Simion is a software package for the simulation of charged particle optics. A retarding potential analyzer rpa, also known as retarding field energy analyzer or gridded energy analyzer when introduced in the 1950s 10, measures the ion energy distribution of a plasma. Rfa,beam energy,beam energy distribution,beam diagnostics. Retarding field energy analyzers rfea have been used extensively to measure the. Experimental analysis of a new retarding field energy analyzer. Ion temperature fluctuation measurements using a retarding.
Retarding field analyzer dreebit ion beam technology. Staib energy analyzers with cylindrical mirror geometry. The semion 800 retarding field energy analyser from impedans ltd measures the ion energy and flux arriving at a surface in a plasma chamber. Measuring the energy distribution of the beam is a form of longitudinal phasespace mapping. Combined with a high precision retarding field optic, the electron energy through the cylindrical mirror field, i. Pdf retarding field energy analyser ion current calibration and. Impedans ltd the cutting edge retarding field energy analyser. S elmore 1,2, s y allan 1, a kirk 1, g fishpool 1, j harrison 1, p tamain 3, m kocan 4, r gaffka 1, r stephen 1, j w bradley 2 and the mast team. We have developed a compact highresolution retarding. Retarding field analyzer principle figure 1 illustrates the basic principle of rfa operation. Its purpose is to analyze the optimal configurations for negative ion beam production and propagation.
Retarding field energy analyzers rfeas are used routinely for the measurement of ion energy distribution functions. The retarding field analyzer is made of a laser cutted hole grid system with holes 0. In this work, we simulate the ion trajectories through a threegridded rfea using the simulation software. A retarding field energy analyzer designed to measure ion energy distributions impacting a radiofrequency biased electrode in a plasma discharge is examined. Impedans ltd semion single the retarding field energy. A retarding field detector to measure the actual energy of. Retarding potential analyzer how is retarding potential. The cesrta programat cornell has allowed for rfa measurements to be taken in a wide variety of beam conditions. A retarding field energy analyzer designed to measure ion energy distributions impacting a radiofrequency biased electrode in a plasma.
This energy analyzer has a cylindrical electrode to overcome the defocusing effects due to spacecharge forces, beam trajectories, aperture effect, etc. The cutting edge semion multi sensor retarding field energy analyser. An improved retarding field analyzer for electron cloud. Instrumental effects in a retarding field energy analyzer s. The propagation of ion beams in a lowdensity gas exploits spacecharge compensation effects, that consists in the generation and confinement by the beam itself of charged particles. Scimedepartment of physics, west virginia university rfea theory and analysis the principle operation of a retarding field analyzer is to sele ct or reject either positive ions or. This data was utilized by the customer to track the source of the problem and optimize tool performance. Direct measurement of the ion energy distribution ied and total ion flux can be performed with the semion system, using our advanced retarding field energy analyser rfea technology. It is useful for being able to assess dispersive or chromatic effects on the beam.
Iedf distortion and resolution considerations for rfea. A new retarding field energy analyzer rfea is designed to diagnose the electron beam of a kband space twt. Simulations and testing of retarding field analyzers for. Both toroidal and poloidal plasma flow velocities do not change across the transition. A simple to construct, highresolution, retarding field analyzer rfa comprising a coneinthecan electrode configuration was developed to eliminate the problems associated with the planar rfa, specifically potential sagging around the discrete wires of the grid and the cutoff energy dependence on. In this experiment we will intercept the beam with a highresolution, retarding potential energy analyzer ea. Upstream and divertor ion temperature measurements on mast by retarding field energy analyser. The system mainly consists of three meshes, the central one being set on high voltage to establish the retarding field, and a faraday cup at the end detecting the beam current. Retarding field energy analyzer ion current calibration and.
Digital aes controller with lockin amplifier and software for auger electron spectroscopy. The often neglected lens effect of the hole in the plane parallel plate through which the beam passes is shown to have significant effect on the energy. What is the abbreviation for retarding field analyzer. Negative ion beam plasma characterization by retarding. Leed and auger electron spectroscopy instrumentation. The current density distribution of directcurrent beam is determined. The system can be placed anywhere inside a plasma reactor, and then, using a single measurement sensor, it measures the energy of ions that strike the substrate surface. A retarding potential analyzer rpa is basically a mixture of a faraday cup and a langmuir probe. Design and operation of a retarding field energy analyzer with. This system is also equipped with a retarding field electron energy analyzer that can be used for both leed and aes. At the university of maryland, experiments have been carried out to study the energy evolution in such intense beams with a highresolution retarding field energy analyzer. A custom semion retarding field energy analyzer was developed to be used in a multishelf plasma processing chamber application. In 1969 palmberg and coworkers developed the cylindrical mirror analyzer cma for detecting auger electrons 16.
Rfa abbreviation stands for retarding field analyzer. The rfea is placed on a biased or grounded electrode. Semion system installation guide ion energy and ion. Home staib energy analyzers with cylindrical mirror geometry.
The reflection effect of secondary electrons on the copper collector of the analyzer is discussed. A simple and compact retarding field energy analyzer for the characterization of broad ion beams of low energy nuclear instruments and methods in physics research section b. This system showed that plasma was not igniting between some shelves, leading to stentcatheter scrap. The analyzer is compact so that the need for differential pumping is avoided. An rfa can measure both the energy distribution by scanning the voltage on a retarding grid and transverse structure throughtheuse of segmentedcollectorsofthe cloud. The retarding field analyzer rfa is an electrostatic charged particle beam energy analyzer which allows for. What does a retarding field energy analyzer measure. Ion energy distribution function measured by retarding field energy analyzers ane aanesland cnrs ecole polytechnique france. A spatially resolved retarding field energy analyzer design suitable for uniformity analysis across the surface of a semiconductor wafer s. The rfea is constructed from process compatible materials and the sensors miniature size allows it to be mounted on the substrate or any other surface inside. Retarding field ion energy analyser for plasma diagnostics. By contrast, their ability to measure ion flux densities has been considered unreliable because of lack of knowledge about the effective transmission of the rfea grids.
Retarding field energy analyzer measurements of ion velocity distributions in a helicon plasma source zane harvey, alex hansen, william s. Fluke energy analyze plus application software for download, analysis and reporting. A retarding electrostatic field energy analyzer for lowenergy beams has been designed, simulated. Using plasma measurement to improve medical device. Staib energy analyzers with cylindrical mirror symmetry. Surprisingly high ion temperature, measured using a retarding field energy analyzer, is found which increases across the transition to improved confinement mode from 40 to 80 ev, while the electron density increases by about 50percent. Retarding field analyzer energy distribution analysis of charged particle beams the retarding field analyzer rfa is an electrostatic charged particle beam energy analyzer which allows for measuring the kinetic energy distribution and the energy spread of the particles up to a beam energy.
Upstream and divertor ion temperature measurements on mast. Coulomb collisions will cause an increase of the beam longitudinal energy spread. The other contains an lk technologies model 3000 hreel spectrometer which has an instrumental resolution of 1 mev as measured by the full width at half max of the elastic peak. Nio1 negative ion optimization 1 is a source of negative hydrogen beams, located at rfx facility in padua. Used with fluke 1730, 1732, 1734, 1736, 1738, 1742, 1746, and 1748. Semion system retarding potential analyser retarding field energy analyser introduction. A retarding field energy analyzer was applied to determine the energy distribution of photoelectrons.
Published 17 may 2012 2012 iop publishing ltd plasma physics and controlled fusion, volume 54, number 6. Retarding field analyzer for ion energy distribution measurements at. Study of deformation of cubetextured aluminum using laser. Construction and operation of a retarding field energy analyzer for a helicon plasma source zane harvey, costel biloiu, and earl e. Similar results associated with the electron impact spectra of a solid sample using a low energy electron diffraction apparatus will be discussed in a separate paper. Integraleed spectrometer model bdl800hr and bdl600hr with integral shutter oci vacuum microengineering inc. A retarding field energy analyzer rfea for measuring the energy distribution of charged particles offers the advantages of a simple structure and suitability for simultaneous observations of beam patterns in two dimensions. Construction and operation of a retarding field energy.
The rfea is used to measure the energy of ions arriving at a surface inside a plasma reactor. Analysis of retarding field energy analyzer transmission. The magnetic and electric field and force software for electromagnetic. Analysis of retarding field energy analyzer transmission by. The retarding field energy analyzer rfa is a simple and reliable diagnostic technique to measure the ion temperature in the scrapeoff layer and edge of magnetic fusion devices. Retarding field energy analyzers rfeas are used routinely for the. Due to the anisotropy of the surface work function in aluminu8m, electrons, of 0. World leading retarding field energy analyzer rfea technology. Retarding field analyzers of the plane parallel plate, the spherical condenser, the faraday cage, and the filter lens types are examined in some detail. It measures energy per charge, much like a faraday cup. A retarding field energy analyzer rfea designed specifically for high energy pulsed.
Study and design of a lenstype retarding field energy. Iedf distortion and resolution considerations for rfea operation at. Impedans has introduced a retarding field energy analyzer rfea called semion single sensor. Semion single the retarding field energy analyzer impedans ltd. Rfea for plasma diagnostics by impedans plasma measurement. The retarding field analyzer rfa is an electrostatic charged particle beam energy analyzer which allows for measuring the kinetic energy distribution and the energy spread of the particles. Hawkins2 1space plasma, power, and propulsion group, research school of physical sciences and engineering, the australian national university, australian capital territory 0200, australia. The semion software suite offers the most advanced analysis of any plasma. Retarding field energy analyser ion current calibration. A spatially resolved retarding field energy analyzer. Design and operation features of a singlesided facing the ion flow rfa for ion temperature measurements in the saskatchewan torusmodified storm tokamak are. Retarding field energy analyzer measurements of ion.
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