Molecular and negative ion production by a standard electron cyclotron resonance ion source

Molecular and negative ion beams, usually produced in special ion sources, play an increasingly important role in fundamental and applied atomic physics. The ATOMKI-ECRIS is a standard ECR ion source, designed to provide highly charged ion (HCI) plasmas and beams. In the present work, H(-), O(-), OH(-), O(2)(-), C(-), C(60)(-) negative ions and H(2)(+), H(3)(+), OH(+), H(2)O(+), H(3)O(+), O(2)(+) positive molecular ions were generated in this HCI-ECRIS. Without any major modification in the source and without any commonly applied tricks (such as usage of cesium or magnetic filter), negative ion beams of several μA and positive molecular ion beams in the mA range were successfully obtained.     

Molecular ion source having low energy spread and single-electron-impact excitation

A cylindrically symmetric electron-bombardment ion source is described that has been useful in beam experiments with molecular ions. Measurements indicate that the ions have a kinetic-energy spread (full-width at half-maximum) of 0.5-1.0 eV, a current of several microamperes, and a population distribution that is consistent with vibrational and rotational factors resulting from single-electron-impact ionization. The source exhibits low noise ( less, similar twice the theoretical shot-noise limit) and has a compact and easily serviceable construction.     

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

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

Upgraded vacuum arc ion source for metal ion implantation

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.     

Microwave ion source for high-current implanter

A long-life, high-current, microwave ion source for an electromagnetic mass separator is described. Ionization takes place due to the 2.45-GHz microwave discharge at a magnetic field intensity which is higher than the electron cyclotron resonance magnetic field. The discharge chamber is a ridged circular waveguide. The discharge region is restricted to a rectangular volume between the ridged electrodes by filling the remaining portions with dielectric. This source operates under low pressure (10(-2)-10(-3) Torr) and with high power efficiency. The incident microwave power is only several hundred watts at maximum output. When PH(3) gas is introduced, the total extracted current is about 40 mA with a 2x40-mm extraction slit. A P(+) ion implantation current of more than 10 mA is obtained by combining the source with a 40-cm radius, 60 degrees deflection magnetic mass separator.     

A subnanosecond pulsed ion source for micrometer focused ion beams

A new, compact design of an ion source delivers nanosecond pulsed ion beams with low emittance, which can be focused to micrometer size. By using a high-power, 25 fs laser pulse focused into a gas region of 10(-6) mbar, ions at very low temperatures are produced in the small laser focal volume of 5 mum diameter by 20 mum length through multiphoton ionization. These ions are created in a cold environment, not in a hot plasma, and, since the ionization process itself does not significantly heat them, have as a result essentially room temperature. The generated ion pulse, up to several thousand ions per pulse, is extracted from the source volume with ion optical elements that have been carefully designed by simulation calculations. Externally triggered, its subnanosecond duration and even smaller time jitter allow it to be superimposed with other pulsed particle or laser beams. It therefore can be combined with any type of collision experiment where the size and the time structure of the projectile beam crucially affect the achievable experimental resolution.     

Gas discharge ion source III. Modified Berkeley multifilament ion source

Total ion current, ion energy, mass and current density distributions, and the impurity content of the ion beams produced by a modified Berkeley multifilament ion source (MFIS) were measured as a function of source configuration, gas pressure, and operating conditions: the 'best' configuration produced beams of 200 mA or more at pressures between 0.40 and 2.0 Pa. In comparison with earlier studies of duoplasmatron and duopigatron sources, the MFIS beams contained less D(+), only ca. 33%, but the beams had much narrower energy distributions and flatter current density distributions. The beams contained 1%-2% impurities which consisted mainly of masses 18, 20, and 22.     

Compact microwave ion source for industrial applications

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.     

Self-triggered channel ion source

An ion source made from a continuous dynode electron multiplier of the straight channel type and an ion reflector device is described. Its principle of operation is based on a continuous self-sustained ion and electron cascade in the multiplier channel. Operating characteristics and the analysis of the ions produced are presented. The intensity of the total ion current delivered (10(-9) to 10(-8) A) is enhanced by at least six orders of magnitude relatively to previously described similar devices. This source, as illustrated, may be used in gaseous mass spectrometry.     

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

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.     

Liquid metal alloy ion source based metal ion injection into a room-temperature electron beam ion source

We have carried out a series of measurements demonstrating the feasibility of using the Dresden electron beam ion source (EBIS)-A, a table-top sized, permanent magnet technology based electron beam ion source, as a charge breeder. Low charged gold ions from an AuGe liquid metal alloy ion source were injected into the EBIS and re-extracted as highly charged ions, thereby producing charge states as high as Au(60 +). The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented.     

Evaluation of a liquid metal ion source for secondary ion mass spectrometry

Positive and negative secondary ion emission of 23 pure elements have been studied for 10 keV In⁺ and 10 keV O₂⁺ bombardment. In⁺ ions were produced in a liquid metal ion source. For most of the elements investigated positive and negative secondary ion yields under In⁺ impact are comparable to those obtained with O₂⁺ primary ions. Admission of oxygen into the sample chamber enhances positive and negative ion intensitities in a strongly element-specific manner. Depth profiles of a Ni/Cr multilayer (100 Å single-layer thickness) using 5 keV In⁺ primary ions show that these ions may also be applied successfully for secondary ion mass spectrometric depth profiling.     

New Cs sputter ion source with polyatomic ion beams for secondary ion mass spectrometry applications

A simple design for a cesium sputter ion source compatible with vacuum and ion-optical systems as well as with electronics of the commercially available Cameca IMS-4f instrument is reported. This ion source has been tested with the cluster primary ions of Si(n)(-) and Cu(n)(-). Our experiments with surface characterization and depth profiling conducted to date demonstrate improvements of the analytical capabilities of the secondary ion mass spectrometry instrument due to the nonadditive enhancement of secondary ion emission and shorter ion ranges of polyatomic projectiles compared to atomic ones with the same impact energy.     

An experimental apparatus for Penning ion source research

An experimental apparatus and the research results of the discharge characteristics of a demountable Penning ion source are described. This apparatus is designed for both fundamental reflective-discharge investigations and the optimization of particular ion-source designs. The use of annular and grid anodes made it possible to visualize the discharge burning region and their structure depending on the pressure, the voltage, and the source geometry. Setting a hot cathode in the cathode unit allows the investigation of the nonself-sustained type of discharge and optimization of the ion-optical system. Replaceable cold cathodes (made of different materials) and a composed magnetic system significantly extend the possibilities of optimizing the ion-source constructions.     

An upgraded ion source for a mass spectrometer

A model analysis of ion sources for dynamic mass spectrometers was performed, and the design of an upgraded ion source, which substantially reduces the ion energy spread, allows optimization of the zone of ion extraction from the source, and provides a high sensitivity of the instrument in the operation with low-energy ionizing electrons (down to threshold energies), was developed. Methodological techniques that allow one to analyze and calculate numerical model variants of ion sources of various designs using the SIMION 3D 7.0 program were developed.     

Emergency power source for an ion vacuum pump

This note describes a simple high-voltage dc generator which serves as an emergency power source for an ion vacuum pump during power interruptions, or failure of the main supply.     

New ion source for KSTAR neutral beam injection system

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.