Search results for "Ion gun"
showing 10 items of 32 documents
Hot-cavity studies for the Resonance Ionization Laser Ion Source
2016
International audience; The Resonance Ionization Laser Ion Source (RILIS) has emerged as an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability, and ability to ionize target elements efficiently and element selectively. GISELE is an off-line RILIS test bench to study the implementation of an on-line laser ion source at the GANIL separator facility. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. The ion source geometry was tested in several configurations in order to find a solution with optimal ionization efficiency an…
Physicochemical parameters - hydration performance relationship of the new endodontic cement MTA Repair HP
2019
Background To characterize the chemical composition and textural parameters of the MTA Repair HP precursor powder and their influence to hydration performance. Material and methods Un-hydrated precursor material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence (XRF), laser diffraction (LD), N2 physisorption and field emission gun scanning electron microscopy (FEG-SEM). Setting time was assessed according to ASTM specification C 266. Hydrated material was analysed by XRD, FT-IR, energy dispersive X-ray (EDX) analysis and FEG-SEM. Results Ca3SiO5 and Ca2SiO4, in addition to CaWO4 as radiopacifier are the main compositional phase…
Trapped ion density distribution in the presence of He-buffer gas
1981
The spatial density distribution of Ba+ ions, confined in a rf quadrupole trap, has been measured by laser scanning across the trap. This allows to determine the ion temperature, assuming thermal equilibrium. Under UHV conditions the average ion energy has been found to be one tenth of the trap potential well depth. Collisions with He at pressures up to 5×10−6 mbar reduce the ion temperature by a factor of 3.
Production of neutron deficient rare isotope beams at IGISOL; on-line and off-line studies
2004
This article reports on recent on-line yield measurements employing the light-ion and heavy-ion reaction-based ion guide systems and new results on a-recoil ion transport properties in ion guides with and without electric fields. In addition, the presently used ion guide designs for fusion evaporation reactions are introduced. The present study investigated different schemes for ion extraction from the gas cell. The addition of an extra ring electrode between the traditional skimmer electrode and the exit hole led to transmission independent of the primary beam intensity as opposed to strong intensity dependence observed earlier with the plain skimmer only. Furthermore, the mass resolving p…
Space-Charge Effects with REXTRAP
2001
The beam quality of radioactive ion beams produced by present target ion source technology is often not sufficient for direct post-acceleration. Furthermore, pulsed beams insure a more efficient use of an accelerator. In the case of REX-ISOLDE, the post accelerator at the CERN ISOLDE facility, a gas-filled Penning trap (REXTRAP) has been chosen for accumulation of the radioactive ions and conversion into cooled bunches. Radial centering of the ions is achieved by applying an rf field with a frequency equal to the cyclotron frequency of the desired ion species. The efficiency achieved in the first tests with different isotopes covering nearly the entire mass range was already >20%. Going to …
Time Characteristics of the Ion Beam Cooler-Buncher at JYFL
2001
A beam cooler for low-energy ion beams was constructed to improve the ion optical properties of radioactive ion beams produced at the IGISOL facility in Jyvaskyla. The beam cooler is a buffer gas filled RF-quadrupole. The delay properties and the possibility to accumulate a continuous IGISOL beam and release it in short bunches is discussed.
Precision mass measurements using a penning trap and highly charged ions produced in an electron beam ion source
1997
A method for precision mass measurements in a Penning trap using highly charged ions produced in an electron beam ion source (CRYSIS) has been developed. The cyclotron frequencies for O8+, 7+, 6+, 5+ and Ar18+, 17+, 16+, 15+, 14+, 13+ ions have been determined by the excitation of the sum frequency v+ + v−. In addition to CRYSIS ions, H+, H2+ and He+ ions were produced by electron bombardment of the H2 rest gas or helium gas introduced through an UHV leak valve into an auxiliary ion trap (or a pre-trap). A technique for fast (seconds) interchanging of the ion species in the precision trap has been implemented to reduce the long term magnetic field drift.
Diagnostics for studies of novel laser ion acceleration mechanisms.
2014
Diagnostic for investigating and distinguishing different laser ion acceleration mechanisms has been developed and successfully tested. An ion separation wide angle spectrometer can simultaneously investigate three important aspects of the laser plasma interaction: (1) acquire angularly resolved energy spectra for two ion species, (2) obtain ion energy spectra for multiple species, separated according to their charge to mass ratio, along selected axes, and (3) collect laser radiation reflected from and transmitted through the target and propagating in the same direction as the ion beam. Thus, the presented diagnostic constitutes a highly adaptable tool for accurately studying novel accelera…
The electron cyclotron resonance ion source with arc-shaped coils concept
2012
The main limitation to further improve the performance of ECR ion sources is set by the magnet technology related to the multipole magnet field used for the closed minimum-B structure. The JYFL ion source group has sought different approaches to improve the strength of the minimum-B structure required for the production of highly charged ion beams. It was found out that such a configuration can be realized with arc shaped coils. The first prototype, electron cyclotron resonance ion source with arc-shaped coils (ARC-ECRIS), was constructed and tested at JYFL in 2006. It was confirmed that such an ion source can be used for the production of highly charged ion beams. Regardless of several cos…
Simulation of H- ion source extraction systems for the Spallation Neutron Source with Ion Beam Simulator.
2012
A three-dimensional ion optical code IBSimu, which is being developed at the University of Jyväskylä, features positive and negative ion plasma extraction models and self-consistent space charge calculation. The code has been utilized for modeling the existing extraction system of the H(-) ion source of the Spallation Neutron Source. Simulation results are in good agreement with experimental data. A high-current extraction system with downstream electron dumping at intermediate energy has been designed. According to the simulations it provides lower emittance compared to the baseline system at H(-) currents exceeding 40 mA. A magnetic low energy beam transport section consisting of two sole…