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Preliminary evaluation of a modified Mueller--Hortig geometry negative ion source using a negative ion source test facility

Description: A negative sputter-type ion source of the Mueller-Hortig geometry is described which utilizes a positive surface ionization source. Among the ion beams which have been produced are: Al-0.2 $mu$A; All0$sup -$-3 $mu$A; Au$sup -$- 6 $mu$A; C$sup -$-25 $mu$A; C$sub 2$$sup -$-20$mu$A; Cl$sup -$-100 $mu$A; Cu$sup - $-0.5 $mu$A; CuO$sup -$-0.8 $mu$A; F$sup -$-40 $mu$A; I$sup -$-26 $mu$A; 0$sup -$- 30 $mu$A; Pt$sup -$-3 $mu$A; S$sup -$-44 $mu$A; TaO$sub 2$$sup -$-2 $mu$A. The yields of Cl$sup -$, F$sup -$, O$sup -$, and S$sup -$ produced from gaseous or high vapor pressure compounds are observed to be sensitively dependent on the metallic surface from which they are generated, indicating an intermediate surface chemical effect. While the source produces very intense beams of the halogens, sulfur, and oxygen and relatively intense beams of the metallic oxides, there appears to be a need for additional surface cesium to ensure maximum negative ion yields from many of the elemental materials. (auth)
Date: January 1, 1975
Creator: Alton, G.D.
Partner: UNT Libraries Government Documents Department

Progress report on VENUS

Description: The construction of VENUS, a next generation superconducting Electron Cyclotron Resonance ion source designed to operate at 28 GHz, is complete. The cryostat including the superconducting magnet assembly was delivered in September 2001. During acceptance tests, the superconducting magnets produced an axial magnetic field strength of 4T at injection, 3T at extraction, and a radial field strength of 2T at the plasma chamber wall without any quenches. These fields are sufficient for optimum operation at 28 GHz. The cryogenic system for VENUS has been designed to operate at 4.2 K with two cryocoolers each providing up to 45 W of cooling at 50 K and 1.5 W at 4 K in a closed loop mode without further helium transfers. However, during the acceptance tests an excessive heat leak of about 3W was measured. In addition, the liquid helium heat exchanger did not work properly and had to be redesigned. The cryogenic system modifications will be described. In addition, an update on the installation of the ion source and its beam line components will be given.
Date: September 3, 2002
Creator: Leitner, Matthaeus A.; Leitner, Daniela; Abbott, Steve R.; Taylor, Clyde E. & Lyneis, Claude
Partner: UNT Libraries Government Documents Department

RF Driven Multicusp H- Ion Source

Description: An rf driven multicusp source capable of generating 1-ms H{sup -} beam pulses with a repetition rate as high as 150 Hz has been developed. This source can be operated with a filament or other types of starter. There is almost no lifetime limitation and a clean plasma can be maintained for a long period of operation. It is demonstrated that rf power as high as 25 kW could be coupled inductively to the plasma via a glass-coated copper-coil antenna. The extracted H{sup -} current density achieved is about 200 mA/cm{sup 2}.
Date: June 1, 1990
Creator: Leung, K.N.; DeVries, G.J.; DiVergilio, W.F.; Hamm, R.W.; Hauck, C.A.; Kunkel, W.B. et al.
Partner: UNT Libraries Government Documents Department


Description: 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.
Date: April 7, 2006
Creator: May, Donald P.
Partner: UNT Libraries Government Documents Department

Primary ion sources for EBIS

Description: This paper gives an introduction into the topic of primary ion sources that can be used to feed ions of normally solid elements into EBIS devices. Starting with a set of typical requirements for primary ion sources, some major types of ion generators are discussed first, with emphasis on their working principles rather than trying to give a fully representative listing of used and proposed generators. Beam-transport issues between primary ion source and EBIS are then examined, and generic characteristics of suitable beam-formation and transport systems are explained.
Date: March 21, 2001
Creator: Keller, R.
Partner: UNT Libraries Government Documents Department

Production of positive ion beams from solids

Description: A technique for making metal ions for cyclotrons is described. Metal and non-metal ions from solids are produced in a Penning ion source by a process that involves ions that are unable to cross the first acceleration gap between the ion source and dee and are accelerated back into the ion source where they sputter charge material into the arc. This material is ionized and extracted from the ion source and accelerated. This technique was used for a large variety of ions, both metal and non-metal, including aluminum from the metal and boron from boron nitride charge materials. The efficiency for making iron ions with different ion support gases was calculated, and these results were experimentally checked. A dual ion source is being designed for a dc Penning ion source test stand which makes an excellent source for producing ions from solids for dc extracted Penning ion sources. (auth)
Date: January 1, 1975
Creator: Hudson, E.D.; Mallory, M.L. & Lord, R.S.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: August 29, 2008
Creator: Raitses, Y.; A., Smirnov & Fisch, N.J.
Partner: UNT Libraries Government Documents Department

P.I.G. sputter source for negative metal ions

Description: From meeting on the American physical society; Washington, District of Columbia, USA (23 Apr 1973). Operating parameters for a cathode sputtering P. I. G. ion source with radial extraction for negative metal ion beam production for injection into the University of Wisconsin tandem accelerator are discussed. Beam emittance and beam intensity measurements are discussed. (WHK)
Date: April 30, 1974
Creator: Smith, H.V. Jr. & Richards, H.T.
Partner: UNT Libraries Government Documents Department

Report on the workshop on ion sources for hadron colliders

Description: 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.
Date: November 1, 1997
Creator: Alessi, J.G.
Partner: UNT Libraries Government Documents Department

Preliminary Results of Plasma Flow Measurements in a 2 KW Segmented Hall Thruster

Description: A 2-kW Hall thruster was developed, built, and operated in an upgraded vacuum facility. The thruster performance and parameters of the plasma flow were measured by new diagnostics for plume measurements and plasma measurements inside the thruster channel. The thruster demonstrated efficient operation in terms of propellant and current utilization efficiencies in the input power range of 0.5-3.5 kW. Preliminary measurements of the ion energy spectra from the thruster axis region and the distribution of plasma parameters in the vicinity of the thruster exit are reported.
Date: March 1, 2003
Creator: Raitses, Y.; Staack, D.; Dunaevsky, A.; Dorf, L. & Fisch, N.J.
Partner: UNT Libraries Government Documents Department

Ionization efficiency studies for xenon ions with thesuperconducting ECR ion source VENUS

Description: Ionization efficiency studies for high charge state xenon ions using a calibrated gas leak are presented. A 75% enriched {sup 129}Xe gas leak with a gas flow equivalent to 5.11p{mu}A was used in all the measurements. The experiments were performed at the VENUS (Versatile ECR ion source for Nuclear Science) ion source for 18 GHz, 28 GHz and double frequency operation. Overall, total ionization efficiencies close to 100% and ionization efficiencies into a single charge state up to 22% were measured. The influence of the biased disk on the ionization efficiency was studied and the results were somewhat surprising. When the biased disk was removed from the plasma chamber, the ionization efficiency was dramatically reduced for single frequency operation. However, using double frequency heating the ionization efficiencies achieved without the biased disk almost matched the ionization efficiencies achieved with the biased probe. In addition, we have studied the influence of the support gas on the charge state distribution of the xenon ions. Either pure oxygen or a mixture of oxygen and helium were used as support gases. The addition of a small amount of helium can increase the ionization efficiency into a single charge state by narrowing the charge state distribution. Furthermore by varying the helium flow the most efficient charge state can be shifted over a wide range without compromising the ionization efficiency. This is not possible using only oxygen as support gas. Results from these studies are presented and discussed.
Date: June 5, 2007
Creator: Leitner, Daniela; Lyneis, Claude M.; Todd, DamonS. & Tarvainen,Olli
Partner: UNT Libraries Government Documents Department

Mass Spectrometer Studies of Ion Sources for One Shot AcceleratorTube

Description: A simple mass spectrometer using 60 degree focusing was set up to study the (illegible) of the ions produced by various types of sources. A schematic diagram of the apparatus is shown in Fig. 1, which is to a large extent self-explanatory. The isolation transformer was simply a piece of RG (illegible) cable about three feet long and was used in order to operate the source at high accelerating voltage allowing the collector to be at essentially ground potential. The collimating slits were 0.05 (illegible) wide and were space 4 (illegible-cm?) apart. The coarse slit immediately preceding the collector cup was 0.3 (illegible) wide. The electrometer was the integrating type which indicated the potential due to the charge collected on known capacitance. The vacuum tube voltmeter indicated the potential of the 0.5 (illegible) capacitor due to the total charge reaching the slit system. It thus served as a monitor of the source output for each firing. The neon lamp was a protection for the condenser against breakdown discharges of the tube.
Date: December 12, 1951
Creator: Brumbaugh, R.; Pon, W.; Seaman, W. & Wiegand, C.
Partner: UNT Libraries Government Documents Department

The RHIC Optically-Pumped Polarized H Ion Source.

Description: 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%.
Date: September 10, 2007
Creator: Zelenski,A.; Zelenski, A.; Kokhanovski, S.; Kponou, A.; Ritter, J. & Zubets, V.
Partner: UNT Libraries Government Documents Department

Laser ion source for low charge heavy ion beams

Description: 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.
Date: August 3, 2008
Creator: Okamura, M.; Pikin, A.; Zajic, V.; Kanesue, T. & Tamura, J.
Partner: UNT Libraries Government Documents Department


Description: 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%.
Date: June 25, 2007
Partner: UNT Libraries Government Documents Department