for the detection of ions emitted from a capillary electrophoresis (CE) system, liquid chromatography, or other small-scale separation methods. And further, the invention provides a very simple diagnostic as to the quality of the separation and the operation of an electrospray source.

Smith, Richard D. (Richland, WA); Wahl, Jon H. (Richland, WA); Hofstadler, Steven A. (Richland, WA)

1996-01-01

225

Ion-electron two-stream instability in EBIS ion sources  

NASA Astrophysics Data System (ADS)

We study the ion-electron two-stream instability, believed to limit the efficiency of EBIS ion sources. We find that it cannot be stabilized by electron kinetic effects, so that it unavoidably leads to heating of the ions. The latter thus spread radially beyond the electron beam radius, explaining the reduced efficiency of the sources. This finally suppresses the instability only when the efficiency is reduced to a few percents of its nominal value.

Jacquet, L.; Tagger, M.

1996-02-01

226

Recent advances in high current vacuum arc ion sources for heavy ion fusion  

Microsoft Academic Search

For a heavy ion fusion induction linac driver, a source of heavy ions with charge states 1+–3+, ?0.5A current beams, ?20?s pulse widths and ?10Hz repetition rates is required. Thermionic sources have been the workhorse for the Heavy Ion Fusion (HIF) program to date, but suffer from heating problems for large areas and contamination. They are limited to low (contact)

Niansheng Qi; Jochen Schein; Rahul R. Prasad; Mahadevan Krishnan; Andre Anders; Joe Kwan; Ian Brown

2001-01-01

227

Electrohydrodynamically driven large-area liquid ion sources  

DOEpatents

A large-area liquid ion source comprises means for generating, over a large area of the surface of a liquid, an electric field of a strength sufficient to induce emission of ions from a large area of said liquid. Large areas in this context are those distinct from emitting areas in unidimensional emitters.

Pregenzer, Arian L. (Corrales, NM)

1988-01-01

228

Electron Beam Ion Source Pre-Injector Diagnostics  

E-print Network

of diagnostics is currently proposed which includes faraday cups, current transformers, profile monitors, current transformer, pepperpot, electron beam ion source PACS: 29.17.+w, 29.25.Ni, 29.27.Fh INTRODUCTION Specification Electron Beam Current 10A Ion Beam Pulse Width 10 - 40 µs Intensity in Desired Charge State 1 x

229

Surface-electrode ion trap with integrated light source  

E-print Network

An atomic ion is trapped at the tip of a single-mode optical fiber in a cryogenic (8 K) surface-electrode ion trap. The fiber serves as an integrated source of laser light, which drives the quadrupolequbit transition of ...

Kim, Tony Hyun

230

Small cluster ions from source of negative ions by cesium sputtering  

NASA Astrophysics Data System (ADS)

We investigated the delivery of small cluster ions using a source of negative ions by cesium sputtering (SNICS). The negative cluster ions of B n, C n, Si n, Co n, Cu n, Ge n, Au n, GeB n and SiB n have been extracted by SNICS. Adequate beam current of some small clusters was obtained by changing several parameters for cluster ion yield. After a comprehensive study of the operation parameters, such as target material selection, target geometry, sputtering voltage and current, the small cluster ion current can be increased by several orders of magnitude, with little change on the monomer ion yield.

Wang, X. M.; Lu, X. M.; Shao, L.; Liu, J. R.; Chu, W. K.

2002-11-01

231

Pulsed operation of hall-current ion sources  

US Patent & Trademark Office Database

In accordance with one specific embodiment of the present invention, a Hall-current ion source is operated in a pulsed mode where the pulse duration is short compared to the time for discharge fluctuations to develop. For a reduced loss of neutral gas, the time between pulses should be less than, or about equal to, the fill time for the ionizable gas in the discharge volume of the Hall-current ion source.

2005-03-22

232

Design and construction of a radiofrequency ion source  

E-print Network

Cun assembly i'! tock Diagram ot Ion Source ~ ~ ~ 7 , 16 . Z3 Circuit of 50 Kilovolt Focusing Supply ~ ~ ~ ~ ~ ~ ~ ~ Z4 Circuit of 5 Kilovolt Extracting "upply. . . . ~. . . Z7 Circui't of l00 AC GsciHator ~ ~ ~ ~ ~ ~ i ~ ~ ~ ~ ~ ~ Zg Gas... '. eak, tssernbly ~ 3l T. ~P ~E 1 Comparison of Ion Sources. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4 ILLUSTK~ TIGN Mounting Plate, Insulator and Focusing Electrode. . . Zl Z Focusing Supply i ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Zl 3 Extracting Supply...

Butler, Charles Thomas

2012-06-07

233

Multiple species beam production on laser ion source for electron beam ion source in Brookhaven National Laboratory.  

PubMed

Extracted ion beams from the test laser ion source (LIS) were transported through a test beam transport line which is almost identical to the actual primary beam transport in the current electron beam ion source apparatus. The tested species were C, Al, Si, Cr, Fe, Cu, Ag, Ta, and Au. The all measured beam currents fulfilled the requirements. However, in the case of light mass ions, the recorded emittance shapes have larger aberrations and the RMS values are higher than 0.06 ??mm?mrad, which is the design goal. Since we have margin to enhance the beam current, if we then allow some beam losses at the injection point, the number of the single charged ions within the acceptance can be supplied. For heaver ions like Ag, Ta, and Au, the LIS showed very good performance. PMID:24593625

Sekine, M; Ikeda, S; Hayashizaki, N; Kanesue, T; Okamura, M

2014-02-01

234

Report on the workshop on ion sources for hadron colliders  

SciTech Connect

A workshop on Ion Sources for Hadron Colliders was held September 4--5, 1997 in Gelnhausen, Germany. This workshop, organized by the WE-Heraeus-Stiftung Foundation, the University of Frankfurt, Brookhaven National Laboratory, and CERN, directly followed the 7th Symposium on Electron Beam Ion Sources and Traps. Various options were reviewed for the development of a high current, intermediate charge state heavy ion source for use on colliders such as RHIC and LHC. In addition to status reports on ECR, EBIS, and laser sources, there was also discussion of issues relevant to the scaling of these sources to intensities as required by RHIC and LHC. The presentations and discussions from this workshop are summarized.

Alessi, J.G.

1997-11-01

235

An ion trap-ion mobility-time of flight mass spectrometer with three ion sources for ion/ion reactions.  

PubMed

This instrument combines the capabilities of ion/ion reactions with ion mobility (IM) and time-of-flight (TOF) measurements for conformation studies and top-down analysis of large biomolecules. Ubiquitin ions from either of two electrospray ionization (ESI) sources are stored in a three dimensional (3D) ion trap (IT) and reacted with negative ions from atmospheric sampling glow discharge ionization (ASGDI). The proton transfer reaction products are then separated by IM and analyzed via a TOF mass analyzer. In this way, ubiquitin +7 ions are converted to lower charge states down to +1; the ions in lower charge states tend to be in compact conformations with cross sections down to approximately 880 A(2). The duration and magnitude of the ion ejection pulse on the IT exit and the entrance voltage on the IM drift tube can affect the measured distribution of conformers for ubiquitin +7 and +6. Alternatively, protein ions are fragmented by collision-induced dissociation (CID) in the IT, followed by ion/ion reactions to reduce the charge states of the CID product ions, thus simplifying assignment of charge states and fragments using the mobility-resolved tandem mass spectrum. Instrument characteristics and the use of a new ion trap controller and software modifications to control the entire instrument are described. PMID:19493684

Zhao, Qin; Soyk, Matthew W; Schieffer, Gregg M; Fuhrer, Katrin; Gonin, Marc M; Houk, R S; Badman, Ethan R

2009-08-01

236

Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclay  

SciTech Connect

One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

Delferriere, O.; Gobin, R.; Harrault, F.; Nyckees, S.; Sauce, Y.; Tuske, O. [Commissariat a l'Energie Atomique, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France)

2012-02-15

237

Multicharged iron ions produced by using induction heating vapor source  

SciTech Connect

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{sup 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.

Kato, Yushi; Kubo, Takashi; Muramatsu, Masayuki; Tanaka, Kiyokatsu; Kitagawa, Atsushi; Yoshida, Yoshikazu; Asaji, Toyohisa; Sato, Fuminobu; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan and Department of Mechanical Engineering, Toyo University, 2100 Kuzirai, Kawagoe-shi, Saitama (Japan); Tateyama Machine Co., Ltd., Tateyama Kagaku Group, 30 Shimonoban, Toyama 930-1305 (Japan); National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Department of Mechanical Engineering, Toyo University, 2100 Kuzirai, Kawagoe-shi, Saitama (Japan); Tateyama Machine Co., Ltd., Tateyama Kagaku Group, 30 Shimonoban, Toyama 930-1305 (Japan); Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2008-02-15

238

Production of multicharged iron ions with inductively heated vapor source  

SciTech Connect

Multiply charged Fe ions are produced from solid material in a 2.45 GHz electron cyclotron resonance (ECR) ion source. We develop an evaporator by induction heating with an induction coil covered by ceramics in vacuum and surrounding the pure Fe rod with noncontact. The typical power and the frequency of the induction currents range from 300 to 800 W and from 30 to 40 kHz, respectively. The evaporator is inserted into the ECR plasma from the mirror endplate along the geometrical axis of the mirror field. Argon gas is usually chosen for supporting gas, and the working pressure is about 10{sup -4}-10{sup -3} Pa. The multicharged Fe ions are extracted from the opposite side of mirror and against the evaporator, and then multicharged Fe ion beam is formed. We compare the production of multicharged iron ions by using this source with our previous methods.

Kato, Yushi; Tomida, Masashi; Kubo, Takashi; Asaji, Toyohisa; Tanaka, Kiyokatsu; Sato, Fuminobu; Iida, Toshiyuki [Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Department of Electronics and Informatics, Toyama Pref. Univ. 5180 Kosugikurokawa, Imizu, Toyama 939-0398 (Japan); Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Tateyama Machine Co., Ltd., Tateyama Kagaku Group, 30 Shimonoban, Toyama 930-1305 (Japan); Tateyama Machine Co., Ltd., Tateyama Kagaku Group, 30 Shimonoban, Toyama 930-1305 (Japan); Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2006-03-15

239

Combinatorial characterization of transparent conductive properties of Ga-doped ZnO films cosputtered from electron cyclotron resonance and rf magnetron plasma sources  

SciTech Connect

The simultaneous sputtering of ZnO and Ga{sub 2}O{sub 3} by electron cyclotron resonance and rf magnetron plasma sources produced Ga-doped ZnO (GZO) films with continuously varying Ga concentration over the substrate surface. Combinatorial evaluation of electrical and optical properties of GZO film grown on silica glass substrate without heater annealing enabled identification of minimum resistivity (0.5 m{Omega} cm) at a Ga{sub 2}O{sub 3} content of 5.5 wt % with an optical transmittance of 90% in the visible wavelength. The monotonically decreasing mobility that was associated with increasing carrier concentration as Ga{sub 2}O{sub 3} content was increased indicated that conduction was governed by ionized impurity scattering. Above the critical Ga{sub 2}O{sub 3} content (6 wt %), carrier concentration decreased since excess Ga atoms that were incorporated beyond the solubility limit at Zn sites hindered large crystalline domains from forming. The ZnO (002) x-ray diffraction peak was suppressed and peaks assigned to Ga{sub 2}O{sub 3} were observed at high Ga{sub 2}O{sub 3} content. The optimum Ga{sub 2}O{sub 3} content shifted to 3.5 wt % at a deposition temperature of 200 deg. C and 2.5 wt % at 300 deg. C, and the minimum resistivity was further decreased to 0.28 m{Omega} cm at 200 deg. C. However, the resistivities at these elevated temperatures were incredibly high both at the lower and higher side of the optimum Ga{sub 2}O{sub 3} content.

Akazawa, Housei [NTT Microsystem Integration Laboratories, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan)

2010-03-15

240

Generation of intense beams of Pb4+-Pb10+ ions in a laser ion source (abstract)  

NASA Astrophysics Data System (ADS)

Experiments were carried out to optimize the yield of Pb4+ ions from a plasma produced by a 100 J CO2 laser. Laser power density on the target surface was varied in the range 1-9×1010 W/cm2 by changing the focal spot size. Data on the generation of Pb4+-Pb10+ ions are presented for 15 and 40 ns laser pulse durations. A 10 mA/80 ?s pulse of Pb4+ ions (about 1012 ions per pulse) was obtained in an extraction aperture with a diameter of 3.4 cm for optimal irradiation conditions. This is comparable with parameters of the MEVVA ion source. The laser ion source can be especially attractive due to the absence of the typical for MEVVA ion source "noise" problem. The emittance of a lead ion beam extracted from the laser-produced plasma was measured at a smaller laser providing parameters of plasma (electron temperature, ion velocities, and charge states) close to that of plasma generated by a 100 J CO2 laser optimized for the yield of Pb4+ ion conditions. The emittance was measured for different extraction voltages with temporal resolution. The value of about 400 pi mm mrad was found for the lead ion beam with a total current of 10 mA and pulse length of 75 ?s.

Kondrashev, S.; Mescheryakov, N.; Sharkov, B.; Shumshurov, A.; Balabaev, A.; Logkin, A.; Konukov, K.; Khomenko, S.; Makarov, K.; Nishchuk, S.; Roerich, V.; Satov, Y.; Smakovskii, Y.; Stepanov, A.

2002-02-01

241

Development of a negative hydrogen ion source for tandem proton accelerator using transformer couled plasma sources  

Microsoft Academic Search

A negative hydrogen ion source based on the transformer coupled plasma (TCP) source has been developed for 1.75 MeV tandem proton accelerator to detect underground explosives and mines. The TCP-based ion source has been designed and constructed for H- beam currents of 10 mA at the extraction voltage of 30 kV. High-density hydrogen plasmas of 1012 cm-3 are generated by

I. S. Hong; Y. S. Hwang; Y. S. Cho

2002-01-01

242

Development of a negative hydrogen ion source for tandem proton accelerator using transformer couled plasma sources  

Microsoft Academic Search

A negative hydrogen ion source based on the transformer coupled plasma (TCP) source has been developed for 1.75 MeV tandem proton accelerator to detect underground explosives and mines. The TCP-based ion source has been designed and constructed for H? beam currents of 10 mA at the extraction voltage of 30 kV. High-density hydrogen plasmas of 1012 cm?3 are generated by

I. S. Hong; Y. S. Hwang; Y. S. Cho

2002-01-01

243

SPUTTER PROBES AND VAPOR SOURCES FOR ECR ION SOURCES  

Microsoft Academic Search

Sputter probes are a promising method for injecting con- trolled quantities of metallic elements inside ECRIS, pro- vided that the sputter rate can be controlled, so that high charge states and low sample consumption rate will be attained. Moreover pressure at the probe and inside the source should be different. With a sputter probe distance of 25 mm from ECRIS

M. Cavenago; A. Galata; M. Sattin; T. Kulevoy; S. Petrenko

244

Remote System for Measuring the Parameters of an Ion Source.  

National Technical Information Service (NTIS)

A multichannel remote system for measuring the parameters of an ion source mounted on a high-voltage terminal is described. The electronic apparatus is made in the CAMAC standard. A 50 m fiber-optical line with a highly energetic source is used for inform...

Y. I. Romanov, I. Turzo

1986-01-01

245

Electron source for a mini ion trap mass spectrometer  

DOEpatents

An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

Dietrich, D.D.; Keville, R.F.

1995-12-19

246

Electron source for a mini ion trap mass spectrometer  

DOEpatents

An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

1995-01-01

247

Ion Sources and Injectors for HIF Induction Linacs  

SciTech Connect

Ion source and injector development is one of the major parts of the HIF program in the USA. Our challenge is to design a cost effective driver-scale injector and to build a multiple beam module within the next couple of years. In this paper, several current-voltage scaling laws are summarized for guiding the injector design. Following the traditional way of building injectors for HIF induction linac, we have produced a preliminary design for a multiple beam driver-scale injector. We also developed an alternate option for a high current density injector that is much smaller in size. One of the changes following this new option is the possibility of using other kinds of ion sources than the surface ionization sources. So far, we are still looking for an ideal ion source candidate that can readily meet all the essential requirements.

Kwan, J.W.; Ahle, L.; Beck, D.N.; Bieniosek, F. M.; Faltens, A.; Grote, D.P.; Halaxa, E.; Henestroza, E.; Herrmannsfeldt, W.B.; Karpenko, V.; Sangster, T.C.

2000-07-24

248

Comment on "Effects of Magnetic Field Gradient on Ion Beam Current in Cylindrical Hall Ion Source  

SciTech Connect

It is argued that the key difference of the cylindrical Hall thruster (CHT) as compared to the end-Hall ion source cannot be exclusively attributed to the magnetic field topology [Tang et al. J. Appl. Phys., 102, 123305 (2007)]. With a similar mirror-type topology, the CHT configuration provides the electric field with nearly equipotential magnetic field surfaces and a better suppression of the electron cross-field transport, as compared to both the end-Hall ion source and the cylindrical Hall ion source of Tang et al.

Raitses, Y.; Smirnov A.; Fisch, N.J.

2008-08-29

249

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

PubMed

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 e?A of C(5+) ion beam should be extracted from the ion source, and the beam emittance better than 75 ?*mm*mrad. In recent commissioning, about 120 e?A of C(5+) ion beam was got when work gas was CH4 while about 262 e?A 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. PMID:24593539

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

250

Transport of negative hydrogen and deuterium ions in RF-driven ion sources  

NASA Astrophysics Data System (ADS)

Negative hydrogen ion sources are major components of neutral beam injection systems for plasma heating in future large-scale fusion experiments such as ITER. In order to fulfill the requirements of the ITER neutral beam injection, a high-performance, large-area RF-driven ion source for negative ions is being developed at the MPI für Plasmaphysik. Negative hydrogen ions are mainly generated on a converter surface by impinging neutral particles and positive ions under the influence of magnetic fields and the plasma sheath potential. The 3D transport code TrajAn has been applied in order to obtain the total and spatially resolved extraction probabilities for H- and D- ions under identical plasma parameters and the realistic magnetic field topology of the ion source. A comparison of the isotopes shows a lower total extraction probability in the case of deuterium ions, caused by a different transport effect. The transport calculation shows that distortions of the spatial distributions of ion birth and extraction by the magnetic electron suppression field are present for both negative hydrogen and deuterium ions.

Gutser, R.; Wünderlich, D.; Fantz, U.; NNBI-Team

2010-04-01

251

Development of ion beams for space effects testing using an ECR ion source  

NASA Astrophysics Data System (ADS)

At LBNL's 88-Inch Cyclotron and Berkeley Accelerator Space Effects (BASE) Facility, a range of ion beams at energies from 1 to 55 MeV/nucleon are used for radiation space effects testing. By bombarding a component with ion beams the radiation component of the space environment can be simulated and single event effects (SEEs) determined. The performance of electronic components used in space flight and high altitude aircraft can then be evaluated. The 88- Inch Cyclotron is coupled to the three electron cyclotron resonance ion sources (ECR, AECR-U, VENUS). These ion sources provide a variety of ion species, ranging from protons to heavy ions such as bismuth, for these tests. In particular the ion sources have been developed to provide "cocktails", a mixture of ions of similar mass-to-charge ratio, which can be simultaneously injected into the cyclotron, but selectively extracted from it. The ions differ in both their linear energy transfer (LET) deposited to the part and in their penetration depth into the tested part. The current heavy ion cocktails available are the 4.5, 10, 16, and 30 MeV per nucleon.

Benitez, Janilee; Hodgkinson, Adrian; Johnson, Mike; Loew, Tim; Lyneis, Claude; Phair, Larry

2013-04-01

252

Recent advances in high current vacuum arc ion sources for heavy ion fusion  

NASA Astrophysics Data System (ADS)

For a heavy ion fusion induction linac driver, a source of heavy ions with charge states 1+-3+, ?0.5 A current beams, ?20 ?s pulse widths and ˜10 Hz repetition rates is required. Thermionic sources have been the workhorse for the Heavy Ion Fusion (HIF) program to date, but suffer from heating problems for large areas and contamination. They are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1+. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum arc ion source. The vacuum arc ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states in short and long pulse bursts and high beam current density. Under a Phase-I STTR from DOE, the feasibility of the vacuum arc ion source for the HIF applications was investigated. We have modified an existing vacuum arc ion source at LBNL to produce a gadolinium ( A?158) ion beam with >0.5 A beam current, 120 keV beam energy, ?6 cm diameter extraction aperture and ?20 ?s pulse width. The average beam current density at the extraction grids was ?17 mA/cm 2. We have measured that >85% Gd ions were in the 3+ charge state, the beam current fluctuation level (rms) was ?3%, pulse-to-pulse variation of the beam (rms) was about 3%, the uniformity of the beam density over its 6 cm diameter was ?98% and the ion longitudinal energy spread was ?1%. Additional measurements were made to improve charge state purity by using other materials and employing an axial magnetic field close to the cathode. Yttrium ( A?89), lead ( A?207), and Ba ( A?137) were tested at similar current parameters with Ba delivering nearly a pure charge state with >95% being in 2+ state. The results of the experiments indicate that the vacuum arc ion source is a good candidate for HIF applications.

Qi, Niansheng; Schein, Jochen; Prasad, Rahul R.; Krishnan, Mahadevan; Anders, Andre; Kwan, Joe; Brown, Ian

2001-05-01

253

Review of MEVVA ion source performance for accelerator injection  

SciTech Connect

The Mevva (metal vapor vacuum arc) ion source provides high current beams of multiply-charged metal ions suitable for use in heavy ion synchrotrons as well as for metallurgical ion implantation. Pulsed beam currents of up to several amperes can be produced at ion energies of up to several hundred keV. Operation has been demonstrate for 48 metallic ion species: Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th and U. When the source is operated optimally the rms fractional beam noise can be as low as 7% of the mean beam current; and when properly triggered the source operates reliably and reproducibly for many tens of thousands of pulses without failure. In this paper we review the source performance referred specifically to its use for synchrotron injection. 15 refs., 3 figs.

Brown, I.G.; Godechot, X. (Lawrence Berkeley Lab., CA (USA)); Spaedtke, P.; Emig, H.; Rueck, D.M.; Wolf, B.H. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany, F.R.))

1991-05-01

254

Spectroscopic applications of the ISOLDE laser ion source  

SciTech Connect

At the ISOLDE facility radioactive ion beams are produced via proton induced reactions in a target which is connected to a laser ion source. For beryllium a two step excitation scheme with laser light at wavelengths of {lambda}=235 nm and {lambda}=297 nm has been developed. Efficient laser ionization of beryllium was achieved with a new optical set-up using frequency tripling with two non-linear BBO crystals to generate laser light in the ultraviolet for the first excitation step. The second step was optimized to reach the 2p{sup 2} {sup 1}S{sub 0} autoionizing state for high ionization efficiency. The isotope shift of {sup 7,9,10,11,12,14}Be could be measured by tuning the wavelength of the first step. The laser ion source has also been used for the preparation of neutron-rich silver ion beams. Tuning the laser frequency of the first step it was possible to ionize selectively low-and high spin isomers of silver isotopes via the hyperfine structure. In both cases it was demonstrated that laser spectroscopy of exotic isotopes can be performed directly with the laser ion source. An outlook on other possible elements for laser spectroscopy using the laser ion source will be given.

Sebastian, V.; Huber, G. [Johannes-Gutenberg Universitaet, Institut fuer Physik, 55099 Mainz (Germany); Catherall, R.; Georg, U.; Jading, Y.; Jonsson, O.; Kugler, E.; Lettry, J.; Ravn, H. L.; Tamburella, C. [CERN, 1211 Geneva (Switzerland); Fedoseyev, V. N.; Mishin, V. I. [Institute of Spectroscopy, Russian Academy of Sciences, 142092 Troitsk (Russian Federation); Koester, U. [Technische Universitaet Muenchen, Physik-Department, 85748 Garching, Bavaria (Germany); Koizumi, M. [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, 370-12 Japan (Japan); Kratz, K.-L. [Johannes-Gutenberg Universitaet, Institut fuer Kernchemie, 55099 Mainz (Germany); Woehr, A. [KU Leuven, Instituut voor Kern- en Stralingfysika, 3001 Leuven (Belgium)

1998-12-21

255

Modeling of negative ion transport in a plasma source  

NASA Astrophysics Data System (ADS)

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.

Riz, David; Paméla, Jérôme

1998-08-01

256

Broad-beam multi-ampere metal ion source  

SciTech Connect

An embodiment of the MEVVA (metal vapor vacuum arc) high current metal ion source has been developed in which the beam is formed from a 10-cm-diam set of extractor grids and which produces a peak beam current of up to several amperes. The source, MEVVA V, operates in a pulsed mode with a pulsewidth, at present, of 0.25 ms and a repetition rate of up to several tens of pulses per second (power supply limited). The multi-cathode feature that was developed for the prior source version, MEVVA IV, has been incorporated here also; one can switch among any of 18 separate cathodes and thus metallic beam species. Maximum beam extraction voltage is over 90 kV, and since the ion charge states are typically from {ital Q}=1 to 5, depending on the metal employed, the ion energy in the extracted beam can thus be up to several hundred keV. This source is a new addition to the MEVVA family of metal ion sources, and we are at present investigating the operational regimes and the limits to the source performance. In this article we describe the source, and present some preliminary results.

Brown, I.G.; Galvin, J.E.; MacGill, R.A. (Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (US)); Paoloni, F.J. (Electrical Engineering Department, University of Wollongong, Wollongong NSW 2500, (Australia))

1990-01-01

257

Broad-beam multi-ampere metal ion source  

SciTech Connect

An embodiment of the MEVVA (metal vapor vacuum arc) high current metal ion source has been developed in which the beam is formed from a 10-cm diameter set of extractor grids and which produces a peak beam current of up to several Amperes. The source, MEVVA V, operates in a pulsed mode with a pulse width at present 0.25 ms and a repetition rate of up to several tens of pulses per second (power supply limited). The multicathode feature that was developed for the prior source version, MEVVA IV, has been incorporated here also; one can switch between any of 18 separate cathodes and thus metallic beam species. Maximum beam extraction voltage is over 90 kV, and since the ion charge state typically from Q = 1 to 5, depending on the metal employed, the ion energy in the extracted beam can thus be up to several hundred keV. This source is a new addition to the MEVVA family of metal ion sources, and we are at present investigating the operational regimes and the limits to the source performance. In this paper we describe the source and present some preliminary results. 10 refs., 4 figs.

Brown, I.G.; Galvin, J.E.; MacGill, R.A.; Paoloni, F.J. (Lawrence Berkeley Lab., CA (USA); Wollongong Univ. (Australia). Dept. of Electrical Engineering)

1989-06-01

258

Experiments with a synchrotron x-ray source and conventional, ECR, and storage-ring ion sources  

SciTech Connect

The present intensities of photon beams produced by synchrotron-radiation x-ray sources and of ion beams from conventional ion sources, electron-cyclotron resonance ion sources (ECRIS), and cooled heavy-ion storage rings (CHISR) make possible investigations of photoionization and photoexcitation processes that have not previously been feasible. An evaluation of the signal and background rates for experiments that employ the different types of ion sources is given here. 11 refs., 3 figs., 6 tabs.

Jones, K.W.; Johnson, B.M.; Meron, M.

1988-01-01

259

The status of the Electron Beam Ion Sources  

SciTech Connect

More than twenty years after its invention, 13 examples of the Electron Beam Ion Sources (EBIS) are in operation worldwide. The substantial progress in operation and insight, achieved over the last few years, made the EBISes become reliable tools for the production of beams of very highly charged, low-energy ions. For example, 8 EBISes produce bare argon on a standard basis. The successful production of hydrogen-like xenon presents the ions with the highest ionization energy, whereas the production of Th80+ presents the highest achieved charge state. Several synchrotrons are fed by EBIS injectors, taking advantage of the EBIS batch mode production, which yields the highest charge states. A few EBISes are used for ion source development. However, most of the EBISes' efforts are directed to research the physics of highly charged ions. Some of those are used to study the electron--ion interaction inside the source. But normally, most EBISes deliver the ions for external experiments, which so far concentrate on the recombination of the highly charged ions with atoms, molecules and surfaces. The ions are typically produced at a potential of 1 to a few kilovolts per charge; but in most cases, the EBIS is mounted on a high voltage platform or is followed by an RFQ, and therefore can generate ion energies from a few hundred volts up to a few hundred kilovolts per charge. The delivered beams have a low emittance and a low energy spread, which is an advantage for high-resolution experiments. This paper presents briefly all operational EBISes, their capabilities, their achievements, and their contribution to physics research. 5 figs., 1 tab., 59 refs.

Stockli, M.P.

1990-01-01

260

The status of the Electron Beam Ion Sources  

SciTech Connect

More than twenty years after its invention, 13 examples of the Electron Beam Ion Sources (EBIS) are in operation worldwide. The substantial progress in operation and insight, achieved over the last few years, made the EBISes become reliable tools for the production of beams of very highly charged, low-energy ions. For example, 8 EBISes produce bare argon on a standard basis. The successful production of hydrogen-like xenon presents the ions with the highest ionization energy, whereas the production of Th80+ presents the highest achieved charge state. Several synchrotrons are fed by EBIS injectors, taking advantage of the EBIS batch mode production, which yields the highest charge states. A few EBISes are used for ion source development. However, most of the EBISes` efforts are directed to research the physics of highly charged ions. Some of those are used to study the electron--ion interaction inside the source. But normally, most EBISes deliver the ions for external experiments, which so far concentrate on the recombination of the highly charged ions with atoms, molecules and surfaces. The ions are typically produced at a potential of 1 to a few kilovolts per charge; but in most cases, the EBIS is mounted on a high voltage platform or is followed by an RFQ, and therefore can generate ion energies from a few hundred volts up to a few hundred kilovolts per charge. The delivered beams have a low emittance and a low energy spread, which is an advantage for high-resolution experiments. This paper presents briefly all operational EBISes, their capabilities, their achievements, and their contribution to physics research. 5 figs., 1 tab., 59 refs.

Stockli, M.P.

1990-12-31

261

Pion source parameters in heavy ion collisions  

SciTech Connect

Following the early work of Goldhaber, Lee, and Pais, many experiments have used the momentum correlations between identical bosons to determine the space-time extent of the pion source for various reactions between elementary hadrons. This technique, known as intensity interferometry, has recently been applied to nuclear collisions at both intermediate and very high energies. Here we report on measurements of the radius and lifetime of the pion source in the reactions 1.8 A GeV /sup 40/Ar + KCl ..-->.. 2..pi../sup +-/ + X, 1.8 A GeV /sup 20/Na + NaF ..-->.. 2..pi../sup -/ + X, and 1.71 A GeV /sup 56/Fe + Fe ..-->.. 2..pi../sup -/ + X. 11 references.

Crowe, K.M.; Bistirlich, J.A.; Bossingham, R.R.; Bowman, H.R.; Clawson, C.W.; Frankel, K.A.; Hashimoto, O.; Humanic, T.J.; Ingersoll, J.G.; Koike, M.

1984-12-01

262

A Test Stand for Ion Sources of Ultimate Reliability  

SciTech Connect

The rationale behind the ITUR project is to perform a comparison between different kinds of H{sup -} ion sources using the same beam diagnostics setup. In particular, a direct comparison will be made in terms of the emittance characteristics of Penning Type sources such as those currently in use in the injector for the ISIS (UK) Pulsed Neutron Source and those of volumetric type such as that driving the injector for the ORNL Spallation Neutron Source (TN, U.S.A.). The endeavour here pursued is thus to build an Ion Source Test Stand where virtually any type of source can be tested and its features measured and, thus compared to the results of other sources under the same gauge. It would be possible then to establish a common ground for effectively comparing different ion sources. The long term objectives are thus to contribute towards building compact sources of minimum emittance, maximum performance, high reliability-availability, high percentage of desired particle production, stability and high brightness. The project consortium is lead by Tekniker-IK4 research centre and partners are companies Elytt Energy and Jema Group. The technical viability is guaranteed by the collaboration between the project consortium and several scientific institutions, such the CSIC (Spain), the University of the Basque Country (Spain), ISIS (STFC-UK), SNS (ORNL-USA) and CEA in Saclay (France)

Enparantza, R.; Uriarte, L.; Romano, P.; Alonso, J.; Ariz, I.; Egiraun, M. [Fundacion Tekniker-IK4, Eibar (Spain); Bermejo, F. J.; Etxebarria, V. [University of the Basque Country, Dpt. Electricity and Electronics, Leioa, Spain, and Consejo Superior de Investgaciones Cientificas, Inst. Estructura de la Materia (Spain); Lucas, J. [Elytt Energy, Portugalete (Spain); Del Rio, J. M. [Jema Group, Lasarte (Spain); Letchford, A.; Faircloth, D. [ISIS Accelerator Division, Rutherford Appleton Laboratory, Didcot (United Kingdom); Stockli, M. [Spallation Neutron Source, Oak Ridge National Lab, Oak Ridge (United States)

2009-03-12

263

Simulations of ionization in a hot cavity surface ion source.  

PubMed

A new numerical Monte Carlo method based model of a hot cavity surface ionization ion source is presented in this paper. The model, intended to support the studies on ionization phenomena in a widely used class of ion sources, takes into account geometry of the ion source and extraction system, ionizer temperature and other features. The results of ion source efficiency calculations for various configurations of the extraction field are reviewed. The dominant role of the ionizer region near the extraction opening is described. Simulated dependences of ionization efficiency on the working parameters like ionizer length and temperature, ionization potential of the substance, and extraction voltage are discussed. A good agreement of the experimental data (e.g., influence of ionizer temperature, current-voltage curve) and the predictions of the model is found. It is also shown that the contribution to the ionization yield from impact of thermionic electrons accelerated by the extraction field may be significant, especially for the substances of small surface ionization coefficient. The simulation results are compared to the predictions of different theoretical models of the ion source--the obtained simulation data are in accordance both with a well-known Kirchner formula and the so called spherical ionizer model. PMID:22380085

Turek, M; Dro?dziel, A; Pyszniak, K; M?czka, D; S?owi?ski, B

2012-02-01

264

Simulations of ionization in a hot cavity surface ion source  

NASA Astrophysics Data System (ADS)

A new numerical Monte Carlo method based model of a hot cavity surface ionization ion source is presented in this paper. The model, intended to support the studies on ionization phenomena in a widely used class of ion sources, takes into account geometry of the ion source and extraction system, ionizer temperature and other features. The results of ion source efficiency calculations for various configurations of the extraction field are reviewed. The dominant role of the ionizer region near the extraction opening is described. Simulated dependences of ionization efficiency on the working parameters like ionizer length and temperature, ionization potential of the substance, and extraction voltage are discussed. A good agreement of the experimental data (e.g., influence of ionizer temperature, current-voltage curve) and the predictions of the model is found. It is also shown that the contribution to the ionization yield from impact of thermionic electrons accelerated by the extraction field may be significant, especially for the substances of small surface ionization coefficient. The simulation results are compared to the predictions of different theoretical models of the ion source—the obtained simulation data are in accordance both with a well-known Kirchner formula and the so called spherical ionizer model.

Turek, M.; Dro?dziel, A.; Pyszniak, K.; Maczka, D.; S?owi?ski, B.

2012-02-01

265

Simulations of ionization in a hot cavity surface ion source  

SciTech Connect

A new numerical Monte Carlo method based model of a hot cavity surface ionization ion source is presented in this paper. The model, intended to support the studies on ionization phenomena in a widely used class of ion sources, takes into account geometry of the ion source and extraction system, ionizer temperature and other features. The results of ion source efficiency calculations for various configurations of the extraction field are reviewed. The dominant role of the ionizer region near the extraction opening is described. Simulated dependences of ionization efficiency on the working parameters like ionizer length and temperature, ionization potential of the substance, and extraction voltage are discussed. A good agreement of the experimental data (e.g., influence of ionizer temperature, current-voltage curve) and the predictions of the model is found. It is also shown that the contribution to the ionization yield from impact of thermionic electrons accelerated by the extraction field may be significant, especially for the substances of small surface ionization coefficient. The simulation results are compared to the predictions of different theoretical models of the ion source--the obtained simulation data are in accordance both with a well-known Kirchner formula and the so called spherical ionizer model.

Turek, M.; Drozdziel, A.; Pyszniak, K. [Institute of Physics, Maria Curie-Sklodowska University, pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin (Poland); MaPczka, D.; Slowinski, B. [Institute of Atomic Energy, Swierk-Otwock, 05-400 Otwock (Poland)

2012-02-15

266

Low fragment polyatomic molecular ion source by using permanent magnets.  

PubMed

Electron-ionization-type polyatomic molecular ion source with low fragment was developed by using a pair of ring-shaped Sm-Co magnets. The magnets were placed forward and backward side of ionization part to confine electrons extracted from a thermionic cathode. Calculated electron trajectory of the developed ion source was 20 times longer than that of an ordinary outer filament configuration that has no magnetic confinement. Mass spectra of the molecular ions generated from n-tetradecane (C14H30) gas exhibited 4 times larger intensity than that of the ordinary configuration in a range of mass/charge from 93 to 210 u. This indicates that suppression of fragment ion was obtained by increase of low energy electrons resulted from the electron confinement. PMID:24593425

Takeuchi, Mitsuaki; Hayashi, Kyouhei; Imanaka, Kousuke; Ryuto, Hiromichi; Takaoka, Gikan H

2014-02-01

267

Grid-controlled metal ion sources for heavy ion fusion accelerators  

Microsoft Academic Search

A variety of metal ions can be generated using vacuum arcs, but due to the nature of these arcs, the flux generated fluctuates in time. We have successfully employed electrostatically biased grids to control the plasma and to provide a well-behaved, space charge limited ion source. The grid prevents the plasma from entering the extraction gap before the main voltage

L. K. Len; S. Jr. Humphries; C. Burkhart

1986-01-01

268

Single-ring magnetic cusp low gas pressure ion source  

DOEpatents

A single-ring magnetic cusp low gas pressure ion source designed for use in a sealed, nonpumped neutron generator utilizes a cathode and an anode, three electrically floating electrodes (a reflector behind the cathode, a heat shield around the anode, and an aperture plate), together with a single ring-cusp magnetic field, to establish and energy-filtering mechanism for producing atomic-hydrogen ions.

Bacon, Frank M. (Albuquerque, NM); Brainard, John P. (Albuquerque, NM); O'Hagan, James B. (Albuquerque, NM); Walko, Robert J. (Albuquerque, NM)

1985-01-01

269

Ferroelectric Plasma Source for Heavy Ion Beam ChargeNeutralization  

SciTech Connect

Plasmas are employed as a source of unbound electrons for charge neutralizing heavy ion beams to allow them 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 {approx} 0.1-1 m would be suitable. To produce one-meter plasma, large-volume plasma sources based upon ferroelectric ceramics are being developed. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source utilizes the ferroelectric ceramic BaTiO{sub 3} to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) will be covered with ceramic, and high voltage ({approx} 1-5 kV) applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. A prototype ferroelectric source 20 cm long has produced plasma densities of 5 x 10{sup 11} cm{sup -3}. The source was integrated into the previous Neutralized Transport Experiment (NTX), and successfully charge neutralized the K{sup +} ion beam. Presently, the one-meter source is being fabricated. The source is being characterized and will be integrated into NDCX for charge neutralization experiments.

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

2005-10-01

270

Emission Characteristics and Stability of Laser Ion Sources  

SciTech Connect

A new classification of laser ion sources concerning their pulse-to-pulse reproducibility in the ion emission is proposed. In particular, we distinguish between plasmas according to the electron distribution changing its characteristics at a laser intensity threshold of 10{sup 14} W/cm{sup 2}. Well reproducible continuous pulsed ion currents are typical for the intensity below the threshold. In contrast to this plasma the 'two-temperature' plasma arising for the intensity above this threshold shows not only a separation of charges in space and time but it also shows irregular and intense outbursts of ions similar to a self pulsing instability leading to a chaos. The sequence of fast ion outbursts visible on time-of-flight spectra is sensitive to details of non-linear interaction of the sub-nanosecond laser beam with the generated plasma.

Krasa, J.; Velyhan, A.; Krousky, E.; Laska, L.; Rohlena, K.; Jungwirth, K. [Institute of Physics A.S.C.R., v.v.i., Prague, 182 21 (Czech Republic); Ullschmied, J. [Institute of Plasma Physics A.S.C.R., v.v.i., Prague, 182 20 (Czech Republic); Lorusso, A.; Velardi, L.; Nassisi, V. [Department of Physics, University of Salento, Laboratorio di Elettronica Applicata e Strumentazione, L.E.A.S. I.N.F.N. sez. di Lecce, CP 193, 73100 Lecce (Italy); Czarnecka, A.; Ryc, L.; Parys, P.; Wolowksi, J. [Institute of Plasma Physics and Laser Microfusion, 00-908 Warsaw (Poland)

2010-10-13

271

Design and development of the CSNS ion source control system  

NASA Astrophysics Data System (ADS)

Now that the CSNS ion source test stand has been stably working for years, an online control system for the CSNS ion source which aims to be more stable and reliable is now under development. F3RP61-2L, a new PLC CPU module running an embedded Linux system, is introduced to the system as an IOC, to function together with the I/O modules of FA-M3 PLC on the PLC-bus. The adoption of the new IOC not only simplifies the architecture of the control system, but also improves the data transmission speed. In this paper, the design and development of the supervisory and control system for the CSNS ion source are described.

Lu, Yan-Hua; Li, Gang; Ouyang, Hua-Fu

2013-07-01

272

Installation of a versatile multiaperture negative ion source.  

PubMed

Neutral Beam Injectors (NBI), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact RF ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H(-) current of 130 mA, 60 kV acceleration voltage, is being installed at Padua, in Consorzio RFX, to provide a test bench for source optimizations in the framework of the accompanying activities in support to the ITER NBI test facility. NIO1 construction and status of the overall installation, including a high voltage deck and an optical cavity ring down spectrometer are here summarized and reported. Plasma and low voltage beam operations are discussed. Development of a sampling beam calorimeter (with small sampling holes, and a segmented cooling circuit) is also discussed. PMID:24593438

Cavenago, M; Serianni, G; Antoni, V; Barbisan, M; Bigi, M; De Muri, M; Fagotti, E; Fellin, F; Kulevoy, T; Minarello, A; Pasqualotto, R; Petrenko, S; Poggi, M; Recchia, M; Rossetto, F; Sattin, M; Valente, M; Veltri, P

2014-02-01

273

Plasma and Ion Sources in Large Area Coatings: A Review  

SciTech Connect

Efficient deposition of high-quality coatings often requires controlled application of excited or ionized particles. These particles are either condensing (film-forming) or assisting by providing energy and momentum to the film growth process, resulting in densification, sputtering/etching, modification of stress, roughness, texture, etc. In this review, the technical means are surveyed enabling large area application of ions and plasmas, with ion energies ranging from a few eV to a few keV. Both semiconductortype large area (single wafer or batch processing with {approx} 1000 cm{sup 2}) and in-line web and glass-coating-type large area (> 10{sup 7} m{sup 2} annually) are considered. Characteristics and differences between plasma and ion sources are explained. The latter include gridded and gridless sources. Many examples are given, including sources based on DC, RF, and microwave discharges, some with special geometries like hollow cathodes and E x B configurations.

Anders, Andre

2005-02-28

274

Modified calutron negative ion source operation and future plans  

SciTech Connect

Negative ion generation has advanced rapidly by employing the concept of surface ionization. The modified calutron has proven to be a successful tool to explore these concepts and provide solutions to the many problems which must be evaluated. Many features of the SITEX (Surface Ionization with Transverse Extraction) ion source are ideally suited to this exploration. Some of these features are; a ribbon-like plasma, electron control by transverse magnetic fields and the ability to separate the Cs oven parameters from those which control the positive ion generation.

Dagenhart, W.K.; Stirling, W.L.; Haselton, H.H.; Kelley, G.G.; Kim, J.; Tsai, C.C.; Whealton, J.H.

1980-01-01

275

Modeling of negative ion transport in a plasma source (invited)  

NASA Astrophysics Data System (ADS)

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.

Riz, David; Paméla, Jérôme

1998-02-01

276

Flow of nanosize cluster-containing plasma in a magnetron discharge  

SciTech Connect

A magnetron source of silver clusters captured by an argon flow with the quadrupole mass filter is used for the analysis of charged clusters after an orifice of the magnetron chamber, and the size distribution function follows from the analysis of clusters deposited on a silicon substrate by an atomic force microscope. Cluster charge near an orifice results from attachment of ions of a secondary plasma that is a tail of a magnetron plasma, and the cluster charge is mostly positive. The character of passage of a buffer gas flow with metal clusters through an orifice is studied both theoretically and experimentally. Assuming the cone shape of the drift chamber near the orifice, we analyze drift of charged clusters in a buffer gas flow towards the orifice if the electric field inside the drift chamber is created by charged rings on the cone surface. Under experimental conditions, when an equilibrium between the buffer gas flow and cluster flux is violated, a typical voltage of rings and parameters of corona discharge for cluster charging are estimated if the electric field does not allow for clusters to reach walls of the drift chamber. The number density of clusters near the orifice is estimated that increases both due to violation of an equilibrium for the cluster flux inside the buffer gas flow and owing to focusing of the cluster by the electric field that is created by electrodes located near walls and due to diffusion motion of clusters. Processes of cluster charging in the magnetron chamber are analyzed.

Smirnov, Boris M. [Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 125412 (Russian Federation); Shyjumon, Ibrahimkutty; Hippler, Rainer [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Felix-Hausdorff-Strasse 6, 17489 Greifswald (Germany)

2007-06-15

277

Note: Flowing ion population from a resonance cavity source  

NASA Astrophysics Data System (ADS)

The experimental low energy plasma for hemispherical analyzers nominal testing thermal plasma facility of Dartmouth College uses a microwave plasma source which generates an ionosphere-like plasma through a two-step process. The plasma is initially generated inside a cylindrical, insulated, resonance cavity. This initial plasma must pass through a sheath in order to enter the main experimental region. This process imparts a significant flow velocity to the ions which has been neglected in previous analysis of this plasma source. We predict the flow energy of the ions to be between 12-15 eV depending on conservation laws and show agreement with experimental results.

Gayetsky, Lisa E.; Lynch, Kristina A.

2011-04-01

278

Note: flowing ion population from a resonance cavity source.  

PubMed

The experimental low energy plasma for hemispherical analyzers nominal testing thermal plasma facility of Dartmouth College uses a microwave plasma source which generates an ionosphere-like plasma through a two-step process. The plasma is initially generated inside a cylindrical, insulated, resonance cavity. This initial plasma must pass through a sheath in order to enter the main experimental region. This process imparts a significant flow velocity to the ions which has been neglected in previous analysis of this plasma source. We predict the flow energy of the ions to be between 12-15 eV depending on conservation laws and show agreement with experimental results. PMID:21529056

Gayetsky, Lisa E; Lynch, Kristina A

2011-04-01

279

Vacuum arc bismuth ion source with film cathode  

NASA Astrophysics Data System (ADS)

A new variant of vacuum arc ion source is described whereby the problems of short cathode lifetime and low charge states, commonly found for low boiling point cathode materials, are avoided. This novel source embodiment has been operated using bismuth as the wanted ionic species. It was found that the ion charge state spectrum can be improved (i.e., increased) significantly, with the charge state of maximum amplitude being increased from Bi1+ to Bi3+, and the number of pulses that were obtained before the cathode needed changing was 108.

Vasilyev, A.

1994-10-01

280

The use of ionic liquid ion sources (ILIS) in FIB applications  

E-print Network

A new monoenergetic, high-brightness ion source can be constructed using an arrangement similar to liquid metal ion sources (LMIS) by substituting the liquid metal with an ionic liquid, or room temperature molten salt. Ion ...

Zorzos, Anthony Nicholas

2009-01-01

281

Ion source with closed drift anode layer plasma acceleration  

NASA Astrophysics Data System (ADS)

Several versions of ion sources with closed drift anode layer plasma acceleration (ALPA sources) were built and tested. Robust, "all iron" design and water cooling permeate an unlimited operation with oxygen and with other high reactive gases. Long time operation of discharges in oxygen, nitrogen, argon, water vapor, propane, acetone, ethyl alcohol vapors, and in different gas cocktails has been tested. Beam parameters, generated in discharges with a voltage of Vd=0.3 to 3 kV will be presented. A simple design, only one simple power supply, and the operation without special electron source are advantages of discussed ALPA sources very suitable for many applications.

Dudnikov, V.; Westner, A.

2002-02-01

282

RF gas plasma source development for heavy ion fusion  

SciTech Connect

Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx}100 ns) for the extracted beam pulse must also be achieved. Progress on these experiments will be presented.

Ahle, L.E.; Hall, R.P.; Molvik, A.W.

2002-02-22

283

rf improvements for Spallation Neutron Source H- ion sourcea)  

NASA Astrophysics Data System (ADS)

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering ˜38 mA H- beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride (AlN) plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier.

Kang, Y. W.; Fuja, R.; Goulding, R. H.; Hardek, T.; Lee, S.-W.; McCarthy, M. P.; Piller, M. C.; Shin, K.; Stockli, M. P.; Welton, R. F.

2010-02-01

284

Recent progress on the superconducting ion source VENUS  

SciTech Connect

The 28 GHz Ion Source VENUS (versatile ECR for nuclear science) is back in operation after the superconducting sextupole leads were repaired and a fourth cryocooler was added. VENUS serves as an R and D device to explore the limits of electron cyclotron resonance source performance at 28 GHz with its 10 kW gryotron and optimum magnetic fields and as an ion source to increase the capabilities of the 88-Inch Cyclotron both for nuclear physics research and applications. The development and testing of ovens and sputtering techniques cover a wide range of applications. Recent experiments on bismuth demonstrated stable operation at 300 e{mu}A of Bi{sup 31+}, which is in the intensity range of interest for high performance heavy-ion drivers such as FRIB (Facility for Rare Isotope Beams). In addition, the space radiation effects testing program at the cyclotron relies on the production of a cocktail beam with many species produced simultaneously in the ion source and this can be done with a combination of gases, sputter probes, and an oven. These capabilities are being developed with VENUS by adding a low temperature oven, sputter probes, as well as studying the RF coupling into the source.

Benitez, J. Y.; Franzen, K. Y.; Hodgkinson, A.; Loew, T.; Lyneis, C. M.; Phair, L.; Saba, J.; Strohmeier, M. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tarvainen, O. [Accelerator Laboratory, Department of Physics, University of Jyvaeskylae, FIN-40014 (Finland)

2012-02-15

285

Construction of a versatile negative ion source and related developments  

NASA Astrophysics Data System (ADS)

The NIO1 project consisting of a 60 kV ion source (9 beamlets of 15 mA each of H-) is jointly developed by Consorzio RFX and INFN-LNL, with the purpose of providing a test ion source, capable of working in continuous mode and in condition similar to larger ion sources for Neutral Beam Injectors. The modular design allows for quick replacement and upgrading of parts. While the main body of the ion source construction is progressing at industry, some parts were separately developed at participating institution, as described in the following. A water free Carbon Fiber Composite (CFC) calorimeter is considered, together with more traditional water cooled calorimeters. A small rf plasma generator was installed at INFN-LNL and several rf matching boxes and a Cesium heater controller prototype were tested. Plasma generator (at ground) is followed by a puller and a positively biased Faraday cup, so that beam current can be measured. Plasma density estimated with a 4 wire Langmuir probe is consistent with plasma rf simulation, even if electron distribution deviation from Maxwellian seems large; new electronics with extended DC voltage sweep and a second Langmuir probe circuit are being tested. Finally preparation of the NIO1 site has begun at RFX and installation of source is expected to start in the end of 2012.

Cavenago, M.; Serianni, G.; Kulevoy, T.; Petrenko, S.; Agostinetti, P.; Antoni, V.; Bigi, M.; Conventi, D.; Fellin, F.; Minarello, A.; De Muri, M.; Pasqualotto, R.; Recchia, M.; Rigato, M.; Sattin, M.; Barbisan, M.; Rossetto, F.; Valente, M.; Veltri, P.

2013-02-01

286

Recent progress on the superconducting ion source VENUS.  

PubMed

The 28 GHz Ion Source VENUS (versatile ECR for nuclear science) is back in operation after the superconducting sextupole leads were repaired and a fourth cryocooler was added. VENUS serves as an R&D device to explore the limits of electron cyclotron resonance source performance at 28 GHz with its 10 kW gryotron and optimum magnetic fields and as an ion source to increase the capabilities of the 88-Inch Cyclotron both for nuclear physics research and applications. The development and testing of ovens and sputtering techniques cover a wide range of applications. Recent experiments on bismuth demonstrated stable operation at 300 e?A of Bi(31+), which is in the intensity range of interest for high performance heavy-ion drivers such as FRIB (Facility for Rare Isotope Beams). In addition, the space radiation effects testing program at the cyclotron relies on the production of a cocktail beam with many species produced simultaneously in the ion source and this can be done with a combination of gases, sputter probes, and an oven. These capabilities are being developed with VENUS by adding a low temperature oven, sputter probes, as well as studying the RF coupling into the source. PMID:22380158

Benitez, J Y; Franzen, K Y; Hodgkinson, A; Loew, T; Lyneis, C M; Phair, L; Saba, J; Strohmeier, M; Tarvainen, O

2012-02-01

287

Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source  

SciTech Connect

A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U{sup 35+} for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.

Higurashi, Y.; Ohnishi, J.; Nakagawa, T.; Haba, H.; Fujimaki, M.; Komiyama, M.; Kamigaito, O. [RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Tamura, M.; Aihara, T.; Uchiyama, A. [SHI Accelerator Service Ltd., 1-17-6 Osaki, Shinagawa, Tokyo 141-0032 (Japan)

2012-02-15

288

Tungsten nanostructure formation in a magnetron sputtering device  

NASA Astrophysics Data System (ADS)

He+ ion induced tungsten nanostructure (tungsten fuzz) has been created for the first time in a magnetron sputtering device. The nanostructure was formed on a W substrate facing the target, the sample surface temperature was held at 1000 K, with an incident ion energy of 56.5 eV, and a helium ion fluence of 2.4 × 1024 m-2.

Petty, T. J.; Bradley, J. W.

2014-10-01

289

ORNL developments in laser ion sources for radioactive ion beam production  

NASA Astrophysics Data System (ADS)

The development of a resonant ionization laser ion source (RILIS) for the production of isotopically pure radioactive ion beams is reported. The application of the laser ion source calls for high elemental selectivity, high efficiency, and fast release of short-lived isotopes. A hot-cavity ion source and three Ti:sapphire lasers pulsed at a 10 kHz rate are employed for the RILIS. The Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate intracavity Pockels cells and output losses due to synchronization delays. The development of ionization schemes for a wide range of elements is important to the success of Ti:sapphire-laser-based RILIS. In off-line studies with stable isotopes, resonant ionization of 14 elements has been studied, leading to new ionization schemes for ten elements. The absolute ionization efficiency of the hot-cavity RILIS has been measured to range from 0.9 % to 40 % for different elements. The mechanisms for ion transportation and confinement in the hot-cavity ion source have been studied using the temporal profiles of the laser-ionized ions. The hot-cavity RILIS has provided beams of neutron-rich Ga isotopes for beta decay studies and enabled the first measurement of the beta decay of the exotic Ga.

Liu, Yuan

2014-06-01

290

Models of radiofrequency coupling for negative ion sources  

SciTech Connect

Radiofrequency heating for ICP (inductively coupled plasma) ion sources depends on the source operating pressure, the presence or absence of a Faraday shield, the driver coil geometry, the frequency used, and the magnetic field configuration: in negative ion source a magnetic filter seems necessary for H{sup -} survival. The result of single particle simulations showing the possibility of electron acceleration in the preglow regime and for reasonable driver chamber radius (15 cm) is reported, also as a function of the static external magnetic field. An effective plasma conductivity, depending not only from electron density, temperature, and rf field but also on static magnetic field is here presented and compared to previous models. Use of this conductivity and of multiphysics tools for a plasma transport and heating model is shown and discussed for a small source.

Cavenago, M.; Petrenko, S. [INFN-LNL, viale dell'Universita n.2, 35020 Legnaro (Italy)

2012-02-15

291

A simple radionuclide-driven single-ion source  

NASA Astrophysics Data System (ADS)

We describe a source capable of producing single barium ions through nuclear recoils in radioactive decay. The source is fabricated by electroplating G148d onto a silicon ?-particle detector and vapor depositing a layer of BaF2 over it. S144m recoils from the alpha decay of G148d are used to dislodge Ba+ ions from the BaF2 layer and emit them in the surrounding environment. The simultaneous detection of an ? particle in the substrate detector allows for tagging of the nuclear decay and of the Ba+ emission. The source is simple, durable, and can be manipulated and used in different environments. We discuss the fabrication process, which can be easily adapted to emit most other chemical species, and the performance of the source.

Montero Díez, M.; Twelker, K.; Fairbank, W.; Gratta, G.; Barbeau, P. S.; Barry, K.; DeVoe, R.; Dolinski, M. J.; Green, M.; LePort, F.; Müller, A. R.; Neilson, R.; O'Sullivan, K.; Ackerman, N.; Aharmin, B.; Auger, M.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Cook, S.; Daniels, T.; Donato, K.; Farine, J.; Giroux, G.; Gornea, R.; Graham, K.; Hagemann, C.; Hall, C.; Hall, K.; Hallman, D.; Hargrove, C.; Herrin, S.; Karelin, A.; Kaufman, L. J.; Kuchenkov, A.; Kumar, K.; Lacey, J.; Leonard, D. S.; Mackay, D.; MacLellan, R.; Mong, B.; Niner, E.; Odian, A.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Pushkin, K.; Rollin, E.; Rowson, P. C.; Sinclair, D.; Slutsky, S.; Stekhanov, V.; Vuilleumier, J.-L.; Wichoski, U.; Wodin, J.; Yang, L.; Yen, Y.-R.

2010-11-01

292

Simulations for the generation and extraction of negative hydrogen ions in RF-driven ion sources  

NASA Astrophysics Data System (ADS)

The injection of energetic neutral hydrogen atoms plays an important part for plasma heating in fusion experiments. In order to fulfill the requirements of the ITER neutral beam injection (NBI), a RF-driven ion source based on the generation of negative ions prior to neutralization has been successfully developed at IPP Garching. Negative hydrogen ions are generated on a cesiated converter surface (plasma grid) by neutral particles and positive ions and are then transported to the extraction apertures, where the ion beam formation process takes place. Numerical models are necessary to include the relevant physical aspects of these processes. The Monte Carlo transport code CSFLOW is used to describe the dynamical behavior of the cesium distribution on the source walls during vacuum operation. The negative ion transport process is simulated by means of the probabilistic ion transport code TRAJAN, focussing on the effects of aperture diameter variations in mono- and multiaperture extraction systems. A simulation of ion beam formation is carried out with the KOBRA3 ray tracing code, which allows a full 3d potential solution without any symmetry restriction. This is necessary to simulate beam steering effects by a non-axisymmetric magnetic field and electrode configuration for the design of the extraction systems for future negative ion experiments.

Gutser, R.; Wü; nderlich, D.; Fantz, U.; Franzen, P.; Heinemann, B.; Nocentini, R.

2009-03-01

293

The RHIC Optically-Pumped Polarized H Ion Source.  

SciTech Connect

The depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the OPPIS (Optically-Pumped Polarized H{sup -} Ion Source) are discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86-90%. This contributed to increasing polarization in the AGS and RHIC to 65-70%.

Zelenski,A.; Zelenski, A.; Kokhanovski, S.; Kponou, A.; Ritter, J.; Zubets, V.

2007-09-10

294

A high-performance electron beam ion source  

SciTech Connect

At Brookhaven National Laboratory, a high current Electron Beam Ion Source (EBIS) has been developed as part of a new preinjector that is under construction to replace the Tandem Van de Graaffs as the heavy ion preinjector for the RHIC and NASA experimental programs. This preinjector will produce milliampere-level currents of essentially any ion species, with q/A {ge} 1/6, in short pulses, for injection into the Booster synchrotron. In order to produce the required intensities, this EBIS uses a 10A electron gun, and an electron collector designed to handle 300 kW of pulsed electron beam power. The EBIS trap region is 1.5 m long, inside a 5T, 2m long, 8-inch bore superconducting solenoid. The source is designed to switch ion species on a pulse-to-pulse basis, at a 5 Hz repetition rate. Singly-charged ions of the appropriate species, produced external to the EBIS, are injected into the trap and confined until the desired charge state is reached via stepwise ionization by the electron beam. Ions are then extracted and matched into an RFQ, followed by a short IH Linac, for acceleration to 2 MeV/A, prior to injection into the Booster synchrotron. An overview of the preinjector is presented, along with experimental results from the prototype EBIS, where all essential requirements have already been demonstrated. Design features and status of construction of the final high intensity EBIS is also be presented.

Alessi,J.; Beebe, E.; Bellavia, S.; Gould, O.; Kponou, A.; Lambiase, R.; Lockey, R.; McCafferty, D.; Okamura, M.; Pikin, A. I.; Raparia, D.; Ritter, J.; Syndstrup, L.

2009-06-08

295

Ion angular distribution in plasma of vacuum arc ion source with composite cathode and elevated gas pressure.  

PubMed

The Metal Vapor Vacuum Arc (MEVVA) ion sources are capable of generating ion beams of almost all metals of the periodic table. For this kind of ion source, a combination of gas feeding with magnetic field allows the simultaneous generation of both metal and gaseous ions. That makes the MEVVA ion source an excellent instrument for science and application. This work presents results of investigation for ion angular distributions in vacuum arc plasma of Mevva-V.Ru ion source for composite cathodes and for elevated gas pressure. It was shown that for all the cathode materials, singly charged ions have wider angular distribution than multiply charged ions. Increasing the working gas pressure leads to a significant change in the angular distribution of gaseous ions, while with the distribution of metal ions gas remains practically unchanged. The reasons for such different influences are discussed. PMID:24593598

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

2014-02-01

296

Plasma spectroscopy of metal ions for hyper-electron cyclotron resonance ion source.  

PubMed

In this research, the optical line spectra of metal ions from ECR plasma were observed using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for the beam tuning process, because it allows to conduct the extraction of the desired metal ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research provides a new approach for its simplification. In this paper the grating monochromator method for metal ion beam tuning such as (40)Ca(12+), (56)Fe(15+), and (85)Rb(20+) of hyper-ECR ion source as an injector for RIKEN Azimuthal Varying Field cyclotron is described. PMID:24593484

Muto, Hideshi; Ohshiro, Yukimitsu; Yamaka, Shoichi; Watanabe, Shin-ichi; Oyaizu, Michihiro; Kubono, Shigeru; Yamaguchi, Hidetoshi; Kase, Masayuki; Hattori, Toshiyuki; Shimoura, Susumu

2014-02-01

297

Progress in ion source injector development at the ion beam therapy center (Heidelberg Ion Beam Therapy Center)  

SciTech Connect

Radiotherapy with heavy ions is an upcoming cancer treatment method with to date unachieved precision. It associates higher control rates particularly for radio-resistant tumor species with reduced adverse effects compared to conventional photon therapy. At Heidelberg Ion Beam Therapy Center two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce a variety of ion beams from protons up to oxygen. The operating time is 330 days per year; our experience after 3 yr of continuous operation will be presented, with special emphasis on stability and breakdowns of components. In addition, the latest enhancement and the results for the operation will be shown.

Winkelmann, T.; Cee, R.; Haberer, T.; Naas, B.; Peters, A. [Heidelberger Ionenstrahl-Therapie Centrum (HIT), D-69120 Heidelberg (Germany)

2010-02-15

298

Technology of ion beam sources used in sputtering  

NASA Technical Reports Server (NTRS)

The technology of broad-beam ion sources is reviewed from the viewpoint of the sputtering-deposition user. This review includes a short description of the development of discharge chambers, accelerator systems, and cathodes; the present alternatives for these components and the expected future improvements.

Kaufman, H. R.

1978-01-01

299

An Electrochemical Approach to Improving the TIMS Ion Source  

Microsoft Academic Search

Thermal ionization mass spectrometry (TIMS) is the method of choice for high precision isotope ratio measurements. However, demands for smaller sample sizes in geochronology and isotope tracer studies are challenging current capabilities of TIMS instrumentation. We have focused our efforts on improving the thermalized ion source in order to increase ionization efficiencies of typically analyzed elements, such as Pb. The

M. B. Cheversia; G. Farmer

2005-01-01

300

Influence of electrode geometry on liquid metal ion source performance  

Microsoft Academic Search

The surface electric field distribution along the axis of a wetted needle type liquid metal ion source has been determined by numerical methods and is shown to exhibit a secondary maximum at the intersection of the cylindrical and conical sections. It is shown that the volume flow rate of the liquid metal film along the cylindrical portion of the emitter

L. W. Swanson; J. Z. Li

1988-01-01

301

Inhomogeneous Magnetic Field Geometry Light Ion Helicon Plasma Source  

NASA Astrophysics Data System (ADS)

Helicon plasma source is a well-known high-density plasma source for many applications including plasma processing and fusion. However, most helicon research has been focused on a uniform static magnetic field and relatively heavy ions. Light ion helicon operation is more sensitive to magnetic field strength and geometry than heavy ions. The axially inhomogeneous Mini-Radio Frequency Test Facility (Mini-RFTF) has a capability for controlling static magnetic fields then is applicative for light ion source plasma operation. Inhomogeneous static magnetic field geometry also can procedure a high velocity to plasma exhaust when combined with ICRF heating enabling the possibility of use in plasma propulsion. In this poster, we will show how the source has been optimized for a hydrogen operation and a specific plasma propulsion concept: The Variable Specific Impulse Magnetoplasma Rocket (VASIMR). Measurements of the rf magnetic fields and profile of plasma parameters for several magnetic field strengths and geometries will be discussed. Comparisons with a RF modeling code EMIR3 also will be reported here.

Mori, Yoshitaka; Nakashima, Hideki; Goulding, R. H.; Carter Baity, M. D., Jr.; Sparks, D. O.; Barber, G. C.; White, K. F.; Jaeger, E. F.; Chang-Díaz, F. R.; Squire, J. P.

2002-11-01

302

Cesium Delivery System for Negative Ion Source at IPR  

NASA Astrophysics Data System (ADS)

The technique of surface production of negative ions using cesium, Cs, has been efficiently exploited over the years for producing negative ion beams with increased current densities from negative ion sources used on neutral beam lines. Deposition of Cs on the source walls and the plasma grid lowers the work function and therefore enables a higher yield of H-, when hydrogen particles (H and/or Hx+) strike these surfaces. A single driver RF based (100 kW, 1 MHz) negative ion source test bed, ROBIN, is being set up at IPR under a technical collaboration between IPR and IPP, Germany. The optimization of the Cs oven design to be used on this facility as well as multidriver sources is underway. The characterization experiments of such a Cs delivery system with a 1 g Cs inventory have been carried out using surface ionization technique. The experiments have been carried by delivering Cs into a vacuum chamber without plasma. The linear motion of the surface ionization detector, SID, attached with a linear motion feedthrough allows measuring the angular distribution of the Cs coming out of the oven. Based on the experimental results, a Cs oven for ROBIN has been proposed. The Cs oven design and experimental results of the prototype Cs oven are reported and discussed in the paper.

Bansal, G.; Pandya, K.; Bandyopadhyay, M.; Chakraborty, A.; Singh, M. J.; Soni, J.; Gahlaut, A.; Parmar, K. G.

2011-09-01

303

Frequency scaling with miniature COmpact MIcrowave and Coaxial ion sources.  

PubMed

We will present recent basic developments about possible extension of the COMIC (for COmpact MIcrowave and Coaxial) devices up to 5.8 GHz in place of the present 2.45 GHz operation [P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81, 02B314 (2010)]. New applications associating multiple COMIC devices for thin film deposition will be described and we will explain why an increase of the current density delivered by each individual ion source could lead to the increase of the deposition rate. For this purpose, we will present results of about two devices working at 5.8 GHz. The first one is a tiny ion source, the world smallest microwave ion source, exactly similar to COMIC but operating at 5.8 GHz with a quarter wave cavity structure and a few watts microwave power consumption. We will show that the frequency scaling effect is effective inside such small machines. The second one is a more ambitious ion source designed around a three quarter wave structure that works with a few tens of watts at 5.8 GHz. PMID:24593653

Sortais, Pascal; André, Thomas; Angot, Julien; Bouat, Sophie; Jacob, Josua; Lamy, Thierry; Sole, Patrick

2014-02-01

304

Handling radiation generated during an ion source commissioning.  

PubMed

Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H(+) ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D(+) beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University. PMID:24593509

Ren, H T; Zhao, J; Peng, S X; Lu, P N; Zhou, Q F; Xu, Y; Chen, J; Zhang, T; Zhang, A L; Guo, Z Y; Chen, J E

2014-02-01

305

Handling radiation generated during an ion source commissioninga)  

NASA Astrophysics Data System (ADS)

Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H+ ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D+ beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University.

Ren, H. T.; Zhao, J.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Xu, Y.; Chen, J.; Zhang, T.; Zhang, A. L.; Guo, Z. Y.; Chen, J. E.

2014-02-01

306

Grating monochromator for electron cyclotron resonance ion source operation  

SciTech Connect

Recently, we started to observe optical line spectra from an ECR plasma using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for beam tuning because it allows the extraction of the desired ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research gives new insights into its simplification. In this paper, the grating monochromator method for beam tuning of a Hyper-ECR ion source as an injector for RIKEN azimuthal varying field (AVF) cyclotron is described.

Muto, Hideshi [Center of General Education, Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino Nagano 391-0292 (Japan)] [Center of General Education, Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino Nagano 391-0292 (Japan); Ohshiro, Yukimitsu; Yamaka, Shouichi; Watanabe, Shin-ichi; Yamaguchi, Hidetoshi; Shimoura, Susumu [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan)] [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan); Oyaizu, Michihiro; Kase, Masayuki [RIKEN Nishina Center for Accelerator-Based Science, Wako Saitama 351-0198 (Japan)] [RIKEN Nishina Center for Accelerator-Based Science, Wako Saitama 351-0198 (Japan); Kubono, Shigeru [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan) [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan); RIKEN Nishina Center for Accelerator-Based Science, Wako Saitama 351-0198 (Japan); Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road 509, Lanzhou 730000 (China); Hattori, Toshiyuki [Heavy Ion Cancer Therapy Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage Chiba 263-855 (Japan)] [Heavy Ion Cancer Therapy Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage Chiba 263-855 (Japan)

2013-07-15

307

Further development of low noise MEVVA ion source  

SciTech Connect

Based on the idea of a space-charge-limited mode of operation, the influence of a pair of electrostatic meshes on the beam parameters of the LBNL MEVVA-5 ion source was investigated. The meshes were placed in the expansion zone of the vacuum arc plasma. Apart from reducing the level of beam current fluctuations, this mode of operation provides significant control over the ion charge state distribution of the extracted beam. These effects can be understood taking not only space charge but also the high-directed ion drift velocities into account that are the same for different ion charge states of a material. The results of simulations of the processes involved are in good agreement with the experimental results.

Oks, Efim; Yushkov, George; Litovko, Irina; Anders, Andre; Brown, Ian

2001-08-28

308

Emittance studies of the Spallation Neutron Source external-antenna H{sup -} ion source  

SciTech Connect

A new Allison-type emittance scanner has been built to characterize the ion sources and low energy beam transport systems at Spallation Neutron Source. In this work, the emittance characteristics of the H{sup -} beam produced with the external-antenna rf-driven ion source and transported through the two-lens electrostatic low energy beam transport are studied. The beam emittance dependence on beam intensity, extraction parameters, and the evolution of the emittance and twiss parameters over beam pulse duration are presented.

Han, B. X.; Stockli, M. P.; Welton, R. F.; Pennisi, T. R.; Murray, S. N.; Santana, M.; Long, C. D. [Spallation Neutron Source (SNS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2010-02-15

309

RF Plasma source for a Heavy Ion Fusion injector  

NASA Astrophysics Data System (ADS)

We are developing high-current ion sources for Heavy Ion Fusion (HIF) applications. Our proposed RF plasma source starts with an array of high current density mini-beamlets (of a few milliampere each at ˜100 mA/cm 2) that are kept separated from each other within a set of acceleration grids. After they have gained sufficient kinetic energy (>1.2 MeV), the mini-beamlets are allowed to merge together to form a high current beam (about 0.5 A) with low emittance. Simulations have been done to maximize the beam brightness within the physical constraints of the source. We have performed a series of experiments on an RF plasma source. A 80-kV 20-?s source has produced up to 5 mA of Ar + in a single beamlet and we measured the emittance of a beamlet, its energy spread, and the fraction of ions in higher charge states. We have also tested a 50-kV 61-hole multi-beamlet array. Two upcoming experiments are being prepared: the first experiment will test full-gradient extraction and transport of 61 beamlets through the first four electrodes, and the second experiment will converge 119 beamlets into an ESQ channel at one-quarter scaled voltage of a 1.6 MV HIF injector.

Westenskow, G. A.; Grote, D. P.; Halaxa, E.; Kwan, J. W.; Waldron, W. L.

2005-05-01

310

Review of laser-driven ion sources and their applications.  

PubMed

For many years, laser-driven ion acceleration, mainly proton acceleration, has been proposed and a number of proof-of-principle experiments have been carried out with lasers whose pulse duration was in the nanosecond range. In the 1990s, ion acceleration in a relativistic plasma was demonstrated with ultra-short pulse lasers based on the chirped pulse amplification technique which can provide not only picosecond or femtosecond laser pulse duration, but simultaneously ultra-high peak power of terawatt to petawatt levels. Starting from the year 2000, several groups demonstrated low transverse emittance, tens of MeV proton beams with a conversion efficiency of up to several percent. The laser-accelerated particle beams have a duration of the order of a few picoseconds at the source, an ultra-high peak current and a broad energy spectrum, which make them suitable for many, including several unique, applications. This paper reviews, firstly, the historical background including the early laser-matter interaction studies on energetic ion acceleration relevant to inertial confinement fusion. Secondly, we describe several implemented and proposed mechanisms of proton and/or ion acceleration driven by ultra-short high-intensity lasers. We pay special attention to relatively simple models of several acceleration regimes. The models connect the laser, plasma and proton/ion beam parameters, predicting important features, such as energy spectral shape, optimum conditions and scalings under these conditions for maximum ion energy, conversion efficiency, etc. The models also suggest possible ways to manipulate the proton/ion beams by tailoring the target and irradiation conditions. Thirdly, we review experimental results on proton/ion acceleration, starting with the description of driving lasers. We list experimental results and show general trends of parameter dependences and compare them with the theoretical predictions and simulations. The fourth topic includes a review of scientific, industrial and medical applications of laser-driven proton or ion sources, some of which have already been established, while the others are yet to be demonstrated. In most applications, the laser-driven ion sources are complementary to the conventional accelerators, exhibiting significantly different properties. Finally, we summarize the paper. PMID:22790586

Daido, Hiroyuki; Nishiuchi, Mamiko; Pirozhkov, Alexander S

2012-05-01

311

Power supply system for negative ion source at IPR  

NASA Astrophysics Data System (ADS)

The first step in the Indian program on negative ion beams is the setting up of Negative ion Experimental Assembly - RF based, where 100 kW of RF power shall be coupled to a plasma source producing plasma of density ~5 × 1012 cm-3, from which ~ 10 A of negative ion beam shall be produced and accelerated to 35 kV, through an electrostatic ion accelerator. The experimental system is modelled similar to the RF based negative ion source, BATMAN presently operating at IPP, Garching, Germany. The mechanical system for Negative Ion Source Assembly is close to the IPP source, remaining systems are designed and procured principally from indigenous sources, keeping the IPP configuration as a base line. High voltage (HV) and low voltage (LV) power supplies are two key constituents of the experimental setup. The HV power supplies for extraction and acceleration are rated for high voltage (~15 to 35kV), and high current (~ 15 to 35A). Other attributes are, fast rate of voltage rise (< 5ms), good regulation (< ±1%), low ripple (< ±2%), isolation (~50kV), low energy content (< 10J) and fast cut-off (< 100?s). The low voltage (LV) supplies required for biasing and providing heating power to the Cesium oven and the plasma grids; have attributes of low ripple, high stability, fast and precise regulation, programmability and remote operation. These power supplies are also equipped with over-voltage, over-current and current limit (CC Mode) protections. Fault diagnostics, to distinguish abnormal rise in currents (breakdown faults) with over-currents is enabled using fast response breakdown and over-current protection scheme. To restrict the fault energy deposited on the ion source, specially designed snubbers are implemented in each (extraction and acceleration) high voltage path to swap the surge energy. Moreover, the monitoring status and control signals from these power supplies are required to be electrically (~ 50kV) isolated from the system. The paper shall present the design basis, topology selection, manufacturing, testing, commissioning, integration and control strategy of these HVPS. A complete power interconnection scheme, which includes all protective devices and measuring devices, low & high voltage power supplies, monitoring and control signals etc. shall also be discussed. The paper also discusses the protocols involved in grounding and shielding, particularly in operating the system in RF environment.

Gahlaut, Agrajit; Sonara, Jashwant; Parmar, K. G.; Soni, Jignesh; Bandyopadhyay, M.; Singh, Mahendrajit; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun

2010-02-01

312

Lithium ion sources for investigations of fast ion transport in magnetized plasmas  

SciTech Connect

In order to study the interaction of ions of intermediate energies with plasma fluctuations, two plasma immersible lithium ion sources, based on solid-state thermionic emitters (Li aluminosilicate) were developed. Compared to discharge based ion sources, they are compact, have zero gas load, small energy dispersion, and can be operated at any angle with respect to an ambient magnetic field of up to 4.0 kG. Beam energies range from 400 eV to 2.0 keV with typical beam current densities in the 1 mA/cm{sup 2} range. Because of the low ion mass, beam velocities of 100-300 km/s are in the range of Alfven speeds in typical helium plasmas in the large plasma device.

Zhang, Y.; Boehmer, H.; Heidbrink, W. W.; McWilliams, R.; Leneman, D.; Vincena, S. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)

2007-01-15

313

Development of the 3rd Generation ECR ion source  

SciTech Connect

The LBNL 3rd Generation ECR ion source has progressed from a concept to the fabrication of a full scale prototype superconducting magnet structure. This new ECR ion source will combine the recent ECR ion source techniques that significantly enhance the production of high charge state ions. The design includes a plasma chamber made from aluminum to provide additional cold electrons, three separate microwave feeds to allow multiple-frequency plasma heating (at 10, 14 and 18 GHz or at 6, 10 and 14 GHz) and very high magnetic mirror fields. The design calls for mirror fields of 4 T at injection and 3 T at extraction and for a radial field strength at the wall of 2.4 T. The prototype superconducting magnet structure which consists of three solenoid coils and six race track coils with iron poles forming the sextupole has been tested in a vertical dewar. After training, the sextupole magnet reached 105% of its design current with the solenoids off. With the solenoids operating at approximately 70% of their full design field, the sextuple coils operated at 95% of the design value which corresponds to a sextupole field strength at the plasma wall of more than 2.1 T.

Lyneis, C.M.; Xie, Z.Q.; Taylor, C.E.

1997-09-01

314

Gas feeding molecular phosphorous ion source for semiconductor implantersa)  

NASA Astrophysics Data System (ADS)

Phosphorus is a much used dopant in semiconductor technology. Its vapors represent a rather stable tetratomic molecular compound and are produced from one of the most thermodynamically stable allotropic forms of phosphorus—red phosphorus. At vacuum heating temperatures ranging from 325 °C, red phosphorus evaporates solely as P4 molecules (P4/P2 ˜ 2 × 105, P4/P ˜ 1021). It is for this reason that red phosphorus is best suited as a source of polyatomic molecular ion beams. The paper reports on experimental research in the generation of polyatomic phosphorus ion beams with an alternative P vapor source for which a gaseous compound of phosphorus with hydrogen - phosphine - is used. The ion source is equipped with a specially designed dissociator in which phosphine heated to temperatures close to 700 °C decomposes into molecular hydrogen and phosphorus (P4) and then the reaction products are delivered through a vapor line to the discharge chamber. Experimental data are presented reflecting the influence of the discharge parameters and temperature of the dissociator heater on the mass-charge state of the ion beam.

Gushenets, V. I.; Oks, E. M.; Bugaev, A. S.; Kulevoy, T. V.; Hershcovitch, A.

2014-02-01

315

Gas feeding molecular phosphorous ion source for semiconductor implanters.  

PubMed

Phosphorus is a much used dopant in semiconductor technology. Its vapors represent a rather stable tetratomic molecular compound and are produced from one of the most thermodynamically stable allotropic forms of phosphorus-red phosphorus. At vacuum heating temperatures ranging from 325?°C, red phosphorus evaporates solely as P4 molecules (P4/P2 ? 2 × 10(5), P4/P ? 10(21)). It is for this reason that red phosphorus is best suited as a source of polyatomic molecular ion beams. The paper reports on experimental research in the generation of polyatomic phosphorus ion beams with an alternative P vapor source for which a gaseous compound of phosphorus with hydrogen - phosphine - is used. The ion source is equipped with a specially designed dissociator in which phosphine heated to temperatures close to 700?°C decomposes into molecular hydrogen and phosphorus (P4) and then the reaction products are delivered through a vapor line to the discharge chamber. Experimental data are presented reflecting the influence of the discharge parameters and temperature of the dissociator heater on the mass-charge state of the ion beam. PMID:24593641

Gushenets, V I; Oks, E M; Bugaev, A S; Kulevoy, T V; Hershcovitch, A

2014-02-01

316

Development of a Compact Neutron Generator to be Used For Associated Particle Imaging Utilizing a RF-Driven Ion Source  

E-print Network

research in the Plasma and Ion Source Technology Group atby the Plasma and Ion Source Technology (PIST) Group at theplasma and ion sources. I will always be grateful to the the members of the Ion Beam Technology

Wu, Ying

2009-01-01

317

Grid-controlled metal ion sources for heavy ion fusion accelerators  

SciTech Connect

A variety of metal ions can be generated using vacuum arcs, but due to the nature of these arcs, the flux generated fluctuates in time. We have successfully employed electrostatically biased grids to control the plasma and to provide a well-behaved, space charge limited ion source. The grid prevents the plasma from entering the extraction gap before the main voltage pulse is applied. The extracte ion is space charge limited, resulting in a constant output current even though the ion flux from the vacuum arc source varies considerably. There are several advantages over conventional sources. For instance, thermionic sources are faced with heating problems for large area configurations, while gas-injection sources cause prefill problems because they take too long to reach equilibrium. We have performed extraction experiments with aluminum and indium arc sources. We have extracted 300 mA of pure Al/sup +/ at 30 kV for 10 ..mu..s. The normalized beam emittance has been measured to be 3 x 10/sup -7/ ..pi..-m-rad.

Len, L.K.; Humphries S. Jr.; Burkhart, C.

1986-01-21

318

Grid-controlled metal ion sources for heavy ion fusion accelerators  

NASA Astrophysics Data System (ADS)

A variety of metal ions can be generated using vacuum arcs, but due to the nature of these arcs, the flux generated fluctuates in time. We have successfully employed electrostatically biased grids to control the plasma and to provide a well-behaved, space charge limited ion source. The grid prevents the plasma from entering the extraction gap before the main voltage pulse is applied. The extracte ion is space charge limited, resulting in a constant output current even though the ion flux from the vacuum arc source varies considerably. There are several advantages over conventional sources. For instance, thermionic sources are faced with heating problems for large area configurations, while gas-injection sources cause prefill problems because they take too long to reach equilibrium. We have performed extraction experiments with aluminum and indium arc sources. We have extracted 300 mA of pure Al+ at 30 kV for 10 ?s. The normalized beam emittance has been measured to be 3×10-7 ?-m-rad.

Len, L. K.; Humphries, S.; Burkhart, C.

1986-01-01

319

Grid-controlled metal ion sources for heavy ion fusion accelerators  

SciTech Connect

A variety of metal ions can be generated using vacuum arcs, but due to the nature of these arcs, the flux generated fluctuates in time. We have successfully employed electrostatically biased grids to control the plasma and to provide a well-behaved, space charge limited ion source. The grid prevents the plasma from entering the extraction gap before the main voltage pulse is applied. The extracted ion current is space charge limited, resulting in a constant output current even though the ion flux from the vacuum arc source varies considerably. There are several advantages over other conventional sources, for instance, thermionic sources are faced with heating problems especially for large area configurations, while gas-injection sources cause prefill problems because they take too long to reach equilibrium. We have performed extraction experiments with aluminium and indium arc sources. We have extracted 300 mA of pure Al/sup +/ at 30 kV for 10 ..mu..s. The normalized beam emittance has been measured to be 8 /times/ 10/sup /minus/7/ ..pi..-m-rad. 3 refs., 5 figs.

Len, L.K.; Humphries, S. Jr.; Burkart, C.

1986-01-01

320

Development of a dc, broad beam, Mevva ion source  

SciTech Connect

We are developing an embodiment of metal vapor vacuum arc (Mevva) ion source which will operate dc and have a very large area beam. In preliminary testing, a dc titanium ion beam was formed with a current of approximately 0.6 A at an extraction voltage of 9 kV (about 18 keV ion energy, by virtue of the ion-charge state distribution) using an 18-cm-diameter set of multiaperture extraction grids. Separately, we have tested and formed a beam from a 50-cm-diameter (2000 cm{sup 2}) set of grids using a pulsed plasma gun. This configuration appears to be very efficient in terms of plasma utilization, and we have formed beams with a diameter of 33 cm (FWHM) and ion current up to 7 A at an extraction voltage of 50 kV (about 100 keV mean ion energy) and up to 20 A peak at the current overshoot part of the beam pulse. Here we describe this part of our Mevva development program and summarize the results obtained to date.

Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; MacGill, R.A. (Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States))

1992-04-01

321

Development of a dc, broad beam, Mevva ion source  

SciTech Connect

We are developing an embodiment of metal vapor vacuum arc (Mevva) ion source which will operate dc and have very large area beam. In preliminary testing, a dc titanium ion beam was formed with a current of approximately 0.6 amperes at an extraction voltage of 9kV (about 18 keV ion energy, by virtue of the ion charge state distribution) and using an 18 cm diameter set of multi-aperture. Separately, we have tested and formed beam from a 50 cm diameter (2000 cm{sub 2}) set of grids using a pulsed plasma gun. This configuration appears to be very efficient in terms of plasma utilization, and we have formed beams with diameter 33 cm (FWHM) and ion current up to 7 amperes at an extraction voltage of 50 kV (about 100 keV mean ion energy) and up to 20 amperes peak at the current overshoot part of the beam pulse. Here we describe this Part Of our Mevva development program and summarize the results obtained to-date.

Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; MacGill, R.A.

1991-09-01

322

Numerical simulation of ion charge breeding in electron beam ion source.  

PubMed

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 of radial profiles and velocity space distributions of the trapped ions are presented. PMID:24593605

Zhao, L; Kim, Jin-Soo

2014-02-01

323

Status and operation of the Linac4 ion source prototypesa)  

NASA Astrophysics Data System (ADS)

CERN's Linac4 45 kV H- ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma, and pulsed high voltages are described. The first experimental results of two prototypes relying on 2 MHz RF-plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H- beam of 16-22 mA which has successfully been used for the commissioning of the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator, and chopper of Linac4.

Lettry, J.; Aguglia, D.; Andersson, P.; Bertolo, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; Chaudet, E.; Gil-Flores, J.; Guida, R.; Hansen, J.; Hatayama, A.; Koszar, I.; Mahner, E.; Mastrostefano, C.; Mathot, S.; Mattei, S.; Midttun, Ø.; Moyret, P.; Nisbet, D.; Nishida, K.; O'Neil, M.; Ohta, M.; Paoluzzi, M.; Pasquino, C.; Pereira, H.; Rochez, J.; Sanchez Alvarez, J.; Sanchez Arias, J.; Scrivens, R.; Shibata, T.; Steyaert, D.; Thaus, N.; Yamamoto, T.

2014-02-01

324

Proceedings of the 10th international workshop on ECR ion sources  

SciTech Connect

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 Developments 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.

Meyer, F W; Kirkpatrick, M I [eds.

1991-01-01

325

H- Ion Sources for High Intensity Proton Drivers  

SciTech Connect

Spallation neutron source user facilities require reliable, intense beams of protons. The technique of H- charge exchange injection into a storage ring or synchrotron can provide the needed beam currents, but may be limited by the ion sources that have currents and reliability that do not meet future requirements and emittances that are too large for efficient acceleration. In this project we are developing an H- source which will synthesize the most important developments in the field of negative ion sources to provide high current, small emittance, good lifetime, high reliability, and power efficiency. We describe planned modifications to the present external antenna source at SNS that involve: 1) replacing the present 2 MHz plasma-forming solenoid antenna with a 60 MHz saddle-type antenna and 2) replacing the permanent multicusp magnet with a weaker electromagnet, in order to increase the plasma density near the outlet aperture. The SNS test stand will then be used to verify simulations of this approach that indicate significant improvements in H- output current and efficiency, where lower RF power will allow higher duty factor, longer source lifetime, and/or better reliability.

Dudnikov, Vadim [Muons, Inc.; Johnson, Rolland P. [Muons, Inc.; Stockli, Martin P [ORNL; Welton, Robert F [ORNL; Dudnikova, Galina [University of Maryland

2010-01-01

326

rf-driven ion sources for industrial applications (invited) (abstract)a)  

NASA Astrophysics Data System (ADS)

The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory have been developing rf-driven ion sources for the last two decades. These sources are being used to generate both positive and negative ion beams. Some of these sources are operating in particle accelerators such as the Spallation Neutron Source (SNS) at Oak Ridge, while others are being employed in various industrial ion beam systems. There are four areas where the rf-driven ion sources are commonly used in industry. (1) In semiconductor manufacturing, rf-driven sources have found important applications in plasma etching, ion beam implantation, and ion beam lithography. (2) In material analysis and surface modification, miniature rf-ion sources can be found in focused ion beam systems. They can provide ion beams of essentially any element in the Periodic Table. The newly developed combined rf ion-electron beam unit improves greatly the performance of the secondary ion mass spectrometry tool. (3) For neutron production, rf ion source is a major component of compact, high flux D-D, D-T, or T-T neutron generators. These neutron sources are now being employed in boron neutron capture therapy (BNCT) as well as in neutron imaging and material interrogation. (4) Large area rf-driven ion source will be used in an industrial design neutral beam diagnostic system for probing fusion plasmas. Such sources can be easily scaled to provide large ion beam current for future fusion reactor applications.

Leung, Ka-Ngo

2008-02-01

327

Magnetron injection gun scaling  

SciTech Connect

Existing analytic design equations for magnetron injection guns (MIG's) are approximated to obtain a set of scaling laws. The constraints are chosen to examine the maximum peak power capabilities of MIG's. The scaling laws are compared with exact solutions of the design equations and are supported by MIG simulations.

Lawson, W.

1988-04-01

328

Concept for a fourth generation electron cyclotron resonance ion source  

SciTech Connect

A fourth generation electron cyclotron resonance ion source with an operating frequency between 40 and 56 GHz has the potential to quadruple the heavy-ion beam currents and provide a cost effective upgrade path for heavy ion drivers in use or in the planning stage at radioactive beam facilities. Design studies show it is feasible to produce the required magnetic fields in the plasma chamber, 7 T axially and 4 T in the radial direction with a magnetic structure using commercially available Nb{sub 3}Sn superconducting materials. In this paper we describe the design of such a magnet structure including a 3D analysis of the Lorentz forces generated by the magnetic fields and the necessary clamping structure to stabilize the conductor against these forces.

Lyneis, C.; Ferracin, P.; Caspi, S.; Hodgkinson, A.; Sabbi, G. L. [Lawrence Berkeley National Laboratory, Berkeley, California 94708 (United States)

2012-02-15

329

Modeling of the rf discharge initiation in a negative ion source  

Microsoft Academic Search

The maintenance free rf ion source is expected to be one of the most promising candidates for the negative ion sources of plasma heating for future fusion reactors. As an alternative to the arc-discharge sources, the rf negative ion sources have been developed for H- production. In order to make clear the condition for the discharge initiation of the rf

S. Yoshinari; T. Hayami; R. Terasaki; A. Hatayama; A. Fukano

2010-01-01

330

Sensitive glow discharge ion source for aerosol and gas analysis  

DOEpatents

A high sensitivity glow discharge ion source system for analyzing particles includes an aerodynamic lens having a plurality of constrictions for receiving an aerosol including at least one analyte particle in a carrier gas and focusing the analyte particles into a collimated particle beam. A separator separates the carrier gas from the analyte particle beam, wherein the analyte particle beam or vapors derived from the analyte particle beam are selectively transmitted out of from the separator. A glow discharge ionization source includes a discharge chamber having an entrance orifice for receiving the analyte particle beam or analyte vapors, and a target electrode and discharge electrode therein. An electric field applied between the target electrode and discharge electrode generates an analyte ion stream from the analyte vapors, which is directed out of the discharge chamber through an exit orifice, such as to a mass spectrometer. High analyte sensitivity is obtained by pumping the discharge chamber exclusively through the exit orifice and the entrance orifice.

Reilly, Peter T. A. (Knoxville, TN)

2007-08-14

331

Spallation neutron source saddle antenna H{sup -} ion source project  

SciTech Connect

In this project we are developing an H{sup -} source which will synthesize the most important developments in the field of negative ion sources to provide high current, high brightness, good lifetime, high reliability, and high power efficiency. We describe two planned modifications to the present spallation neutron source external antenna source in order to increase the plasma density near the output aperture: (1) replacing the present 2 MHz plasma-forming solenoid antenna with a 13 MHz saddle-type antenna and (2) replacing the permanent multicusp magnetic system with a weaker electromagnet.

Dudnikov, Vadim; Johnson, Rolland P. [Muons, Inc., Batavia, Illinois 60510 (United States); Dudnikova, Galina [University of Maryland, College Park, Maryland 20742 (United States); Stockli, Martin; Welton, Robert [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2010-02-15

332

Lifetime of the Highly Efficient H- Ion Sources  

SciTech Connect

Factors limiting the operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. Noiseless discharges with lower gas and cesium densities are produced in experiments with modified discharge cells. With these discharge cells it is possible to increase the emission aperture and extract the same beam with a lower discharge current and with correspondingly increased source lifetime. A design of an advanced CSPS is presented. Optimization of the discharge cells in a Penning H{sup -} ion source is a viable method for increasing the phase space of the stable region for noiseless discharge production. With this method, cesium usage would be decreased, potentially resulting in longer source lifetimes.

Bollinger, D.S.; /Fermilab; Dudnikov, V.G.; /MUONS Inc., Batavia; Faircloth, D.C.; Lawrie, S.R.; /Rutherford

2012-05-01

333

Improvement in brightness of multicusp-plasma ion source  

SciTech Connect

The beam brightness of a multicusp-plasma ion source has been substantially improved by optimizing the source configuration and extractor geometry. The current density of a 2 keV He{sup +} beam extracted from a 7.5-cm-diameter source operating at 2.5 kW RF power is {approx}100 mA/cm{sup 2}, which is {approx}10 times larger than that of a beam extracted from a 5-cm-diameter source operating at 1 kW RF power. A smaller focused beam spot size is achieved with a counter-bored extractor instead of a conventional (''through-hole'') extractor, resulting another order of magnitude improvement in beam current density. Measured brightness can be as high as 440 A/cm{sup 2}Sr, which represents a 30 times improvement over prior work.

Ji, Q.; Jiang, X.; King, T-J.; Leung, K-N.; Standiford, K.; Wilde, S.B.

2002-05-24

334

Kinetic solutions for electrons in multi-cusp ion source  

SciTech Connect

Some analytical kinetic solutions are obtained for the primary and plasma electrons in multi-cusp ion source. The characteristics based on these solutions are discussed, such as frictional coefficient, collision frequency, electron current, electron diffusion, electron density, and electrical conductivity. A code based on one of these solutions is developed to discuss the plasma electrons diffusion; the simulation results are qualitatively consistent with our current experiences.

Zhan Hualin; Hu Chundong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2011-11-28

335

Compact ECR ion source with permanent magnets for carbon therapy  

NASA Astrophysics Data System (ADS)

Ion sources for the medical facilities should have the following characteristics of easy maintenance, low electric power, good stability, and long operation time without trouble (1 year or longer). For this, a 10 GHz compact electron cyclotron resonance ion source (ECRIS) with all permanent magnets was developed. The beam intensity and stability for C4+ were 280 e ?A and better than 6% during 20 h with no adjustment of any source parameters. These results were acceptable for the medical requirements. Recently, many plans were proposed to construct the next generation cancer treatment facility. For such a facility we have designed an all permanent magnet ECRIS, in which a high magnetic field is chosen for increasing the beam intensity. 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. The source has a diameter of 32 cm and a length of 29.5 cm. Details of the design of this source and its background are described in this article.

Muramatsu, M.; Kitagawa, A.; Sakamoto, Y.; Sato, Y.; Yamada, S.; Ogawa, H.; Drentje, A. G.; Biri, S.; Yoshida, Y.

2004-05-01

336

Long Plasma Source for Heavy Ion Beam Charge Neutralization  

SciTech Connect

Plasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to focus them to a small spot size and compress their axial length. The plasma source should operate at low neutral pressures and without strong externally-applied fields. To produce long plasma columns, sources based upon ferroelectric ceramics with large dielectric coefficients have been developed. The source utilizes the ferroelectric ceramic BaTiO{sub 3} to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) is covered with ceramic material. High voltage ({approx} 8 kV) is applied between the drift tube and the front surface of the ceramics. A BaTiO{sub 3} source comprised of five 20-cm-long sources has been tested and characterized, producing relatively uniform plasma in the 5 x 10{sup 10} cm{sup -3} density range. The source was integrated into the NDCX device for charge neutralization and beam compression experiments, and yielded current compression ratios {approx} 120. Present research is developing multi-meter-long and higher density sources to support beam compression experiments for high energy density physics applications.

Efthimion, P.C.; Gilson, E.P.; Grisham, L.; Davidson, R.C.; Logan, B.G.; Seidl, P.A.; Waldron, W.

2008-06-01

337

ELECTRON CYCLOTRON RESONANCE DISCHARGE AS A SOURCE FOR HYDROGEN AND DEUTERIUM IONS PRODUCTION  

E-print Network

beams of negative hydrogen ions is provoked predominantly by international and national programs1 ELECTRON CYCLOTRON RESONANCE DISCHARGE AS A SOURCE FOR HYDROGEN AND DEUTERIUM IONS PRODUCTION electrons and thermoelectrons in negative hydrogen and deuterium ion production. The obtained data

Boyer, Edmond

338

Ion beam extraction from electron cyclotron resonance ion sources and the subsequent low energy beam transport  

NASA Astrophysics Data System (ADS)

Electron Cyclotron Resonance Ion Sources (ECRIS) are capable of delivering high currents of Highly Charged Ions (HCIs) to heavy ion accelerators (e.g.: to the future FRIB). The use of a sextupole magnet for confinement of the plasma inside the source imposes a unique triangular structure on the beam. This, together with the multitude of ion species that are extracted at the same time and the high axial magnetic field at the plasma aperture, resulting from additional confining solenoids, make the simulation and design of ECRIS extraction systems particularly challenging. The first objective of this thesis was to refine and test a semi-empirical simulation model of the formation and extraction of HCIs from ECR ion sources as well as their transport through the subsequent Low Energy Beam Transport (LEBT) system. To this end, a set of utility functions was written to simplify performing the simulations. In the LEBT system, another interesting, yet so far unanswered, question arises: The influence of space-charge effects on the beam and the level of space-charge compensation in the ECRIS beam line. This interesting topic quickly became the second main objective of the thesis. A Retarding Field Analyzer (RFA) was built and systematic measurements of the neutralization level in ECRIS LEBT systems were done for the first time as part of this thesis (this intensity and pressure regime was previously not well explored). The measured neutralization levels for typical ECRIS beams were found to be between 0% and 50% and agreed reasonably well with a simple formula developed by Gabovich et al. for highly neutralized proton and H- beams after it was re-derived and extended in this thesis for low neutralization and multiple species. Preliminary tests of the refined and integrated simulation model for the ECR ion sources VENUS and SuSI and their respective low energy beam transport systems include comparisons of measured beam currents, cross sections and emittances with the simulation results. These tests suggest that the model is suited for the simulation of ion beam extraction and transport for medium to high charge states of medium to heavy ions, but not for the lowest charge states and lightest ions (He1+, protons). Finally, as an example application of the developed software, a variable-energy (300 kV - 3 MV) electrostatic accelerator was simulated and redesigned for the DIANA project, a new proposed underground laboratory for nuclear astrophysics.

Winklehner, Daniel

339

A Bayesian Nonlinear Source Separation Method for Smart Ion-selective Electrode Arrays  

E-print Network

1 A Bayesian Nonlinear Source Separation Method for Smart Ion-selective Electrode Arrays Leonardo T--Potentiometry with ion-selective electrodes (ISEs) provides a simple and cheap approach for estimating ionic activities--Blind source separation, ion-selective electrode, chemical sensor array, Bayesian approach. I. INTRODUCTION ION-selective

Paris-Sud XI, Université de

340

PROGRESS AND PERSPECTIVE FOR HIGH FREQUENCY, HIGH PERFORMANCE SUPERCONDUCTING ECR ION SOURCES  

Microsoft Academic Search

Next-generation heavy ion beam accelerators require a great variety of high charge state ions with an order of magnitude higher beam intensity than is currently routinely available. Driven by this increasing demand for high performance ECR ion sources and enabled by advances in superconducting magnet technology, third generation superconducting (SC) ECR ion sources have been developed world-wide. The superconducting VENUS

D. Leitner; J. Y. Benitez; M L Galloway; T. J. Loew; C. M. Lyneis; D. S. Todd; Lawrence Berkeley

341

Performance of the LAMPF optically pumped polarized ion source  

SciTech Connect

In 1992, the LAMPF optically pumped polarized ion source (OPPIS) was used in experiments demanding a wide range of currents and polarizations. OPPIS was operated in different configurations to meet the differing current and polarization requirements for each experiment. We describe methods used to increase beam polarization at the expense of current for experiments that were count rate limited. OPPIS can be operated at 50 [mu]A, giving 56% polarization, 25 [mu]A with 65% polarization, or 2 [mu]A with 77% polarization. The source reliability in 1992 was excellent, easily exceeding 95%. Contributions to experimental systematic errors made by the source were measured in 1992. We speculate about further improvements that can be made to OPPIS.

York, R.L.; Tupa, D.; Swenson, D.R.; McNaughton, M.W.; vanDyck, O.B.

1993-01-01

342

Performance of the LAMPF optically pumped polarized ion source  

SciTech Connect

In 1992, the LAMPF optically pumped polarized ion source (OPPIS) was used in experiments demanding a wide range of currents and polarizations. OPPIS was operated in different configurations to meet the differing current and polarization requirements for each experiment. We describe methods used to increase beam polarization at the expense of current for experiments that were count rate limited. OPPIS can be operated at 50 {mu}A, giving 56% polarization, 25 {mu}A with 65% polarization, or 2 {mu}A with 77% polarization. The source reliability in 1992 was excellent, easily exceeding 95%. Contributions to experimental systematic errors made by the source were measured in 1992. We speculate about further improvements that can be made to OPPIS.

York, R.L.; Tupa, D.; Swenson, D.R.; McNaughton, M.W.; vanDyck, O.B.

1993-07-01

343

High power impulse magnetron sputtering using a rotating cylindrical magnetron  

SciTech Connect

Both the industrially favorable deposition technique, high power impulse magnetron sputtering (HIPIMS), and the industrially popular rotating cylindrical magnetron have been successfully combined. A stable operation without arcing, leaks, or other complications for the rotatable magnetron was attained, with current densities around 11 A cm{sup -2}. For Ti and Al, a much higher degree in ionization in the plasma region was observed for the HIPIMS mode compared to the direct current mode.

Leroy, W. P.; Mahieu, S.; Depla, D.; Ehiasarian, A. P. [Department of Solid State Sciences, Ghent University, Krijgslaan 281/S1, 9000 Ghent (Belgium); Nanotechnology Center for PVD Research, Sheffield Hallam University, S1 1WB Sheffield (United Kingdom)

2010-01-15

344

RF-Plasma Source Commissioning in Indian Negative Ion Facility  

SciTech Connect

The Indian program of the RF based negative ion source has started off with the commissioning of ROBIN, the inductively coupled RF based negative ion source facility under establishment at Institute for Plasma research (IPR), India. The facility is being developed under a technology transfer agreement with IPP Garching. It consists of a single RF driver based beam source (BATMAN replica) coupled to a 100 kW, 1 MHz RF generator with a self excited oscillator, through a matching network, for plasma production and ion extraction and acceleration. The delivery of the RF generator and the RF plasma source without the accelerator, has enabled initiation of plasma production experiments. The recent experimental campaign has established the matching circuit parameters that result in plasma production with density in the range of 0.5-1x10{sup 18}/m{sup 3}, at operational gas pressures ranging between 0.4-1 Pa. Various configurations of the matching network have been experimented upon to obtain a stable operation of the set up for RF powers ranging between 25-85 kW and pulse lengths ranging between 4-20 s. It has been observed that the range of the parameters of the matching circuit, over which the frequency of the power supply is stable, is narrow and further experiments with increased number of turns in the coil are in the pipeline to see if the range can be widened. In this paper, the description of the experimental system and the commissioning data related to the optimisation of the various parameters of the matching network, to obtain stable plasma of required density, are presented and discussed.

Singh, M. J.; Bandyopadhyay, M.; Yadava, Ratnakar; Chakraborty, A. K. [ITER- India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujrat (India); Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J. [Institute for Plasma Research, Bhat Gandhinagar, Gujrat (India); Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

2011-09-26

345

RF-Plasma Source Commissioning in Indian Negative Ion Facility  

NASA Astrophysics Data System (ADS)

The Indian program of the RF based negative ion source has started off with the commissioning of ROBIN, the inductively coupled RF based negative ion source facility under establishment at Institute for Plasma research (IPR), India. The facility is being developed under a technology transfer agreement with IPP Garching. It consists of a single RF driver based beam source (BATMAN replica) coupled to a 100 kW, 1 MHz RF generator with a self excited oscillator, through a matching network, for plasma production and ion extraction and acceleration. The delivery of the RF generator and the RF plasma source without the accelerator, has enabled initiation of plasma production experiments. The recent experimental campaign has established the matching circuit parameters that result in plasma production with density in the range of 0.5-1×1018/m3, at operational gas pressures ranging between 0.4-1 Pa. Various configurations of the matching network have been experimented upon to obtain a stable operation of the set up for RF powers ranging between 25-85 kW and pulse lengths ranging between 4-20 s. It has been observed that the range of the parameters of the matching circuit, over which the frequency of the power supply is stable, is narrow and further experiments with increased number of turns in the coil are in the pipeline to see if the range can be widened. In this paper, the description of the experimental system and the commissioning data related to the optimisation of the various parameters of the matching network, to obtain stable plasma of required density, are presented and discussed.

Singh, M. J.; Bandyopadhyay, M.; Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J.; Yadava, Ratnakar; Chakraborty, A. K.; Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U.

2011-09-01

346

An Electrochemical Approach to Improving the TIMS Ion Source  

NASA Astrophysics Data System (ADS)

Thermal ionization mass spectrometry (TIMS) is the method of choice for high precision isotope ratio measurements. However, demands for smaller sample sizes in geochronology and isotope tracer studies are challenging current capabilities of TIMS instrumentation. We have focused our efforts on improving the thermalized ion source in order to increase ionization efficiencies of typically analyzed elements, such as Pb. The current state of the thermalized ion emitter is a boro- or phosho- silica gel doped with the element of interest and loaded onto a resistively heated Re or Ta filament. To date, little is known about the ion formation mechanism in the silica gel, and typical ionization efficiencies for elements such as Pb, Cr, Ru, and Ag are in the range of 0.05-2%. Previous workers found that Ag-doped borosilicate glasses heated under high vacuum emitted monatomic metallic species, predominately Ag0 with subordinate Ag+. As suspected, under low fO2 conditions, elements exist in their reduced state. We have attempted to use modern electrochemical methods to increase the abundance of oxidized metal ions emitted from the molten borosilicate glass ion emitter. By treating the molten glass as the electrolyte in the electrochemical cell, and varying the voltage to Pt reference and counter electrodes, we aim to find the potential range to oxidize the doped metal element from neutral to ionized species, and therefore increase the number of analyzable ions within the mass spectrometer, and hence directly increase the ionization efficiencies and analytical precision of measured isotope ratios. We have built a high vacuum test chamber in which to perform electrochemical experiments. Thus far, we have produced a simple cyclic voltammogram that shows that even with the borosilicate glass heated to 1600°C, the glass is acting as a resistor, and is not completely molten, which is essential to mimic mass spectrometer conditions, and to using the glass as the electrolyte in the electrochemical cell. We will continue to perform experiments in order to determine the potential in which to oxidize a doped metal element. Provided we achieve positive results with the test chamber, we will miniaturize our electrochemical cell so that it may function as the ion source within the sample chamber of the mass spectrometer.

Cheversia, M. B.; Farmer, G.

2005-12-01

347

Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron Source  

SciTech Connect

An over-dense microwave driven ion source capable ofproducing deuterium (or hydrogen) beams at 100-200 mA/cm2 and with atomicfraction>90 percent was designed and tested with an electrostaticlow energy beam transport section (LEBT). This ion source wasincorporatedinto the design of an Accelerator Driven Neutron Source(ADNS). The other key components in the ADNS include a 6 MeV RFQaccelerator, a beam bending and scanning system, and a deuterium gastarget. In this design a 40 mA D+ beam is produced from a 6 mm diameteraperture using a 60 kV extraction voltage. The LEBT section consists of 5electrodes arranged to form 2 Einzel lenses that focus the beam into theRFQ entrance. To create the ECR condition, 2 induction coils are used tocreate ~; 875 Gauss on axis inside the source chamber. To prevent HVbreakdown in the LEBT a magnetic field clamp is necessary to minimize thefield in this region. Matching of the microwave power from the waveguideto the plasma is done by an autotuner. We observed significantimprovement of the beam quality after installing a boron nitride linerinside the ion source. The measured emittance data are compared withPBGUNS simulations.

Vainionpaa, J.H.; Gough, R.; Hoff, M.; Kwan, J.W.; Ludewigt,B.A.; Regis, M.J.; Wallig, J.G.; Wells, R.

2007-02-15

348

CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source  

SciTech Connect

An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm{sup 2} and with atomic fraction > 90% was designed and tested with an electrostatic low energy beam transport section (LEBT). This ion source was incorporated into the design of an Accelerator Driven Neutron Source (ADNS). The other key components in the ADNS include a 6 MeV RFQ accelerator, a beam bending and scanning system, and a deuterium gas target. In this design a 40 mA D{sup +} beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to create {approx} 875 Gauss on axis inside the source chamber. To prevent HV breakdown in the LEBT a magnetic field clamp is necessary to minimize the field in this region. Matching of the microwave power from the waveguide to the plasma is done by an autotuner. They observed significant improvement of the beam quality after installing a boron nitride liner inside the ion source. The measured emittance data are compared with PBGUNS simulations.

Vainionpaa, J.H.; Gough, R.; Hoff, M.; Kwan, J.W.; Ludewigt,B.A.; Regis, M.J.; Wallig, J.G.; Wells, R.

2007-02-27

349

Targets for ion sources for RIB generation at the Holifield Radioactive Ion Beam Facility  

SciTech Connect

The Holifield Radioactive Ion Beam Facility (HRIBF), now under construction at the Oak Ridge National Laboratory, is based on the use of the well-known on-line isotope separator (ISOL) technique in which radioactive nuclei are produced by fusion type reactions in selectively chosen target materials by high-energy proton, deuteron, or He ion beams from the Oak Ridge Isochronous Cyclotron (ORIC). Among several major challenges posed by generating and accelerating adequate intensities of radioactive ion beams (RIBs), selection of the most appropriate target material for production of the species of interest is, perhaps, the most difficult. In this report, we briefly review present efforts to select target materials and to design composite target matrix/heat-sink systems that simultaneously incorporate the short diffusion lengths, high permeabilities, and controllable temperatures required to effect maximum diffusion release rates of the short-lived species that can be realized at the temperature limits of specific target materials. We also describe the performance characteristics for a selected number of target ion sources that will be employed for initial use at the HRIBF as well as prototype ion sources that show promise for future use for RIB applications.

Alton, G.D.

1995-12-31

350

Industrial ion source technology. [for ion beam etching, surface texturing, and deposition  

NASA Technical Reports Server (NTRS)

Plasma probe surveys were conducted in a 30-cm source to verify that the uniformity in the ion beam is the result of a corresponding uniformity in the discharge-chamber plasma. A 15 cm permanent magnet multipole ion source was designed, fabricated, and demonstrated. Procedures were investigated for texturing a variety of seed and surface materials for controlling secondary electron emission, increasing electron absorption of light, and improved attachment of biological tissue for medical implants using argon and tetrafluoromethane as the working gases. The cross section for argon-argon elastic collisions in the ion-beam energy range was calculated from interaction potentials and permits calculation of beam interaction effects that can determine system pumping requirements. The data also indicate that different optimizations of ion-beam machines will be advantageous for long and short runs, with 1 mA-hr/cm being the rough dividing line for run length. The capacity to simultaneously optimize components in an ion-beam machine for a single application, a capacity that is not evident in competitive approaches such as diode sputtering is emphasized.

Kaufman, H. R.

1977-01-01

351

Development of C{sub 60} plasma ion source for time-of-flight secondary ion mass spectrometry applications  

SciTech Connect

Initial data from a multicusp ion source developed for buckminsterfullerene (C{sub 60}) cluster ion production are reported in this article. A C{sub 60}{sup +} beam current of 425 nA and a C{sub 60}{sup -} beam current of 200 nA are obtainable in continuous mode. Compared to prior work using electron impact ionization, the multicusp ion source provides at least two orders of magnitude increase in the extractable C{sub 60}{sup +} beam current. Mass spectra for both positive and negative bismuth cluster ions generated by the multicusp ion source are also included.

Ji Qing; Chen Ye; Ji Lili; Hahto, Sami; Leung, Ka-Ngo; Lee, Tae Geol; Moon, Dae Won [Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Nano-Bio Fusion Research Center, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)

2008-02-15

352

Carbon Nanotube Based Deuterium Ion Source for Improved Neutron Generators  

SciTech Connect

Field ionization uses high electric fields to cause the ionization and emission of ions from the surface of a sharp electrode. We are developing a novel field ionization neutron generator using carbon nanotubes (CNT) to produce the deuterium ion current. The generator consists of three major components: a deuterium ion source made of carbon nanotubes, a smooth negatively-biased target electrode, and a secondary electron suppression system. When a negative high voltage is applied on the target electrode, a high gradient electric field is formed at the tips of the carbon nanotubes. This field is sufficiently strong to create deuterium (D) ions at or near the nanotubes which are accelerated to the target causing D-D reactions to occur and the production of neutrons. A cross magnetic field is used to suppress secondary emission electrons generated on the target surface. We have demonstrated field ionization currents of 70 nA (1 {mu}A/cm{sup 2}) at hydrogen gas pressure of 10 mTorr. We have found that the current scales proportionally with CNT area and also with the gas pressure in the range of 1 mTorr to 10 mTorr. We have demonstrated pulse cut-off times as short as 2 {mu}sec. Finally, we have shown the feasibility of generating neutrons using deuterium gas.

Fink, R. L.; Jiang, N.; Thuesen, L. [Applied Nanotech, Inc., 3006 Longhorn Blvd., Ste 107, Austin, TX 78758 (United States); Leung, K. N. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Antolak, A. J. [Sandia National Laboratories, Livermore, CA 94550 (United States)

2009-03-10

353

Magnetron sputtered boron films  

DOEpatents

A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence. 8 figs.

Makowiecki, D.M.; Jankowski, A.F.

1998-06-16

354

Magnetron sputtered boron films  

DOEpatents

A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence.

Makowiecki, Daniel M. (Livermore, CA); Jankowski, Alan F. (Livermore, CA)

1998-01-01

355

Development of a negative hydrogen ion source for tandem proton accelerator using transformer couled plasma sources  

NASA Astrophysics Data System (ADS)

A negative hydrogen ion source based on the transformer coupled plasma (TCP) source has been developed for 1.75 MeV tandem proton accelerator to detect underground explosives and mines. The TCP-based ion source has been designed and constructed for H- beam currents of 10 mA at the extraction voltage of 30 kV. High-density hydrogen plasmas of 1012cm-3 are generated by 13.56 MHz radio frequency (rf) power with the threshold power of 1 kW. Negative hydrogen beam currents of up to 0.7 mA at the extraction voltage of 30 kV are extracted with the rf power of 1.5 kW. Extracted beam currents follow the magnitudes of plasma densities which can be adjusted by changing rf power and neutral gas pressure. The e/H- ratio of down to 70 has been achieved with a simple magnetic filter.

Hong, I. S.; Hwang, Y. S.; Cho, Y. S.

2002-02-01

356

Micro Ion Source Program NA22 Plutonium Detection Portfolio Final Report  

Microsoft Academic Search

The purpose of the micro ion source program was to enhance the performance of thermal ionization mass spectrometry (TIMS) for various actinides and fission products. The proposal hypothesized that when ions are created at the ion optic center of the mass spectrometer, ion transmission is significantly increased and the resulting ion beam is more sharply focused. Computer modeling demonstrated this

James E. Delmore

2010-01-01

357

MONO1001 : A source for singly charged ions applied to the production of multicharged fullerene beams  

E-print Network

MONO1001 : A source for singly charged ions applied to the production of multicharged fullerene study of the production of multiply charged fullerene beams based on an ECR ion source. As collision, clusters and particularly of fullerenes, we have further developed the ion source ECRIS MONO10001

Boyer, Edmond

358

Ionic Liquid Ion Source Emitter Arrays Fabricated on Bulk Porous Substrates for Spacecraft Propulsion  

E-print Network

Propulsion Daniel George Courtney, Paulo Lozano June 2011 SSL # 9-11 #12;#12;Ionic Liquid Ion Source Emitter;Ionic Liquid Ion Source Emitter Arrays Fabricated on Bulk Porous Substrates for Spacecraft PropulsionIonic Liquid Ion Source Emitter Arrays Fabricated on Bulk Porous Substrates for Spacecraft

359

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

NASA Astrophysics Data System (ADS)

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 252Cf 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 252Cf source to produce radioactive beams with intensities up to 106 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 23Na8+, 15.6% for 84Kr17+, and 13.7% for 85Rb19+ 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 143Cs27+ and 14.7% for 143Ba27+. The project has been commissioned with a radioactive beam of 143Ba27+ 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.

Vondrasek, R.; Levand, A.; Pardo, R.; Savard, G.; Scott, R.

2012-02-01

360

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

PubMed

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 (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 (252)Cf source to produce radioactive beams with intensities up to 10(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 (23)Na(8+), 15.6% for (84)Kr(17+), and 13.7% for (85)Rb(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 (143)Cs(27+) and 14.7% for (143)Ba(27+). The project has been commissioned with a radioactive beam of (143)Ba(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. PMID:22380254

Vondrasek, R; Levand, A; Pardo, R; Savard, G; Scott, R

2012-02-01

361

High-resolution mass spectrometer for liquid metal ion sources.  

PubMed

Recently, a mass spectrometer for liquid metal ion sources (LMIS) has been built and set into operation. This device uses an E × B-filter as mass dispersive element and provides sufficient resolution to analyse the emission of clusters from LMIS to much higher mass ranges (>2000 amu) than commercially available mass filters for focused ion beam systems. It has also been shown that for small masses the composition of clusters from different isotopes can be resolved. Furthermore, a rather high fluence of monodisperse clusters in the range of 10(6)-10(7) clusters/s can be achieved with this setup. This makes it a promising tool for the preparation of mass selected clusters. In this contribution, theoretical considerations as well as technical details and the results of first measurements are presented. PMID:24089821

Wortmann, Martin; Ludwig, Arne; Meijer, Jan; Reuter, Dirk; Wieck, Andreas D

2013-09-01

362

Method for the production of atomic ion species from plasma ion sources  

DOEpatents

A technique to enhance the yield of atomic ion species (H{sup +}, D{sup +}, O{sup +}, N{sup +}, etc.) from plasma ion sources. The technique involves the addition of catalyzing agents to the ion discharge. Effective catalysts include H{sub 2}O, D{sub 2}O, O{sub 2}, and SF{sub 6}, among others, with the most effective being water (H{sub 2}O) and deuterated water (D{sub 2}O). This technique has been developed at Argonne National Laboratory, where microwave generated plasmas have produced ion beams comprised of close to 100% purity protons (H{sup +}) and close to 100% purity deuterons (D{sup +}). The technique also increases the total yield of protons and deuterons by converting unwanted ion species, namely, H{sub 2}{sup +}, H{sub 3}{sup +} and D{sub 2}{sup +}, D{sub 3}{sup +}, into the desired ion species, H{sup +} and D{sup +}, respectively. 4 figs.

Spence, D.; Lykke, K.

1998-08-04

363

Next Generation H? Ion Sources for the SNS  

NASA Astrophysics Data System (ADS)

The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H- ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H- ion source based on an A1N ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to ˜100 mA (60 Hz, 1 ms) have been observed and sustained currents >60 mA (60 Hz, 1 ms) have been demonstrated on the test stand. Accelerated beam currents of ˜40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H- beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

Welton, R. F.; Stockli, M. P.; Murray, S. N.; Crisp, D.; Carmichael, J.; Goulding, R. H.; Han, B.; Tarvainen, O.; Pennisi, T.; Santana, M.

2009-03-01

364

Magnetic-field configuration fitted to the microwave ion-source plasma  

Microsoft Academic Search

Microwave ion sources for implantation have many advantages, such as the long life of source operation and the cleanliness of extracted beam, over the traditional dc-arc-discharge-type ion sources. We reported that optimizing the plasma-chamber structure made the microwave source exceed most of traditional dc-arc-discharge sources in extracted-ion currents of most species that are used for fabricating modern ultralarge scale integrations.

Noriyuki Sakudo; Hiroyuki Ito; Yasuhiko Matsunaga; Keiji Hayashi; Atsushi Miyamoto; Yoshiaki Tazaki

2002-01-01

365

Time evolution of bremsstrahlung and ion production of an electron cyclotron resonance ion source  

SciTech Connect

Bremsstrahlung radiation measurement is one of the most commonly used plasma diagnostics methods. Most of the bremsstrahlung measurements with electron cyclotron resonance (ECR) ion sources have been performed in continuous operation mode yielding information only on the steady state bremsstrahlung emission. This article describes the results of bremsstrahlung and ion current measurement with the JYFL 14 GHz ECRIS operated in pulsed mode. The experiments reveal information about the bremsstrahlung radiation in plasma conditions before reaching the equilibrium. The time scale of bremsstrahlung production is compared to ion production time scale for different charge states. The bremsstrahlung data is presented with 2 millisecond time intervals as a function of neutral gas pressure and microwave power. Data from hundreds of microwave pulses is combined in order to have a sufficient amount of events at each time step. The relevant plasma physics phenomena during both, the leading and the trailing edge of the RF pulse, are discussed.

Tarvainen, Ollie [Los Alamos National Laboratory; Ropponen, Tommi [UNIV OF JYVASKYLA; Jones, Peter [UNIV OF JYVASKYLA; Peura, Pauli [UNIV OF JYVASKYLA

2008-01-01

366

New methods of enhancing ion beam intensities from two types of sputter negative ion sources  

Microsoft Academic Search

In the Munich HICONEX 834 source [2] Cs2CrO4, CsI and CsF as target additives have been investigated. It is shown that adding Cs2CrO4 in suitable ratios improves Cs coverage and achieves the effect of the simultaneous spraying of O2. The intensities of Fe-, Ag- and Cu- ion beams increase by 10, 6 and 3.5 times the values obtained with pure

Du Guangtian

1989-01-01

367

Ion source development and radiobiology applications within the LIBRA project  

NASA Astrophysics Data System (ADS)

In view of their properties, laser-driven ion beams have the potential to be employed in innovative applications in the scientific, technological and medical areas. Among these, a particularly high-profile application is particle therapy for cancer treatment, which however requires significant improvements from current performances of laser-driven accelerators. The focus of current research in this field is on developing suitable strategies enabling laser-accelerated ions to match these requirements, while exploiting some of the unique features of a laser-driven process. LIBRA is a UK-wide consortium, aiming to address these issues, and develop laser-driven ion sources suitable for applicative purposes, with a particular focus on biomedical applications. We will report on the activities of the consortium aimed to optimizing the properties of the beams, by developing and employing advanced targetry and by exploring novel acceleration regimes enabling production of beams with reduced energy spread. Employing the TARANIS Terawatt laser at Queen's University, we have initiated a campaign investigating the effects of proton irradiation of biological samples at extreme dose rates (> 109 Gy/s).

Borghesi, M.; Kar, S.; Prasad, R.; Kakolee, F. K.; Quinn, K.; Ahmed, H.; Sarri, G.; Ramakrishna, B.; Qiao, B.; Geissler, M.; Ter-Avetisyan, S.; Zepf, M.; Schettino, G.; Stevens, B.; Tolley, M.; Ward, A.; Green, J.; Foster, P. S.; Spindloe, C.; Gallegos, P.; Robinson, A.. L.; Neely, D.; Carroll, D. C.; Tresca, O.; Yuan, X.; Quinn, M.; McKenna, P.; Dover, N.; Palmer, C.; Schreiber, J.; Najmudin, Z.; Sari, I.; Kraft, M.; Merchant, M.; Jeynes, J. C.; Kirkby, K.; Fiorini, F.; Kirby, D.; Green, S.

2011-05-01

368

Heavy-ion sources: The Star, or the Cinderella, of the ion-implantation firmament? (invited)  

NASA Astrophysics Data System (ADS)

The Star, because of the invaluable contribution which the heavy-ion source has already made to the successful development of semiconductor implantation. And the Star, too, because it is evident that the key characteristics of such sources, which are now used on a quite routine industrial basis—their reliability, their ease of operation and, above all, their extraordinary versatility—have still not been fully exploited. This ensures that there is still scope, at least in the short term, for further optimization, which will go some way to meet the increasingly stringent industrial doping requirements. The Cinderella, because of my belief that these heavy-ion sources have now contributed to the successful operation of ion implanters so well, and for so long, that their present level of performance is mistakenly taken for granted. The result has been a paucity of meaningful research and development. Despite this, in this article I aim to show that, like Cinderella, who was so neglected that her true merit was long overlooked, there is the prospect too of achieving the significantly larger improvements in beam quality which the semiconductor industry will eventually be seeking.

Freeman, Harry

2000-02-01

369

Field desorption ion source development for neutron generators  

NASA Astrophysics Data System (ADS)

A new approach to deuterium ion sources for deuterium-tritium neutron generators is being developed. The source is based upon the field desorption of deuterium from the surfaces of metal tips. Field desorption studies of microfabricated field emitter tip arrays have been conducted for the first time. Maximum fields of 3 V/Å have been applied to the array tip surfaces to date, although achieving fields of 2 V/Å to 2.5 V/Å is more typical. Both the desorption of atomic deuterium ions and the gas-phase field ionization of molecular deuterium have been observed at fields of roughly 2 and 2-3 V/Å, respectively, at room temperature. The desorption of common surface adsorbates such as hydrogen, carbon, water, and carbon monoxide is observed at fields exceeding ˜1 V/Å. In vacuo heating of the arrays to temperatures of the order of 800 °C can be effective in removing many of the surface contaminants observed.

Solano, I.; Reichenbach, Birk; Schwoebel, P. R.; Chichester, D. L.; Holland, C. E.; Hertz, K. L.; Brainard, J. P.

2008-03-01

370

Characteristics of the positive ion source at reduced gas feed.  

PubMed

The neutral beam injector of steady state superconducting tokamak (SST1-NBI) at IPR is designed for injecting upto 1.7 MW of neutral beam (Hº, 30-55 keV) power to the tokamak plasma for heating and current drive. Operations of the positive ion source (PINI or Plug-In-Neutral-Injector) of SST1-NBI were carried out on the NBI test stand. The PINI was operated at reduced gas feed rate of 2-3 Torr l/s, without using the high speed cryo pumps. Experiments were conducted to achieve a stable beam extraction by optimizing operational parameters namely, the arc current (120-300 A), acceleration voltage (16-40 kV), and a suitable control sequence. The beam divergence, power density profiles, and species fractions (H(+):H2 (+):H3 (+)) were measured by using the diagnostics such as thermal calorimetry, infrared thermography, and Doppler shift spectroscopy. The maximum extracted beam current was about 18 A. A further increase of beam current was found to be limited by the amount of gas feed rate to the ion source. PMID:25430113

Sharma, S K; Bharathi, P; Prahlad, V; Patel, P J; Choksi, B; Jana, M R; Bansal, L K; Qureshi, K; Sumod, C B; Vadher, V; Thakkar, D; Gupta, L N; Rambabu, S; Parmar, S; Contractor, N; Sahu, A K; Pandya, B; Sridhar, B; Pandya, S; Baruah, U K

2014-11-01

371

Development and discharge characteristics of negative hydrogen ion source for the SKKUCY-9 cyclotron  

NASA Astrophysics Data System (ADS)

A negative hydrogen ion source was designed and manufactured for the SKKUCY-9 cyclotron at Sungkyunkwan University. This ion source is a penning ionization gauge type source. We analyzed the electromagnetic field distribution for simulation of electron temperature, electron trajectory, and average electric field in the anode using CST Particle Studio. We applied the ion bombardment position by electric field simulation data and confirmed the thermal distribution of the cathode. The anode structure was developed using these simulation results. The penning discharge of plasma in the ion source occurred at 0.4 T. This ion source operates with a hydrogen flow of 1-5 cm3/min. The ignition voltage is approximately 1.7 kV and the arc current varies from 0.1 A to 2 A. The structure of the ion source was constructed and the experimental results are in good agreement and can be useful information for the operation of a negative ion source.

Yeon, Yeong Heum; Ghergherehchi, Mitra; Mu, XiangJie; Gad, Khaled Mohamed Mohamed; Chai, Jong Seo

2014-11-01

372

Pure Material Vapor Source by Induction Heating Evaporator for an Electron Cyclotron Resonance Ion Source  

SciTech Connect

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{sup -4} to 10{sup -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.

Matsui, Y.; Watanabe, T.; Satani, T.; Sato, F.; Kato, Y.; Iida, T. [Devision of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences, 4-9-1 Anagaw a, Inage-ku, Chiba-shi, Chiba, 263-8555 (Japan); Tanaka, K. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama, 930-1305 (Japan); Yoshida, Y. [Department of Mechanical Engineering, Toyo Univ., 2100 Kuzirai, Kawagoe-shi, Saitama, 350-0185 (Japan)

2008-11-03

373

Physics and modeling of an end-Hall (gridless) ion source  

SciTech Connect

In an end-Hall source, an ion beam is extracted from a magnetized plasma and accelerated by the plasma electric field without grids. The principle of end-Hall sources is similar to that of Hall effect thrusters (or closed-drift thrusters), but their design is optimized for processing applications (ion beam assisted deposition or substrate cleaning) rather than propulsion. The beam divergence is larger in end-Hall ion sources, and these sources can operate at low ion energies. Although end-Hall sources are commonly used in the surface processing industry, no detailed modeling of these sources is available, and their operation is quite empirical. In this paper, a self-consistent, two-dimensional, quasineutral model of an end-Hall ion source is developed and used in order to improve the understanding of the basic physics of these plasma sources and to quantify the parameters controlling the properties of the extracted ion beam.

Oudini, N. [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Hagelaar, G. J. M.; Boeuf, J.-P.; Garrrigues, L. [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, LAPLACE, F-31062 Toulouse (France)

2011-04-01

374

Characterization of a distributed plasma ionization source (DPIS) for ion mobility spectrometry and mass spectrometry.  

PubMed

A recently developed atmospheric pressure ionization source, a distributed plasma ionization source (DPIS), was characterized and compared to commonly used atmospheric pressure ionization sources with both mass spectrometry (MS) and ion mobility spectrometry (IMS). The source consisted of two electrodes of different sizes separated by a thin dielectric. Application of a high RF voltage across the electrodes generated plasma in air yielding both positive and negative ions. These reactant ions subsequently ionized the analyte vapors. The reactant ions generated were similar to those created in a conventional point-to-plane corona discharge ion source. The positive reactant ions generated by the source were mass identified as being solvated protons of general formula (H(2)O)(n)H(+) with (H(2)O)(2)H(+) as the most abundant reactant ion. The negative reactant ions produced were mass identified primarily as CO(3)(-), NO(3)(-), NO(2)(-), O(3)(-) and O(2)(-) of various relative intensities. The predominant ion and relative ion ratios varied depending upon source construction and supporting gas flow rates. A few compounds including drugs, explosives and amines were selected to evaluate the new ionization source. The source was operated continuously for 3 months and although surface deterioration was observed visually, the source continued to produce ions at a rate similar that of the initial conditions. PMID:18804628

Waltman, Melanie J; Dwivedi, Prabha; Hill, Herbert H; Blanchard, William C; Ewing, Robert G

2008-10-19

375

Design of the 3rd generation ECR ion source  

SciTech Connect

Development of the 3rd Generation ECR ion source has progressed from a concept described in the last ECR Ion Source Workshop to the fabrication of a full scale prototype superconducting magnet structure. The prototype consists of three solenoid coils and six race track coils with iron poles forming the sextupole. The design calls for mirror fields of 4 T at injection and 3 T at extraction and for a radial field strength at the wall of 2.4 T. The prototype magnet will be tested this spring in an existing vertical cryostat to determine its operating characteristics including maximum operating values, training characteristics and to study the interaction between the solenoid and sextupole coils. Design of the ECR plasma chamber includes aluminum walls to provide an enhanced source of cold electrons, up to three separate microwave feeds to allow simultaneous heating of the plasma electrons at 10, 14 and 18 GHz or at 6, 10 and 14 GHz. Water cooling of the plasma chamber walls and the injection and extraction plates is planned so that up to 10 kW of microwave power can be used without excessive heating of the chamber components. Experience with the AECR-U at LBNL shows that increasing the magnetic fields and using two frequency heating allows operation at lower neutral pressures and higher microwave power density. Both of these conditions are needed to produce very high charge states from elements with masses greater than xenon and the resulting higher energy, more intense heavy beams from the 88-Inch Cyclotron would provide new research opportunities.

Lyneis, C.M.; Xie, Z.Q.; Taylor, C.E.

1997-02-01

376

Magic-T-Coupled Magnetrons  

NASA Technical Reports Server (NTRS)

Outputs of two magnetrons added coherently in scheme based on resonant waveguide coupling and injection phase locking. In addition, filaments are turned off after starting. Overall effect is relatively-inexpensive, lowpower, noisy magnetrons generate clean carrier signals of higher power that ordinarily require more expensive klystrons.

Dickinson, R. M.

1985-01-01

377

Measurement of hold-up times in a thermal ion source for metallic and monoxide ions of lanthanum and cerium  

Microsoft Academic Search

Hold-up times of ions in a thermal ion source were measured for lanthanum and cerium together with neighboring elements in the periodic table. The hold-up times of metallic and monoxide ions of both lanthanum and cerium were found to be almost the same and much longer than those of cesium, barium, praseodymium and neodymium ions. The observed long hold-up times

S. Ichikawa; T. Sekine; H. Iimura; M. Oshima

1992-01-01

378

A relativistic magnetron with a thermionic cathode  

NASA Astrophysics Data System (ADS)

A 500-kV, S-band magnetron has been designed and tested. An oxide cathode was used in an attempt to achieve 1 ?s pulse lengths by using the pre-pulse space charge to shield the cathode from vacuum dc breakdown. The magnetron was designed according to conventional, nonrelativistic scaling laws and is unstrapped, utilizing a symmetric, axial output into a circular vacuum waveguide. Initially, focus electrodes were used to prevent axial electron losses but arcing between these and the anode limited the voltage below the ?-mode oscillation threshold. Operation occurred in various space harmonics, as predicted by the relativistic Buneman-Hartree oscillation threshold equation. Removal of the focus electrodes allowed ?-mode operation at voltages of ˜400 kV, powers of ˜20 MW, and pulse lengths of ˜35 ns. It is believed that high energy electrons strike the anode, ejecting ionized copper which neutralizes the space charge and creates a low impedance plasma channel, thereby preventing operation at pulse lengths longer than ˜35 ns for this design. The pulse lengths correlate well with a simple estimate of the ion transit time across the anode-cathode gap rather than the 1-5 cm/?s plasma diode closure rate frequently observed. The low powers obtained are a consequence both of the reduced efficiencies characteristic of relativistic magnetrons and operation at voltages well below the relativistic optimum.

Ballard, W. P.; Self, S. A.; Crawford, F. W.

1982-11-01

379

Studies in ion source development for application in heavy ion fusion  

SciTech Connect

The overall purpose of these experiments is to contribute to the development of ion injector technology in order to produce a driver for use in a heavy-ion-fusion (HIF) power generating facility. The overall beam requirements for HIF are quite demanding; a short list of the constraints is the following: (1) Low cost (a large portion of overall cost will come from the beam system); (2) Bright, low emittance beam; (3) Total beam energy 5MJ; (4) Spot size 3mm (radius); (5) Pulse Duration 10ns; (6) Current on target 40kA; (7) Repetition Rate 5Hz; (8) Standoff from target 5m; and (9) Transverse Temp < 1 keV. The reasons for employing ion beams in inertial fusion systems become obvious when the repetition rate required is considered. While laser drivers are useful in producing a proof-of-concept, they will be incapable of application in power generation. Consequently attempts in the U.S. to achieve a power generating system make use of linear ion accelerators. It is apparent that the accelerator system requires the highest quality input as obtainable. Therefore injector design is an essential portion of the entire inertial fusion system. At Lawrence Berkeley and Lawrence Livermore National Laboratories experiments are being conducted using two injector formats. For this project I have conducted a series of studies using both. The next two sections provide a brief description of the sources used for my experiments.

Kapica, Jonathan G.

2004-05-30

380

An ion species model for positive ion sources - part II analysis of hydrogen isotope effects  

E-print Network

A one dimensional model of the magnetic multipole volume plasma source has been developed for application to intense ion/neutral atom beam injectors. The model uses plasma transport coefficients for particle and energy flow to create a detailed description of the plasma parameters along an axis parallel to that of the extracted beam. In this paper the isotopic modelling of positive hydrogenic ions is considered and compared with experimental data from the neutral beam injectors of the Joint European Torus. The use of the code to gain insights into the processes contributing to the ratios of the ionic species is demonstrated and the conclusion is drawn that 75% of the atomic ion species arises from ionization of dissociated molecules and 25% from dissociation of the molecular ions. However whilst the former process is independent of the filter field, the latter is sensitive to the change in distribution of fast and thermal electrons produced by the magnetic filter field and an optimum combination of field stre...

Surrey, E

2014-01-01

381

Monte Carlo Modeling of a Cavity Ion Source  

NASA Astrophysics Data System (ADS)

Mass spectrometry is a powerful analytical tool, but is limited by sensitivity and precision, which are crucial for samples that contain low concentrations of the elements of interest. One way to increase this sensitivity and precision is with more efficient ion sources. Thermal ionization mass spectrometry (TIMS), which yields some of the most sensitive and precise isotope ratio data, uses Re or Ta ribbon filaments as ion sources. These generally ionize material with <1% efficiency (percent of ions counted). The cavity ion source (CIS) has recently been explored as an alternative to filaments. In contrast to flat filaments, the CIS is a hollowed Re or W rod. The CIS ionizes refractory elements with much higher efficiency than TIMS filaments. For example, filaments ionize U with ~0.1% efficiency, whereas CIS studies have reported efficiencies up to 39%. The filament and the CIS use the same mechanism to ionize material (i.e., thermal ionization), but the CIS forces the sample to interact with the ionizing surface many times by confining the evaporated sample to a cavity. The CIS is heated by electron bombardment, evaporating the sample just as it would on a filament. However, before being lost to the environment, the sample diffuses to the cavity's opening. While diffusing, the sample collides with the walls of the hot cavity hundreds or thousands of times. Each collision is an opportunity to ionize the evaporated sample atoms. Typical probabilities for ionization (per collision) for actinides are <1%, but having thousands of collisions greatly raises the final ionization efficiency. However, each ionized atom has the potential to recombine (i.e., gain an electron and become neutral) with additional collisions in the CIS. The probability of recombination is much higher than the probability of ionization for a single collision. Therefore, a critical design feature of a CIS is to ensure that ions are extracted after they form. The subject of this study is how to design a CIS to maximize ionization and minimize recombination. This work models a CIS using SIMION 7.0 to determine how the ionization efficiency (and thus ionization and recombination rate) depends on the cavity's length, radius and extraction potential. The model assumes a Re cavity held at a steady-state temperature of 2750 K, with a circular extraction electrode. The study predicts that ionization efficiency is not strongly dependent on cavity dimensions or extraction potential (as long as it is >1kV), but wider cavities and higher extraction potentials increase the cavity's efficiency, while longer cavities do not. The most efficient CIS modeled had a length of ~3cm and an inner radius ~5mm. As such, a CIS can be fitted to a commercially available mass spectrometer with relative ease. Once operational, an instrument fitted with a CIS could dramatically change the field of mass spectrometry by facilitating analysis of pictogram quantities of elements using high precision Faraday cup detectors in place of secondary electron multipliers.

Lewis, L. A.; Borg, L. E.; Hutcheon, I. D.

2011-12-01

382

Long pulse production of high current D{sup -} ion beams in the JT-60 negative ion source  

SciTech Connect

The first long pulse production of high power D{sup -} ion beams has been demonstrated in the JT-60 U negative ion sources, each of which was designed to produce 22 A, 500 keV D{sup -} ion beams. Voltage holding capability and the grid power loading were examined for long pulse production of high power D{sup -} ion beams. From the correlation between voltage holding and the light intensity of cathodoluminescence from the Fiber Reinforced Plastic insulators, the acceleration voltage for stable voltage holding capability was found to be less than 320-340 kV where the light was sufficiently suppressed. By tuning the extraction voltage, the grid power loadings in the ion sources were decreased to the allowable levels for long pulse injection without a significant reduction of the beam power. After tuning the acceleration and extraction voltages, D{sup -} ion beams of 12.5 and 9.8 A were produced at 340 keV with cesium seeding at a rate of {approx}14 {mu}g/s into the ion sources. The pulse duration of these D{sup -} ion beams was extended step by step, and then was successfully extended up to 18 s without degradation of the negative ion production. The D{sup -} ion beams were neutralized to yield 3.6 MW D{sup 0} beams by a gas cell, and then injected into the JT-60 U plasma. Further, a slight reduction of D{sup -} ion beam power allowed the longer injection duration of 21 s at a D{sup 0} beam power of 3.2 MW. The success in the long pulse production of a high power D{sup -} ion beam shows that negative ion beams can be produced during a few tens of seconds without degradations of negative ion production and the voltage holding in a large Cs-seeded negative ion source.

Hanada, M.; Kamada, M.; Akino, N.; Ebisawa, N.; Honda, A.; Kawai, M.; Kazawa, M.; Kikuchi, K.; Komata, M.; Mogaki, K.; Noto, K.; Ohshima, K.; Takenouchi, T.; Tanai, Y.; Usui, K.; Yamazaki, H.; Ikeda, Y.; Grisham, L. R. [Japan Atomic Energy Agency, 801-1 Mukohyama-Naka, Ibaraki 310-0193 (Japan); Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States)

2008-02-15

383

Performance of a corona ion source for measurement of sulfuric acid by chemical ionization mass spectrometry  

NASA Astrophysics Data System (ADS)

The performance of an ion source based on corona discharge has been studied. This source is used for the detection of gaseous sulfuric acid by chemical ionization mass spectrometry (CIMS) through the reaction of NO3- ions with H2SO4. The ion source is operated under atmospheric pressure and its design is similar to the one of a radioactive (americium-241) ion source which has been used previously. The results show that the detection limit for the corona ion source is sufficiently good for most applications. For an integration time of 1 min it is ~6 × 104 molecule cm-3 of H2SO4. In addition, only a small cross-sensitivity to SO2 has been observed for concentrations as high as 1 ppmv in the sample gas. This low sensitivity to SO2 is achieved even without the addition of an OH scavenger. When comparing the new corona ion source with the americium ion source for the same provided H2SO4 concentration, both ion sources yield almost identical values. These features make the corona ion source investigated here favorable over the more commonly used radioactive ion sources for most applications where H2SO4 is measured by CIMS.

Kürten, A.; Rondo, L.; Ehrhart, S.; Curtius, J.

2011-03-01

384

Performance of a corona ion source for measurement of sulfuric acid by chemical ionization mass spectrometry  

NASA Astrophysics Data System (ADS)

The performance of an ion source based on corona discharge has been studied. This source is used for the detection of gaseous sulfuric acid by chemical ionization mass spectrometry (CIMS) through the reaction of NO3- ions with H2SO4. The ion source is operated under atmospheric pressure and its design is similar to the one of a radioactive (Americium 241) ion source which has been used previously. Our results show that the detection limit for the corona ion source is sufficiently good for most applications. For an integration time of one minute it is ~6 × 104 molecules of H2SO4 per cm3. In addition, only a small cross-sensitivity to SO2 has been observed for concentrations as high as 1 ppmv in the sample gas. This low sensitivity to SO2 is achieved even without the addition of an OH scavenger. When comparing the new corona ion source with the americium ion source for the same provided H2SO4 concentration, both ion sources yield almost identical values. These features make the corona ion source investigated here favorable over the more commonly used radioactive ion sources for most applications where H2SO4 is measured by CIMS.

Kürten, A.; Rondo, L.; Ehrhart, S.; Curtius, J.

2010-11-01

385

An ion source upgrade for an axial injection based commercial cyclotron  

NASA Astrophysics Data System (ADS)

The TRIUMF H - volume-cusp ion source technology licensed by Dehnel Consulting Ltd ranges in output current from 1 to 15 mA with beam energies in the 22-30 keV range. For those Cyclone 30 cyclotrons installed with an early 1980's style Lawrence Berkeley Lab (LBL) volume-cusp ion source, an upgrade to a 5 mA TRIUMF H - volume-cusp ion source would pay dividends in terms of longer filament, filament post and ion source lens lifetime, as well as less eroded material build-up in the source. In addition, the 5 mA ion source would approximately double the beam current available to inject into the cyclotron while reducing the emittance by about a factor of four. The new system has the potential to significantly boost radioisotope production at Cyclone 30 facilities utilizing the older style LBL ion source.

Dehnel, M. P.; Stewart, T.; Roeder, M.; Le Du, K.

2005-12-01

386

Multiple delivery cesium oven system for negative ion sources  

SciTech Connect

Distribution of cesium in large negative ion beam sources to be operational in ITER, is presently based on the use of three or more cesium ovens, which operate simultaneously and are controlled remotely. However, use of multiple Cs ovens simultaneously is likely to pose difficulties in operation and maintenance of the ovens. An alternate method of Cs delivery, based on a single oven distribution system is proposed as one which could reduce the need of simultaneous operation of many ovens. A proof of principle experiment verifying the concept of a multinozzle distributor based Cs oven has been carried out at Institute for Plasma Research. It is also observed that the Cs flux is not controlled by Cs reservoir temperature after few hours of operation but by the temperature of the distributor which starts behaving as a Cs reservoir.

Bansal, G.; Bhartiya, S.; Pandya, K.; Bandyopadhyay, M.; Singh, M. J.; Soni, J.; Gahlaut, A.; Parmar, K. G.; Chakraborty, A. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

2012-02-15

387

Polarized H/sup -/ ion source development for the AGS  

SciTech Connect

The polarized H/sup -/ ion source that Argonne National Laboratory and Yale University are building for the AGS polarized beam facility is based on the crossed-beam concept in which a polarized atomic-hydrogen beam, H/sup 0/, is ionized to H/sup -/ by a fast neutral cesium beam, Cs/sup 0/. We describe our studies which will aid in achieving a high intensity polarized H/sup -/ beam. In particular, we describe time-of-flight studies on the atomic beam and the effect of dissociation nozzle cooling on the velocity distribution. The cesium gun design is described, and a brief discussion of the H/sup 0/-Cs/sup 0/ interaction region is given.

Schultz, P.F.; Moffett, D.R.; Colton, E.P.; Kponou, A.; Hughes, V.W.

1981-01-01

388

New high temperature plasma ion source for the TRISTAN ISOL facility  

SciTech Connect

A vigorous program of ion source development at TRISTAN has led to several types of ion sources that are especially suited to extended operation at a reactor-based ISOL facility. The latest of these is a high temperature plasma ion source in which a 5 gm /sup 235/U target is located in the cathode and can be heated to 2500/sup 0/C. The ion source has a lifetime of >1000 hours and produces a wide array of elements, including Pd. Off-line investigations indicate that the source functions primarily in an electron impact mode of ionization and exhibits typical ionzation efficiencies of >30% for Xe.

Piotrowski, A.; Gill, R.L.; McDonald, D.C.

1986-08-01

389

Study of negative ion transport phenomena in a plasma source  

NASA Astrophysics Data System (ADS)

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.

Riz, D.; Paméla, J.

1996-07-01

390

Numerical study of the characteristics of the ion and fast atom beams in an end-Hall ion source  

SciTech Connect

An end-Hall ion source is a cylindrical magnetized device of few centimeters in length able to generate an ion beam with a current of typically 1 A and ion energies in the range of 100 eV. This ion source does not use acceleration grids, has a relatively large ion beam divergence, and is well suited for ion assisted deposition processes. In this paper, a self-consistent two-dimensional quasi-neutral model of an end-Hall ion source is used to understand the parameters controlling the characteristics of the extracted. The model results underline the role of charge exchange collisions on beam properties. The calculated energy distribution functions reveal the existence of groups of slow ions and fast neutrals. Ion mean energy corresponds to roughly 60% of the discharge voltage, while the root mean square deviation from the mean energy corresponds to about 33% of the discharge voltage, as in experiments. The influence of the position of the electron emitting source on the ion angular distribution is also shown.

Oudini, N. [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Garrigues, L.; Hagelaar, G. J. M.; Boeuf, J. P. [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); CNRS, LAPLACE, F-31062 Toulouse (France)

2012-10-15

391

Operational Experience with The GTS-LHC Ion Source and Future Developments of The CERN Ion Injector  

E-print Network

Since 2010 the GTS-LHC source delivers lead ions for heavy ion physics at the LHC. Several modifications allowed the improvement the source reliability and the beam stability. The attempts to improve the beam intensity were less successful. The different modifications and actual performance figures will be presented in this paper. In addition to the heavy ion physics program of the LHC new ion species will be requested for different experiments in the future. The fixed target experiment NA61 requires primary argon and xenon beams. And a future biomedical facility asks for light ions in the range helium to neon. Approaches to prepare these beams and to modify the ion injector towards a light ion front end are presented.

Kuchler, D; Lombardi, A; O'Neil, M; Scrivens, R; Stafford-Haworth, J; Thomae, R

2012-01-01

392

Ionic liquid ion source emitter arrays fabricated on bulk porous substrates for spacecraft propulsion  

E-print Network

Ionic Liquid Ion Sources (ILIS) are a subset of electrospray capable of producing bipolar beams of pure ions from ionic liquids. Ionic liquids are room temperature molten salts, characterized by negligible vapor pressures, ...

Courtney, Daniel George

2011-01-01

393

Ion source development for the on-line isotope separator at JAEA  

NASA Astrophysics Data System (ADS)

A forced electron beam induced arc discharge (FEBIAD-B2) type ion source and a surface ionization type one with a uranium target have been developed for the JAEA-ISOL. The ion sources were utilized to produce medium-heavy neutron-rich radioactive ion beams for acceleration with Tokai radioactive ion accelerator complex (TRIAC). In the FEBIAD-B2 type ion source, a target container containing about 1 g/cm 2 of 238UC x target is directly attached to a plasma chamber. While the surface ionization type one, 238UC x target is located inside the ion source as an internal target. With both ion sources, about 100 isotopes produced in the proton-induced fission of uranium with separation efficiencies of 0.1-30% have been mass-separated.

Osa, Akihiko; Ichikawa, Shin-ichi; Matsuda, Makoto; Sato, Tetsuya K.; Jeong, Sun-Chan

2008-10-01

394

Kinetic modeling of particle dynamics in H(-) negative ion sources (invited).  

PubMed

Progress in the kinetic modeling of particle dynamics in H(-) negative ion source plasmas and their comparisons with experiments are reviewed, and discussed with some new results. Main focus is placed on the following two topics, which are important for the research and development of large negative ion sources and high power H(-) ion beams: (i) Effects of non-equilibrium features of EEDF (electron energy distribution function) on H(-) production, and (ii) extraction physics of H(-) ions and beam optics. PMID:24593433

Hatayama, A; Shibata, T; Nishioka, S; Ohta, M; Yasumoto, M; Nishida, K; Yamamoto, T; Miyamoto, K; Fukano, A; Mizuno, T

2014-02-01

395

A New ECR Ion Source for Nuclear Astrophysics Studies  

NASA Astrophysics Data System (ADS)

The Laboratory for Experimental Nuclear Astrophysics (LENA) is a low energy facility designed to study nuclear reactions of astrophysical interest at energies which are important for nucleosysthesis. In general, these reactions have extremely small cross sections, requiring intense beams and efficient detection systems. Recently, a new, high intensity electron-cyclotron-resonance (ECR) ion source has been constructed (based on a design by Wills et al.[1]), which represents a substantial improvement in the capabilities of LENA. Beam is extracted from an ECR plasma excited at 2.45 GHz and confined by an array of permanent magnets. It has produced H^+ beams in excess of 1 mA on target over the energy range 100 - 200 keV, which greatly increases our ability to measure small cross sections. Initial measurements will focus on the ^23Na(p,?)^24Mg reaction, which is of interest in a variety of astrophysical scenarios. The present uncertainty in the rate of this reaction is the result of an unobserved resonance expected at Elab =144 keV, which should be detectable using beams from the new ECR source. In collaboration with Arthur E. Champagne and Thomas B. Clegg, University of North Carolina, Chapel Hill and TUNL. [3pt] [1] J. S. C. Wills et al., Rev. Sci. Instrum. 69, 65 (1999).

Cesaratto, John M.

2008-10-01

396

Improvement of a plasma uniformity of the 2nd ion source of KSTAR neutral beam injectora)  

NASA Astrophysics Data System (ADS)

The 2nd ion source of KSTAR (Korea Superconducting Tokamak Advanced Research) NBI (Neutral Beam Injector) had been developed and operated since last year. A calorimetric analysis revealed that the heat load of the back plate of the ion source is relatively higher than that of the 1st ion source of KSTAR NBI. The spatial plasma uniformity of the ion source is not good. Therefore, we intended to identify factors affecting the uniformity of a plasma density and improve it. We estimated the effects of a direction of filament current and a magnetic field configuration of the plasma generator on the plasma uniformity. We also verified that the operation conditions of an ion source could change a uniformity of the plasma density of an ion source.

Jeong, S. H.; Kim, T. S.; Lee, K. W.; Chang, D. H.; In, S. R.; Bae, Y. S.

2014-02-01

397

Source fabrication and lifetime for Li+ ion beams extracted from alumino-silicate sources  

SciTech Connect

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm{sup 2} have been measured from lithium alumino-silicate ion sources at a temperature of #24;~1275#14;{degrees} C. At higher extraction voltages, the source appears to become emission limited with J #21;{>=} 1.5 mA/cm{sup 2}, and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, {<=}#20;0.25 mm thick, has a measured lifetime of ~#24;40 hours at ~#24;1275#14;{degrees} C, when pulsed at 0.05 Hz and with pulse length of #24;~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. The source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W

2012-03-05

398

Source fabrication and lifetime for Li{sup +} ion beams extracted from alumino-silicate sources  

SciTech Connect

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm{sup 2} have been measured from lithium alumino-silicate ion sources at a temperature of ?1275{degrees}C. At higher extraction voltages, the source appears to become emission limited with J ? 1.5 mA/cm{sup 2}, and J increases weakly with the applied voltage. A source with an alumino-silicate coating 6.35 mm in diameter and ?0.25 mm thick, has a lifetime of ?40 hours at ?1275{degrees}C, when pulsed at 0.05 Hz and with pulse length of ?6 ?s each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Furthermore, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be extended if the temperature is reduced between pulses.

Greenway, W. G.; Kwan, J. W.

2012-02-10

399

Characterization of the plasma-switch interaction in the LBL HIF ion source  

SciTech Connect

A new way to characterize the performance of the LBL HIF ion source has been found. In the LBL source, ions are drawn from an arc-generated plasma reservoir in which the electrons are confined by a negative-biased switch'' mesh. Stagnation of the plasma is prevented by absorption of the excess ion flow on this mesh. The ion beam is generated by an external negative voltage that provides Child-Langmuir extraction of the ions through the switch mesh. We elucidate the physics requirements of the source and deduce switch mesh parameters needed for successful operation. 2 refs., 2 figs.

Hewett, D.W. (Lawrence Livermore National Lab., CA (USA)); Rutkowski, H.L. (Lawrence Berkeley Lab., CA (USA))

1990-12-10

400

Characterization of the plasma-switch interaction in the LBL HIF ion source  

SciTech Connect

A new way to characterize the performance of the LBL HIF ion source has been found. In the LBL source, ions are drawn from an arc-generated plasma reservoir in which the electrons are confined by a negative-biased switch'' mesh. Stagnation of the plasma is prevented by absorption of the excess ion flow on this mesh. The ion beam is generated by an external negative voltage that provides Child-Langmuir extraction of the ions through the switch mesh. We elucidate the physics requirements of the source and deduce switch mesh parameters needed for successful operation. 2 refs., 2 figs.

Hewett, D.W. (Lawrence Livermore National Lab., CA (USA)); Rutkowski, H.L. (Lawrence Berkeley Lab., CA (USA))

1990-01-01

401

ECR (Electron Cyclotron Resonance) source for the HHIRF (Holifield Heavy Ion Research Facility) tandem accelerator  

SciTech Connect

Electron Cyclotron Resonance, ECR, ion source technology has developed rapidly since the original pioneering work of R. Geller and his group at Grenoble in the early 1970s. These ion sources are capable of producing intense beams of highly charged positive ions and are used extensively for cyclotron injection, linac injection, and atomic physics research. In this paper, the advantages of using an ECR heavy-ion source in the terminal of the Holifield Heavy Ion Research Facility (HHIRF) 25-MV tandem accelerator is discussed. A possible ECR system for installation in the HHIRF tandem terminal is described.

Olsen, D.K.; Alton, G.D.; Dowling, D.T.; Haynes, D.L.; Jones, C.M.; Juras, R.C.; Lane, S.N.; Meigs, M.J.; Mills, G.D.; Mosko, S.W.; Tatum, B.A.

1990-01-01

402

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

DOEpatents

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.

Smith, Richard D. (Richland, WA); Kim, Taeman (Richland, WA); Tang, Keqi (Richland, WA); Udseth, Harold R. (Richland, WA)

2003-06-24

403

Plasma ion source for in situ ion bombardment in a soft x-ray magnetic scattering diffractometer  

SciTech Connect

A new plasma ion source for in situ keV He ion bombardment of solid state samples or thin films was designed and built for ion fluences between 1 x 10{sup 12} and 1 x 10{sup 17} ions/cm{sup 2}. The system was designed to be mounted to different diffraction chambers for soft x-ray resonant magnetic scattering. Without breaking the vacuum due to He-ion bombardment, structural and magnetic modifications of the samples can be studied in situ and element specifically.

Lengemann, Daniel; Engel, Dieter; Ehresmann, Arno [Institute of Physics, EP IV, University of Kassel, Heinrich-Plett-Str.40, 34132 Kassel (Germany) and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Str.40, 34132 Kassel (Germany)

2012-05-15

404

Particle contamination formation in magnetron sputtering processes  

SciTech Connect

Defects caused by particulate contamination are an important concern in the fabrication of thin film products. Often, magnetron sputtering processes are used for this purpose. Particle contamination generated during thin film processing can be detected using laser light scattering, a powerful diagnostic technique which provides real-time, {ital in situ} imaging of particles {gt}0.3 {mu}m on the target, substrate, or in the plasma. Using this technique, we demonstrate that the mechanisms for particle generation, transport, and trapping during magnetron sputter deposition are different from the mechanisms reported in previously studied plasma etch processes, due to the inherent spatial nonuniformity of magnetically enhanced plasmas. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density. There, film redeposition induces filament or nodule growth. Sputter removal of these features is inhibited by the dependence of sputter yield on angle of incidence. These features enhance trapping of plasma particles, which then increases filament growth. Eventually the growths effectively {open_quotes}short-circuit{close_quotes} the sheath, causing high currents to flow through these features. This, in turn, causes mechanical failure of the growth resulting in fracture and ejection of the target contaminants into the plasma and onto the substrate. Evidence of this effect has been observed in semiconductor fabrication and storage disk manufacturing. Discovery of this mechanism in both technologies suggests it may be universal to many sputter processes. {copyright} {ital 1997 American Vacuum Society.}

Selwyn, G.S. [Physics Division, M/S E526, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Physics Division, M/S E526, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Weiss, C.A. [Materials Research Corporation, 200 Route 303, North Congers, New York 10920 (United States)] [Materials Research Corporation, 200 Route 303, North Congers, New York 10920 (United States); Sequeda, F.; Huang, C. [Seagate Peripherals Disk Division, 311 Turquoise Street, Milpitas, California 95035 (United States)] [Seagate Peripherals Disk Division, 311 Turquoise Street, Milpitas, California 95035 (United States)

1997-07-01

405

Optical spectroscopy and performance tests with a solid state laser ion source at HRIBF  

Microsoft Academic Search

An ISOLDE-type hot-cavity laser ion source based on high-repetition-rate Ti:Sapphire lasers has been set up at the Holifield radioactive ion beam facility. To assess the feasibility of the all-solid-state laser system for applications at advanced radioactive ion beam facilities, spectroscopy and performance tests have been conducted with this source. The results of recent studies on excitation schemes, source efficiency, beam

T. Gottwald; C. Geppert; F. Schwellnus; K. Wies; K. Wendt; Yuan Liu; Cyrus Baktash; James R Beene; Charles C Havener; Herbert F Krause; David Robert Schultz; Daniel W Stracener; C Randy Vane; T. Kessler; B. Tordoff

2008-01-01

406

Magnetron Sputtered Gold Contacts on N-gaas  

NASA Technical Reports Server (NTRS)

Direct current planar magnetron sputtering was used to deposit gold Schottky barrier electrical contacts on n-type GaAs of varying doping densities. The electrical character of the contact was determined from current voltage and electron beam induced voltage data. Without reducing the surface concentration of carbon and oxide, the contacts were found to be rectifying. There is evidence that energetic neutral particles reflected from the magnetron target strike the GaAs and cause interfacial damage similar to that observed for ion sputtering. Particle irradiation of the surface during contact deposition is discussed.

Buonaquisti, A. D.; Matson, R. J.; Russell, P. E.; Holloway, P. H.

1984-01-01

407

Ion source developments for the production of radioactive isotope beams at TRIUMFa)  

NASA Astrophysics Data System (ADS)

At the ISAC facility at TRIUMF radioactive ions are produced by bombarding solid targets with up to 100 ?A of 500 MeV protons. The reaction products have to diffuse out of the hot target into an ion source. Normally, singly charged ions are extracted. They can be transported either directly to experiments or via an ECR charge state breeder to a post accelerator. Several different types of ion sources have to be used in order to deliver a large variety of rare isotope beams. At ISAC those are surface ion sources, forced electron beam arc discharge (FEBIAD) ion sources and resonant laser ionization sources. Recent development activities concentrated on increasing the selectivity for the ionization to suppress isobaric contamination in the beam. Therefore, a surface ion rejecting resonant laser ionization source (SIRLIS) has been developed to suppress ions from surface ionization. For the FEBIAD ion source a cold transfer line has been introduced to prevent less volatile components from reaching the ion source.

Ames, F.; Bricault, P.; Heggen, H.; Kunz, P.; Lassen, J.; Mjøs, A.; Raeder, S.; Teigelhöfer, A.

2014-02-01

408

Study of ion beam extraction and transport from an electron cyclotron resonance ion source.  

PubMed

We have started an experimental and theoretical program to better understand the extraction and transport of intense multiply charged ion beams from an electron cyclotron resonance ion source (ECRIS). In this paper we present the first results of this program concerning a simple, monocomponent He(+) beam extracted from an ECRIS. We have calculated the ion trajectories starting from the ECRIS plasma electrode up to the image plane of the analyzing magnet taking into account space-charge effects and fringe fields. The initial phase-space distribution of the He(+) beam at the extraction aperture has been calculated with a particle-in-cell code. To check the simulations we have measured beam profiles with a viewing screen both before and after the analyzing magnet. In addition also measurements with a pepperpot emittance meter located behind the analyzing magnet have been performed. We find good agreement between these measurements and simulations showing that (i) there is a significant compensation of the space charge and that (ii) our analyzing magnet causes a severe increase in effective beam emittance. PMID:20192446

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

2010-02-01

409

The accuracy of heavy-ion mass measurements using time of flight-ion cyclotron resonance in a Penning trap  

NASA Astrophysics Data System (ADS)

Ion motion in a Penning trap and the electrical signals it can produce have been analyzed for the purpose of identifying the important causes of uncertainty in high-accuracy mass measurements of heavy ions. The role of the azimuthal quadrupole electric field in signal pickup, and its effects on ion motion at the sum frequency of the cyclotron and magnetron motions, have been identified. A useful scheme for calculating the signal strength and strength of the interaction between an applied field and the ion motion has been developed. The important sources of uncertainty in using the sum frequency of the cyclotron and magnetron motions for determining the ion mass are discussed. Particular application is made to the case of cyclotron resonance detection by observation of the time of flight of ejected ions.

Bollen, G.; Moore, R. B.; Savard, G.; Stolzenberg, H.

1990-11-01

410

Simulation and beamline experiments for the superconducting electron cyclotron resonance ion source VENUS  

SciTech Connect

The particle-in-cell code WARP has been enhanced to incorporate both two- and three-dimensional sheath extraction models giving WARP the capability of simulating entire ion beam transport systems including the extraction of beams from plasma sources. In this article, we describe a method of producing initial ion distributions for plasma extraction simulations in electron cyclotron resonance (ECR) ion sources based on experimentally measured sputtering on the source biased disk. Using this initialization method, we present preliminary results for extraction and transport simulations of an oxygen beam and compare them with experimental beam imaging on a quartz viewing plate for the superconducting ECR ion source VENUS.

Todd, Damon S.; Leitner, Daniela; Lyneis, Claude M.; Grote, David P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2008-02-15

411

Simulation and beamline experiments for the superconducting electron cyclotron resonance ion source VENUS.  

PubMed

The particle-in-cell code WARP has been enhanced to incorporate both two- and three-dimensional sheath extraction models giving WARP the capability of simulating entire ion beam transport systems including the extraction of beams from plasma sources. In this article, we describe a method of producing initial ion distributions for plasma extraction simulations in electron cyclotron resonance (ECR) ion sources based on experimentally measured sputtering on the source biased disk. Using this initialization method, we present preliminary results for extraction and transport simulations of an oxygen beam and compare them with experimental beam imaging on a quartz viewing plate for the superconducting ECR ion source VENUS. PMID:18315106

Todd, Damon S; Leitner, Daniela; Lyneis, Claude M; Grote, David P

2008-02-01

412

High temperature electron beam ion source for the production of single charge ions of most elements of the Periodic Table  

NASA Astrophysics Data System (ADS)

A new type of a high temperature electron beam ion source (HTEBIS) with a working temperature up to 2500 °C was developed for production of single charge ions of practically all elements. Off-line tests and on-line experiments making use of the developed ion source coupled with uranium carbide targets of different density, have been carried out. The ionization efficiency measured for stable atoms of many elements varied in the interval of 1-6%. Using the HTEBIS, the yields and on-line production efficiency of neutron rich isotopes of Mn, Fe, Co, Cu, Rh, Pd, Ag, Cd, In, Sn and isotopes of heavy elements Pb, Bi, Po and some others have been determined. The revealed confinement effect of the ions produced in the narrow electron beam inside a hot ion source cavity has been discussed.

Panteleev, V. N.; Andrighetto, A.; Barzakh, A. E.; Fedorov, D. V.; Ivanov, V. S.; Moroz, F. V.; Orlov, S. Yu.; Seliverstov, M. D.; Stroe, L.; Tecchio, L.; Volkov, Yu. M.

2003-05-01

413

A compact ion source and accelerator based on a piezoelectric driver  

SciTech Connect

Compact ion sources and accelerators using piezoelectric devices for the production of energetic ion beams are being evaluated. A coupled source-accelerator is being tested as a neutron source to be incorporated into oil-well logging diagnostics. Two different ion sources are being investigated, including a piezoelectric transformer-based plasma source and a silicon-based field ion source. The piezoelectric transformer plasma ion source uses a cylindrical, resonantly driven piezoelectric crystal to produce high voltage inside a confined volume filled with low pressure deuterium gas. The plasma generated in the confined chamber is ejected through a small aperture into an evacuated drift region. The silicon field ion source uses localized electric field enhancement produced by an array of sharp emitters etched into a silicon blank to produce ions through field desorption ionization. A second piezoelectric device of a different design is used to generate an accelerating potential on the order of 130 kV; this potential is applied to a deuterated target plate positioned perpendicular to the ion stream produced by either plasma source. This paper discusses the results obtained by the individual components as they relate to the final neutron source.

Norgard, P.; Kovaleski, S. D.; VanGordon, J. A.; Baxter, E. A.; Gall, B. B.; Kwon, Jae Wan; Kim, Baek Hyun [Electrical and Computer Engineering Department, University of Missouri, 349 Engineering Building West, Columbia, MO 65211 (United States); Dale, G. E. [High Power Electrodynamics Group, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

2013-04-19

414

Test bench to commission a third ion source beam line and a newly designed extraction systema)  

NASA Astrophysics Data System (ADS)

The HIT (Heidelberg Ion Beam Therapy Center) is the first hospital-based treatment facility in Europe where patients can be irradiated with protons and carbon ions. Since the commissioning starting in 2006 two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce a variety of ion beams from protons up to oxygen. In the future a helium beam for regular patient treatment is requested, therefore a third ion source (Supernanogan source from PANTECHNIK S.A.) will be integrated. This third ECR source with a newly designed extraction system and a spectrometer line is installed at a test bench at HIT to commission and validate this section. Measurements with different extraction system setups will be presented to show the improvement of beam quality for helium, proton, and carbon beams. An outlook to the possible integration scheme of the new ion source into the production facility will be discussed.

Winkelmann, T.; Cee, R.; Haberer, T.; Naas, B.; Peters, A.

2012-02-01

415

Test bench to commission a third ion source beam line and a newly designed extraction system.  

PubMed

The HIT (Heidelberg Ion Beam Therapy Center) is the first hospital-based treatment facility in Europe where patients can be irradiated with protons and carbon ions. Since the commissioning starting in 2006 two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce a variety of ion beams from protons up to oxygen. In the future a helium beam for regular patient treatment is requested, therefore a third ion source (Supernanogan source from PANTECHNIK S.A.) will be integrated. This third ECR source with a newly designed extraction system and a spectrometer line is installed at a test bench at HIT to commission and validate this section. Measurements with different extraction system setups will be presented to show the improvement of beam quality for helium, proton, and carbon beams. An outlook to the possible integration scheme of the new ion source into the production facility will be discussed. PMID:22380336

Winkelmann, T; Cee, R; Haberer, T; Naas, B; Peters, A

2012-02-01

416

Development of an H- ion source for Japan Proton Accelerator Research Complex upgradea)  

NASA Astrophysics Data System (ADS)

A cesium (Cs) free H- ion source driven with a lanthanum hexaboride (LaB6) filament was adopted as an ion source for the first stage of the Japan Proton Accelerator Research Complex (J-PARC). At present, the maximum H- ion current produced by the ion source is 38 mA, using which J-PARC can produce a proton beam power of 0.6 MW by accelerating it with the 181 MeV linac and the 3 GeV rapid cycling synchrotron. In order to satisfy the beam power of 1 MW required for the second stage of the J-PARC in the near future, we have to increase the ion current to more than 60 mA. Therefore, we have started to develop a Cs-seeded ion source by adding an external Cs-seeding system to a J-PARC test ion source that has a structure similar to that of the J-PARC ion source except for the fact that the plasma chamber is slightly larger. As a result, a H- ion current of more than 70 mA was obtained from the ion source using a tungsten filament instead of a LaB6 filament with a low arc discharge power of 15 kW (100 V, 150 A).

Ohkoshi, K.; Namekawa, Y.; Ueno, A.; Oguri, H.; Ikegami, K.

2010-02-01

417

Development of an H- ion source for Japan Proton Accelerator Research Complex upgrade.  

PubMed

A cesium (Cs) free H(-) ion source driven with a lanthanum hexaboride (LaB(6)) filament was adopted as an ion source for the first stage of the Japan Proton Accelerator Research Complex (J-PARC). At present, the maximum H(-) ion current produced by the ion source is 38 mA, using which J-PARC can produce a proton beam power of 0.6 MW by accelerating it with the 181 MeV linac and the 3 GeV rapid cycling synchrotron. In order to satisfy the beam power of 1 MW required for the second stage of the J-PARC in the near future, we have to increase the ion current to more than 60 mA. Therefore, we have started to develop a Cs-seeded ion source by adding an external Cs-seeding system to a J-PARC test ion source that has a structure similar to that of the J-PARC ion source except for the fact that the plasma chamber is slightly larger. As a result, a H(-) ion current of more than 70 mA was obtained from the ion source using a tungsten filament instead of a LaB(6) filament with a low arc discharge power of 15 kW (100 V, 150 A). PMID:20192386

Ohkoshi, K; Namekawa, Y; Ueno, A; Oguri, H; Ikegami, K

2010-02-01

418

Investigations of the emittance and brightness of ion beams from an electron beam ion source of the Dresden EBIS type  

SciTech Connect

We have characterized ion beams extracted from the Dresden EBIS-A, a compact room-temperature electron beam ion source (EBIS) with a permanent magnet system for electron beam compression, using a pepper-pot emit